Low procedure-related mortality achieved with alcohol septal ablation in European patients

Two thirds of patients with hypertrophic cardiomyopathy (HCM) suffer from a left ventricular obstruction associated with more symptoms and worse prognosis [1] ; [2]. According to American and European Guidelines on HCM, there are two main therapeutic alternatives for treating the left ventricular obstruction: surgical myectomy and alcohol septal ablation (ASA) [1] ; [2]. Both these alternatives are considered safe and effective. However, Panaich et al. have recently demonstrated real world American data from the Nationwide Inpatient Sample (NIS) database showing an almost 6% in-hospital mortality rate associated with surgical myectomy [3]. This study is important because it contradicts lower, previously established post-operative mortality rates, which were estimated to be ~ 1% and were calculated using data from high-volume centers. Importantly, however, current guidelines on HCM have been based only on results of these high-volume centers [1] ; [2]. Along this line, Maron et al. recently found that in five major high-volume HCM centers in North America, the 30-day operative mortality rate was only 0.4% over the past 15 years (n = 3.696, mean age 54 ± 14 years) [4], i.e., one fifteenth of mortality rate reported by Panaich et al. [3]. A recent meta-analysis of long-term outcomes after septal reduction therapy, including 24 studies from tertiary HCM centers around the world, showed that the peri-procedural mortality rate of ASA was 1.3%, compared to 2.5% in patients undergoing myectomy [5]. However, when studies from before the year 2000 were excluded, as Maron et al. suggest [4], these figures became similarly low (1.3% vs. 1.1%, respectively). The same held true for the long-term mortality rates.