Comprehensive improvement in cardiac function following myosin inhibition after the ineffectiveness of myectomy and alcohol septal ablation: a case report.

Background: Hypertrophic cardiomyopathy affects approximately 1 in 500 adults and is often associated with left ventricular outflow tract obstruction. Despite guideline-directed medical therapy and septal reduction procedures, a significant number of patients remain symptomatic. Recently, cardiac myosin inhibitors such as mavacamten have emerged as promising therapeutic options. By directly targeting the underlying hypercontractility, mavacamten can reduce left ventricular outflow tract gradients and improve functional capacity. Case summary: This report highlights the effects of myosin inhibition in a 72-year-old male patient with symptomatic hypertrophic obstructive cardiomyopathy. The patient was refractory to standard medical as well as interventional therapies (myectomy and septal ablation). Initiation of mavacamten therapy led to marked clinical improvement, including increased exercise capacity and weight loss due to improved physical activity. Echocardiography revealed regression of septal wall thickness, reduction of the left ventricular outflow tract gradient, and improvement of diastolic function. Furthermore, electrocardiogram changes consistent with hypertrophyincluding voltage criteria and T wave inversions-resolved completely. The cardiac biomarkers have normalized. Discussion: Myosin inhibition has the potency to reverse multiple pathophysiological mechanisms in hypertrophic obstructive cardiomyopathy-even in patients with advanced age and with long-standing, resistant, and symptomatic disease. The treatment effects could be observed rapidly.