Cardiology and Heart Surgery

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 in her office at Children's National.

Making the case for a comprehensive national registry for pediatric CKD

Marva Moxey-Mims in her office 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.,” 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.

Darren Klugman

Children’s National cardiac intensive care experts named to leadership of Pediatric Cardiac Intensive Care Society

Darren Klugman

Darren Klugman, M.D., medical director of the cardiac intensive care unit (ICU) at Children’s National Health System, has been re-elected to the executive board of the Pediatric Cardiac Intensive Care Society (PCICS).

Darren Klugman, M.D., medical director of the cardiac intensive care unit (ICU) at Children’s National Health System, has been re-elected to the executive board of the Pediatric Cardiac Intensive Care Society (PCICS). Klugman will serve a second term as secretary of the organization, which serves to promote excellence in pediatric critical care medicine.

Melissa B. Jones, CPNP-AC, a critical care nurse practitioner at Children’s National, received the honor of being elected Vice President of PCICS. She will take on this leadership role for two years before assuming the presidency of the society in 2020.  Another critical care nurse practitioner at Children’s National, Christine Riley, CPNP-AC, was elected to serve a two-year term on the board of directors.

Congenital heart disease (CHD) is the most common birth defect. There have been many advances in the treatment of children with cardiovascular disorders, leading to a reduction in mortality. However, the extreme complexity of this treatable disease requires specialized care from disciplines beyond cardiology, including critical care, cardiac surgery and anesthesia. PCICS was formed to provide an international professional forum for promoting excellence in pediatric cardiac critical care.

Children’s National has had a large role in PCICS since its inception in 2003. David Wessel, M.D., executive vice president and chief medical officer, Hospital and Specialty Services, was one of the founding members of the international society. Children’s National served as the host of the 13th Annual International Meeting of PCICS in December of 2017 with many experts including Richard Jonas, M.D., division chief of cardiac surgery and co-director of the Children’s National Heart Institute, and Ricardo Muñoz, M.D., division chief of cardiac critical care medicine and executive director of telemedicine, giving talks. Many Children’s National specialists again will lend their expertise to this year’s PCICS annual meeting in Miami, Fla., in December.

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 HeartRhythmNikki 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 catherization would provide more precision by directly calcuating 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.

banner year

2017: A banner year for innovation at Children’s National

banner year

In 2017, clinicians and research faculty working at Children’s National Health System published more than 850 research articles about a wide array of topics. A multidisciplinary Children’s Research Institute review group selected the top 10 articles for the calendar year considering, among other factors, work published in high-impact academic journals.

“This year’s honorees showcase how our multidisciplinary institutes serve as vehicles to bring together Children’s specialists in cross-cutting research and clinical collaborations,” says Mark L. Batshaw, M.D., Physician-in-Chief and Chief Academic Officer at Children’s National. “We’re honored that the National Institutes of Health and other funders have provided millions in awards that help to ensure that these important research projects continue.”

The published papers explain research that includes using imaging to describe the topography of the developing brains of infants with congenital heart disease, how high levels of iron may contribute to neural tube defects and using an incisionless surgery method to successfully treat osteoid osteoma. The top 10 Children’s papers:

Read the complete list.

Dr. Batshaw’s announcement comes on the eve of Research and Education Week 2018 at Children’s National, a weeklong event that begins April 16, 2018. This year’s theme, “Diversity powers innovation,” underscores the cross-cutting nature of Children’s research that aims to transform pediatric care.

Ricardo Munoz

Ricardo Muñoz, M.D., joins Children’s National as Chief of Cardiac Critical Care Medicine, Executive Director of Telemedicine and Co-Director of Heart Institute

Ricardo Munoz

Children’s National Health System is pleased to announce Ricardo Muñoz, M.D., as chief of the Division of Cardiac Critical Care Medicine and co-director of the Children’s National Heart Institute. Dr. Muñoz also will serve as the executive director of Telemedicine Services at Children’s National, working to leverage advances in technology to improve access to health care for underserved communities and developing nations.

Within the new division of Cardiac Critical Care Medicine, Dr. Muñoz will oversee the work of a multidisciplinary team, including critical care nurse practitioners and nurses, respiratory and physical therapists, nutritionists, social workers and pharmacists, in addition to a medical staff with one of the highest rates of double-boarded specialists in cardiology and critical care.

