A Study to Evaluate Mavacamten Impact on Myocardial Structure in Participants With Symptomatic Obstructive Hypertrophic Cardiomyopathy

Inclusion Criteria:

Diagnosed with obstructive hypertrophic cardiomyopathy (oHCM), in accordance with current American College of Cardiology Foundation/American Heart Association and European Society of Cardiology guidelines as below:
Left ventricular outflow tract (LVOT) peak gradient ≥ 30 mm Hg and ≥ 50 mm Hg after Valsalva or after exercise
Left ventricular ejection fraction (LVEF) ≥ 55% at rest
New York Heart Association (NYHA) functional class II or III symptoms

Exclusion Criteria:

A known infiltrative or storage disorder causing cardiac hypertrophy that mimics oHCM
Documented obstructive coronary artery disease or history of myocardial infarction
A history of resuscitated sudden cardiac arrest or life-threatening ventricular arrhythmia within 6 months prior to screening
An implantable cardioverter defibrillator (ICD) or pacemaker, or another contraindication for cardiac magnetic resonance imaging (CMR)

Note: Other protocol-defined inclusion/exclusion criteria apply