Long-term outcomes and risk factors for mortality of patients with hypertrophic obstructive cardiomyopathy undergoing septal myectomy.

Abstract

We aimed to evaluate the long-term surgical outcomes of patients with hypertrophic obstructive cardiomyopathy and explore the risk factors for mortality, especially those related to atrial fibrillation. We retrospectively reviewed 150 consecutive patients with hypertrophic obstructive cardiomyopathy who underwent surgical treatment between March 2003 and December 2020. Fifty (33.3%, age 53.7±16.1 years) patients underwent isolated septal myectomy (SM), 79 (52.7%, age 52.3±12.6 years) underwent SM with mitral valve intervention (SM + MVI), and 21 (14.0%, age 57.1±13.5 years) underwent SM with mitral valve replacement (SM + MVR). Overall peak left ventricular outflow tract pressure gradient at rest was significantly decreased from 91.9±43.2 to 13.3±13.0 mmHg (P<0.0001). Survival rates were 96.7%, 89.1%, and 81.5% at 30 days, 5 years, and 10 years, respectively. Patients in the SM + MVI group survived longer than those in SM + MVR or isolated SM groups (94.1% vs. 75.4% vs. 88.0%, respectively, at 5 years, P=0.05). Patients with preoperative atrial fibrillation had a worse 5-year survival rate than those without atrial fibrillation (73.4% vs. 92.8%, respectively, P<0.001). Preoperative atrial fibrillation was an independent risk factor for late mortality in multivariable analysis. Notably, those whose atrial fibrillation was successfully eradicated by surgical ablation had a better 5-year survival rate than other patients (87.7% vs. 28.6%, respectively, P<0.001). Surgical outcomes in hypertrophic obstructive cardiomyopathy are favorable in the long-term, except in patients with preoperative atrial fibrillation. Therefore, intraoperative ablation for preoperative atrial fibrillation in hypertrophic obstructive cardiomyopathy should be actively considered to improve patient outcomes.