Étude du remodelage cardiaque après traitement par Mavacamten dans la cardiomyopathie hypertrophique obstructive

Introduction: obstructive hypertrophic cardiomyopathy (HCM) is characterized by hypercontractility, dynamic left ventricular outflow tract (LVOT) obstruction, and diastolic dysfunction, associated with adverse cardiac remodeling. Mavacamten, a selective cardiac myosin inhibitor, has demonstrated efficacy in reducing obstruction and improving symptoms. Its long-term impact on cardiac remodeling remains to be clarified. Methods: we conducted a single-center retrospective observational study including 59 patients with symptomatic obstructive HCM treated with mavacamten at Bordeaux university hospital. Clinical, biological, and echocardiographic parameters were assessed at baseline and during follow-up up to 12 months of treatment. Results: After one year of treatment, sustained improvements were observed (mean percentage change from baseline, all p < 0.05) in maximal left ventricular wall thickness (–11%), indexed left ventricular mass (–15%), indexed left atrial volume (–18%), E/e′ ratio (–17%), mitral regurgitation, and LVOT obstruction gradients (rest [–78%], post-Valsalva [–86%], post-exercise [–80%]). Septal and lateral e′ velocities increased by +16% and +11%, respectively, and were associated with a reduction in pulmonary arterial pressures (–20%). Left ventricular ejection fraction decreased moderately (–8%), without change in global longitudinal strain. Clinical improvement was observed (median New York Heart Association (NYHA) class from 3 to 1, p < 0.001), associated with a reduction in N-terminal pro-brain natriuretic peptide (NT-proBNP levels) (– 83%). Discussion: in real-world clinical practice, Mavacamten appears to induce, beyond relief of LVOT obstruction, favorable ventricular and atrial remodeling at one year. These findings suggest a global impact on the pathophysiology of obstructive HCM. Confirmation of a long-term prognostic benefit remains necessary.