Cardiology & Heart Surgery

dystrophin protein

Experimental drug shows promise for slowing cardiac disease and inflammation

dystrophin protein

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, which provides instructions for making dystrophin, a protein found mostly in skeletal, respiratory and heart muscles.

Vamorolone, an experimental medicine under development, appears to combine the beneficial effects of prednisone and eplerenone – standard treatments for Duchenne muscular dystrophy (DMD) – in the heart and muscles, while also showing improved safety in experimental models. The drug does so by simultaneously targeting two nuclear receptors important in regulating inflammation and cardiomyopathy, indicates a small study published online Feb. 11, 2019, in Life Science Alliance.

DMD is a progressive X-linked disease that occurs mostly in males. It is characterized by muscle weakness that worsens over time, and most kids with DMD will use wheelchairs by the time they’re teenagers. DMD is caused by mutations in the DMD gene, which provides instructions for making dystrophin, a protein found mostly in skeletal, respiratory and heart muscles.

Cardiomyopathy, an umbrella term for diseases that weaken the heart, is a leading cause of death for young adults with DMD, causing up to 50 percent of deaths in patients who lack dystrophin. A collaborative research team co-led by Christopher R. Heier, Ph.D., and Christopher F. Spurney, M.D., of Children’s National Health System, is investigating cardiomyopathy in DMD. They find genetic dystrophin loss provides “a second hit” for a specific pathway that worsens cardiomyopathy in experimental models of DMD.

“Some drugs can interact with both the mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) since these two drug targets evolved from a common ancestor. However, we find these two drug targets can play distinctly different roles in heart and skeletal muscle. The GR regulates muscle inflammation, while the MR plays a key role in heart health,” says Heier, an assistant professor at Children’s National and lead study author. “In our study, the experimental drug vamorolone safely targets both the GR to treat chronic inflammation and the MR to treat the heart.”

After gauging the efficacy of various treatments in test tubes, the study team looked at whether any could mitigate negative impacts of the MR on heart health. Wild type and mdx experimental models were implanted with pumps that activated the MR. These models also received a daily oral MR antagonist (or inhibitor) drug, and either eplerenone, spironolactone or vamorolone. Of note:

  • MR activation increased kidney size and caused elevated blood pressure (hypertension).
  • Treatment with vamorolone maintained normal kidney size and prevented hypertension.
  • MR activation increased mdx heart mass and fibrosis. Vamorolone mitigated these changes.
  • MR activation decreased mdx heart function, while vamorolone prevented declines in function.
  • Daily prednisone caused negative MR- and GR-mediated side effects, such as hyperinsulinemia, whereas vamorolone safely improved heart function without these side effects.

“These findings have the potential to help current and future patients,” Heier says. “Clinicians already prescribe several of these drugs. Our new data support the use of MR antagonists such as eplerenone in protecting DMD hearts, particularly if patients take prednisone. The experimental drug vamorolone is currently in Phase IIb clinical trials and is particularly exciting for its unique potential to simultaneously treat chronic inflammation and heart pathology with improved safety.”

In addition to Heier and senior author Spurney, study co-authors include Qing Yu, Alyson A. Fiorillo, Christopher B. Tully, Asya Tucker and Davi A. Mazala, all of Children’s National; Kitipong Uaesoontrachoon and Sadish Srinivassane, AGADA Biosciences Inc.; and Jesse M. Damsker, Eric P. Hoffman and Kanneboyina Nagaraju, ReveraGen BioPharma.

Financial support for research described in this report was provided by Action Duchenne; the Clark Charitable Foundation; the Department of Defense under award W81XWH-17-1-047; the Foundation to Eradicate Duchenne; the Intellectual and Developmental Disabilities Research Center under award U54HD090257 (through the National Institutes of Health’s (NIH) Eunice Kennedy Shriver National Institute of Child Health and Human Development); and the NIH under awards K99HL130035, R00HL130035, L40AR068727 and T32AR056993.

Financial disclosure:  Co-authors employed by ReveraGen BioPharma were involved in creating this news release.

mitochondria

Treating nephrotic-range proteinuria with tacrolimus in MTP

mitochondria

Mitochondria are the cell’s powerplants and inside them the MTP enzymatic complex catalyzes three steps in beta-oxidation of long-chain fatty acids.

In one family, genetic lightning struck twice. Two sisters were diagnosed with mitochondrial trifunctional protein (MTP) deficiency. This is a rare condition that stops the body from converting fats to energy, which can lead to lactic acidosis, recurrent breakdown of muscle tissue and release into the bloodstream (rhabdomyolysis), enlarged heart (cardiomyopathy) and liver failure.

Mitochondria are the cell’s powerplants and inside them the MTP enzymatic complex catalyzes three steps in beta-oxidation of long-chain fatty acids. MTP deficiency is so rare that fewer than 100 cases have been reported in the literature says Hostensia Beng, M.D., who presented an MTP case study during the American Society of Nephrology’s Kidney Week.

The 7-month-old girl with known MTP deficiency arrived at Children’s National lethargic with poor appetite. Her laboratory results showed a low corrected serum calcium level, elevated CK level and protein in the urine (proteinuria) at a nephrotic range. The infant was treated for primary hypoparathyroidism and rhabdomyolysis.

Even though the rhabdomyolysis got better, the excess protein in the girl’s urine remained at worrisome levels. A renal biopsy showed minimal change disease and foot process fusion. And electron microscopy revealed shrunken, dense mitochondria in visceral epithelial cells and endothelium.

“We gave her tacrolimus, a calcineurin inhibitor that we are well familiar with because we use it after transplants to ensure patient’s bodies don’t reject the donated organ. By eight months after treatment, the girl’s urine protein-to-creatinine (uPCR) ratio was back to normal. At 35 months, that key uPCR measure rose again when tacrolimus was discontinued. When treatment began again, uPCR was restored to normal levels one month later,” Dr. Beng says.

The girl’s older sister also shares the heterozygous deletion in the HADHB gene, which provides instructions for making MTP. That missing section of the genetic how-to guide was predicted to cause truncation and loss of long-chain-3-hydroxyacl CoA dehydrogenase function leading to MTP deficiency.

The older sister was diagnosed with nephrotic syndrome and having scar tissue in the kidney’s filtering unit (focal segmental glomerulosclerosis) when she was 18 months old. By contrast, she developed renal failure and progressed to end stage renal disease at 20 months of age.

“Renal involvement has been reported in only one patient with MTP deficiency to date, the older sister of our patient,” Dr. Beng adds.

Podocytes are specialized cells in the kidneys that provide a barrier, preventing plasma proteins from leaking into the urine. Podocytes, however, need energy to function and are rich in mitochondria.

“The proteinuria in these two sisters may be related to their mitochondrial dysfunction. Calcineurin inhibitors like tacrolimus have been reported to reduce proteinuria by stabilizing the podocyte actin cytoskeleton. Tacrolimus was an effective treatment for our patient, who has maintained normal renal function, unlike her sister,” Dr. Beng says.

American Society of Nephrology’s Kidney Week presentation

  • “Treatment of nephrotic-range proteinuria with tacrolimus in mitochondrial trifunctional protein deficiency

Hostensia Beng, M.D., lead author; Asha Moudgil, M.D., medical director, transplant, and co-author; Sun-Young Ahn, M.D., MS, medical director, nephrology inpatient services, and senior author, all of Children’s National Health System.

E coli bacteria

Urinary bacteria in spinal cord injury cases may tip balance toward UTIs

E coli bacteria

Patients with spinal cord injuries nearly universally have bacteria present in their urine regardless of whether they have a urinary tract infection.

The fallout from spinal cord injury doesn’t end with loss of mobility: Patients can have a range of other issues resulting from this complex problem, including loss of bladder control that can lead to urine retention. One of the most serious implications is urinary tract infections (UTIs), the most common cause of repeat hospitalization in people with spinal cord injuries, explains Hans G. Pohl, M.D., associate chief in the division of Urology at Children’s National Health System.

Diagnosing UTIs in people with spinal cord injuries is trickier than in people who are otherwise healthy, Dr. Pohl explains. Patients with spinal cord injuries nearly universally have bacteria present in their urine regardless of whether they have a UTI. It’s unclear whether these bacteria are innocent bystanders or precursors to UTIs in patients who don’t yet show symptoms. And although antibiotics can wipe out this bacterial population, these drugs can have undesirable side effects and frequent use can promote development of antibiotic-resistant bacteria.

Although clinical dogma has long promoted the idea that “healthy” urine is sterile, Dr. Pohl and colleagues have shown that a variety of bacteria live in urine, even in people without symptoms. These microorganisms, like the intestinal microbiome, live in harmony with their hosts and may even help promote health. However, it’s unclear what this urinary microbiome might look like for patients with spinal cord injury before, during and after UTIs.

To start investigating this question, Dr. Pohl and co-authors recently reported a case study they published online Sept. 21, 2018, in Spinal Cord Series and Cases. The case report about a 55-year-old man who had injured the thoracic segment of his spinal cord—about the level of the bottom of his shoulder blades—in a skiing accident when he was 19 was selected as “Editor’s Choice” for the journal’s October 2018 issue.  The patient had a neurogenic bladder, which doesn’t function normally due to impaired communication with the spinal cord. To compensate for this loss of function, this patient needed to have urine removed every four to six hours by catheterization.

Over eight months Dr. Pohl, the study’s senior author, and colleagues collected 12 urine samples from this patient:

  • One was collected at a time the patient didn’t show any symptoms of a UTI
  • Nine were collected when the patient had UTI symptoms, such as bladder spasticity
  • Two samples were collected when the patient had finished antibiotic treatment for the UTI.

The researchers split each sample in half. One part was put through a standard urinalysis and culture, much like what patients with a suspected UTI would receive at the doctor’s office. The other part was analyzed using a technique that searched for genetic material to identify bacteria that might be present and to estimate their abundance.

