Midterm Outcomes: A Comprehensive Approach to Surgery for Hypertrophic Obstructive Cardiomyopathy

Background: Left ventricular outflow tract (LVOT) obstruction in obstructive hypertrophic cardiomyopathy (HCM) is caused by a constellation of abnormalities. This study reviewed outcomes of a comprehensive approach to correct these abnormalities during surgery. Methods: This was a single-institution study of patients with HCM who underwent septal myectomy from 2016 to 2023. Their New York Heart Association functional classification and most recent echocardiogram that estimated LVOT gradient and mitral valve function were tracked. Results: The study included 103 patients with a mean age of 54 years (interquartile range, 40-67 years) and common comorbidities: hypertension (50%) and atrial fibrillation (25%). On average, the preprocedure resting echocardiogram showed an LVOT gradient of 36.4 mm Hg and moderate or severe mitral regurgitation in 50.5% of patients. All patients underwent septal myectomy, and associated abnormalities contributing to LVOT obstruction were addressed. Elongation of the anterior leaflet of the mitral valve was typically treated with papillary muscle realignment (72%). Aberrant papillary muscle heads and elongated secondary chordae tendineae contributing to systolic anterior motion were resected (66%). Myocardial bands, including apicoseptal bands contributing to LVOT obstruction, were resected (68%). With an average follow-up of 4 years, 91% of patients were considered to be in New York Heart Association functional class I or II. Long-term echocardiographic follow-up showed a mean peak LVOT gradient of 11 mm Hg (interquartile range, 4-13 mm Hg). Only 1 patient had more than mild mitral regurgitation. Conclusions: A comprehensive surgical approach to HCM that addresses the entire constellation of abnormalities associated with HCM, including mitral valve anterior leaflet elongation, aberrant or displaced mitral valve subvalvular apparatus, and myocardial bands, leads to outstanding midterm outcomes.