Real-World Experience With Mavacamten in SRT-Eligible Obstructive HCM.

Area of Science:

• Cardiology
• Pharmacology

Background:

• Obstructive hypertrophic cardiomyopathy (oHCM) is a significant cardiovascular condition.
• Mavacamten, a cardiac myosin inhibitor, shows promise in improving oHCM symptoms and reducing left ventricular outflow tract (LVOT) gradients.
• Limited real-world data exists on long-term outcomes, safety, and impact on septal reduction therapy (SRT) eligibility for mavacamten.

Purpose of the Study:

• To assess the real-world effectiveness and safety of mavacamten in oHCM patients.
• To evaluate mavacamten's impact on patients meeting guideline-based criteria for SRT.
• To compare institutional SRT volumes before and after mavacamten approval.

Main Methods:

• Retrospective review of oHCM patients treated with mavacamten (April 2022 - December 2025) who met SRT eligibility criteria.
• Assessment of clinical and echocardiographic outcomes at baseline and follow-up.
• Comparison of institutional SRT volumes pre- and post-mavacamten approval.

Main Results:

• Mavacamten treatment led to significant reductions in resting and Valsalva LVOT gradients (P < 0.001).
• 92% of patients experienced improvement in NYHA functional class, with none remaining eligible for or undergoing SRT.
• Adverse events included transient LVEF reduction (11%) and new/recurrent atrial fibrillation (13%).

Conclusions:

• Mavacamten demonstrated sustained hemodynamic and symptomatic improvement in SRT-eligible oHCM patients in a real-world setting.
• The drug was generally well-tolerated, with manageable adverse events.
• Institutional SRT volumes decreased significantly in the post-mavacamten era, suggesting a shift in treatment paradigms.