The researchers found a variety of different bacteria present in these urine samples. Regardless of the patient’s health status and symptoms, the majority of these bacterial species are known to be pathogenic or potentially pathogenic. By contrast, this patient’s urine microbiome appeared to largely lack bacterial species known to be either neutral or with potentially probiotic properties, such as Lactobacillus.

All of the bacteria that grew in culture also were identified by their genetic material in the samples. However, genetic sequencing also identified a possible novel uropathogenic species called Burkholderia fungorum that didn’t grow in the lab in five of the samples. This bacterium is ubiquitous in the environment and has been identified in soil- and plant-based samples. It also has been discovered in the respiratory secretions of patients with cystic fibrosis, in patients with a heart condition called infectious endocarditis, in the vaginal microbiota of patients with bacterial vaginosis, and in the gut of patients with HIV who have low T-cell counts. Dr. Pohl says it’s unclear whether this species played an infectious role in this patient’s UTI or whether it’s just part of his normal urine flora.

“Consistent with our previous work, this case report demonstrates that rather than healthy urine being sterile, there is a diverse urine bacterial ecosystem during various states of health and disease,” Dr. Pohl says. “Rather than UTIs resulting from the growth or overgrowth of a single organism, it’s more likely that a change in the healthy balance of the urine ecosystem might cause these infections.”

By monitoring the relative abundance of different bacteria types present in the urine of patients with spinal cord injury and combining this information with a patient’s symptoms, Dr. Pohl says doctors may be able to make more accurate UTI diagnoses in this unique population.

In addition to Dr. Pohl, study co-authors include Marcos Pérez-Losada, Ljubica Caldovic, Ph.D., Bruce Sprague and Michael H. Hsieh, M.D., Children’s National; Emma Nally, Suzanne L. Groah and Inger Ljungberg, MedStar National Rehabilitation Hospital; and Neel J. Chandel, Montefiore Medical Center.

Nobuyuki Ishibashi

Cortical dysmaturation in congenital heart disease

Nobuyuki Ishibashi

On Jan. 4, 2019, Nobuyuki Ishibashi, M.D., the director of the Cardiac Surgery Research Laboratory and an investigator with the Center for Neuroscience Research at Children’s National Health System, published a review in Trends in Neurosciences about the mechanisms of cortical dysmaturation, or disturbances in cortical development, that can occur in children born with congenital heart disease (CHD). By understanding the early-life impact and relationship between cardiac abnormalities and cortical neuronal development, Dr. Ishibashi and the study authors hope to influence strategies for neonatal neuroprotection, mitigating the risk for developmental delays among CHD patients.

Dr. Ishibashi answers questions about this review and CHD-neurodevelopmental research:

  1. Tell us more about your research. Why did you choose to study these interactions in this patient population?

My research focuses on studying how CHD and neonatal cardiac surgery affect the rapidly-developing brain. Many children with CHD, particularly the most complex anomalies, suffer from important behavioral anomalies and neurodevelopmental delays after cardiac surgery. As a surgeon scientist, I want to optimize treatment strategy and develop a new standard of care that will reduce neurodevelopmental impairment in our patients.

  1. How does this study fit into your larger body of work? What are a few take-home messages from this paper?

Our team and other laboratories have recently identified a persistent perinatal neurogenesis that targets the frontal cortex – the brain area responsible for higher-order cognitive functions. The main message from this article is that further understanding of the cellular and molecular mechanisms underlying cortical development and dysmaturation will likely help to identify novel strategies to treat and improve outcomes in our patients suffering from intellectual and behavioral disabilities.

  1. What do you want pediatricians and researchers to know about this study? Why is it important right now?

Although the hospital mortality risk is greatly reduced, children with complex CHD frequently display subsequent neurological disabilities affecting intellectual function, memory, executive function, speech and language, gross and fine motor skills and visuospatial functions. In addition to the impact of the neurological morbidity on the patients themselves, the toll on families and society is immense. Therefore it is crucial to determine the causes of altered brain maturation in CHD.

  1. How do you envision this research influencing future studies and pediatric health outcomes? As a researcher, how will you proceed?

In this article we placed special emphasis on the need for well-designed preclinical studies to define disturbances in cortical neurogenesis due to perinatal brain injury. I believe that further study of the impact of hypoxemia on brain development is of broad relevance — not just for children with congenital heart disease, but for other populations where intellectual and behavioral dysfunctions are a source of chronic morbidity, such as survivors of premature birth.

  1. What discoveries do you envision being at the forefront of this field?

One of the important questions is: During which developmental period, prenatal or postnatal, is the brain most sensitive to developmental and behavioral disabilities associated with hypoxemia? Future experimental models will help us study key effects of congenital cortical development anomalies on brain development in children with CHD.

  1. What impact could this research make? What’s the most striking finding and how do you think it will influence the field?

Although cortical neurogenesis at fetal and adult stages has been widely studied, the development of the human frontal cortex during the perinatal period has only recently received greater attention as a result of new identification of ongoing postnatal neurogenesis in the region responsible for important intellectual and behavioral functions. Children’s National is very excited with the discoveries because it has opened new opportunities that may lead to regeneration and repair of the dysmature cortex. If researchers identify ways to restore endogenous neurogenic abilities after birth, the risk of neurodevelopment disabilities and limitations could be greatly reduced.

  1. Is there anything else you would like to add that we didn’t ask you about? What excites you about this research?

In this article we highlight an urgent need to create a truly translational area of research in CHD-induced brain injury through further exploration and integration of preclinical models. I’m very excited about the highly productive partnerships we developed within the Center for Neuroscience Research at Children’s National, led by an internationally-renowned developmental neuroscientist, Vittorio Gallo, Ph.D., who is a co-senior author of this article. Because of our collaboration, my team has successfully utilized sophisticated and cutting-edge neuroscience techniques to study brain development in children born with CHD. To determine the causes of altered brain maturation in congenital heart disease and ultimately improve neurological function, we believe that a strong unity between cardiovascular and neuroscience research must be established.

Additional study authors include Camille Leonetti, Ph.D., a postdoctoral research fellow with the Center for Neuroscience Research and Children’s National Heart Institute, and Stephen Back, M.D., Ph.D., a professor of pediatrics at Oregon Health and Science University.

The research was supported by multiple grants and awards from the National Institutes of Health, inclusive of the National Heart Lung and Blood Institute (RO1HL139712), the National Institute of Neurological Disorders and Stroke (1RO1NS054044, R37NS045737, R37NS109478), the National Institute on Aging (1RO1AG031892-01) and the National Institute of Child Health and Human Development (U54HD090257).

Additional support for this review was awarded by the American Heart Association (17GRNT33370058) and the District of Columbia Intellectual and Developmental Disabilities Research Center, which is supported through the Eunice Kennedy Shriver National Institute of Child Health and Human Development program grant 1U54HD090257.

AlgometRX

Breakthrough device objectively measures pain type, intensity and drug effects

AlgometRX

Clinical Research Assistant Kevin Jackson uses AlgometRx Platform Technology on Sarah Taylor’s eyes to measure her degree of pain. Children’s National is testing an experimental device that aims to measure pain according to how pupils react to certain stimuli. (AP Photo/Manuel Balce Ceneta)

Pediatric anesthesiologist Julia C. Finkel, M.D., of Children’s National Health System, gazed into the eyes of a newborn patient determined to find a better way to measure the effectiveness of pain treatment on one so tiny and unable to verbalize. Then she realized the answer was staring back at her.

Armed with the knowledge that pain and analgesic drugs produce an involuntary response from the pupil, Dr. Finkel developed AlgometRx, a first-of-its-kind handheld device that measures a patient’s pupillary response and, using proprietary algorithms, provides a diagnostic measurement of pain intensity, pain type and, after treatment is administered, monitors efficacy. Her initial goal was to improve the care of premature infants. She now has a device that can be used with children of any age and adults.

“Pain is very complex and it is currently the only vital sign that is not objectively measured,” says Dr. Finkel, who has more than 25 years of experience as a pain specialist. “The systematic problem we are facing today is that healthcare providers prescribe pain medicine based on subjective self-reporting, which can often be inaccurate, rather than based on an objective measure of pain type and intensity.” To illustrate her point, Dr. Finkel continues, “A clinician would never prescribe blood pressure medicine without first taking a patient’s blood pressure.”

The current standard of care for measuring pain is the 0-to-10 pain scale, which is based on subjective, observational and self-reporting techniques. Patients indicate their level of pain, with zero being no pain and ten being highest or most severe pain. This subjective system increases the likelihood of inaccuracy, with the problem being most acute with pediatric and non-verbal patients. Moreover, Dr. Finkel points out that subjective pain scores cannot be standardized, heightening the potential for misdiagnosis, over-treatment or under-treatment.

Dr. Finkel, who serves as director of Research and Development for Pain Medicine at the Sheikh Zayed Institute for Pediatric Surgical Innovation at Children’s National, says that a key step in addressing the opioid crisis is providing physicians with objective, real-time data on a patient’s pain level and type, to safely prescribe the right drug and dosage or an alternate treatment.,

She notes that opioids are prescribed for patients who report high pain scores and are sometimes prescribed in cases where they are not appropriate. Dr. Finkel points to the example of sciatica, a neuropathic pain sensation felt in the lower back, legs and buttocks. Sciatica pain is carried by touch fibers that do not have opioid receptors, which makes opioids an inappropriate choice for treating that type of pain.

A pain biomarker could rapidly advance both clinical practice and pain research, Dr. Finkel adds. For clinicians, the power to identify the type and magnitude of a patient’s nociception (detection of pain stimuli) would provide a much-needed scientific foundation for approaching pain treatment. Nociception could be monitored through the course of treatment so that dosing is targeted and personalized to ensure patients receive adequate pain relief while reducing side effects.

