Septal myectomy after failed alcohol ablation: Does previous percutaneous intervention compromise outcomes of myectomy?

Abstract

The impact of prior alcohol septal ablation in patients who require septal myectomy for hypertrophic obstructive cardiomyopathy is unknown. Thirty-one patients with unsuccessful alcohol septal ablation who underwent septal myectomy were matched 1:2 to patients having had a myectomy as the only invasive procedure for hypertrophic obstructive cardiomyopathy. Study outcomes were cardiac death, advanced heart failure, and appropriate implantable cardioverter defibrillator discharge. The results of surgery, echocardiograms, and pathology specimens were compared between groups. Patients with previous alcohol septal ablation had increased diastolic dysfunction in preoperative echocardiography, as well as more implantable cardioverter defibrillators implanted (32% vs 11%, P = .01), more arrhythmias in preoperative Holter monitoring (43% vs 13%, P = .02), and a higher incidence of postoperative complete heart block (19.4% vs 1.6%, P < .01). Two patients died early postoperatively in the prior alcohol septal ablation group, and no patients died in the primary myectomy group. One patient in each group had an implantable cardioverter defibrillator (P = .52). At a mean follow-up of 3.2 years, 7 of 31 patients and 6 of 62 patients progressed to advanced heart failure in the prior alcohol septal ablation group and the primary myectomy group, respectively (P = .1) Histopathologic analysis demonstrated greater interstitial (70% vs 26%, P < .01) and endocardial fibrosis (87% vs 67%, P = .04) in the alcohol septal ablation group. Patients with prior alcohol septal ablation undergoing surgical septal myectomy may have an increased risk of cardiac death, advanced heart failure, and implantable cardioverter defibrillator discharges. This supports septal myectomy as the preferred treatment for septal reduction therapy, avoiding scarring and diastolic dysfunction inherent to alcohol septal ablation.