Factors associated with excess female mortality in obstructive hypertrophic cardiomyopathy

Background Several studies have reported excess female mortality in patients with hypertrophic cardiomyopathy, but the cause is unknown. Aims To compare risk-factors for disease-related death in both sexes in a geographical cohort of patients with obstructive hypertrophic cardiomyopathy (oHCM). Methods and results Data-bases in all ten hospitals within West Gotaland Region yielded 250 oHCM-patients (123 females, 127 males). Mean follow-up was 18.1 y. Risk-factors for disease-related death were evaluated by Cox-hazard regression and Kaplan-Meier survival-curves, with sex-comparisons of distribution of risk-factors and therapy in total and age-matched (n = 166) groups. At diagnosis females were older, median 62 y vs. 51 y, (P < 0.001), but not different in outflow-gradients and median NYHA-class. However, septal hypertrophy was more advanced: 10.6 [IQR = 3.2] vs. 9.6 [2.5] mm/m(2) BSA; P = 0.002. Females had higher disease-related mortality than males (P = <0.001), with annual mortality 2.9% vs. 1.5% in age-matched groups (P = 0.010 log-rank). For each risk-category identified (NYHA-class >= III, outflow-gradient >= 50 mmHg), a higher proportion of females died (P = 0.0004; P = 0.001). Calcium-blocker therapy was a risk-factor (P = 0.005) and was used more frequently in females (P = 0.034). A beta-blocker dose above cohort-median reduced risk for disease-related death in both males (HR = 0.32; P = 0.0040) and in females (HR = 0.49; P = 0.020). Excess female deaths occurred in chronic heart-failure (P = 0.001) and acute myocardial infarctions (P = 0.015). Fewer females received beta-blocker therapy after diagnosis (64% vs. 78%, P = 0.018), in a smaller dose (P = 0.007), and less frequently combined with disopyramide (7% vs. 16%, P = 0.048). Conclusion Addressing sex-disparities in the timing of diagnosis and pharmacological therapy has the potential to improve the care of females with oHCM.

Automated summary

Several studies have reported higher disease-related mortality in females with obstructive hypertrophic cardiomyopathy (oHCM) compared to males. This study aimed to compare risk factors for disease-related death between sexes in a geographical cohort of oHCM patients. The results showed that females had a higher disease-related mortality rate and more advanced septal hypertrophy at diagnosis. Calcium-blocker therapy was a risk factor that was used more frequently in females. However, a higher dose of beta-blocker therapy reduced the risk of disease-related death in both males and females. This study highlights the importance of addressing sex disparities in the diagnosis and pharmacological therapy for oHCM patients.