“A validated measure to show whether or not an opioid is indicated for a given patient could ease the health care system’s transition from overreliance on opioids to a more comprehensive and less harmful approach to pain management,” says Dr. Finkel.

She also notes that objective pain measurement can provide much needed help in validating complementary approaches to pain management, such as acupuncture, physical therapy, virtual reality and other non-pharmacological interventions.

Dr. Finkel’s technology, called AlgometRx, has been selected by the U.S. Food and Drug Administration (FDA) to participate in its “Innovation Challenge: Devices to Prevent and Treat Opioid Use Disorder.” She is also the recipient of Small Business Innovation Research (SBIR) grant from the National Institute on Drug Abuse.

Girl complaining to doctor about stitch in side

Treating children and teens with undiagnosed stomach problems?

Girl complaining to doctor about stitch in side

Children and teens exhibiting symptoms of orthostatic intolerance (OI) or gastrointestinal (GI) distress may benefit from a new diagnostic tool, pairing a tilt table test with manometry, which combines the two fields and can yield better results in some cases than testing for either symptom alone.

A combination of two diagnostic tools to test for cardiovascular and gastrointestinal function provides potential answers for patients left feeling sick and with inconclusive results.

Imagine you’re a pediatrician and see a teenage patient who complains of gastrointestinal (GI) distress: nausea, bloating and abdominal pain. She hasn’t altered her diet or taken new medications. An ultrasound of her internal organs from a radiologist comes back clear. You refer her to a gastroenterologist to see if her GI tract, a tube that runs from her mouth to the bottom of her stomach, and houses many organs, including the esophagus, intestines and stomach, has inflammation or structural anomalies. The symptoms, depending on the severity of the problem, could range from mildly irritating to intrusive, leading to missed days from work or school.

The gastroenterologist may analyze her GI tract with an endoscope and often takes a biopsy to look at a sample of the intestinal lining for lesions and inflammation. The results, like the ultrasound, may come back clear.

While an “all-clear” diagnosis is good news for patients awaiting the results of a test for a disease process, these results frustrate patients with chronic GI problems. Without a definitive diagnosis, these patients and their doctors often worry about ‘missing something’ and are left searching for solutions—and scheduling more tests.

Research published in The Journal of Pediatrics, entitled “Utility of Diagnostic Studies for Upper Gastrointestinal Symptoms in Children with Orthostatic Intolerance,” and discussed on Oct. 24 at the 2018 Single Topic Symposium at the Annual Meeting of the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), entitled Advances in Motility and in Neurogastroenterology (AIMING) for the future, now provides doctors with preliminary answers and a tool to test for orthostatic intolerance (OI).

The research team, a mix of cardiologists and gastroenterologists from Children’s National Health System, examined consecutive medical records of over 100 children and young adults with OI, a result of insufficient blood flow returning to the heart after standing up from a reclined position, which could result in lightheadedness or fainting, as well as gastrointestinal symptoms, including nausea and vomiting.

All patients had antroduodenal manometry, a test that uses a catheter, placed during an upper GI endoscopy, to measure the motility of the stomach and of the upper small intestines, in conjunction with a tilt-table test to measure blood pressure and heart rate changes with a change in posture. A gastric emptying study (GES) was performed in about 80 percent of the patients. The study found that antroduodenal manometry combined with the tilt-table test provided the best insights into adolescents and young adults with OI and GI symptoms.

Anil Darbari, M.D., MBA, a study author and the director of the comprehensive GI motility program at Children’s National, mentions the research highlights advances in the field of GI motility. It provides insights into the underlying pathophysiology of the conditions affecting the function of the GI tract and a roadmap to offer a multidisciplinary approach to help patients with sensory or motor GI motility problems, including those with OI or postural orthostatic tachycardia syndrome (POTS).

According to the National Institutes of Health, POTS is a form of OI, which affects more than 500,000 Americans, and most cases are diagnosed in women between the ages of 15 and 50. The cause of POTS is unknown but may begin after major surgery, trauma, a viral illness, pregnancy or before menstruation. The goal of treatment is to improve circulation and alleviate associated symptoms, including blurred vision, headaches, shortness of breath, weakness, coldness or pain in the extremities and GI symptoms, such as nausea, cramps and vomiting.

Dr. Darbari mentions that when his team and other GI motility doctors see patients for predominant GI symptoms, the patients may be frustrated because their primary GI providers often cannot find anything  wrong with their GI tracts— based on the routine testing including laboratory studies, radiological tests and endoscopy with biopsy, at least that they can find. Dr. Darbari isn’t surprised since the symptoms of GI distress and POTS often overlap. Nausea is seen in up to 86 percent of OI patients, a number similar to lightheadedness, which affects 87 percent of OI or POTS patients.

“The physicians and GI specialists are frustrated because they can’t find anything wrong so they think the patient is making up these symptoms,” says Dr. Darbari. “It’s a dichotomous relationship between the patient and physician because of the traditional tests, which almost always come back normal. This is where the field of neurogastroenterology or GI motility comes in. We’re able to explain what’s happening based on the function or motility of the GI tract.”

Dr. Darbari mentions that combining these two fields—testing for cardiovascular function and GI motility—provides the science behind these sought-out answers. The problem, and pain that patients feel affects the neuro-gastro part of the intestine, as opposed to appearing as inflammation, lesions or structural damage.

When asked about how this research may change the field of gastroenterology, Dr. Darbari explains that it’s important to continue to study the underlying mechanisms that control these symptoms. More research, especially from the basic science point of view, is needed to look at how the nerves interact with the muscles. He hopes that scientists will look at the nerve and how the nerve is laid out, as well as how the GI function interacts with that of the cardiovascular system.

Understanding this relationship will help gastroenterologists better understand how to manage these conditions. Right now the solutions involve integrative therapy, such as prescribing sensory modulation, which could include pain management, behavior modification, massage therapy, aroma therapy, acupuncture, meditation and/or hypnotherapy, in addition to or in place of medications to decrease sensory perception in the GI tract. The treatment varies for each patient.

The prospect of giving families answers, and continuing to guide treatment based on the best science, is also what motivates Lindsay Clarke, PA-C, a study author and the coordinator of the GI Motility program at Children’s National, to continue to search for solutions.

“I spend a lot of time on the phone with these families between appointments, between visits, and between procedures,” says Clarke. “They have seen other gastroenterologists. They have had GI testing. Nothing comes back to show why they are feeling this way. This research gives them real information. We can now say that your symptoms are real. We’ve found the connection between what you’re feeling and what’s going on inside of your body.”

“It’s a huge quality-of-life issue for these patients,” adds Dr. Darbari about the benefits of having data to guide treatment. “These are often well-appearing kids. People, including medical professionals, often brush off their symptoms because the patients look good. They don’t have lesions or any redness or swelling, compared, for example, to patients with inflammatory bowel disease, who appear unwell or who have clear physical, laboratory and radiological findings. They don’t appear to be broken.”

The study authors note patient dissatisfaction, health care provider frustration, high costs of care and potentially hazardous diagnostic studies often accompany endoscopic and radiologic studies that fail to reveal significant abnormalities.

Clarke envisions that the use of the dual tilt-table test and antroduodenal manometry may also encourage families to explore multidisciplinary treatment earlier on in a patient’s life, such as physical therapy or sensory therapy, to alleviate symptoms and the overall number of outpatient visits. It provides them the understanding to enroll in a multidisciplinary and comprehensive programs, and programs that offer complementary therapies for management of these complex symptoms.

“This study shows that it’s important to look beyond individual organs and to treat the whole child,” says Clarke. “We’re still not sure about which kinds of sensory therapies work best and we don’t want to overstate the aims of integrative treatments, especially since it may vary for each child, but as clinicians we’re looking forward to talking to families about potential solutions, cautiously, as the science unfolds.”

Additional study authors include Lana Zhang, M.D., Jeffrey Moak, M.D., Sridhar Hanumanthaiah, M.B.B.S., and Robin Fabian, R.N., from the Division of Cardiology at Children’s National, John Desbiens, B.S., from the Division of Gastroenterology at Children’s National, and Rashmi D. Sahay, M.D., from the Division of Biostatistics and Epidemiology at Cincinnati Children’s Hospital Medical Center.

Photo of nurses in the cardiac intensive care unit at Children's National

Can pyruvate support metabolic function following heart surgery?

Photo of nurses in the cardiac intensive care unit at Children's National

Nurses rush a child to the cardiac intensive care unit at Children’s National Health System.

Can pyruvate, the end product of glycolysis, help improve cardiovascular function in children who have cardiopulmonary bypass surgery and suffer from low cardiac output syndrome (LCOS)? This question is one that Rafael Jaimes, Ph.D., a staff scientist at Children’s National Heart Institute, a division of Children’s National Health System, is studying, thanks to a two-year grant from the American Heart Association.

The competitive grant awards Dr. Jaimes with $110,000 to study how pyruvate may help improve cardiac output among pediatric patients with LCOS. The compound aims to stimulate metabolic function, now treated by inotropic agents, such as dobutamine and milrinone. These agents ensure optimal delivery of oxygen from the heart to the brain, as well as to other organs in the body, following heart surgery. While these agents help patients with cardiac dysfunction, there is still a critical need for safe and effective therapies.

“If there’s any detriment in cardiac output, the heart’s function begins to degrade,” explains Dr. Jaimes. “You see a downward spiral effect with reduced cardiac output because the heart is dependent on its own perfusion. It needs to pump blood throughout the body to survive.”

This is where the pyruvate study, and the grant, will be applied: Can pyruvate target the essential muscle of the heart and reverse this cardiac destabilization – and as soon as possible?

“By increasing the metabolic output of the heart’s local muscle, cardiac output increases,” Dr. Jaimes explains. “That’s going to lead to better recovery.”

