Introduction Angina with no obstructive coronary artery disease (ANOCA) is a common syndrome with unmet clinical needs. Microvascular and vasospastic angina are relevant but may not be diagnosed without measuring coronary vascular function. The relationship between cardiovascular magnetic resonance (CMR)-derived myocardial blood flow (MBF) and reference invasive coronary function tests is uncertain. We hypothesise that multiparametric CMR assessment will be clinically useful in the ANOCA diagnostic pathway.
Methods/analysis The Stratified Medical Therapy Using Invasive Coronary Function Testing In Angina (CorMicA) trial is a prospective, blinded, randomised, sham-controlled study comparing two management approaches in patients with ANOCA. We aim to recruit consecutive patients with stable angina undergoing elective invasive coronary angiography. Eligible patients with ANOCA (n=150) will be randomised to invasive coronary artery function-guided diagnosis and treatment (intervention group) or not (control group). Based on these test results, patients will be stratified into disease endotypes: microvascular angina, vasospastic angina, mixed microvascular/vasospastic angina, obstructive epicardial coronary artery disease and non-cardiac chest pain. After randomisation in CorMicA, subjects will be invited to participate in the Coronary Microvascular Angina Cardiac Magnetic Resonance Imaging (CorCMR) substudy. Patients will undergo multiparametric CMR and have assessments of MBF (using a novel pixel-wise fully quantitative method), left ventricular function and mass, and tissue characterisation (T1 mapping and late gadolinium enhancement imaging). Abnormalities of myocardial perfusion and associations between MBF and invasive coronary artery function tests will be assessed. The CorCMR substudy represents the largest cohort of ANOCA patients with paired multiparametric CMR and comprehensive invasive coronary vascular function tests.
Ethics/dissemination The CorMicA trial and CorCMR substudy have UK REC approval (ref.16/WS/0192).
Trial registration number NCT03193294.
- myocardial perfusion
- cardiovascular magnetic resonance
- coronary microvascular dysfunction
- endoEndothelial dysfunction
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Contributors CB designed the study. DC wrote the first draft and revised draft with TJF, L-YH, AC, VO, KM, MM, PR, SW, RG, KB, SP, NS, AM, KGO, RT, AA and CB.
Funding This work was supported by the British Heart Foundation (BHF) (PG/17/2532884; RE/13/5/30177). The trial sponsor is the Golden Jubilee Research Foundation. The BHF has supported DC (FS/14/15/30661), TJF (RE/13/5/30177) and CB (RE/13/5/30177; FS/14/15/30661; FS172632744; PG-17- 25-32884).
Competing interests CB is employed by the University of Glasgow, which holds consultancy and research agreements with companies that have commercial interests in the diagnosis and treatment of angina. The companies include Abbott Vascular, AstraZeneca, Boehringer Ingelheim, Menarini Pharmaceuticals and Siemens Healthcare. KGO has received consultant and speaker fees from Abbott Vascular and Volcano Corporation which manufacture pressure wires. SW has worked as a consultant for Abbott Vascular. None of these companies have had any involvement with this study. None of the other authors have any potential conflicts of interest.
Patient consent for publication Not required.
Ethics approval The BHF CorMicA trial and prespecified CorCMR substudy has full UK National Research Ethics Service approval (Reference 16/WS/0192).
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data are available.
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