An article in the New England Journal of Medicine (Vol. 394, No. 6, pp. 616-618, February 5, 2026) discusses the use of mavacamten in nonobstructive hypertrophic cardiomyopathy. Mavacamten is a selective, allosteric and reversible cardiac myosin inhibitor that modulates the number of myosin heads entering contraction. This drug is approved for the treatment of symptomatic obstructive hypertrophic cardiomyopathy in adult NYHA class II-III patients. The EXPLORER-HCM study included 251 patients randomized to mavacamten (n=123) or placebo (n=128) for 30 weeks. Mavacamten improved exercise capacity, reduced obstruction in the outflow tract of the left ventricle, improved NYHA classification and subjective assessment of health status. In the mavacamten arm, postexercise LVOT gradient decreased by 37 mmHg and NYHA improved by ≥1 class in 41% of patients. In 2 patients, the left ventricular ejection fraction decreased below 50%, which returned to normal after stopping the drug for 4 weeks.[1][2][3]