Better recovery could be measured by how fast a child recovers from heart surgery as well as how much time they spend in the hospital, clinically referred to as throughput. A faster recovery could also influence a child’s quality of life and reduce overall health care costs.

Based on preliminary data that shows pyruvate improves cardiac function in experimental models after ischemic insult, which is what happens when pediatric patients undergo cardiac surgery, Dr. Jaimes believes the results will likely replicate themselves in his preclinical models.

To start, he’ll test pyruvate using 100 blood samples and discarded tissue from patients. The blood samples will be tested for metabolic markers, including measured pyruvate levels.

Part of what encouraged Dr. Jaimes to study how this compound could complement or replace standard therapies was the encouragement he received from his mentors in the field.

“Nobody has looked into using pyruvate for almost 30 years,” says Dr. Jaimes. “It’s not commercially favorable, there’s no patent on it, it doesn’t have a lot of marketability and there are no financial incentives, so it’s been put aside.”

As part of a discussion with cardiologists at a medical conference in Washington, Dr. Jaimes brought up the idea of using pyruvate for pediatric heart surgeries and received positive feedback.

“Once everyone’s eyes lit up, I knew I was on to something,” says Dr. Jaimes about the encouragement he received to pursue this study.

“You put lactate and glucose in your IV solutions,” adds Dr. Jaimes. “Pyruvate is an essential nutrient. It’s almost an essential sugar so there’s no reason not to put it in. If these cardiologists are intrigued by the project, maybe the American Heart Association will be, too.”

In addition to funding the study, which could support future research about how metabolic makers in the blood can be stimulated to fast-track recovery following heart surgery, the American Heart Association grant is specific to pediatric health outcomes.

“The current state of pharmaceutical treatment for patients recovering from cardiac surgery is designed and created for adults,” says Dr. Jaimes. “From our research in pediatrics, we know that children aren’t small adults.”

Dr. Jaimes explains that children are different on an anatomical and physiological level. Their cells even look and function different, compared to adult cells, because they haven’t matured yet.

While congenital heart defects are rare, they affect 1 percent, or 40,000 births worldwide, they often require multiple surgeries throughout a child’s lifespan. LCOS impacts 25 percent of patients following cardiopulmonary bypass and the timing of treatment is important. In severe cases, insufficient cardiac output following surgery could impact a child’s long-term development, ranging from reasoning, learning, attention and executive function, to developing age-appropriate language and social skills.

“The metabolic insufficiencies I’m looking at, which may help improve the muscle function of the heart, are just one piece of a bigger puzzle in pediatric cardiology,” notes Dr. Jaimes about ongoing research at Children’s National Heart Institute. “We already know pyruvate is safe. We just have to see if it’s effective in supporting a patient’s recovery in the intensive care unit.”

Dr. Jaimes will work with his research mentor Nikki Posnack, Ph.D., assistant professor at the Children’s National Heart Institute, on this preclinical study throughout the grant’s lifecycle, which starts in early January 2019 and ends in late December 2020.

Shriprasad Deshpande

Accelerating advanced cardiac treatments for tiny patients

Shriprasad Deshpande

Shriprasad Deshpande, M.B.B.S., M.S., a pediatric cardiologist, joins Children’s National Health System as the director of the advanced cardiac therapies and heart transplant program.

Shriprasad Deshpande, M.B.B.S., M.S., a pediatric cardiologist, has joined Children’s National Health System as the director of the advanced cardiac therapies and heart transplant program.

Dr. Deshpande, an intensivist and heart failure and transplant cardiologist, will work within the Children’s National Heart Institute (the Division of Cardiology and the Division of Cardiac Intensive Care) to guide the diagnosis and treatment of pediatric heart failure. He will also work with researchers, surgeons and engineers to accelerate the field of biomedical research and make it easy for patients to receive advanced therapies, such as mechanical pumps to support circulation, and, if necessary, heart transplant.

“Subspecializing in personalized care is critical for all patients right now, not just adults,” says Dr. Deshpande. “This is one of the reasons I’m looking forward to working with Children’s National, a leader in the many subdivisions of pediatric medicine and research.

“Our priority is to recognize the special needs of infants and children as they relate to heart failure,” he adds. “We want to provide the best care and advance science at the same time.”

As an example, a grant from the National Institutes of Health enabled Dr. Deshpande to test ventricular assist devices for infants. Through another NIH grant, he analyzed the safety of organ transplants by testing a donor’s DNA, instead of conducting invasive biopsies in children.

“The field of cardiology is in a unique position now to take advantage of discoveries happening in science, technology and engineering,” says Dr. Deshpande. “In addition to thinking about the logistics of heart transplants, we’re thinking about how we can delay the need for a heart transplant, understand how to grow tissue better and utilize technology to improve these outcomes. We’re investing in a child’s quality of life.”

As the medical director of Mechanical Circulatory Support Program at Children’s Healthcare of Atlanta, Dr. Deshpande led the mechanical circulatory support program and created a subspecialty clinic to provide treatment for pediatric heart failure patients. He started the Muscular Dystrophy Cardiomyopathy clinic, which analyzes and treats cardiovascular comorbidities associated with muscular dystrophy. While he was an assistant professor of pediatrics at Emory University School of Medicine, he created a curriculum for pediatric cardiologists and for nurses training in the cardiac intensive critical care unit.

Dr. Deshpande has published more than 70 studies and abstracts and will oversee clinical practice models, subspecialty clinics and academic research efforts at Children’s. His current research portfolio, inclusive of grants from the NIH and other funding agencies, is robust and varied: He’s studying how to improve mechanical support for complex heart disease patients, how to improve the performance of current pumps and how to develop new algorithms for these devices. Improving the diagnosis of transplant rejection, using technology to improve compliance and using new technologies to diagnose rejection, without invasive biopsies, are his other research interests.

Dr. Deshpande serves as the chair of the scientific committee at the nonprofit Enduring Hearts and is on the American Heart Association’s Strategically Focused Research Network committee.

Asha Moudgil examines a young patient

Preventing cardiovascular disease after pediatric kidney transplant

Asha Moudgil examines a young patient

Pediatric nephrologist Asha Moudgil, M.D. examines a kidney transplant patient.

As obesity has continued to rise among children in the U.S., so has a condition called metabolic syndrome – a constellation of factors, including high abdominal fat, insulin resistance, high blood pressure, high triglycerides and low amounts of high-density lipoprotein (“good” cholesterol), that increase future risk of cardiovascular disease.

Although metabolic syndrome is dangerous in otherwise healthy children, it’s particularly so for those who’ve received kidney transplants due to chronic kidney disease, says pediatric nephrologist Asha Moudgil, M.D., medical director of transplant at Children’s National Health System. Dr. Moudgil and Children’s National co-authors, Registered Dietitian Kristen Sgambat, Ph.D., RD, and Cardiologist Sarah Clauss, M.D., published a literature review in the February 2018 Clinical Kidney Journal outlining recent research about the cardiovascular effects of metabolic syndrome after kidney transplantation.

“Simply having this transplant multiplies the risk of cardiovascular disease in this vulnerable population,” Dr. Moudgil says. “Combined with lifestyle factors that are driving up metabolic syndrome in general, it’s a ‘one-two punch’ for these patients.”

Dr. Moudgil explains that chronic kidney disease itself leads to poor growth, resulting in shorter stature that’s a risk factor for developing increased waist-to-height ratio upon becoming overweight. When children with this condition undergo long-awaited transplants, it reverses some factors that were suppressing appetite and keeping weight in check: The chronically high levels of urea in their blood decrease after transplant, improving their appetites; and there’s no need to maintain the restrictive diets they had been required to follow for kidney health prior to transplant.

The pharmaceutical regimen that patients follow post-transplant often includes steroids that independently contribute to weight gain and insulin resistance. Combined with the typical American high-fat, high-sugar, and high-sodium diet and low levels of physical activity, the majority of patients with chronic kidney disease gain significant weight after they receive transplants. The prevalence of obesity doubles the first year after transplantation, from about 15 percent to 30 percent, not only driving up cardiovascular disease risk but endangering the longevity of their transplant.

At the same time, says Sgambat, risk factors before and after transplantation drive up prevalence of other parts of metabolic syndrome. These include hypertension, which affects the majority of patients with chronic kidney disease before transplant and typically worsens due to sodium and water retention from immunosuppressive drugs. Dyslipidemia, or abnormal lipid concentrations in the blood, is also common among pediatric kidney transplant patients. One study included in the review showed that 71 percent of patients had high triglycerides three months post-transplant.

Ethnicity also can drive up risk for metabolic syndrome and cardiovascular disease. For example, the literature review says, individuals of African descent have a higher risk of these two conditions potentially due to genetic factors, such as high risk apolipoprotein L1 gene variants.

Together, these factors spur production of inflammatory molecules that trigger the development of early cardiovascular disease. Many kidney transplant recipients die from cardiovascular complications in early adulthood, Sgambat says, driving the need for early detection.

To that end, Dr. Moudgil says pediatric patients don’t typically show overt abnormalities in standard measures of cardiac functioning, such as echocardiography. As an alternative, she and colleagues cover three tools in the literature review that could offer advanced insight into whether patients have initial signs of cardiovascular disease. One of these is carotid intima-media thickness, a measure of the thickness of the carotid artery that can be obtained noninvasively by ultrasound. Another is myocardial strain imaging by speckle tracking echocardiography, a global measure of how the heart changes shape while beating. Cardiac magnetic resonance imaging (MRI), a relatively new technique, is already showing promise in detecting signs of early cardiovascular dysfunction.

A far simpler way to gauge cardiovascular risk, Sgambat adds, is calculating patients’ waist-to-height ratio. This measure doesn’t require sophisticated tools and can be tracked in any clinic over time, alerting patients to health-altering changes before it’s too late.

