Clinical Outcomes With Mavacamten Use in Patients With Obstructive Hypertrophic Cardiomyopathy Using Real-World Data

To examine the association of mavacamten therapy with cardiovascular outcomes compared with standard medical management in patients with obstructive hypertrophic cardiomyopathy (oHCM).

The study population was identified using retrospective electronic health record data from the TriNetX network between April, 28th 2022 and August, 31st 2024. Appropriate International Classification of Diseases, Tenth Revision diagnosis codes and medication records were used to distinguish patients with oHCM receiving mavacamten from those receiving standard medical management. The primary outcome was a composite cardiovascular outcome, defined as the first occurrence of ventricular tachycardia, ventricular fibrillation, cardiac arrest, or all-cause mortality. The risk of the composite outcome with mavacamten therapy compared with standard medical management was estimated using a Cox model with inverse probability weighting.

Among 12,784 patients with oHCM (6810 [53.3%] females; median age, 66 years [IQR, 55 to 74 years]), 550 and 12,234 patients were included in the mavacamten and standard medical management groups, respectively. There were 13 (2.4%) and 560 (4.6%) events of the composite outcome in the mavacamten and standard medical management groups, respectively. In the multivariable Cox proportional analysis utilizing inverse probability weighting, mavacamten therapy was associated with a significantly lower risk of composite outcome (hazard ratio, 0.51; 95% CI, 0.28 to 0.93; P=.026) compared with medical management. Additional analysis including individuals taking glucagon-like peptide 1 agonists and sodium-glucose cotransporter 2 inhibitors found that the use of mavacamten was associated with a lower risk of the composite outcome compared with standard medical management (hazard ratio, 0.52; 95% CI, 0.28 to 0.94; P=.032). The event rate of heart failure with reduced ejection fraction (HFrEF) remained low at less than 1% in both groups.

In this nationwide study leveraging real-world data, mavacamten therapy was associated with a lower risk of adverse cardiovascular outcomes in patients with oHCM. The low rate of HFrEF in the mavacamten group highlights the efficacy of the Risk Evaluation and Mitigation Strategy program in maintaining patient safety and offsetting any potential excess risk of HFrEF. Given the observational nature of the study and low event rates, further research is needed to confirm these results.