Researchers analysed 25 years of US death records to understand what's happening with hypoplastic left heart syndrome (HLHS), a rare congenital condition where the left side of the heart doesn't develop properly. It affects about 3 in every 100 babies born with heart defects. The study examined 10,138 deaths between 1999 and 2024 to track whether survival rates were improving.
From 1999 to 2021, the trend was encouraging: mortality rates dropped steadily by about 2% each year, driven by better surgical techniques and intensive care. Then the pattern reversed. After 2020, deaths stopped declining and began rising, reaching 358 cases by 2024—the highest in recent years.
The pandemic likely disrupted lifesaving scheduled surgeries
The timing matters. The uptick in deaths coincides with the period when many hospitals postponed non-urgent procedures and faced staffing challenges. For teenagers with HLHS, who rely on a precise sequence of three major staged surgeries (Norwood, Glenn, and Fontan procedures) to survive, any delay can be dangerous. The study doesn't prove that pandemic disruptions caused the rise, but the correlation is striking and suggests that interruptions to scheduled care have real, fatal consequences.
Boys are consistently at higher risk than girls
Throughout the entire 25-year period, boys and men had higher mortality rates than girls and women, even though both groups benefited from surgical advances. The study doesn't explain why, but the pattern is consistent enough that it warrants attention. This doesn't mean boys can't thrive with HLHS—many do—but it suggests they may need closer monitoring or different care strategies than girls.
Protect your teen's surgical timeline and stay connected to care
- Obtain a written surgical roadmap from your cardiologist, including dates for remaining procedures and warning signs requiring immediate hospital visits.
- Maintain uninterrupted cardiology follow-ups and protect scheduled surgeries from any delays or postponements.
- If your son has HLHS, ask your cardiologist whether sex-specific risk factors apply to his case and what additional monitoring might help.