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

Background: 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.

Methods: 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.

Results: 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%).

Conclusions: 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.