Optimal ablation pattern on Intraprocedural echocardiography is associated with favorable clinical outcomes of alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Background: Alcohol septal ablation (ASA) is used to treat drug-refractory hypertrophic obstructive cardiomyopathy (HOCM). Intraprocedural echocardiography is essential for identifying the septal area perfused by each septal branch; however, its role in determining the procedural endpoint of ASA remains unclear. This retrospective study aimed to evaluate the impact of intraprocedural echocardiographic findings on clinical outcomes and left ventricular pressure gradient (LVPG) after ASA.

Methods: Overall, 120 patients with HOCM who underwent ASA at a single center were divided into two groups based on the presence of optimal ablation. Optimal ablation was defined as the ablated area fully covering the targeted septal myocardium from the point of contact with the onset of the accelerated flow to the basal septum and dense acoustic shadowing accompanying the ablated area. Clinical outcomes and LVPG changes were evaluated using inverse probability of treatment weighting.

Results: Significantly more patients showed a New York Heart Association (NYHA) functional class improvement of ≥2 stages or achievement of class I in the optimal ablation group (n = 74) than in the non-optimal ablation group (94 % vs. 62 %; p < 0.001). The optimal ablation group had a significantly greater percentage reduction in LVPG at 1-year after ASA (82 ± 18 % vs. 64 ± 18 %; p = 0.001). Multivariate analyses revealed that optimal ablation was an independent predictor of a NYHA functional class improvement of ≥2 stages or achievement of class I (odds ratio, 11.3; 95 % confidence interval, 3.43-39.1; p < 0.001) and a percentage reduction in LVPG (p = 0.001).

Conclusions: Intraprocedural echocardiographic findings of optimal ablation were associated with favorable clinical outcomes and a significant reduction in LVPG.