“It’s even more important to treat cardiovascular risk factors aggressively in this population,” Sgambat says. “Getting a concrete measure that something is trending in the wrong direction may motivate patients to change their diet or lifestyle in ways that a simple recommendation may not.”

Craig Sable

Can a vaccine prevent the earliest forms of rheumatic heart disease?

Craig Sable

Craig Sable, M.D., associate chief of the division of cardiology and director of echocardiography at Children’s National Health System, earned a lifetime achievement award, formally known as the 2018 Cardiovascular Disease in the Young (CVDY) Meritorious Achievement Award, on Nov. 10 at the American Heart Association’s Scientific Sessions 2018.

The CVDY Council bestows the prestigious award to individuals making a significant impact in the field of cardiovascular disease in the young. The CVDY Council supports the mission to improve the health of children and adults with congenital heart disease and acquired heart disease during childhood through research, education, prevention and advocacy.

Dr. Sable is recognized for his entire body of research, education and advocacy focused on congenital and acquired heart disease, but especially for his rheumatic heart disease (RHD) research in Uganda.

Over the past 15 years, Dr. Sable has brought more than 100 doctors and medical staff to Kampala, the capital and largest city in Uganda, partnering with more than 100 local doctors and clinicians to develop a template for a sustainable infrastructure to diagnose, treat and prevent both RHD and congenital heart disease.

RHD is a result of damage to the heart valves after acute rheumatic fever (ARF). The process starts with a sore throat from streptococcal infection, which many children in the United States treat with antibiotics.

“For patients who develop strep throat, their body’s reaction to the strep throat, in addition to resolving its primary symptoms, can result in attacking the heart,” says Dr. Sable. “The initial damage is called acute rheumatic fever. In many cases this disease is self-limited, but if undetected, over years, it can lead to long-term heart valve damage called rheumatic heart disease. Unfortunately, once severe RHD develops the only treatment is open-heart surgery.”

In 2017, Sable and the researchers published a study in the New England Journal of Medicine about the global burden of RHD, which is often referred to as a disease of poverty.

RHD is observed more frequently in low- and middle-income countries as well as in marginalized communities in high-income countries. RHD has declined on a global scale, but it remains the most significant cause of morbidity and mortality from heart disease in children and young adults throughout the world.

In 2017 there were 39.4 million causes of RHD, which resulted in 285,000 deaths and 9.4 million disability-adjusted life-years.

In 2018 the World Health Organization issued a referendum recognizing rheumatic heart disease as an important disease that member states and ministries of health need to prioritize in their public health efforts.

The common denominator that drives Dr. Sable and the global researchers, many of whom have received grants from the American Heart Association to study RHD, is the impact that creating a scalable solution, such as widespread adoption of vaccines, can have on entire communities.

“The cost of an open-heart surgery in Uganda is $5,000 to $10,000, while treatment for a child with penicillin for one year costs less than $1,” says Dr. Sable. “Investment in prevention strategies holds the best promise on a large scale to eradicate rheumatic heart disease.”

Sable and the team have screened more than 100,000 children and are conducting the first randomized controlled RHD trial, enrolling nearly 1,000 children, to examine the effectiveness of using penicillin to prevent progression of latent or subclinical heart disease, the earliest form of RHD.

During the Thanksgiving holiday weekend, Dr. Sable and a team of surgeons will fly back to Uganda to operate on children affected by RHD, while also advancing their research efforts to produce a scalable solution, exported on a global scale, to prevent RHD in its earliest stages.

Dr. Sable and colleagues from around the world partner on several grant-funded research projects. Over the next few years, the team hopes to answer several important questions, including: Does penicillin prevent the earliest form of RHD and can we develop a vaccine to prevent RHD?

To view the team’s previously-published research, visit Sable’s PubMed profile.

To learn about global health initiatives led by researchers at Children’s National, visit www.GHICN.org.

Charles Berul and Rohan Kumthekar demonstrate tiny pacemaker

A new prototype for tiny pacemakers, faster surgery

Charles Berul and Rohan Kumthekar demonstrate tiny pacemaker

Charles Berul, M.D., chief of cardiology at Children’s National, and Rohan Kumthekar, M.D., a cardiology fellow working in Dr. Berul’s bioengineering lab at the Sheikh Zayed Institute for Pediatric Surgical Innovation, explore ways to make surgical procedures for infants and children less invasive.

Rohan Kumthekar, M.D., a cardiology fellow working in Dr. Charles Berul’s bioengineering lab at the Sheikh Zayed Institute for Pediatric Surgical Innovation, part of Children’s National Health System, presented a prototype for a miniature pacemaker at the American Heart Association’s Scientific Sessions 2018  on Sunday, Nov. 11. The prototype, approximately 1 cc, the size of an almond, is designed to make pacemaker procedures for infants less invasive, less painful and more efficient, measured by shorter surgeries, faster recovery times and reduced medical costs.

Kumthekar, a Cardiovascular Disease in the Young Travel Award recipient, delivered his oral abstract, entitled “Minimally Invasive Percutaneous Epicardial Placement of a Custom Miniature Pacemaker with Leadlet under Direct Visualization,” as part of the Top Translational Science Abstracts in Pediatric Cardiology session.

“As cardiologists and pediatric surgeons, our goal is to put a child’s health and comfort first,” says Kumthekar. “Advancements in surgical fields are tending toward procedures that are less and less invasive. There are many laparoscopic surgeries in adults and children that used to be open surgeries, such as appendix and gall bladder removals. However, placing pacemaker leads on infants’ hearts has always been an open surgery. We are trying to bring those surgical advances into our field of pediatric cardiology to benefit our patients.”

Instead of using open-chest surgery, the current standard for implanting pacemakers in children, doctors could implant the tiny pacemakers by making a relatively tiny 1-cm incision just below the ribcage.

“The advantage is that the entire surgery is contained within a tiny 1-cm incision, which is what we find groundbreaking,” says Kumthekar.

With the help of a patented two-channel, self-anchoring access port previously developed by Berul’ s research group, the operator can insert a camera into the chest to directly visualize the entire procedure. They can then insert a sheath (narrow tube) through the second channel to access the pericardial sac, the plastic-like cover around the heart. The leadlet, the short extension of the miniature pacemaker, can be affixed onto the surface of the heart under direct visualization. The final step is to insert the pacemaker into the incision and close the skin, leaving a tiny scar instead of two large suture lines.

The median time from incision to implantation in this thoracoscopic surgery study was 21 minutes, and the entire procedure took less than an hour on average. In contrast, pediatric open-heart surgery could take up to several hours, depending on the child’s medical complexities.

“Placing a pacemaker in a small child is different than operating on an adult, due to their small chest cavity and narrow blood vessels,” says Kumthekar. “By eliminating the need to cut through the sternum or the ribs and fully open the chest to implant a pacemaker, the current model, we can cut down on surgical time and help alleviate pain.”

The miniature pacemakers and surgical approach may also work well for adult patients with limited vascular access, such as those born with congenital heart disease, or for patients who have had open-heart surgery or multiple previous cardiovascular procedures.

The miniature pacemakers passed a proof-of-concept simulation and the experimental model is now ready for a second phase of testing, which will analyze how the tailored devices hold up over time, prior to clinical testing and availability for infants.

“The concept of inserting a pacemaker with a 1-cm incision in less than an hour demonstrates the power of working with multidisciplinary research teams to quickly solve complex clinical challenges,” says Charles Berul, M.D., a guiding study author, electrophysiologist and the chief of cardiology at Children’s National.

Berul’s team from Children’s National collaborated with Medtronic PLC, developers of the first implantable pacemakers, to develop the prototype and provide resources and technical support to test the minimally-invasive surgery.

The National Institutes of Health provided a grant to Berul’s research team to develop the PeriPath, the all-in-one 1-cm access port, which cut down on the number of incisions by enabling the camera, needle, leadlet and pacemaker to be inserted into one port, through one tiny incision.

Other study authors listed on the abstract presented at Scientific Sessions 2018 include Justin Opfermann, M.S., Paige Mass, B.S., Jeffrey P. Moak, M.D., and Elizabeth Sherwin, M.D., from Children’s National, and Mark Marshall, M.S., and Teri Whitman, Ph.D., from Medtronic PLC.

Marva Moxey Mims

Making the case for a comprehensive national registry for pediatric CKD

Marva Moxey Mims

“It’s of utmost importance that we develop more sensitive ways to identify children who are at heightened risk for developing CKD.,” says Marva Moxey-Mims, M.D. “A growing body of evidence suggests that this includes children treated in pediatric intensive care units who sustained acute kidney injury, infants born preterm and low birth weight, and obese children.”

Even though chronic kidney disease (CKD) is a global epidemic that imperils cardiovascular health, impairs quality of life and heightens mortality, very little is known about how CKD uniquely impacts children and how kids may be spared from its more devastating effects.

That makes a study published in the November 2018 issue of the American Journal of Kidney Diseases all the more notable because it represents the largest population-based study of CKD prevalence in a nationally representative cohort of adolescents aged 12 to 18, Sun-Young Ahn, M.D., and Marva Moxey-Mims, M.D., of Children’s National Health System, write in a companion editorial published online Oct. 18, 2018.

In their invited commentary, “Chronic kidney disease in children: the importance of a national epidemiological study,” Drs. Ahn and Moxey-Mims point out that pediatric CKD can contribute to growth failure, developmental and neurocognitive defects and impaired cardiovascular health.

“Children who require renal-replacement therapy suffer mortality rates that are 30 times higher than children who don’t have end-stage renal disease,” adds Dr. Moxey-Mims, chief of the Division of Nephrology at Children’s National. “It’s of utmost importance that we develop more sensitive ways to identify children who are at heightened risk for developing CKD. A growing body of evidence suggests that this includes children treated in pediatric intensive care units who sustained acute kidney injury, infants born preterm and low birth weight, and obese children.”

