Hypertrophic obstructive cardiomyopathy-alcohol septal ablation vs. myectomy: a meta-analysis

Our purpose is to conduct a meta-analysis of all published studies comparing alcohol septal ablation (ASA) and myectomy (MM) for drug refractory hypertrophic obstructive cardiomyopathy (HOCM). Alcohol septal ablation is a less invasive alternative to MM for relief of symptoms in patients with drug refractory HOCM. An extensive search of PubMed identified five non-randomized studies comparing ASA and MM. Of 351 patients studied, 183 underwent ASA and 168 underwent MM. Patients undergoing ASA were older (mean age 54.4 +/- 6.3 vs. 45.0 +/- 4.4 years, P = 0.02). All patients were in New York Heart Association (NYHA) class II-IV. Baseline left ventricular outflow tract (LVOT) gradient was comparable (81.4 +/- 14.3 mmHg in ASA vs. 77.4 +/- 15.5 mmHg in MM, P = 0.2). Although resting LVOT gradient after septal reduction therapy in both groups was < 20 mmHg at follow-up, patients undergoing MM had lower LVOT gradient (18.2 +/- 6.7 vs. 10.8 +/- 6.3 mmHg, P < 0.001). Patients in both groups had comparable improvement in NYHA class (1.5 +/- 0.3 in ASA vs. 1.3 +/- 0.2, P = 0.2) at follow-up. A higher percentage of patients undergoing ASA required permanent pacemaker (PPM) implantation for complete heart block (18.4 +/- 7.9 vs. 3.3 +/- 3.9%, P = 0.04). There was no significant in-hospital mortality difference between the two groups. Alcohol septal ablation and MM provide significant reduction in LVOT gradient and NYHA functional class on mid-term follow-up. A higher percentage of patients required PPM after ASA. Randomized trials are needed to confirm current findings.