Outcomes of surgical septal myectomy for obstructive hypertrophic cardiomyopathy after previous septal reduction therapy.

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 after previous septal-reduction therapy (SRT).

METHODS

From January 1989 to March 2022, 145 patients underwent reintervention by septal myectomy for residual LVOT obstruction after previous SRT; 72 patients had previous alcohol septal ablation (ASA) and 73 had previous surgical septal myectomy. Baseline patient characteristics, echocardiographic parameters, and surgical outcomes were compared between these 2 groups.

RESULTS

Patients who had previous ASA were more likely to be male (50.0% vs 30.1%; P = .015), be older (median age 57.5 years vs 48.3 years; P < .001), and have a greater body mass index (32.7 kg/m2 vs 30.0 kg/m2; P = .011). After repeat SRT by septal myectomy, there was no significant difference in the incidence of postoperative complete heart block, necessitating permanent pacemaker, between the 2 groups (8.3% vs 2.7%; P = .151). One (0.7%) patient died within 30 days of surgery. Over a median follow-up of 7.5 years (interquartile range, 3.0-13.8), there were 20 deaths. Kaplan-Meier 5-, 10-, and 15-year survival rates were 100%, 91%, and 76% for the previous septal myectomy group, and 93%, 81%, and 64% for the previous ASA group (P = .207).

CONCLUSIONS

Septal myectomy for residual or recurrent LVOT obstruction in patients who had previous ASA is safe, with an acceptably low rate of postoperative complete heart block. Surgical outcomes and late survival rates in patients with complete heart block ASA were satisfactory and comparable with patients who underwent repeat myectomy.