[Therapeutic effects of alcohol septal ablation in mildly symptomatic patients with hypertrophic obstructive cardiomyopathy].

Objective: To observe the therapeutic effects of alcohol septal ablation (ASA) in mildly symptomatic patients (NYHA class Ⅱ) with hypertrophic obstructive cardiomyopathy(HOCM). Methods: This retrospective study included 150 mildly symptomatic patients with HOCM hospitalized in Beijing Anzhen Hospital affiliated to Capital Medical University from March 2001 to December 2017, consisting of medical therapy group ( n =102) and ASA group ( n =48). Baseline clinical data were collected, patients were followed up to a mean of 6.0 (3.5, 8.1) years. Overall and HCM-related mortality events (including chronic heart failure, atrial fibrillation related stroke, sudden cardiac death) were observed in the two groups. Moreover, the improvement of NYHA function classification and left ventricular outflow tract gradient (LVOTG) were also evaluated. Survival analysis was performed by Kaplan-Meier method. Results: Age of this cohort was (52.9±14.5)years, 92 cases(61.3%) were male. In the follow-up, LVOTG was reduced from (85.8±35.4)mmHg (1 mmHg=0.133 kPa) to (27.7±19.8)mmHg ( P <0.001) in the ASA group, and from (66.3±35.0)mmHg to (56.5±27.7)mmHg in medical therapy group( P <0.01). At the last clinical follow-up, there were 32 patients (66.7%) whose LVOTG were<30 mmHg, septal thickness decreased from (20.3±3.8)mm to (16.1±3.4)mm ( P <0.001), NYHA classification was also remarkably improved ( P <0.001). New-onset atrial fibrillation tended to be lower in the ASA group compared to medical therapy group (9.3%(4/43) vs. 20.8%(20/96), P =0.096). Eleven patients (10.8%) in the medical therapy group and 2 patients (4.2%) in the ASA group died during the follow-up. One patient received pacemaker during the peri-procedural period, 1 patient was implanted with two-chamber pacemaker due to Ⅲ° atrioventricular block at 10 years after operation in the ASA group. Survival free of all-cause mortality of ASA group at 5 and 10 years was 97.9% and 97.9%, respectively, which was comparable to the medical therapy group ( P =0.231). Survival free of HCM-related mortality was similar between the two groups ( P =0.397). Conclusions: Compared with medical therapy in mildly symptomatic patients with HOCM, long-term survival rate is similar after ASA. Meanwhile, ASA can remarkably reduce LVOTG and improve the clinical status of the patients. Therefore, ASA may be used as an alternative therapy for mildly symptomatic HOCM patients.