Cardiac Myosin Inhibitors in Hypertrophic Cardiomyopathy: From Sarcomere to Clinic.

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disease characterized by unexplained left ventricular hypertrophy, often resulting from pathogenic variants of sarcomeric protein genes. Conventional treatments, such as the use of beta blockers or calcium channel blockers, focus on symptomatic control but do not address the underlying hypercontractility at the sarcomere level. Recent advances in molecular understanding have led to the development of cardiac myosin inhibitors that directly modulate sarcomeric function by reducing myosin-actin cross-bridge formation and adenosine triphosphatase (ATPase) activity. Mavacamten and aficamten have shown promising results in phase 2 and 3 clinical trials, improving symptoms, exercise capacity, and left ventricular outflow tract gradients in patients with obstructive HCM. This review summarizes the current understanding of HCM pathophysiology, diagnostic strategies, and conventional treatments with a focus on the mechanisms of action of myosin inhibitors, clinical evidence supporting their use, and future directions for improvement. We also discuss their potential applications in non-obstructive HCM and the importance of precision medicine guided by genetic profiling.