Assessment of safety and efficacy of morrow septal myectomy and alcohol septal ablation in patients with obstructive hypertrophic cardiomyopathy: the results of a pilot randomized trial

Aim. The aim of this randomized study was to evaluate the safety and efficacy of septal myectomy (SM) and alcohol septal ablation (ASA) in patients with an obstructive form of hypertrophic cardiomyopathy. Methods. The study included 76 patients eligible for ASA and Morrow myectomy. The patients were divided into two equal groups: one for ASA (n = 38), the other for SM. The primary endpoint (combined) was to assess the safety, which included 30-day complications after surgery (mortality, bleeding, tamponade, stroke, development of VT / VF) and the frequency of pacemaker/ICD implantation. Secondary endpoints focused on the evaluation of pressure gradient (efficiency), repeated operations, clinical and functional indicators, volume and mass of the ablation zone and dissected infarction. Control observation period was 12 months. Results. By the end of control observations, it was found out that SM is a safer technique as compared to ASA, the complication rate was 13 % and 47 % respectively (logrank test p = 0.0021; Cox: HR 11.4 95% CI [1.52 -11.1] p = 0.005). No significant differences in early (30 days) postoperative complications were found (log-rank test p = 0.24; Cox: HR 2.52, 95% CI [0.48-12.9] p = 0.27). Rhythm disturbances requiring pacemaker implantation / ICD (log-rank test p = 0.0029; Cox: HR 95% CI 4.92 [1.06-22.74] p = 0.042) were the most common complication. In both groups, there was a significant reduction of the LVOT gradient, p