We enrolled 366 consecutive patients (58 ± 12 years, 54% women) who were treated using ASA and followed-up for 5.1 ± 4.5 years.
The in-hospital and 30-day mortality were 0.5% and 0.8%, respectively; the ASA-related morbidity was < 20%. Overall, 52 patients died during 1867 patient-years, which means the all-cause mortality rate was 2.8% per year. The mortality rates of sudden death and sudden death with an appropriate implantable cardioverter-defibrillator (ICD) discharge were 0.4% and 1% per year, respectively. Patients with sudden death or appropriate ICD discharge experienced these mortality events at younger age than patients who died of other hypertrophic obstructive cardiomyopathy-related causes (60.8 years [range, 52-71.5 years] vs 72.4 years [range, 64.2-75.2 years]; P = 0.048). A total of 292 patients (80%) had an outflow gradient ≤ 30 mm Hg, and 327 patients (89%) were in New York Heart Association class ≤ II at the last clinical check-up.
ASA had low procedure-related mortality, with subsequent 1% occurrence of sudden mortality events per year and 2.8% mortality rate per year in the long-term follow-up. Patients with sudden death or ICD discharge experienced the mortality events approximately 1 decade earlier than patients who died from other causes not related to hypertrophic cardiomyopathy.