Gender Disparities in Clinical Outcome After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy in the Chinese Han Population: A Cohort Study

Background Sex differences in the long-term prognosis of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) patients undergoing alcohol septal ablation (ASA) remain unclear, especially in the Chinese Han population. Method This cohort study included 320 HOCM Chinese Han patients who underwent ASA because of symptomatic left ventricular outflow tract (LVOT) obstruction. Patients were grouped according to sex: females (mean +/- standard deviation age [SD] 50.7 +/- 6.8 years) and males (mean6SD age 52.6 +/- 7.3 years). Individuals were followed over the long term. Results Pre-procedure, women had more symptoms (New York Heart Association [NYHA] class III-IV 67.3% vs 56.3%, p=0.03), more atrial fibrillation (23.5% vs 14.6%, p=0.047) than men. Transient complete atrioventricular block after ASA was more common in woman than in men (34.0 vs 23.4%; p=0.048). Residual LVOT gradient, post-procedural residual left ventricular wall thickness, NYHA functional class, and adverse arrhythmic events were comparable between the two groups. The 10-year survival rate (77% vs 89%, p=0.037) and the annual adverse arrhythmic event rate (1.3% vs 0.4%, p<0.01) following ASA were significantly worse in women compared with men. Kaplan-Meier analysis showed a significantly lower survival in women compared with men (p=0.023). In multivariable modelling, female sex remained independently associated with higher all-cause mortality (hazard ratio, 1.12; 95% confidence interval, 1.08-1.27; p=0.03) when adjusted for age, NYHA class III-IV symptoms, and other cardiovascular comorbidities. Conclusions Female patients with HOCM undergoing ASA tended to have more severe symptoms and adverse arrhythmic events. The 10-year survival rate after ASA was significantly worse in women compared with men with HOCM. Sex may need to be considered as an important factor in the clinical management of patients with symptomatic HOCM.