U-shaped Catheter Strategy for Percutaneous Endocardial Septal Radiofrequency Ablation in Hypertrophic Obstructive Cardiomyopathy: A Retrospective Comparative Study.

BACKGROUND: Percutaneous endomyocardial septal radiofrequency ablation (PESA) has emerged as a promising septal reduction therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM). OBJECTIVE: To compare the efficacy and safety of a novel U-shaped catheter strategy with the conventional retrograde catheter approach during PESA in patients with HOCM. METHODS: This single-center retrospective study included 27 patients with HOCM undergoing PESA: 15 treated with the U-shaped catheter strategy (U group) and 12 matched controls treated with the conventional catheter strategy (C group). Procedures were guided by three-dimensional electroanatomical mapping and intracardiac echocardiography, with 12-month follow-up. RESULTS: Both groups demonstrated significant improvements in symptoms, NYHA functional class, and echocardiographic parameters at 12-month follow-up. Compared with the C group, the U group achieved a significantly higher catheter-tissue contact force (20.39 ± 3.50 g vs. 17.17 ± 2.13 g, p < 0.01) and a shorter total radiofrequency delivery time (1217.17 ± 612.38 s vs. 1537.94 ± 302.88 s, p = 0.01). The resting left ventricular outflow tract (LVOT) gradient at 12 months was significantly lower in the U group than in C group (32 [29-45] mmHg vs. 48.5 [43.34-58.75] mmHg, p = 0.03). No major complications occurred in either group. Transient atrioventricular (AV) block and left bundle branch block (LBBB) were observed but required no further intervention. CONCLUSIONS: The U-shaped catheter strategy for PESA was associated with improved procedural efficiency and greater reduction in LVOT obstruction compared with the conventional catheter approach, while maintaining a favorable safety profile.