https://doi.org/10.1007/s00392-025-02625-4
1Universitätsklinikum Schleswig-Holstein Innere Medizin III mit den Schwerpunkten Kardiologie und internistische Intensivmedizin Kiel, Deutschland
Background: Hypertrophic cardiomyopathy (HCM) is the most prevalent genetic myocardial disorder. While variable phenotypes of HCM exist, key features include hypercontractility, asymmetric left ventricular hypertrophy, diastolic dysfunction and dynamic left ventricular outflow tract (LVOT) obstruction which are due to enhanced cardiac actin-myosin interactions. As LVOT obstruction is closely associated with symptom burden and adverse prognosis, it constitutes a major therapeutic target in obstructive HCM. Mavacamten, a selective myosin inhibitor, has demonstrated significant improvements in patients with obstructive HCM in clinical trials. The aim of our analysis was to provide a real-world experience with mavacamten.
Methods: This study included the first twelve patients at our center with symptomatic obstructive HCM who were initiated on mavacamten after it had been approved in the European Union in June 2023. Main inclusion criteria were: age ≥ 18 years, significant LVOT obstruction (peak LVOT gradient ≥ 50 mmHg at rest or provoked), New York Heart Association (NYHA) class ≥ II despite maximally tolerated medical therapy and left ventricular ejection fraction (LVEF) ≥ 55%. Baseline and follow-up data included clinical characteristics, echocardiography data and NT-proBNP levels.
Results: Median age at baseline was 61 years (IQR 46-68 years) and eight patients (67%) were female. Following initial dose titration, maintenance dose of mavacamten was 2.5 mg (o.d.) in one patient, 5 mg (o.d.) in eight patients and 10 mg (o.d.) in three patients. Median LVOT gradient was 89 mmHg before treatment and 17 mmHg during follow-up. Median NT-proBNP levels at baseline were 1379 ng/l and 188 ng/l during follow-up. Nine (75%) patients reported an improvement in NYHA class of at least one class. No patient treated with mavacamten had an indication for septal reduction therapy during follow-up. No major side effects were observed. LVEF remained ≥ 55% in all patients under maintenance dose of mavacamten.
Conclusion: In this real-world, single-center analysis, treatment of obstructive HCM with mavacamten was safe and effective.