Tag Archive for: Tetralogy of Fallot

Team performing cardiac surgery at Children's National

Long-term outcomes are key measure of CHD care quality and safety

Short-term outcomes data may be one benchmark of the quality and safety found in a pediatric cardiac surgery program, but according to the team at Children’s National Hospital, it shouldn’t be the sole factor in how referring physicians and families make decisions about where to seek care.

Instead, physicians and families need more information about what to expect for a child’s entire lifespan. To meet this need, the Division of Cardiac Surgery at Children’s National has launched the Children’s National Cardiac Outcomes Registry (CNCOR), a first-of-its-kind database that captures outcomes from 15-plus years of congenital heart surgical repairs for specific congenital heart conditions.

What it means

Today, most pediatric heart programs publicly share their outcomes based on benchmarks defined by the Society for Thoracic Surgeons (STS). For cardiac surgery, the data points are focused on the short-term outcomes for various procedures, ranging from 30 days to one year after surgery.

However, as surgical procedures have been refined and multi-disciplinary teams continually improve their knowledge of how to treat children with these congenital heart defects, more children with these conditions are living far beyond those time frames. One metric, operative mortality for “index cases” defined by the STS (excluding VAD and ECMO), measures how many children having heart surgery with the cardiopulmonary bypass die during surgery or within the 30 days after surgery.

Recently at Children’s National, the Cardiac Surgery, Cardiac Intensive Care Unit, Cardiology and Cardiac Anesthesia teams had a remarkable year with zero operative mortality, or no deaths, for the types of cases included in this benchmark. While it’s impossible to expect zero mortality to continue indefinitely when caring for children with the most severe and complex heart conditions — as is the case at Children’s National — the national average operative mortality for these procedures is closer to 3%.

Yves d’Udekem, M.D., Ph.D., chief of Cardiac Surgery at Children’s National, says that this achievement is not one he expected to “ever see in his lifetime” and is a testament to the teams’ dedication to providing the highest quality care every day. However, he also noted, “Achieving such impressive statistics for short-term measures has never been, is not, and will never be my objective. We also need to look beyond it. What happens to this patient 5, 10 or 15 years down the line? That’s what we want to know.”

Children’s National leads the way

The CNCOR collects long-term data from 20 years of cardiac surgical procedures at Children’s National. This data has allowed Children’s National to create a series of charts that show predicted long-term outcomes for specific congenital heart conditions.

The charts are now available in a new Cardiac Surgery Long-Term Outcomes section on the website, organized by specific types of congenital heart disease, including:

  • Tetralogy of Fallot
  • Aortic arch coarctation
  • Atrioventricular septal defects
  • Transposition of the great arteries

For most conditions, data is available showing long-term mortality as well as re-operation or re-intervention rates for children who underwent these procedures at Children’s National, going as far back as the year 2000. Eventually, the database might expand to include indicators such as exercise capacity and neurological outcomes.

What’s next

The launch of the CNCOR is the start of efforts by the team at Children’s National to provide what Dr. d’Udekem calls “proper” benchmarking based on the whole life of a patient rather than a single event in time.

If more institutions collect and report this data and make it available, patients, families and practitioners who refer to cardiac surgery will have a true lifetime perspective of what a surgical procedure at a specific institution may mean for a child.

sonogram showing tetralogy of Fallot

Tetralogy of Fallot repair technique demonstrates low reoperation rates

Cardiac surgeons at Children’s National Hospital have used a uniform transventricular strategy for tetralogy of Fallot repair for more than 15 years. A large, retrospective study published in the Journal of Thoracic and Cardiovascular Surgery demonstrates that few patients who received a repair using this method required a reoperation to implant a pulmonary valve in the first 10 years after their primary repair surgery.

What it is

The study is one of the first to report statistically significant outcomes of the transventricular approach applied uniformly in a single institution. It provides tangible evidence of the short- and mid-term postoperative outcomes from 244 consecutive patients who underwent tetralogy of Fallot repair at Children’s National between 2004 and 2019. Infants received the repair between 42 and 106 days after birth.

Tetralogy of Fallot is a condition of several related congenital heart defects that occur due to abnormal development of the prenatal heart during the first eight weeks of pregnancy.

