MERIT HCM
Research type
Research Study
Full title
Myocardial Energetic Restoration in the Treatment of Obstructive Hypertrophic Cardiomyopathy (MERIT-HCM) Study
IRAS ID
367806
Contact name
Andrew Crean
Contact email
Sponsor organisation
University of Manchester
Clinicaltrials.gov Identifier
Duration of Study in the UK
3 years, 0 months, 2 days
Research summary
Hypertrophic Cardiomyopathy (HCM) is the most common hereditary heart condition, characterised by muscle thickening that often obstructs blood flow out of the heart and is associated with a chronic state of energy loss. This energy deficit can be signalled by a reduced energy score called phosphocreatine-to-ATP ratio (PCr/ATP).
Recently, a new class of medication called cardiac myosin inhibitors have been introduced which directly targets heart muscle proteins (sarcomeres), reduces contraction strength and can help relieve blood flow obstruction. Mavacamten is one such medication that is now licensed and routinely prescribed, at specialist clinics within Manchester Foundation Trust. While clinical trials show cardiac myosin inhibitor improves physical capacity and symptoms, it is still poorly understood how this affects the fundamental energy balance within the heart.
Our prospective, observational study aims to prove this mechanism in the HCM population. We will recruit 20 patients at Manchester Foundation Trust initiating the medication as part of their routine clinical care. The key research procedure involves a specialised, non-invasive MRI technique called phosphorus-31 magnetic resonance spectroscopy (31P-MRS) which accurately measures the heart's energy score.
Each participant will undergo this research scan at baseline and again after 24 weeks of myosin inhibitor therapy. This will coincide with standard clinical assessments, including blood tests, ECGs, and echocardiograms.
Our objective is to determine how energy scores are affected and improve over time with medication. If positive, this finding could establish the PCr/ATP ratio as a crucial, objective biomarker for monitoring therapeutic response and informing personalised dosing strategies in the future.
Two optional parts of the study are also offered: an additional stress perfusion MRI during the study scans to assess blood flow to the heart muscle, and an optional extra MRI scan about 12 months of treatment to look at longer‑term changes. Participation in these optional components is entirely voluntary.
REC name
Wales REC 5
REC reference
26/WA/0083
Date of REC Opinion
30 Mar 2026
REC opinion
Favourable Opinion