The Central Role of Echocardiography in Mavacamten Therapy for Obstructive Hypertrophic Cardiomyopathy: A Comprehensive Review

Mavacamten is a cardiac myosin inhibitor used in adults with symptomatic obstructive hypertrophic cardiomyopathy (HCM). Echocardiography is central to selecting suitable patients, confirming left ventricular outflow tract (LVOT) obstruction, excluding inappropriate use when left ventricular ejection fraction (LVEF) is < 55% and guiding dose titration during treatment. This narrative review summarises the practical echocardiographic approach to mavacamten therapy, with emphasis on reproducible LVOT gradient assessment, goal-directed Valsalva manoeuvres, LVEF monitoring, mitral valve and systolic anterior motion assessment, mitral regurgitation, diastolic function and left atrial size. Current regulatory monitoring requires echocardiographic assessment during early titration and permits 6-monthly maintenance surveillance only in stable patients meeting defined criteria, including LVEF ≥ 55% and Valsalva LVOT gradient < 30 mmHg, or a decision not to uptitrate. The review also discusses unresolved issues, including exercise echocardiography, global longitudinal strain, atrial fibrillation, reverse remodelling, implementation variability and the broader emergence of cardiac myosin inhibitors such as aficamten. Standardised acquisition and reporting are essential to ensure that treatment decisions reflect true physiological response rather than technical variability.