Mitral valve repair during septal myectomy in obstructive hypertrophic cardiomyopathy

Abstract

Hypertrophic cardiomyopathy is a common genetic heart disease characterized predominantly by non-dilated hypertrophy of the left ventricle, in the absence of other cardiac, systemic, or metabolic diseases that can cause the observed degree of hypertrophy. The main features of left ventricular outflow tract obstruction include anatomical - basal septal hypertrophy in combination with a relatively small left ventricular cavity, leading to a change in the geometry of the outflow tract from the left ventricle, pushing the mitral valve apparatus forward, and functional - systolic anterior motion of elongated mitral valve leaflets with subsequent mitral-septal contact. Primary anatomical changes of the mitral valve make the valve more susceptible to abnormal flow vectors generated in the left ventricle cavity, creating the conditions for systolic anterior motion and mitral regurgitation. Septal myectomy, performed by experienced surgeons in specialized centers, eliminates obstruction at all levels of the left ventricular outflow tract, with a clinical success rate of 90-95% and a mortality rate of less than 1%. Some surgeons complement septal myectomy with intervention on the mitral valve, taking into account anatomical features when isolated septal myectomy may be ineffective. The choice of the most optimal concurrent intervention on the mitral valve during septal myectomy is undefined. Techniques for valve-sparing mitral valve surgery have been developed, including resection of secondary chords, edge-to-edge repair, anterior leaflet plication, and others. This review presents the hemodynamic outcomes of concomitant interventions on the mitral valve in addition to septal myectomy in patients with obstructive hypertrophic cardiomyopathy.