Non-surgical septal myocardial reduction by coil embolization for hypertrophic obstructive cardiomyopathy: early and 6 months follow-up

AIMS: To evaluate the feasibility and the incidence of complete heart block (CHB) after non-surgical septal myocardial reduction by coil embolization in hypertrophic obstructive cardiomyopathy (HOCM). METHODS AND RESULTS: Twenty patients with HOCM and drug-refractory symptoms underwent non-surgical myocardial septal reduction by coil embolization with detachable coils. Occlusion of septal perforator branches was successfully performed in all patients. We detected neither ventricular tachycardia nor CHB. One patient presented an interventricular septal defect after the procedure, and died 19 days later. Cardiac magnetic resonance imaging showed, in all patients, an increase in areas of hyperenhancement in the interventricular septum (IVS) compared with baseline. At 6-month follow-up, NYHA functional class and peak oxygen consumption were significantly improved compared with baseline (14.8 +/- 4.5 vs. 18.5 +/- 4.5 mL/kg/min; P = 0.001, respectively). Echocardiography showed a significant reduction of the IVS thickness and left ventricular outflow tract gradient (21 +/- 3 vs. 17 +/- 4 mm, P < 0.0001; 80 +/- 29 to 35 +/- 29 mmHg, P < 0.0001, respectively). CONCLUSION: The results of this pilot non-randomized study suggest that non-surgical septal myocardial reduction by coil embolization in HOCM is feasible and does not induce CHB. Larger studies, ideally with a randomized comparison between coil embolization and alcohol septal ablation, are warranted.