Clinical

Abstract

Noseworthy and colleagues (Am J Cardiol 2009 Jul 1;104(1):128-32 PMID: 19576333) assessed the risk of sudden cardiac death (SCD) and ventricular arrhythmias after alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) among 89 patients. Patients were classified as either high-risk or low-risk based on established clinical indications for ICD implantation. No mortality was attributable to SCD at a mean follow-up of 5.0 +/− 2.3 years in the entire cohort. Among the 42 patients with an ICD or permanent pacemaker, 9 had documented VT/VF, cardiac arrest, or appropriate ICD therapy, resulting in an annual event rate of 4.9%/year. The annual event rate for VT/VF, cardiac arrest, or appropriate ICD therapy was 2.8%/year (4 of 29 patients) in low-risk patients and 13.4% in high-risk patients (5 of 13 patients). A 10-mm Hg increase in the immediate post-ASA gradient was associated with a hazard ratio of 2.66 for arrhythmic events (95% confidence interval 1.55 to 4.56, p <0.001). The authors conclude that in patients with highly symptomatic drug-refractory HCM undergoing ASA there was no mortality attributable to SCD and an annual rate of VT/VF, cardiac arrest, or appropriate ICD therapy of 4.9%/year.