At its early stages, pediatric CKD usually has few symptoms, and clinicians around the world lack validated biomarkers to spot the disease early, before it may become irreversible.

While national mass urine screening programs in Japan, Taiwan and Korea have demonstrated success in early detection of CKD, which enabled successful interventions, such an approach is not cost-effective for the U.S., Drs. Ahn and Moxey-Mims write.

According to the Centers for Disease Control and Prevention, 1 in 10 U.S. infants in 2016 was born preterm, prior to 37 weeks gestation. Because of that trend, the commentators advocate for “a concerted national effort” to track preterm and low birth weight newborns. (These infants are presumed to have lower nephron endowment, which increases their risk for developing end-stage kidney disease.)

“We need a comprehensive, national registry just for pediatric CKD, a database that represents the entire U.S. population that we could query to glean new insights about what improves kids’ lifespan and quality of life. With a large database of anonymized pediatric patient records we could, for example, assess the effectiveness of specific therapeutic interventions, such as angiotensin-converting enzyme inhibitors, in improving care and slowing CKD progression in kids,” Dr. Moxey-Mims adds.

Nikki Gillum Posnack

Do plastic chemicals contribute to the sudden death of patients on dialysis?

Nikki Gillum Posnack

Nikki Posnack, Ph.D., assistant professor with the Children’s National Heart Institute, continues to explore how repeat chemical exposure from medical devices influences cardiovascular function.

In a review published in HeartRhythm, Nikki Posnack, Ph.D., an assistant professor at the Children’s National Heart Institute, and Larisa Tereshchenko, M.D., Ph.D., FHRS, a researcher with the Knight Cardiovascular Institute at Oregon Health and Science University, establish a strong foundation for a running hypothesis: Replacing BPA- and DEHP- leaching plastics for alternative materials used to create medical devices may help patients on dialysis, and others with impaired immune function, live longer.

While Drs. Tereshchenko and Posnack note clinical studies and randomized controlled trials are needed to test this theory, they gather a compelling argument by examining the impact exposure to chemicals from plastics used in dialysis have on a patient’s short- and long-term health outcomes, including sudden cardiac death (SCD).

“As our society modifies our exposure to plastics to mitigate health risks, we should think about overexposure to plastics in a medical setting,” says Posnack. “The purpose of the review in HeartRhythm is to gather data about the impact chemical compounds, leached from plastic devices, have on cardiovascular outcomes for patients spending prolonged periods of time in the hospital.”

In this review, the authors explore chemical risk exposures in a medical setting, starting with factors that influence sudden cardiac death (SCD) among dialysis patients.

Why study dialysis patients?

SCD in dialysis patients accounts for one-third of deaths in this population. This prompts a need to develop prevention strategies, especially among patients with end-stage renal disease (ESRD).

The highest mortality rate observed among dialysis patients is during the first year of hemodialysis, a dialysis process that requires a machine to take the place of the kidneys and remove waste from the bloodstream and replenish it with minerals, such as potassium, sodium and calcium. During this year, mortality during hemodialysis is observed more frequently during the first three months of treatment, especially among older patients.

Possible reasons for an increased risk of an earlier death include chemical exposure, which is casually associated with altered cardiac function, as well as genetic risks for irregular heart rhythms and heart failure. In the HeartRhythm review, Drs. Tereshchenko and Posnack analyze factors that influence mortality:

Hemodialysis treatment, dialysis, is associated with plastic chemical exposure

Drs. Tereshchenko and Posnack note that dialysis tubing and catheters are commonly manufactured using polyvinyl chloride (PVC) polymers. The phthalate plastics used to soften PVC can easily leech if exposed to lipid-like substances, like blood. Research shows phthalate chemical concentrations increase during a four-hour dialysis.

Di(2-ethylhexyl) phthalate (DEHP) is a common plastic used to manufacture dialysis tubes, thanks to its structure and economy.

Bisphenol-A (BPA) is another common material used in medical device manufacturing. From the membranes of medical tools to resins, or external coatings and adhesives, BPA leaves behind a chemical residue on PVC medical devices.

In reviewing the research, the authors find dialysis patients are often exposed to high levels of DEHP and BPA. The amount of exposure to these chemicals varies in regards to room temperature, time of contact, other circuit coatings and the flow rate of dialysis. A faster flow rate correlates with reductions in chemical leaching and lower mortality rates.

Plastic chemical exposure is casually associated with altered cardiac function

Drs. Tereshchenko and Posnack note a causal relationship already exists between chemicals absorbed from plastics and cardiovascular outcomes.

Dr. Posnack’s previous research found BPA concentrations impaired electrical conduction in neonatal cardiomyocytes – young, developing heart cells – potentially altering the heart’s normal rhythm and function.

To the best of their knowledge, no clinical research has been conducted on DEHP exposure and SCD. However, proof-of-concept models find in vivo phthalate exposure alters autonomic regulation, which can slow down natural heart-rate rhythm and create a lag in recovery time to stressful stimuli. For humans, this type of stressful stimulation would be equivalent to recovering from a bike ride, car accident, or in this case, ongoing dialysis treatment with impaired immune function.

In other models, BPA exposure has been shown to cause bradycardia, or a delayed heart rate. In excised whole heart models, BPA has also been shown to alter cardiac electrical activity.

Abnormal electrophysiological substrate in end-stage renal disease

Since the heart and kidneys work in tandem to transport blood throughout the body, and manage vital functions, such as our heart rate, blood flow and breathing, the authors cite additional factors that lead to ongoing heart and kidney problems, with a look at end-stage renal disease (ESRD).

General heart-function kidney risks include abnormal electrophysiological (EP) substrate, the underlying electrical activity of the cardiac tissue, and genetic risk factors, including the TBX3 gene, a gene associated with a unique positioning of the heart and SCD.

“We don’t want to cite alarm about having a medical procedure or about relying on external help, such as dialysis, for proper kidney function,” says Posnack. “Especially since dialysis is a life-saving medical intervention for patients with inadequate kidney function.”

Pre-existing abnormal EP substrate interacts with plastic chemical exposure in incident dialysis, which increases risk of SCD in genetically predisposed ESRD patients

To summarize their findings, Drs. Tereshchenko and Posnack list a handful of support areas, starting with observations about reductions in cardiovascular mortality and SCD following kidney transplants. They note hemodialysis catheters are associated with larger DEHP exposure and a higher risk of SCD, compared to arteriovenous fistulas, highways surgically created to connect blood from the artery to the vein.

Drs. Posnack and Tereshchenko also note a correlative observation about higher SCD rates observed six hours after hemodialysis, when peak levels of DEHP and BPA are circulating in the bloodstream.

To compare and control for these factors among dialysis patients, the researchers cite different mortality patterns with hemodialysis and peritoneal dialysis. Patients on hemodialysis experience higher mortality during the first year of treatment, compared to peritoneal dialysis, who have higher mortality rates after the second year of treatment. Hemodialysis relies on a machine to take the place of kidney function, while peritoneal dialysis relies on a catheter, a small tube surgically inserted into the stomach.

“Our goal is to build on our previous research findings by analyzing variables that have yet to be studied before, and to update the field of medicine in the process,” says Dr. Posnack. “This includes investigating the cardiovascular risks of using BPA- and DEHP-materials to construct medical devices. Ultimately, we hope to determine whether plastic materials contribute to cardiovascular risks, and investigate whether patients might benefit from the use of alternative materials for medical devices.

Drs. Tereshchenko and Posnack note that despite the associations between chemical exposure from medical devices and increased cardiovascular risks, there are no restrictions in the United States on the use of phthalates and BPA chemicals used to manufacture medical devices.

Their future research will explore how replacing BPA- and DEHP-leaching plastics influence mortality and morbidity rates of ESRD patients on dialysis, as well as other patients exposed to repeat chemical exposure, such as patients having cardiac surgery.

“We want to make sure we identify and then work to minimize any potential risks of plastic exposure in a medical setting,” adds Dr. Posnack. “Our goal is to put the health and safety of patients first.”

Dr. Posnack’s research is funded by two grants (R01HL139472, R00ES023477) from the National Institutes of Health.

Pregnant-Mom

Safeguarding fetal brain health in pregnancies complicated by CHD

Pregnant-Mom

During the last few weeks of pregnancy, certain regions of the fetal brain experience exponential growth but also are more vulnerable to injury during that high-growth period.

Yao Wu, Ph.D., a research postdoctoral fellow in the Developing Brain Research Laboratory at Children’s National Health System, has received a Thrasher Research Fund early career award to expand knowledge about regions of the fetal brain that are vulnerable to injury from congenital heart disease (CHD) during pregnancy.

CHD, the most common birth defect, can have lasting effects, including overall health issues; difficulty achieving milestones such as crawling, walking or running; and missed days at daycare or school, according to the Centers for Disease Control and Prevention. Brain injury is a major complication for infants born with CHD. Catherine Limperopoulos, Ph.D., director of Children’s brain imaging lab, was the first to provide in vivo evidence that fetal brain growth and metabolism in the third trimester of pregnancy is impaired within the womb.

“It remains unclear which specific regions of the fetal brain are more vulnerable to these insults in utero,” Limperopoulos says. “We first need to identify early brain abnormalities attributed to CHD and understand their impact on infants’ later behavioral and cognitive development in order to better counsel parents and effectively intervene during the prenatal period to safeguard brain health.”

