Dynamic LVOT Obstruction After Mitral Valve Repair in HCM

BACKGROUND: Mitral valve repair (MVr) can alter left ventricular outflow tract (LVOT) geometry and precipitate dynamic LVOT obstruction (LVOTO) in patients with underlying hypertrophic cardiomyopathy (HCM). Cardiac myosin inhibitors are now a Class I recommendation for symptomatic obstructive HCM, yet their role in post-surgical LVOTO remains undefined. CASE SUMMARY: A 66-year-old woman with prior MVr developed progressive symptomatic dynamic LVOTO with resting and Valsalva gradients of 33 and 48 mmHg, systolic anterior motion (SAM), and NYHA class II-III symptoms. Mavacamten produced marked gradient reduction to 7 mmHg at rest and with Valsalva, with SAM resolution and symptomatic improvement to NYHA class II. Dose reduction to 2.5 mg led to gradient recurrence; re-escalation to 5 mg restored suppression, suggesting a reproducible dose-dependent effect. DISCUSSION: Mavacamten effectively reduced dynamic LVOTO despite surgically altered mitral geometry, expanding the therapeutic scope of myosin inhibition to a post-surgical population not well represented in the major trials. TAKE-HOME MESSAGES: Dynamic LVOTO may emerge or progress after mitral valve repair in patients with underlying hypertrophic cardiomyopathy. Mavacamten may provide effective non-surgical suppression of post-repair dynamic LVOTO despite surgically altered mitral geometry.