Robert Hamilton, MD: The Potential Impact of Identifying Fetal Congenital Heart Block

Robert Hamilton, MD, discusses his upcoming ACR presentation, “Fetal Cardiac Targets Identify the Autoantibodies Associated with Congenital Heart Block,” including the clinical significance of identifying autoantibodies linked to heart block and the next steps for his team.

As anti-Ro only identifies heart block outcomes in 2% of pregnancies with anti-Ro antibodies, clinicians end up screening approximately 50 pregnancies for every 1 pregnancy that will ultimately be affected. Additionally, the screening is quite intensive and involves fetal cardiac ultrasounds, performed weekly, from 16 to 25 weeks gestation. Hamilton and his team aim to minimize these efforts via identifying autoantibodies in this patient population. The research also emphasizes therapeutic targets. Moderately effective therapies for preventing heart blocks, such as hydroxychloroquine, are currently utilized in an untargeted way.

“For the prevention of congenital heart block, one could target therapies more directly,” Hamilton hypothesized. “Understanding the targets of congenital heart block may actually lead to new therapies, or at least a companion biomarker that can identify which pregnancies should be treated with novel therapies and how those novel therapies might be affecting the auto antibody levels.”

Hamilton and his team plan on focusing on identifying epitopes earlier in pregnancy, possibly pre-conception, to evaluate how predictive these new markers can be.

“Congenital heart block is a preventable disorder,” Hamilton underscores. “I'm not a rheumatologist, I'm actually a children's heart rhythm specialist who ends up implanting pacemakers in these children once they're born and replacing their pacemakers every 6 to 10 years or so. This is actually the most common reason that we implant pacemakers in children. Over 35% of pacemaker operations are related to congenital heart block. I'd really like to put myself out of business. I'd like to find a way to identify the pregnancies and treat them and prevent this source of congenital heart block and not have to have these children exposed to these repeated pacing procedures.”