Outcomes of Surgical Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy After Prior Septal Reduction Therapy

Younus Qamar; Hartzell V Schaff; Alejandra Castro-Varela; Hao Cui; Joseph A Dearani; Jeffrey B Geske; Mackram F Eleid; Alexander T Lee; Brian Lahr; Steve R Ommen

doi:10.1016/j.jtcvs.2024.05.002

Outcomes of Surgical Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy After Prior Septal Reduction Therapy

J Thorac Cardiovasc Surg. 2024 May 13:S0022-5223(24)00380-5. doi: 10.1016/j.jtcvs.2024.05.002. Online ahead of print.

Authors

Affiliations

¹ Department of Cardiovascular Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905.
² Department of Cardiovascular Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905. Electronic address: schaff@mayo.edu.
³ Department of Cardiovascular Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN 55905.
⁴ Department of Quantitative Health Sciences, Mayo Clinic, 200 First St. SW, Rochester, MN 55905.

PMID: 38750691
DOI: 10.1016/j.jtcvs.2024.05.002

Abstract

Objective: To compare early and late outcomes of septal myectomy in patients with obstructive hypertrophic cardiomyopathy who presented with residual or recurrent left ventricular outflow tract (LVOT) obstruction following prior septal reduction therapy (SRT).

Methods: From January 1989 to March 2022, 145 patients underwent reintervention by septal myectomy for residual LVOT obstruction following prior SRT; 72 patients had prior alcohol septal ablation (ASA), and 73 had prior surgical septal myectomy (SM). Baseline patient characteristics, echocardiographic parameters, and surgical outcomes were compared between these two groups.

Results: Patients who had prior ASA were more likely to be male (50.0% vs 30.1%; P=0.015), older (median age 57.5 years vs. 48.3 years; P<0.001) and have a greater body mass index (32.7 kg/m²vs. 30.0 kg/m²; P=0.011). After repeat SRT by septal myectomy, there was no significant difference in the incidence of postoperative complete heart block (CHB), necessitating permanent pacemaker, between the two groups (8.3% vs. 2.7%; P=0.151). One (0.7%) patient died within 30 days of surgery. Over a median follow-up of 7.5 years (IQR 3.0-13.8), there were 20 deaths. Kaplan-Meier 5-, 10-, and 15-year survival rates were 100%, 91%, and 76% for the prior SM group, and 93%, 81%, and 64% for the prior ASA group (P=0.207).

Conclusion: Septal myectomy for residual or recurrent LVOT obstruction in patients who had prior ASA is safe with an acceptably low rate of postoperative CHB. Surgical outcomes and late survival rates in patients with prior ASA were satisfactory and comparable to patients who underwent repeat myectomy.

Keywords: alcohol septal ablation; complete heart block; left ventricular outflow tract obstruction; obstructive hypertrophic cardiomyopathy; septal myectomy; septal reduction therapy.