Microcoil embolisation for ablation of septal hypertrophy in hypertrophic obstructive cardiomyopathy

Background and aim: Percutaneous transcatheter occlusion with ethanol injection of septal arteries is an efficient treatment procedure of hypertrophic obstructive cardiomyopathy (HOCM). The aim of our study was to evaluate the feasibility and efficiency of septal artery embolisation with microcoils.Methods: Microcoils were delivered through the guide-wire lumen of a 2mm-diameter coaxial balloon positioned inside the target vessel as distally as possible. One or more 0.018"-straight microcoils (Hilal straight coils, Cook, USA) were used for each target vessel until complete flow obstruction was achieved. The intraventricular pressure gradient was measured before, during and after the procedure. Septal branch occlusion was finally documented by coronary angiography.Results: We treated 7 patients (5 males; mean age: 48±10 years). All patients were symptomatic (NYHA class III or IV). The target vessels were successfully occluded in all patients without complications. Moderate pain was recorded during and after the procedure and the CK level increased five- to ten-fold. The pressure gradient diminished during the procedure from 72±21 mmHg to 30±15 mmHg. The number of coils delivered ranged from 3 to 7 per patient. The embolised septal branches included 1 vessel in 5 patients, 2 vessels in 1 patient and 3 vessels in 1 case. After the procedure, the pressure gradient, evaluated by transthoracic echocardiography, was 34±16 mmHg and 42±12 mmH at 3 month-follow-up. Clinical improvement was recorded in all patients after the procedure (NYHA class I or II). Temporary pacing was necessary in 3 patients during and immediately after the procedure but no patient needed permanent pacing.Conclusions: Microcoil embolisation is an efficient and safe approach for transcatheter ablation of septal hypertrophy in HOCM. This technique induced myocardial necrosis without the toxic effects of alcohol, reducing the risk of complications such as permanent pacemaker implantation or ethanol flow to other myocardial regions