Long-Term Impact of Pregnancy on Clinical Outcomes in Individuals With Hypertrophic Cardiomyopathy

The effect of pregnancy on individuals with hypertrophic cardiomyopathy (HCM) is not well investigated.

The purpose of this study was to assess the impact of pregnancy on all-cause mortality and clinical outcomes among individuals with HCM.

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 2 groups: 1) those with a history of pregnancy/high-risk pregnancy supervision; and 2) 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 (defined as sudden cardiac death, appropriate shocks, sustained ventricular tachycardia/ventricular fibrillation), major adverse cardiovascular events (MACE), and acute heart failure exacerbation during 10 years of follow-up.

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-year follow-up. There was no difference in MACE (adjusted OR: 1.02; 95% CI: 0.85-1.22; P = 0.80) and arrhythmic events (adjusted OR: 0.93; 95% CI: 0.73-1.18; P = 0.55) between both groups. In subgroup analysis of obstructive HCM, the findings were similar between both pregnancy and no pregnancy groups.

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.