Abstract 4118242: Impact of Pregnancy on Individuals with Hypertrophic Cardiomyopathy: Long-Term Clinical Outcomes - Population-Based Study

Background: The effect of pregnancy on individuals with Hypertrophic Cardiomyopathy (HCM) is not well investigated. Objective: To assess the impact of pregnancy on all-cause mortality and clinical outcomes among individuals with HCM Methods: Using the TriNetX research network, we identified individuals within reproductive age ( ≥ 18-45 years) with a diagnosis of HCM between 2012 and 2022 (n=10,936). Patients were stratified based on pregnancy history into two groups (a) those with a history of pregnancy/high-risk pregnancy supervision and (b) those without a history of pregnancy or subsequent antenatal/pregnancy supervision encounters throughout the study period. Propensity-score matching resulted in 3,399 patients in each cohort. The primary outcome was all-cause mortality. Secondary outcomes include a composite of arrhythmic events (SCD and SCD equivalents), major adverse cardiovascular events (MACE), and acute heart failure (HF) exacerbation during 10 years of follow-up. Results: Pregnancy in patients with HCM was associated with a comparable risk of all-cause mortality (adjusted OR:0.89; 95% CI: 0.7-1.14; p =0.37) at 10 years follow-up. MACE and acute HF exacerbation outcomes were lower in the pregnancy group; however, the arrhythmic events (SCD) did not differ between groups (adjusted OR: 0.93, 95%CI: 0.73-1.18; p =0.55). Conclusion: Pregnancy in individuals with HCM was not associated with a higher risk of adverse outcomes at long-term follow-up. Further efforts are warranted to better understand the short-term outcomes in this high-risk population