Why it matters

The data show that, at Children’s National, 96.7% of children who underwent tetralogy of Fallot repair within the first year of life using this transventricular approach were able to avoid having an additional surgery to receive a replacement pulmonary valve for up to a decade after their initial repair.

It also shows a benefit of this approach soon after birth. The authors believe that having the repair earlier (on average, 71 days after birth in this study) provides long-term benefits to the growth and development of both the brain and heart. The repair also protects the heart’s function over time by preventing the development of dangerous ventricular arrhythmias.

The big picture

Short- and mid-term post-surgical outcome data like the information presented in this study are an important indicator of the expertise, care quality and overall safety associated with the cardiac surgery team performing the procedure.

These findings provide critical insight into the effectiveness of specific treatment approaches for infants with tetralogy of Fallot and can help both clinicians and families better understand the benefits and risks of these procedures.

Read the full study in the Journal of Thoracic and Cardiovascular Surgery.

newborn baby

Study suggests chronic hypoxia delays cardiac maturation in CHD

newborn baby

Every year, nearly 40,000 babies are born with a congenital heart defect (CHD) — the leading cause of birth defect-associated infant illness and death.

Every year, nearly 40,000 babies are born with a congenital heart defect (CHD) — the leading cause of birth defect-associated infant illness and death. An event that may contribute to cyanotic CHD is the lack of oxygen, known as hypoxia, before and after birth, impacting gene expression and cardiac function that delay postnatal cardiac maturation, according to a new pre-clinical model led by researchers at Children’s National Hospital.

Single ventricle, transposition of the great arteries, truncus arteriosus and severe forms of tetralogy of Fallot, such cyanotic congenital heart diseases have lower circulating blood oxygen levels. The lack of oxygen in the blood begins prenatally and continues after birth until definitive repair, suggesting a delay on cardiac maturation.

There is little research on the underpinnings that explain the lack of oxygen’s effects on the developing heart, which could help inform adequate therapies in the pediatric population to promote cardiovascular health across the lifetime. The researchers developed the first pre-clinical model that explores the effects of chronic hypoxia in perinatal and postnatal stages on the developing heart under conditions seen in cyanotic CHD.

“To the best of our knowledge, ours is the first study to perform complete gene expression arrays on animals after perinatal hypoxia,” said Jennifer Romanowicz, senior noninvasive imaging fellow at Boston Children’s Hospital and lead author of the study. “Not only did these studies allow us to determine the effects of hypoxia on heart development, but the detailed results of our study will be available to other researchers to independently address other questions about perinatal hypoxia and heart development.”

The study published in the American Journal of Physiology: Heart and Circulatory Physiology suggests that chronic lack of oxygen alters the electrical properties of heart tissue, called the electrophysiological substrate, and the contractile apparatus, a muscle composed of proteins that control cardiac contraction. Multiple genes involved with the contractile apparatus were expressed differently in the non-human subjects.

“What was remarkable was that most abnormalities normalized after the animals recovered in normal oxygen levels,” said Romanowicz. “This is an optimistic sign that early repair of cyanotic congenital heart disease may allow the heart to finish development.”

The researchers placed pregnant non-human subjects in hypoxic chambers starting on embryonic day 16, mimicking the second trimester in humans. The same subjects gave birth in the hypoxic chambers, and the newborns were kept there until postnatal day eight when the heart muscle maturation is nearly complete. To understand how human infants recover with normalized oxygen levels after surgical repair of cyanotic CHD, the researchers moved hypoxic subjects to normal oxygen conditions for recovery and tested again at postnatal day 30.

“Next steps include using a pre-clinical model of cyanotic congenital heart disease that more accurately represents human neonatal physiology,” said Devon Guerrelli, Ph.D. candidate at Children’s National. We plan to work with the cardiac surgery team at Children’s National to investigate changes in the myocardium due to hypoxia in pediatric patients who are undergoing surgical repair.”

Nikki Posnack, Ph.D., principal investigator at Sheikh Zayed Institute for Pediatric Surgical Innovation and Nobuyuki Ishibashi, M.D., director of Cardiac Surgery Research Laboratory at Children’s National, led and guided the team of researchers involved in the study.

heart and medical equiptment

How much do you know about congenital heart defects?