One-year follow-up of percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy in 312 patients: predictors of hemodynamic and clinical response

Abstract

Aim: The aim of this study was to analyze hemodynamic and clinical outcome in a cohort of 312 patients who were followed up over a period of 12 months after alcohol septal ablation (PTSMA) for symptomatic hypertrophic obstructive cardiomyopathy (HOCM).

Methods and results: PTSMA was intended in 337 patients with HOCM (mean age: 54+/-15 years), with 312 procedures completed by injection of 2.8+/-1.2 ml of alcohol. In 25 patients (8%) the intervention was aborted, mostly because of contrast echocardiographic findings. In the 312 patients who received alcohol, permanent pacing was necessary in 22 cases (7%); and in-hospital mortality was 1.3% (four patients). During follow-up, contact to six patients (2%) was lost, and three additional patients (1%) died. The 299 patients who either underwent non-invasive reassessment in our institution or transmitted followup data from their local physician formed the study population. Improvement in symptoms was reported by 272 patients (91%). Mean NYHA functional class was reduced from 2.9+/-0.4 to 1.5+/-0.7 (p<0.0001) along with a gradient reduction (echo-Doppler) from 59+/-32 to 8+/-15 mmHg at rest, and from 120+/-42 to 28+/-32 mmHg with provocation (p<0.0001 each). Exercise capacity improved from 94+/-51 to 119+/-40 watts (p=0.001), and peak oxygen consumption from 18+/-4 to 21+/-6 ml/ kg/min (p=0.01). Younger age and higher outflow gradients at baseline and immediately after intervention were associated with a less favorable hemodynamic outcome. The degree of limitation of exercise capacity at baseline was the only predictor of symptomatic improvement.

Conclusions: Catheter-based septal ablation is an effective non-surgical technique for reducing symptoms and outflow gradients in HOCM. In contrast to a previous study, in this cohort of 312 patients there was no association between post-interventional enzyme release and hemodynamic success. Younger patients with high baseline gradients, however, tended to have a less favorable hemodynamic outcome with higher residual gradients.