Percutaneous transluminal septal myocardial ablation in drug-resistant hypertrophic obstructive cardiomyopathy: 18-month follow-up results.

OBJECTIVE: Surgery has been the only therapeutic option in patients with hypertrophic obstructive cardiomyopathy (HOCM) who are resistant to standard treatment. Percutaneous transluminal septal myocardial ablation (PTSMA) by alcohol-induced occlusion of the septal artery for the reduction of left ventricular outflow tract (LVOT) gradient is a novel method. However, long-term clinical follow-up is insufficient. This study reports the acute and mid-term results after PTSMA in symptomatic patients with HOCM. METHODS: Six patients (4 men and 2 women) with symptomatic HOCM and inadequate response to pharmacologic therapy had their major septal branches ablated with alcohol. Mean duration of follow-up was 1.5 years. RESULTS: There was reduction in LVOT gradient in all patients (100%) with a mean reduction of 50 mmHg. Two patients developed complete heart block (CHB) and 3 patients developed bifascicular block. CHB persisted in 1 patient. Two patients died within 8 days of the procedure; one due to cerebrovascular accident and 1 due to asystole. The patient who died of asystole had CHB but refused permanent pacemaker implantation. CHB reverted in 1 patient and bifascicular blocks persisted in 3 patients. Clinical and echocardiographic follow-up was achieved in the 4 surviving patients after 1.5 years. All surviving patients had LVOT gradient reduction and clinical improvement. CONCLUSION: PTSMA for HOCM is a non-surgical technique for reducing LVOT gradient. Heart blocks are one potential complication, and may require pacemaker implantation. Long-term follow-up and a larger series of patients are required to determine conclusive therapeutic significance.