Echocardiography. 2026 Jul;43(7):e70540. doi: 10.1111/echo.70540.
ABSTRACT
BACKGROUND: Hypertrophic obstructive cardiomyopathy (HOCM) causes dynamic left ventricular outflow tract (LVOT) obstruction and disabling symptoms; many patients do not respond to conventional agents. Mavacamten, a selective cardiac myosin inhibitor, improves gradients, but the dose-time response in routine practice remains unclear.
AIMS: To evaluate longitudinal echocardiographic, biomarker, and safety changes associated with clinically guided mavacamten therapy compared with conventional pharmacotherapy in symptomatic HOCM.
METHODS: In this single-center prospective comparative cohort study, 95 symptomatic HOCM patients were included, of whom 48 received mavacamten and 47 received conventional pharmacotherapy. Mavacamten was initiated at 2.5 mg daily and titrated (2.5-10 mg) based on resting LVOT gradient (LVOTG) and ejection fraction (LVEF). Follow-up assessments were performed at baseline and at scheduled visits at 3, 6, and 9 months. Longitudinal echocardiographic trajectories were analyzed using observed mean changes with 95% confidence intervals (CIs), and baseline imbalance was assessed using inverse probability weighting. The predefined LVOTG response endpoint was defined as a reduction in resting LVOTG of ≥ 30 mmHg from baseline at the last available follow-up.
RESULTS: Mavacamten was associated with a downward trajectory in resting LVOTG during follow-up, whereas the control group remained relatively stable. BNP decreased significantly in the mavacamten group, whereas no significant paired change was observed in the control group. The predefined LVOTG response endpoint was achieved by 9 of 48 patients (18.8%) in the mavacamten group and 1 of 42 patients (2.4%) in the control group (Fisher exact p = 0.0175; OR = 9.46, 95% CI 1.14-78.20). No patient experienced LVEF < 50%.
CONCLUSIONS: In symptomatic HOCM, clinically guided mavacamten therapy was associated with reductions in resting LVOT gradient and BNP, while LVEF remained preserved during short-term follow-up. These findings support individualized dose titration with echocardiographic monitoring, while dose-stratified and response analyses should be interpreted cautiously because of limited subgroup sizes.
PMID:42461338 | DOI:10.1111/echo.70540