Outcomes After Repeat Alcohol Septal Ablation in Patients With Obstructive Hypertrophic Cardiomyopathy

Alcohol septal ablation (ASA) may necessitate a repeat procedure if the obstructive myocardium is not sufficiently ablated; however, the outcomes after repeat ASA are not well studied.

The objective of the study was to evaluate outcomes in patients with obstructive hypertrophic cardiomyopathy after repeat ASA.

Of the 663 patients with obstructive hypertrophic cardiomyopathy who underwent ASA, 84 with repeat ASA were analyzed. Residual left ventricular (LV) obstruction was stratified according to proximal or distal obstruction. The primary outcome was the absence of symptomatic residual LV obstruction, defined as NYHA functional class I or LV gradient <50 mm Hg, or both at 12 months after repeat ASA. Factors associated with the primary outcome were assessed using logistic regression. Secondary outcomes included cardiovascular mortality, fatal arrhythmia, heart failure hospitalization, and 3rd intervention.

Of the 84 patients, 41 had proximal and 43 had distal obstruction. Five patients failed to achieve technical success. One patient with proximal obstruction died due to infection during the index hospitalization. At 12 months after repeat ASA, 80.7% (67/83) achieved the primary endpoint: 90.0% (36/40) with proximal obstruction and 72.1% (31/43) with distal obstruction. The primary outcome was associated with proximal obstruction (adjusted OR: 4.06; 95% CI: 1.09-18.3). During a median follow-up of 7.1 years, there were 13 deaths (15.5%). Cardiovascular mortality and heart failure hospitalization were similar between those with proximal or distal obstruction, whereas fatal arrhythmia and 3rd interventions were more frequent in distal obstruction.

The site of residual obstruction may be important for understanding long-term outcomes after repeat ASA, but this requires further studies.