September 22, 2025Circulation1 citationsOpen Access
View Full PaperTreatment Response to Mavacamten in Patients With Obstructive Hypertrophic Cardiomyopathy: 96-Week Results From the EXPLORER Cohort of the MAVA–Long-Term Extension Cardiac Magnetic Resonance Imaging Substudy
Structured PICO
Does long-term treatment with mavacamten improve cardiac magnetic resonance imaging parameters in patients with obstructive hypertrophic cardiomyopathy?
P
Population
Patients with Obstructive Hypertrophic Cardiomyopathy from the EXPLORER cohort enrolled in the MAVA-Long-Term Extension Cardiac Magnetic Resonance Imaging Substudy
I
Intervention
Mavacamten 5 mg/day initiation with echocardiography-guided titration
C
Comparator
Baseline values or placebo from the initial 30-week EXPLORER-HCM trial
O
Outcome
Exploratory end points including left ventricular (LV) mass index, LV maximum wall thickness, volumes and function, focal and diffuse myocardial fibrosis, and LV ejection fraction (LVEF)surrogate
This substudy evaluates the 96-week effects of mavacamten on cardiac remodeling and fibrosis using CMR in patients with obstructive hypertrophic cardiomyopathy.
Abstract
All participants provided written informed consent?a In EXPLORER-HCM. patients received mavacamten or placebo for 30 weeks. After trial completion and a variable washout period, patients could enroll in MAVA- LTE. with initiation of mavacamten 5 mg/day and echocardiography-guided titration. CMR assessments were conducted as previously detailed? with analyses at baseline and week 30 of EXPLORER-HCM and weeks |24 and 96 of MAVA-LTE (data extraction on March 9, (2023). Exploratory end points included left ventricular (LV) mass index, LV maximum wall thickness, volumes land function (left atrial volume maximum index, LV end- diastolic volume index, LV end-sys tolic volume index, and myocardial contractile fraction), focal and diffuse mocar- dial fibrosis (6-SD late gadolinium enhancement LGE and average extracellular volume fraction), and LV ejec- tion fraction (LVEF).