Multiple-Branch Alcohol Septal Ablation Is Associated with Reduced Cardiovascular Events: Insights from a...

Alcohol septal ablation (ASA) is an established intervention for patients with drug-refractory obstructive hypertrophic cardiomyopathy. Whereas some patients require ASA with multiple target septal branches due to a residual pressure gradient, the prognostic effect of multiple-branch ablation remains unclear. Thus, we aimed to investigate the association of multiple-branch ablation with cardiovascular (CV) events after ASA.

This multicentre trans-Pacific study enrolled patients who underwent ASA at 4 institutions in the US and Japan. Patients were categorized into single- and multiple-branch ablation groups. CV events, defined as a composite of CV death, repeated septal reduction therapy, and heart failure hospitalization, were compared in 2 groups within 1 year after ASA was performed. To address potential confounding, inverse probability of treatment weighting (IPTW) was performed, based on the propensity scores for multiple-branch ablation. Odds ratios (ORs) were examined for CV events before and after the IPTW was performed.

This study enrolled 151 patients who underwent ASA (single-branch, n = 66; multiple-branch, n = 85). The multiple-branch ablation group had higher peak gradients, which became comparable after ASA was performed. CV events were significantly lower in the multiple-branch ablation group, both before the IPTW (OR 0.33, 95% confidence interval [CI] 0.10-0.96, P = 0.049) and after the IPTW (OR 0.27, 95% CI 0.10-0.68, P = 0.01) was performed. The effect of the reduced incidence was primarily due to a decrease in heart failure hospitalization.

This study demonstrated that ASA with multiple target branches may be an effective treatment option for reducing CV events in morphologically and hemodynamically eligible patients with obstructive hypertrophic cardiomyopathy.