Septal myectomy for obstructive hypertrophic cardiomyopathy: Comparison of outcomes of the transapical beating-heart and transaortic on-pump approaches.

BACKGROUND

Transaortic on-pump septal myectomy (SM) is the established standard for surgical septal reduction, but transapical beating-heart SM recently has emerged as a less invasive alternative. This study compares the early outcomes of these 2 approaches to performing SM in patients with obstructive hypertrophic cardiomyopathy (oHCM).

METHODS

We analyzed the outcomes of 200 consecutive patients undergoing transapical beating-heart myectomy and 200 patients receiving transaortic on-pump myectomy. The primary outcome was procedural success, defined as a peak left ventricular outflow tract (LVOT) gradient <30 mm Hg on predismissal echocardiography. Secondary outcomes included transfusion and postoperative atrial fibrillation rates and intensive care unit (ICU) length of stay.

RESULTS

Both techniques significantly reduced LVOT gradient (median reduction: transapical, 102 mm Hg to 15 mm Hg; transaortic, 88 mm Hg to 12 mm Hg; P < .001 for both). Transapical beating-heart myectomy was associated with a shorter ICU stay (median, 24.0 hours vs 26.0 hours; P < .001), a lower atrial fibrillation rate (9.5% vs 30.0%; P < .001), and fewer transfusions (8.0% vs 22.0%; P < .001) but resulted in a higher incidence of new-onset left bundle branch block (63.8% vs 37.0%; P < .001) and longer postoperative hospital stay (median, 11 days vs 5 days; P < .001), owing mainly to institutional protocols. Overall 30-day mortality was 0.5% (n = 1) in the transapical beating-heart myectomy group and 1.0% (n = 2) in the transaortic on-pump myectomy group (P = .562).

CONCLUSIONS

Transapical beating-heart SM provides comparable hemodynamic outcomes to transaortic on-pump myectomy with advantages in ICU recovery time, transfusion rates, and postoperative atrial fibrillation. It may be a viable, less invasive alternative for selected oHCM patients. Further studies, including randomized trials, are needed to assess long-term outcomes.