Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Obstructive Cardiomyopathy

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.