Contemporary Surgical Management of Hypertrophic Cardiomyopathy in the United States

Background: The primary surgical therapy for hypertrophic cardiomyopathy with obstruction is septal myectomy (SM). The current outcomes of SM with and without concomitant mitral operations in the United States was examined using The Society of Thoracic Surgeons database. Methods: From July 2014 through June 2017, 4,274 SM operations were performed. Emergent status, endocarditis, aortic stenosis, and planned aortic valve operations were excluded. In the final cohort of 2,382 patients, 1,581 (66.4%) received SM alone (group 1), and 801 (33.6%) had SM with mitral valve repair or replacement (group 2). Group 2 was subdivided into mitral valve repair (MVr [n = 500]) and mitral valve replacement (MVR [n = 301]). Baseline characteristics were compared and risk-adjusted operative mortality and major morbidity were evaluated between treatment groups. Results: Baseline comorbidity was lower in group 1 versus group 2 and for MVr versus MVR. Operative mortality and major morbidity was lower for group 1 versus 2 (1.6% versus 2.8%, p = 0.046, and 10.9% versus 20.0%, p < 0.001, respectively). For patients with severe 3-4+ mitral regurgitation, SM alone was effective in reducing mitral regurgitation in 85.5% (355 of 415), and SM with MVr was effective in 88.0% (176 of 200; p = 0.4061). After risk adjustment, odds ratio for composite of mortality and major morbidity for group 2 versus group 1 was 1.8 (95% confidence interval: 1.4 to 2.4, p < 0.0001). Conclusions: Septal myectomy for hypertrophic cardiomyopathy is safe. Septal myectomy alone may have risk-adjusted outcome advantages over SM with mitral valve repair or replacement. Septal myectomy and SM with MVr provide similar reduction in mitral regurgitation. Further longitudinal analyses are required to define technical efficacy and outcomes in selected pathoanatomic groups.