During the last few weeks of pregnancy, certain regions of the fetal brain experience exponential growth but also are more vulnerable to injury during that high-growth period. The grant, $26,749 over two years, will underwrite “Brain Development in Fetuses With Congenital Heart Disease,” research that enables Wu to utilize quantitative, non-invasive magnetic resonance imaging (MRI) to compare fetal brain development in pregnancies complicated by CHD with brain development in healthy fetuses of the same gestational age.Wu will leverage quantitative, in vivo 3-D volumetric MRI to compare overall fetal and neonatal brain growth as well as growth in key regions including cortical grey matter, white matter, deep grey matter, lateral ventricles, external cerebrospinal fluid, cerebellum, brain stem, amygdala and the hippocampus.

The research is an offshoot of a prospective study funded by the National Institutes of Health that uses advanced imaging techniques to record brain growth in 50 fetuses in pregnancies complicated by CHD who need open heart surgery and 50 healthy fetuses. MRI studies are conducted during the second trimester (24 to 28 weeks gestational age), third trimester (33 to 37 weeks gestational age) and shortly after birth but before surgery. In addition, fetal and neonatal MRI measurements will be correlated with validated scales that measure infants’ and toddlers’ overall development, behavior and social/emotional maturity.

“I am humbled to be selected for this prestigious award,” Wu says. “The findings from our ongoing work could be instrumental in identifying strategies for clinicians and care teams managing high-risk pregnancies to optimize fetal brain development and infants’ overall quality of life.”

Dr.-Jonas.-WSPCHS

Snapshot: The Sixth Scientific Meeting of the World Society for Pediatric and Congenital Heart Surgery

Dr.-Jonas.-WSPCHS

Dr. Richard Jonas shows surgical advancements using 3D heart models, which participants could bring back to their host institutions.

On July 22, 2018, more than 700 cardiac specialists met in Orlando, Fla. for the Sixth Scientific Meeting of the World Society for Pediatric and Congenital Heart Surgery (WSPCHS 2018).

The five-day conference hosted a mix of specialists, ranging from cardiothoracic surgeons, cardiologists and cardiac intensivists, to anesthesiologists, physician assistants and nurse practitioners, representing 49 countries and six continents.

To advance the vision of WSPCHS – that every child born with a congenital heart defect should have access to appropriate medical and surgical care – the conference was divided into eight tracks: cardiac surgery, cardiology, anesthesia, critical care, nursing, perfusion, administration and training.

Richard Jonas, M.D., outgoing president of WSPCHS and the division chief of cardiac surgery at Children’s National Health System, provided the outgoing presidential address, delivered the keynote lecture on Transposition of the Great Arteries (TGA) and guided a surgical skills lab with printed 3-D heart models.

Other speakers from Children’s National include:

  • Gil Wernovsky, M.D., a cardiac critical care specialist, presented on the complex physiology of TGA, as well as long-term consequences in survivors of neonatal heart surgery, including TGA and single ventricle.
  • Mary Donofrio, M.D., a cardiologist and director of the Fetal Heart Program, presented “Prenatal Diagnosis: Improving Accuracy and Planning Delivery for babies with TGA,” “Systemic Venous Abnormalities in the Fetus,” “Intervention for Fetal Lesions Causing High Output Heart Failure” and “Fetal Cardiac Care – Can We Improve Outcomes by Altering the Natural History of Disease?”
  • Gerard Martin, M.D., a cardiologist and medical director of global services, presented “Is the Arterial Switch as Good as We Thought It Would Be?” and “Impact, MAPIT, NCPQIC – How and Why We Should All Embrace Quality Metrics.”
  • Pranava Sinha, M.D., a cardiac surgeon, presented the abstract “Cryopreserved Valved Femoral Vein Homografts for Right Ventricular Outflow Tract Reconstruction in Infants.”

Participants left with knowledge about how to diagnose and treat complex congenital heart disease, and an understanding of the long-term consequences of surgical management into adulthood. In addition, they received training regarding standardized practice models, new strategies in telemedicine and collaborative, multi-institutional research.

“It was an amazing experience for me to bring my expertise to a conference which historically concentrated on surgical and interventional care and long-term follow-up,” says Dr. Donofrio. “The collaboration between the fetal and postnatal care teams including surgeons, interventionalists and intensive care doctors enables new strategies to be developed to care for babies with CHD before birth. Our hope is that by intervening when possible in utero and by planning for specialized care in the delivery room, we can improve outcomes for our most complex patients”.

The Johns Hopkins University School of Medicine, Florida Board of Nursing, American Academy of Nurse Practitioners National Certification Program, American Nurses Credentialing Center and the American Board of Cardiovascular Perfusion provided continuing medical credits for eligible providers.

“I was so proud to be a member of the Children’s National team at this international conference,” notes Dr. Wernovsky. “We had to the opportunity to share our experience in fetal cardiology, outpatient cardiology, cardiac critical care, cardiac nursing and cardiac surgery with a worldwide audience, including surgical trainees, senior cardiovascular surgeons and the rest of the team members necessary to optimally care for babies and children with complex CHD. In addition, members of the nursing staff shared their research about advancements in the field. It was quite a success – both for our team and for all of the participants.”

Washington Adult Congenital Heart Program staff

The Washington Adult Congenital Heart Program earns national accreditation from the Adult Congenital Heart Association

Washington Adult Congenital Heart Program staff

The Washington Adult Congenital Heart Program (WACH), part of Children’s National, earns accreditation from the Adult Congenital Heart Association for providing high-level, integrated care to patients with congenital heart disease.

Anitha John, M.D., Ph.D., a congenital heart disease (CHD) specialist and the director of the Washington Adult Congenital Heart Program (WACH) at Children’s National Health System, is a master of creating and leading multidisciplinary teams and networks to drive innovative standards to accelerate personalized treatment for adults born with heart conditions.

The Adult Congenital Heart Association (ACHA), a national organization dedicated to advancing adult congenital heart disease (ACHD) care, announces WACH as one of 19 medical centers in the country – and the first in the Mid-Atlantic region – to earn its accreditation, which signifies a center that provides high-level, comprehensive care.

WACH receives this accreditation by meeting ACHA’s criteria, which includes medical services and personnel requirements, and going through a rigorous accreditation process, both of which were developed over a number of years through a collaboration with doctors, physician assistants, nurse practitioners, nurses and ACHD patients.

There are 1.4 million adults in the U.S. living with one of many different types of congenital heart defects, ranging among simple, moderate and complex.

“There are now more adults than children in the U.S. with CHD,” said Mark Roeder, President and CEO of ACHA. “Accreditation will elevate the standard of care and have a positive impact on the futures of those living with this disease. Coordination of care is key, and this accreditation program will make care more streamlined for ACHD patients, improving their quality of life.”

A study published in Circulation examined mortality rates among 70,000 patients living with CHD over a 15-year period, from 1990 to 2005, and saw mortality rates fall with referrals to specialized ACHD care centers.

“This accreditation lets patients and other specialists know what to expect if they visit our center,” says Dr. John. “While the field of congenital heart disease is small enough to personalize, it’s large enough to standardize. I’m grateful to work with a wonderful team to provide this type of high-level care.”

Dr. John has a unique background to elevate standards of ACHD care, while creating tailored prescriptions. She is one of a handful of physicians with subspecialty training in ACHD, which she completed at the Mayo Clinic. Her formal training in internal medicine and general pediatrics, completed at Brown University, fits well with the subspecialty training she received as a pediatric cardiology fellow at Children’s Hospital of Philadelphia. Her research now focuses on clinical outcomes in congenital cardiology and advancing multicenter research efforts in adult congenital cardiology.

From March 2016 to 2018, Dr. John led the Alliance for Adult Research in Congenital Cardiology, the major multicenter research group in the U.S. focused on ACHD research. She’s also working with experts and patient advocates to guide efforts to set up a future ACHD patient registry, which will continue to guide research efforts and educate providers about ACHD care.

To help facilitate collaboration, Dr. John guides quarterly meetings of the Mid-Atlantic ACHD regional group.  Established in 2011 through Children’s National, the group has expanded to include ACHD providers from over 18 programs/practices from across the East Coast. This group provides a forum for patient case discussion and programmatic support. More importantly, the professional collaboration has served to not only improve patient care but also provides support to providers as they continue to care for a growing population of patients. This type of collaboration fosters mutual understanding and sets the stage for a relaxed but collegial environment where questions flow and learning occurs.

To further facilitate education, she created an inaugural patient day at the 7th Annual Adult Congenital Heart Disease in the 21st Century conference this past year, allowing patients to have their own educational summit – while opening the opportunity to providers to stay an extra day to learn about patient-centered care. The conference relies heavily on the participation of the Mid-Atlantic ACHD regional group of providers.

Patients learned as much about 3D heart models, pacemakers and noninvasive surgical techniques as they did about personalized approaches to lifestyle care, from practicing mindfulness to hearing about communication strategies to use with their medical teams and families. A variety of experts, from cardiac surgeons to clinical social workers, led the panels and breakout sessions.

“We’re empowering patients to become an active participant and an engaged member of their medical care team,” adds Dr. John.

ACHA supports WACH’s efforts and spoke at the conference, complementing its mission to serve and support the more than one million adults with CHD, their families and the medical community.

The WACH team includes not only Dr. John, but ACHD cardiologists Seiji Ito, M.D., and Tacy Downing, M.D.; Pranava Sinha, M.D., surgical director; Rachel Steury, R.N.P., advanced practitioner; Nancy Klein, R.N., clinical coordinator; Emily Stein, M.S.W., social worker; Whitney Osborne, M.P.H., clinical research coordinator, and Ruth Phillippi, M.S., program coordinator. The team works together seamlessly to fulfill the program mission of achieving clinical excellence, promoting research and providing education in the care of adults of with CHD.

For more information about WACH or to take advantage of resources for ACHD providers, please contact 202-821-6289 or visit www.ChildrensNational.org/WACH.

