The sex gap in hypertrophic cardiomyopathy

Key sex differences have been explored in multiple cardiac conditions. However, sex impact in hypertrophic cardiomyopathy outcome is unclear. We aimed to characterize sex impact in overall and cardiovascular (CV) mortality in a nationwide hypertrophic cardiomyopathy registry.

We analyzed 1042 adult patients, 429 (41%) women, from a national registry of hypertrophic cardiomyopathy, with mean age at diagnosis 53±16 years and a mean follow-up of 65±75 months. At baseline, women were older (56±16 vs 51±15 years; P <.001), more symptomatic (56.4%, vs 51.7%; P <.001) and had more heart failure (42.0% vs 24.2%. P <.001), diastolic dysfunction (75.2% vs 64.1% P=.001), moderate/severe mitral regurgitation (33.4% vs 21.7%; P=.003), and higher B-type natriuretic peptide levels (920 [366-2412] mg/dL vs 487 [170-1087] mg/dL; P <.001). Women underwent fewer stress tests and cardiac magnetic resonance.

Kaplan-Meier survival curves showed higher overall (8.4% vs 5.0%; P=.026) and CV mortality (5.5% vs 2.2%; P=.004) in women. Cox proportional hazard regression showed that female sex was an independent predictor of overall (HR, 2.05; 95%CI, 1.11-3.78; P=.021) and CV mortality (HR, 3.16; 95%CI, 1.25-7.99; P=.015). Women had more heart failure-related death (2.6% vs 0.8%, P=.024). Despite similar sudden cardiac death (SCD) risk, women received fewer implantable cardioverter-defibrillators (10.9% vs 15.6%; P=.032) and, in patients without cardioverter-defibrillators, SCD occurred more commonly in women (1.8% vs 0.4%; P=.031).

In this nationwide registry, female sex was an independent predictor of overall and CV-related death, with more heart failure-related death. Despite similar SCD risk, women were undertreated with implantable cardioverter-defibrillators. These data highlight the need for an improved clinical approach in women with HCM.