Influence of operator volume on early outcomes of septal myectomy for isolated hypertrophic obstructive cardiomyopathy

BACKGROUND: Guidelines on the diagnosis and management of hypertrophic cardiomyopathy (HCM) recommend that septal myectomy be performed by experienced operators. However, the impact of operator volume on surgical treatment outcomes for isolated HCM has been poorly investigated. METHODS: From 2002 to 2014, 435 consecutive patients with isolated HCM undergoing myectomy at the Fuwai Hospital were retrospectively enrolled. All 29 surgeons were divided into beginner surgeons (operator volume ≤20) and experienced surgeons (operator volume >20) according to the guidelines for the diagnosis and treatment of HCM. Propensity score matching of patients in the two groups was performed. RESULTS: Baseline differences included advanced New York Heart Association classification and older age in the experienced surgeon group. After matching, in the beginner surgeon group (107 cases), residual obstruction (18.7% vs. 0.9%, P<0.001) was more common, and the postoperative left ventricular outflow tract pressure gradient (20.7±15.1 vs. 14.3±7.4 mmHg, P<0.001) was higher than that of the experienced surgeon group. In the experienced surgeon group (107 cases), the incidence of mitral valve replacement (1.9% vs. 11.2%, P<0.001) and permanent pacemaker implantation (1.9% vs. 3.7%, P<0.001) was significantly lower than that in the beginner surgeon group. However, there was no difference in procedural mortality (1.9% vs. 1.9%) between the two groups. CONCLUSIONS: Operator volume is an important factor in achieving better obstruction obliteration after septal myectomy in patients with isolated HCM.