“We are honored to welcome Dr. Ricardo Muñoz to Children’s National,” says David Wessel, M.D., executive vice president and chief medical officer of Hospital and Specialty Services. “He is a pioneer and innovator in the fields of cardiac critical care and telemedicine and will undoubtedly provide a huge benefit to our patients and their families along with our cardiac critical care and telemedicine teams.”

Dr. Muñoz comes to Children’s National from Children’s Hospital of Pittsburgh of UPMC. During his 15-year tenure there, he established the cardiac intensive care unit and co-led the Heart Center in a multidisciplinary effort to achieve some of the best outcomes in the nation. He also is credited with pioneering telemedicine for pediatric critical care, providing nearly 4,000 consultations globally.

“Children’s National has a longstanding reputation of excellence in cardiac critical care, and I am pleased to be able to join the team in our nation’s capital to not only deliver top-quality care to patients regionally, but also around the world,” says Dr. Muñoz. “The early identification and treatment of pediatric congenital heart disease patients has made rapid improvements in recent decades, but there is a shortage of intensivists to care for these children during what is often a complex recovery course.”

Dr. Muñoz attended medical school at the Universidad del Norte, Barranquilla, Colombia, and completed his residency in pediatrics at the Hospital Militar Central, Bógota, Colombia. He continued his training as a general pediatrics and pediatric critical care fellow at Massachusetts General Hospital, and as a pediatric cardiology fellow at Boston Children’s Hospital. He then joined the faculty at Harvard Medical School and served as an attending physician in the Cardiac Intensive Care Unit at Boston Children’s.

Dr. Muñoz is board certified in pediatrics, pediatric critical care and in pediatric cardiology. He is a fellow of the American Academy of Pediatrics, the American College of Critical Care Medicine and the American College of Cardiology. Additionally, he is the primary editor and co-author of multiple textbooks and award-winning handbooks in pediatric cardiac intensive care, including Spanish language editions.

As pediatric use of iNO increased, mortality rates dropped

Smiling-baby-boy

iNO, a colorless odorless gas, is used to treat hypoxic respiratory failure in infants born full-term and near term.

Use of inhaled nitric oxide (iNO) among pediatric patients has increased since 2005 and, during a 10-year time period, mortality rates dropped modestly as the therapeutic approach was applied to a broader range of health ailments, according to an observational analysis presented Feb. 26, 2018, during the 47th Critical Care Congress.

iNO, a colorless odorless gas, is used to treat hypoxic respiratory failure in infants born full-term and near term and also has become an important therapy for acute respiratory distress syndrome and pulmonary hypertension in newborns.

Jonathan Chan, M.D., a Children’s National Health System critical care fellow, analyzed de-identified data from patient visits from January 2005 to December 2015 at 47 children’s hospitals around the nation. Dr. Chan included 18,343 patients in the analysis. Among the findings:

  • As a group, the children had an overall mortality rate of 22.7 percent. The mortality rate dropped from 29.1 percent in 2005 to 21.2 percent in 2015.
  • The median adjusted cost per admission was an estimated $158,740 ($5,846 per patient day).

“This large observational study indicates that the use of iNO grew from 2005 to 2015,” Dr. Chan says. “While hospital stays grew longer during the study period, we saw a decrease in mortality of 0.01 percent per year.”

The highest number of admissions with iNO use included:

Dr. Chan notes that because this is a retrospective observational analysis, the study’s findings should be interpreted as exploratory.

“Off-label use of iNO continues to increase among pediatric patients. And an increasing proportion of admissions are for specialty areas other than neonatal care,” he adds. “Increasing off-label use of iNO is associated with decreased mortality. But it also is associated with an increased length of stay, higher hospital costs and more units of iNO administered.”

47th Critical Care Congress presentation

Monday, Feb. 26, 2018

Murfad Peer

Mechanically-assisted circulation for the failing Fontan

Murfad Peer

“Right now, the only way to really fix a failing Fontan is with a heart transplant, but the number of donor hearts is fixed and the number of people needing transplants has been increasing over time,” explains Murfad Peer, M.D. “So we are in a really tight spot. We need to do something, and we need to do it quickly.”

The only treatment currently available for patients born with single ventricle heart defects is the Fontan operation. And, while the operation provides excellent long-term palliation and survival, Fontan hearts eventually fail, and there are limited treatment options to help these patients make it to a heart transplant. A team led by  Murfad Peer, M.D., a cardiac surgeon at Children’s National, is trying to increase the survivorship of these patients with a heart pump.

