Evaluation of the effect of mavacamten on left ventricular function in obstructive hypertrophic cardiomyopathy using myocardial work.

OBJECTIVE

To evaluate the effect of 12-week Mavacamten on left ventricular function in obstructive hypertrophic cardiomyopathy (oHCM) using myocardial work analysis, and explore its role in myocardial energy metabolism.

METHODS

Thirty-five oHCM patients and 35 matched healthy controls were enroled. Patients received Mavacamten for 12 weeks. At baseline and post-treatment, we measured LVOT gradient, LVEF, GLS, myocardial work parameters [GWI, GCW, GWW, GWE], mitral regurgitation severity, and SAM.

RESULTS

Myocardial work parameters showed good reproducibility (ICCs > 0.75). After 12 weeks, resting and provoked LVOT gradients significantly decreased (both p < 0.001). Proportions of moderate/severe mitral regurgitation and SAM reduced. GWI, GCW, and GWW decreased (p < 0.001), while GWE increased (p < 0.001). NT-proBNP decreased and NYHA functional class improved (p < 0.001). LVEF, GLS, and left atrial diameter showed no significant changes. Compared with controls, baseline oHCM patients had lower GWI, GCW, GWE and higher GWW (all p < 0.001). After treatment, GWE remained lower than controls (p < 0.001), and GWW remained higher (p < 0.001).

CONCLUSION

Twelve-week Mavacamten reduces LVOT obstruction in oHCM, accompanied by decreased GWI and increased GWE, while preserving systolic function and improving symptoms. Myocardial work parameters may serve as novel non-invasive references for treatment evaluation.