Radiofrequency Ablation for Patients with Hypertrophic Obstructive Cardiomyopathy Accompanied by Severe Left Ventricular Outflow Tract Obstruction.

Abstract

Patients with hypertrophic obstructive cardiomyopathy (HOCM) have few available nonsurgical treatment options. The feasibility of CARTOSound-guided catheter radiofrequency ablation (RFA) has been reported previously; however, relevant data are limited. The objective is to retrospectively evaluate the effectiveness and safety of CARTOSound-guided RFA for patients with HOCM. Thirty-seven patients with successive HOCM accompanied by severe left ventricular outflow tract (LVOT) obstruction underwent CARTOSound-guided RFA were reviewed. The intracardiac echocardiography (ICE) images obtained were merged with the CARTO system to create a shell of the left ventricle. The systolic anterior motion-septal contact area marked from the ICE images was considered the target area for the current delivery of RFA. Follow-up data of the LVOT gradient examined before, 1 month, 6 months, 1 year, and every year after catheter-mediated RFA were accessed. The symptoms of 30 patients (81.1%) improved during the follow-up after RFA. The symptoms of all 30 patients were alleviated from the New York Heart Association (NYHA) class IV/III/II to the NYHA class II/I. A sustained and significant gradient reduction was observed in 28 patients (75.7%). The invasive pressure gradient of LVOT was 84.43 ± 27.55 mm Hg before RFA and 42.78 ± 36.38 mm Hg after RFA (P < .001), with a decrease of 41.65 ± 19.72 mm Hg. The median drop in pressure gradient was 36.0% (1.0-67.0%). Catheter-mediated RFA is an effective and safe treatment for patients with HOCM. However, its long-term efficacy and safety should be validated in the future by conducting multicenter clinical trials with large sample sizes.