“Right now, the only way to really fix a failing Fontan is with a heart transplant, but the number of donor hearts is fixed and the number of people needing transplants has been increasing over time,” explains Dr. Peer. “Most of these Fontan patients are so sick they are not even candidates for a transplant. So we are in a really tight spot. We need to do something, and we need to do it quickly.”

Currently in the United States, more than 800 Fontan procedures are done every year. The operation involves connecting the superior and inferior vena cava directly to the pulmonary artery so that deoxygenated blood flows straight to the lungs.

“When you do a Fontan, you do a series of surgeries that basically bypass the right heart, so that blood flow to the lungs is passive — it’s going to the lungs because of venous pressure,” says Dr. Peer. “There’s no ventricle actually pumping blood directly to the lungs.”

So, while the Fontan operation has facilitated the survival of a generation of children born with congenital heart disease, it does not recreate normal circulation. And, after about 15 to 20 years, the pressure on the right side of the heart becomes so high in some patients that blood starts backing up into the veins, resulting in organ failure.

One way to keep blood flowing is by adding a pump. Dr. Peer and his team hypothesized this could be accomplished by returning circulation to the way it was before the Fontan operation, and then supporting the ventricle with a standard commercially available continuous flow ventricular assist device (VAD) that pumps blood into the lungs and the aorta.

“We took a commercially available left-ventricle assist device and split the outflow graft so that it could flow both into the systemic circulation and into the lungs,” says Dr. Peer.

The team tested their mechanically assisted single ventricle circulation (MASVC) in an animal model of functionally univentricular circulation, and they were able to sustain the animal for two hours. The results were published in January 2018, in the World Journal for Pediatric and Congenital Heart Surgery.

Going forward, the team plans on testing MASVC for longer periods of time to determine its long-term durability. Dr. Peer is also working on computer modeling MASVC in a patient using an MRI.

NPosnack-Heart-image

NIH funding to improve devices and safeguard cardiovascular health

Nearly 15 million blood transfusions are performed each year in the U.S., and pediatric patients alone receive roughly 425,000 transfused units. Endocrine-disrupting chemicals, such as bisphenol A and di-2-ethylhexyl-phthalate (DEHP), can leach from some plastic devices used in such transfusions. However, it remains unclear how many complications following a transfusion can be attributed to the interplay between local and systemic reactions to these chemical contaminants.

NPosnack-Heart-image

Top: Live, excised heart that is being perfused with a crystalloid buffer via the aorta. The heart is stained with a voltage-sensitive fluorescent dye, which is excited by an LED light source. Bottom, right: Cardiac action potentials are optically mapped across the epicardial surface in real-time by monitoring changes in the fluorescence signal that are proportional to changes in transmembrane voltage. Bottom, left: An activation map (middle) depicts the speed of electrical conduction across the heart surface. Credit: Rafael Jaimes, Ph.D.; Luther Swift, Ph.D.; Manelle Ramadan, B.S.; Bryan Siegel, M.D.; James Hiebert, B.S., all of Children’s National Health System; and Daniel McInerney, student at The George Washington University.

The National Heart, Lung and Blood Institute within the National Institutes of Health has awarded a $3.4 million, five-year grant to Nikki Gillum Posnack, Ph.D., assistant professor at the Children’s National Heart Institute within the Sheikh Zayed Institute for Pediatric Surgical Innovation (SZI) at Children’s National Health System, to answer that question and to provide insights that could accelerate development of safer biomaterials.

According to the Food and Drug Administration, patients who are undergoing IV therapy, blood transfusion, cardiopulmonary bypass or extracorporeal membrane oxygenation or who receive nutrition through feeding support tubes have the potential to be exposed to DEHP.

Posnack led a recent study that found that an experimental model exposed to DEHP experienced altered autonomic regulation, heart rate variability and cardiovascular reactivity and reported the findings Nov. 6, 2017, in the American Journal of Physiology. The pre-clinical model study is the first to show such an association between phthalate chemicals used in everyday medical devices like IV tubing and cardiovascular health.

In the follow-on research, Posnack and colleagues will:

  • Use in vivo and whole heart models to define the extent to which biomaterial leaching and chemical exposure alters cardiovascular and autonomic function in experimental models
  • Determine whether biocompatibility and incidental chemical exposure are linked to cardiovascular and autonomic abnormalities experienced by pediatric patients post transfusion
  • Compare and contrast alternative biomaterials, chemicals and manufacturing techniques to identify safer transfusion device options.