Graph showing magnesium reduces arrhythmia risk

Magnesium helps prevent postsurgical arrhythmias in pediatric patients

Graph showing magnesium reduces arrhythmia risk

Magnesium (Mg) helps reduce arrhythmias, irregular heart rhythms, in adults. It also helps alleviate the symptoms of postoperative atrial fibrillation, or AFib, which can lead to blood clots, stroke and heart failure. Can it help prevent postsurgical arrhythmias in pediatric patients with congenital heart disease?

New research from Children’s National Health System finds a 25- or 50-mg dose of Mg used during congenital heart surgery (CHS) helps prevent arrhythmias, especially junctional ectopic tachycardia (JET) and atrial tachycardia (AT), common arrhythmias following CHS, according to a study published in the August 2018 edition of The Journal of Thoracic and Cardiovascular Surgery.

To reach this conclusion, the researchers separated 1,871 CHS patients from Children’s National into three groups: a control group of 750 patients who had surgery without Mg, a group of 338 patients receiving a 25-mg /kg dose of Mg during surgery and a group of 783 patients receiving a 50-mg/kg dose of Mg during surgery. The data looked at CHS cases over eight years, from 2005 to 2013, to determine if Mg administration during surgery alleviates postoperative arrhythmias and if the amount, measured by a 25- or 50-mg/kg dose, makes a difference.

“This study, the first conducted in pediatric patients, finds administering magnesium during congenital heart surgery reduces the likelihood of postsurgical arrhythmias,” says Charles Berul, M.D., a study author and the chief of cardiology at Children’s National. “We don’t detect a dose-dependent relationship, which means a small or larger amount of magnesium is equally effective at preventing arrhythmias following surgery.”

The researchers found that up to one-third of CHS patients experience postoperative arrhythmias, with JET and AT accounting for more than two-thirds of arrhythmias following CHS. They note that despite the administration of Mg during surgery, there continues to be a high incidence of postoperative arrhythmias – affecting 18 percent or about one in five CHS patients.

“We hope this study guides future research to see if adding new or additional agents to magnesium eliminates, or further reduces, postoperative arrhythmias,” notes Dr. Berul. “For now, we’re happy to find an algorithm to put into practice and to share with other medical centers, as a way to help pediatric patients recover from congenital heart surgery—stronger, faster and with a reduced risk of complications.”

The researchers note that postoperative arrhythmias impact the recovery period of CHS, increase the duration of intubation and CICU stay and prolong hospital stay.

Making the grade: Children’s National is nation’s Top 5 children’s hospital

Children’s National rose in rankings to become the nation’s Top 5 children’s hospital according to the 2018-19 Best Children’s Hospitals Honor Roll released June 26, 2018, by U.S. News & World Report. Additionally, for the second straight year, Children’s Neonatology division led by Billie Lou Short, M.D., ranked No. 1 among 50 neonatal intensive care units ranked across the nation.

Children’s National also ranked in the Top 10 in six additional services:

For the eighth year running, Children’s National ranked in all 10 specialty services, which underscores its unwavering commitment to excellence, continuous quality improvement and unmatched pediatric expertise throughout the organization.

“It’s a distinct honor for Children’s physicians, nurses and employees to be recognized as the nation’s Top 5 pediatric hospital. Children’s National provides the nation’s best care for kids and our dedicated physicians, neonatologists, surgeons, neuroscientists and other specialists, nurses and other clinical support teams are the reason why,” says Kurt Newman, M.D., Children’s President and CEO. “All of the Children’s staff is committed to ensuring that our kids and families enjoy the very best health outcomes today and for the rest of their lives.”

The excellence of Children’s care is made possible by our research insights and clinical innovations. In addition to being named to the U.S. News Honor Roll, a distinction awarded to just 10 children’s centers around the nation, Children’s National is a two-time Magnet® designated hospital for excellence in nursing and is a Leapfrog Group Top Hospital. Children’s ranks seventh among pediatric hospitals in funding from the National Institutes of Health, with a combined $40 million in direct and indirect funding, and transfers the latest research insights from the bench to patients’ bedsides.

“The 10 pediatric centers on this year’s Best Children’s Hospitals Honor Roll deliver exceptional care across a range of specialties and deserve to be highlighted,” says Ben Harder, chief of health analysis at U.S. News. “Day after day, these hospitals provide state-of-the-art medical expertise to children with complex conditions. Their U.S. News’ rankings reflect their commitment to providing high-quality care.”

The 12th annual rankings recognize the top 50 pediatric facilities across the U.S. in 10 pediatric specialties: cancer, cardiology and heart surgery, diabetes and endocrinology, gastroenterology and gastrointestinal surgery, neonatology, nephrology, neurology and neurosurgery, orthopedics, pulmonology and urology. Hospitals received points for being ranked in a specialty, and higher-ranking hospitals receive more points. The Best Children’s Hospitals Honor Roll recognizes the 10 hospitals that received the most points overall.

This year’s rankings will be published in the U.S. News & World Report’s “Best Hospitals 2019” guidebook, available for purchase in late September.

Baby in the NICU

Getting to the heart of cardiac output

Baby in the NICU

To keep infants in the neonatal intensive care unit (NICU) as healthy as possible, it’s important to keep close tabs on their vital signs. During their NICU stay, most babies have continuous monitoring of their blood pressure, respiratory rate and blood oxygen saturation. And although continuous monitoring of heart rate is also typically standard, other information about heart function – such as cardiac output, a measure of how well the heart is pumping blood – remains a challenge to obtain in these vulnerable babies.

Clinical markers like blood pressure, heart rate and urine output are available, but they are indirect measures of cardiac output, how much blood the heart pumps per minute. Less invasive techniques, such as Doppler ultrasound, can be imprecise. Respiratory mass spectrometry or catheterization would provide more precision by directly calculating cardiac output but carry risks or are not feasible for neonates.

Clinicians at Children’s National Health System hypothesized that COstatus monitors could offer a way to directly measure cardiac output among neonates. The COstatus monitor – a minimally invasive way to measure hemodynamics – captures cardiac output, total end diastolic volume, active circulation volume and central blood volume.

The research team tested the approach by leveraging ultrasound dilution: Injecting saline, which has an ultrasound velocity of 1533m/second, slows the ultrasound velocity of blood from its normal rate of 1580m/second and produces a dilution curve.

“It is feasible to directly measure neonatal cardiac output by ultrasound dilution via the COstatus monitor in the first two weeks of life with no adverse events,” says Khodayar Rais-Bahrami, M.D., a Children’s neonatologist and senior author for the research presented during the Pediatric Academic Societies 2018 annual meeting. “When we took consecutive measurements, we saw very little variance in the parameters.”

The COstatus monitor uses an extracorporeal loop that is connected to arterial and venous catheters. The 12 neonates included in the study already had umbilical venous catheters as well as either a peripheral arterial line or umbilical arterial catheter. The infants ranged in weight from 0.72 to 3.74 kg and were born at 24 to 41.3 gestational weeks.

The infants’ cardiac output was measured 54 times from 1 to 13 days of life. Up to two measurement sessions occurred daily for a maximum of four days. The mean cardiac output was 0.43 L/minute with a mean cardiac index of 197mL/kg/minute.

Future research will describe normal cardiac output ranges for neonates as well as how these measurements evolve during the first week of life.

In addition to Dr. Rais-Bahrami, study co-authors include Simranjeet S. Sran, M.D., and Mariam Said, M.D., a Children’s neonatologist.

Nikki Gillum Posnack

Examining BPA’s impact on developing heart cells

Nikki Gillum Posnack

“We know that once this chemical enters the body, it can be bioactive and therefore can influence how heart cells function,” says Nikki Gillum Posnack, Ph.D. “This is the first study to look at the impact BPA exposure can have on heart cells that are still developing.”

More than 8 million pounds of bisphenol A (BPA), a common chemical used in manufacturing plastics, is produced each year for consumer goods and medical products. This endocrine disruptor reaches 90 percent of the population, and excessive exposure to BPA, e.g., plastic bottles, cash register receipts, and even deodorant, is associated with adverse cardiovascular events that range from heart arrhythmias and angina to atherosclerosis, the leading cause of death in the U.S.

To examine the impact BPA could have in children, researchers with Children’s National Heart Institute and the Sheikh Zayed Institute for Pediatric Surgical Innovation evaluated the short-term risks of BPA exposure in a preclinical setting. This experimental research finds developing heart cells respond to short-term BPA exposure with slowed heart rates, irregular heart rhythms and calcium instabilities.

While more research is needed to provide clinical recommendations, this preclinical model paves the way for future study designs to see if young patients exposed to BPA from medical devices or surgical procedures have adverse cardiac events and altered cardiac function.

“Existing research explores the impact endocrine disruptors, specifically BPA, have on adults and their cardiovascular and kidney function,” notes Nikki Gillum Posnack, Ph.D., a study author and assistant professor at Children’s National and The George Washington University. “We know that once this chemical enters the body, it can be bioactive and therefore can influence how heart cells function. This is the first study to look at the impact BPA exposure can have on heart cells that are still developing.”

The significance of this research is that plastics have revolutionized the way clinicians and surgeons treat young patients, especially patients with compromised immune or cardiac function.

Implications of Dr. Posnack’s future research may incentivize the development of alternative products used by medical device manufacturers and encourage the research community to study the impact of plastics on sensitive patient populations.

“It’s too early to tell how this research will impact the development of medical devices and equipment used in intensive care settings,” notes Dr. Posnack. “We do not want to interfere with clinical treatments, but, as scientists, we are curious about how medical products and materials can be improved. We are extending this research right now by examining the impact of short-term BPA exposure on human heart cells, which are developed from stem cells.”

This research, which appears as an online advance in Nature’s Scientific Reports, was supported by the National Institutes of Health under awards R00ES023477, RO1HL139472 and UL1TR000075, Children’s Research Institute and the Children’s National Heart Institute. NVIDIA Corporation provided GPUs, computational devices, for this study.