Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Obstructive Cardiomyopathy

Abstract

Background: In patients with disabling symptoms caused by hypertrophic obstructive cardiomyopathy (HOCM), echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) could be a less invasive treatment option. Objectives: This study aimed to investigate the safety and efficacy of the PIMSRA for left ventricular outflow tract (LVOT) gradient reduction in HOCM. Methods: The study enrolled 15 patients with HOCM. These patients underwent electrocardiography, imaging, and blood biochemistry examination over 6 months of follow-up. Results: At 6 months of follow-up, patients showed significant reductions in peak LVOT gradients (resting gradient: from 88.00 [66.00] mm Hg to 11.00 [6.00] mm Hg; p = 0.001; stress-induced gradient: from 117.00 [81.00] mm Hg to 25.00 [20.00] mm Hg; p = 0.005) and interventricular septum (IVS) thickness (anterior IVS: from 25.00 [21.00] mm to 14.00 [12.00] mm; p = 0.001; posterior IVS: from 24.00 [21.00] mm to 14.00 [11.50] mm; p = 0.001). The reductions in IVS thickness and LVOT gradients were associated with improvement in New York Heart Association functional classification (from 3.00 [2.00] to 1.00 [1.00]; p < 0.001), total exercise time (from 6.00 [5.50] min to 9.00 [8.00] min; p = 0.007), and pro B-type natriuretic peptide levels (from 924.00 [370.45] pg/ml to 137.45 [75.73] pg/ml; p = 0.028). No patient had bundle branch block or complete heart block. Conclusions: PIMSRA is a safe and effective treatment approach for severe, symptomatic HOCM and results in sustained improvement in exercise capacity, persistent reduction in LVOT gradient, and sustained improvement in cardiac function.