“Ultimately, we hope to strengthen the evidence base used to inform decisions by the scientific, medical and regulatory communities about whether chemical additives that have endocrine-disrupting properties should be used to manufacture medical devices,” Posnack says. “Our findings also will highlight incentives that could accelerate development of alternative biomaterials, additives and fabrication techniques to improve safety for patients undergoing transfusion.”

Nikki Gillum Posnack

Experimental model study links phthalates and cardiovascular health

Nikki Gillum Posnack

“Because phthalate chemicals are known to migrate out of plastic products, our study highlights the importance of adopting safer materials, chemical additives and/or surface coatings for use in medical devices to reduce the risk of inadvertent exposure,” explains study senior author Nikki Gillum Posnack, Ph.D.

An experimental model exposed to di-2-ethylhexyl-phthalate (DEHP), a chemical that can leach from plastic-based medical devices, experienced altered autonomic regulation, heart rate variability and cardiovascular reactivity, according to a study published online Nov. 6, 2017 by the American Journal of Physiology. The pre-clinical model study is the first to show such an association between phthalate chemicals used in everyday medical devices like IV tubing and cardiovascular health.

“Plastics have revolutionized medical devices, transformed how we treat blood-based diseases and helped to make innovative cardiology procedures possible,” says Nikki Gillum Posnack, Ph.D., study senior author and assistant professor at the Children’s National Heart Institute within the Sheikh Zayed Institute for Pediatric Surgical Innovation (SZI) at Children’s National Health System. “Because phthalate chemicals are known to migrate out of plastic products, our study highlights the importance of adopting safer materials, chemical additives and/or surface coatings for use in medical devices to reduce the risk of inadvertent exposure.”

According to the Food and Drug Administration, patients who are undergoing IV therapy, blood transfusion, cardiopulmonary bypass or extracorporeal membrane oxygenation or who receive nutrition through feeding support tubes have the potential to be exposed to DEHP.

Patients undergoing extensive interventions to save their lives may be exposed to multiple plastic-based devices that supply oxygen and nutrition or that pump newly oxygenated blood to oxygen-starved organs.

“These interventions keep very fragile kids alive. What’s most important is getting patients the care they need when they need it,” Posnack says. “In the biomaterials field, our ultimate goal is to reduce inadvertent risks to patients that can result from contact with plastic products by identifying replacement materials or safer coatings to lower overall risk.”

In order to assess the safety of phthalate chemicals used in such medical devices, the Children’s-led research team implanted adult experimental models with radiofrequency transmitters that monitored their heart rate variability, blood pressure and autonomic regulation. Then, they exposed the experimental models to DEHP, a softener used in making the plastic polymer, polyvinyl chloride, flexible.

DEHP-treated pre-clinical models had decreased heart rate variability with lower-than-normal variation in the intervals between heart beats. The experimental models also showed an exaggerated mean arterial pressure response to ganglionic blockade. And in response to a stressor, the experimental models in the treatment group displayed enhanced cardiovascular reactivity as well as prolonged blood pressure recovery, according to the study team.

“The autonomic nervous system is a part of the nervous system that automatically regulates such essential functions as blood pressure and breathing rate without any conscious effort by the individual,” Posnack adds. “Because alterations in the autonomic balance provide an early warning sign of trouble – before symptoms of hypertension or atherosclerosis manifest – our findings underscore the importance of additional studies to explore the potential impact of phthalate chemicals on organ function.”

Billie Lou Short, M.D., chief of Children’s Division of Neonatology, called the paper an “important study” that builds on a foundation laid in the late 199os by Children’s researchers who were the first to show that plasticizers migrated from tubing in the extracorporeal membrane oxygenation (ECMO) circuit. Children’s researchers also led a study published in 2004 that evaluated the effect of plasticizers on the human reproductive system. A small number of adolescents who had undergone ECMO as newborns did not experience the complications that had been seen in in experimental models, Dr. Short says.

Posnack’s study co-authors include Rafael Jaimes III, Ph.D., SZI staff scientist; Meredith Sherman, SZI research technician; and Adam Swiercz, Narine Muselimyan and Paul J. Marvar, all of The George Washington University.

