OBJECTIVE To determine the long term outcome in patients treated with percutaneous transluminal septal myocardial ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM).

DESIGN AND SETTING Observational, single centre study.

PATIENTS 25 patients (13 women, 12 men, mean (SD) age 54.7 (15.0) years) with drug treatment resistant New York Heart Association (NYHA) class 2.8 (0.6) symptoms attributed to a high left ventricular outflow gradient (LVOTG) and a coronary artery anatomy suitable for intervention.

INTERVENTION PTSMA by injection of 4.1 (2.6) ml of alcohol (96%) into 1.4 (0.6) septal perforator arteries to ablate the hypertrophied interventricular septum.

OUTCOME MEASURES During in-hospital follow up, enzyme rise, the frequency of atrioventricular conduction lesions requiring permanent DDD pacing, and in-hospital mortality were assessed. Long term follow up (30 (4) months, range 24–36 months) included symptoms, echocardiographic measurements of left atrial and left ventricular dimensions and function, and LVOTG.

RESULTS Mean postinterventional creatine kinase rise was 780 (436) U/l. During PTSMA 13 patents developed total heart block, permanent pacing being necessary in five of them. One 86 year old patient died from ventricular fibrillation associated with intensive treatment (β mimetic and theophylline) for coexistent severe obstructive airway disease. After three months, three patients underwent re-PTSMA because of a dissatisfactory primary result, leading to LVOTG elimination in all of them. During long term follow up, LVOTG showed sustained reduction (3 (6) mm Hg at rest and 12 (19) mm Hg with provocation) associated with stable symptomatic improvement (NYHA class 1.2 (1.0)) and without significant global left ventricular dilatation.

CONCLUSIONS PTSMA is an effective non-surgical technique for reduction of symptoms and LVOTG in HOCM. Prospective, long term observations of larger populations are necessary in order to determine the definitive significance of the procedure.