Transapical Beating-Heart Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy After Failed Septal Reduction Therapy.

Abstract

This study sought to report an experience of transapical beating-heart septal myectomy (TA-BSM) for obstructive hypertrophic cardiomyopathy (oHCM) after failed septal reduction therapy (SRT, including transaortic septal myectomy, alcohol septal ablation, and radiofrequency ablation of the intraventricular septum) and to compare clinical outcomes with those in patients undergoing primary TA-BSM. From August 2022 through April 2024, 40 patients with unsuccessful SRTs who underwent TA-BSM were matched 1:3 with patients having TA-BSM as their only invasive procedure for oHCM. The primary outcome was procedural success, defined as a resting or provoked left ventricular outflow tract gradient <30/50 mm Hg and mitral regurgitation grade ≤1+ (of 4+) at 3-month follow-up. Patients with prior SRT had higher incidences of preoperative right bundle branch block (20% vs 4%), left bundle branch block (10% vs 2%), and nonsustained ventricular tachycardia (20% vs 3%). At 3-month follow-up, procedural success was achieved in 34 (85%) patients with prior SRT and in 106 (88%) with primary TA-BSM. The resting left ventricular outflow tract gradient was significantly reduced in both the prior SRT (17 mm Hg vs 79 mm Hg) and primary TA-BSM (13 mm Hg vs 73 mm Hg) groups. Mitral regurgitation improved (achieving ≤grade 1+) in 36 (90%) of 40 patients in the prior SRT group and in 111 (92%) of 120 patients in the primary TA-BSM group (P = .75). In addition, patients' quality of life was significantly improved postoperatively. TA-BSM with intraoperative real-time transesophageal echocardiographic guidance can provide satisfactory outcomes in patients with oHCM. Equipoise of outcomes after TA-BSM supports its application in symptomatic patients after all types of failed SRT.