Nobuyuki Ishibashi

Children’s receives NIH grant to study use of stem cells in healing CHD brain damage

Nobuyuki Ishibashi

“Bone marrow stem cells are used widely for stroke patients, for heart attack patients and for those with developmental diseases,” explains Nobuyuki Ishibashi, M.D. “But they’ve never been used to treat the brains of infants with congenital heart disease. That’s why we are trying to understand how well this system might work for our patient population.”

The National Institutes of Health (NIH) awarded researchers at Children’s National Health System $2.6 million to expand their studies into whether human stem cells could someday treat and even reverse neurological damage in infants born with congenital heart disease (CHD).

Researchers estimate that 1.3 million infants are born each year with CHD, making it the most common major birth defect. Over the past 30 years, advances in medical technology and surgical practices have dramatically decreased the percentage of infants who die from CHD – from a staggering rate of nearly 100 percent just a few decades ago to the current mortality rate of less than 10 percent.

The increased survival rate comes with new challenges: Children with complex CHD are increasingly diagnosed with significant neurodevelopmental delay or impairment. Clinical studies demonstrate that CHD can reduce oxygen delivery to the brain, a condition known as hypoxia, which can severely impair brain development in fetuses and newborns whose brains are developing rapidly.

Nobuyuki Ishibashi, M.D., the study’s lead investigator with the Center for Neuroscience Research and director of the Cardiac Surgery Research Laboratory at Children’s National, proposes transfusing human stem cells in experimental models through the cardio-pulmonary bypass machine used during cardiac surgery.

“These cells can then identify the injury sites,” says Dr. Ishibashi. “Once these cells arrive at the injury site, they communicate with endogenous tissues, taking on the abilities of the damaged neurons or glia cells they are replacing.”

“Bone marrow stem cells are used widely for stroke patients, for heart attack patients and for those with developmental diseases,” adds Dr. Ishibashi. “But they’ve never been used to treat the brains of infants with congenital heart disease. That’s why we are trying to understand how well this system might work for our patient population.”

Dr. Ishibashi says the research team will focus on three areas during their four-year study – whether the stem cells:

  • Reduce neurological inflammation,
  • Reverse or halt injury to the brain’s white matter and
  • Help promote neurogenesis in the subventricular zone, the largest niche in the brain for creating the neural stem/progenitor cells leading to cortical growth in the developing brain.

At the conclusion of the research study, Dr. Ishibashi says the hope is to develop robust data so that someday an effective treatment will be available and lasting neurological damage in infants with congenital heart disease will become a thing of the past.

Dr. Laura Olivieri holding a 3D printed heart

Cardiology and radiology experts to participate in CMR 2018

Later this month, the international cardiovascular magnetic resonance (CMR) community will gather in Barcelona, Spain, for CMR 2018, a joint meeting organized by the European Association of Cardiovascular Imaging (EACVI) and the Society for Cardiovascular Magnetic Resonance (SCMR). Among the many attendees will be several cardiology and radiology experts from Children’s National Heart Institute:

  • Pediatric cardiology fellow Ashish Doshi, M.D., will be giving a talk titled, “Subendocardial resting perfusion defect in a case of acute fulminant myocarditis,” and will also present a poster titled, “Native T1 measurements in pediatric heart transplant patients correlate with history of prior rejection episodes.”
  • Pediatric cardiology fellow Rohan Kumthekar, M.D., will present a poster titled, “Native T1 values can identify pediatric patients with myocarditis.”
  • Cardiologist Laura Olivieri, M.D., will present two posters: “Native T1 measurements from CMR identify severity of myocardial disease over time in patients with Duchenne muscular dystrophy on therapy,” and “Feasibility of noncontrast T1 and T2 parametric mapping in assessment of acute ventricular ablation lesions in children.”
  • Pediatric cardiology fellow Neeta Sethi, M.D., will present a poster titled, “Cardiac magnetic resonance T2 mapping in the surveillance of acute allograft rejection in pediatric cardiac transplant patients.”

Additionally, Drs. Doshi and Sethi and Ileen Cronin, FNP-BC, a nurse practitioner in the Cardiac Catheterization Laboratory/Interventional Cardiac Magnetic Resonance (ICMR) Program, received travel awards to attend the conference.

CMR 2018 will be held January 31-February 3, 2018 and will focus on the theme of “Improving Clinical Value by Technical Advances.” The meeting’s emphasis will be on the common goal of improving clinical outcomes in cardiovascular disease through innovation in basic MR development and medical engineering.