Mavacamten for Symptomatic Obstructive Hypertrophic Cardiomyopathy During Active Chemotherapy

The role of cardiac myosin inhibitors in patients with obstructive hypertrophic cardiomyopathy (oHCM) and active malignancy remains unexplored.

A 68-year-old woman with colon cancer presented with worsening dyspnea. Echocardiography showed severe asymmetric septal hypertrophy, systolic anterior motion of the mitral valve, and a peak left ventricular outflow tract gradient of 115 mm Hg. Beta-blocker therapy failed to control symptoms. After multidisciplinary cardio-oncology evaluation, mavacamten therapy was initiated. Within 4 weeks, the patient's left ventricular outflow tract gradient decreased to 10 mm Hg, her NYHA functional class improved to I, and her NT-proBNP levels dropped markedly. Chemotherapy continued without interruption. Nine months later, her oncologic disease progressed, and palliative care was adopted.

This case highlights mavacamten as a safe and effective therapy for oHCM in a patient actively receiving chemotherapy. It underscores the potential value of cardiac myosin inhibition in complex comorbid scenarios.

Mavacamten can substantially improve quality of life in oHCM, even in patients with active malignancy.