Rationale and design of the British Heart Foundation (BHF) Coronary Microvascular Angina (CorMicA) stratified medicine clinical trial

Abstract

BackgroundCoronary angiography is performed to assess for obstructive coronary artery disease (CAD), but “nonobstructive CAD” is a common finding. Microvascular or vasospastic angina may be relevant, but routine confirmatory testing is not evidence based and thus rarely performed.AimThe aim was to assess the effect of stratified medicine guided by coronary function testing on the diagnosis, treatment, and well-being of patients with angina and nonobstructive CAD.DesignThe BHF CorMicA trial is a prospective, multicenter, randomized, blinded, sham-controlled trial of stratified medicine (NCT03193294). All-comers referred for elective coronary angiography for investigation of suspected CAD will be screened. Following informed consent, eligible patients with angina and nonobstructive CAD will be randomized 1:1 immediately in the catheter laboratory to either coronary artery function–guided diagnosis and treatment (intervention group) or not (control group). Coronary function will be assessed using a pressure-temperature–sensitive guidewire and adenosine followed by pharmacological testing with intracoronary acetylcholine. Patients will be stratified into endotypes with linked therapy. The primary outcome is change in Seattle Angina Questionnaire score at 6 months. Secondary outcomes include safety, feasibility, diagnostic utility (impact on diagnosis and diagnostic certainty), and clinical utility (impact on treatment and investigations). Health status is a key secondary outcome assessed according to the following domains: quality of life, treatment satisfaction, illness perception, physical activity, and anxiety-depression score. Patients with obstructive disease who are not randomized will form a registry group who will be followed up as a comparator for secondary outcomes including health status. Health and economic outcomes will be evaluated in the longer term using electronic health record linkage.ValueCorMicA is a proof-of-concept clinical trial of a disruptive stratified intervention with potential benefits to patients and health care providers.

Systemic microvascular dysfunction in microvascular and vasospastic angina

“…Patients were prospectively recruited from the larger British Heart Foundation Coronary Microvascular Angina (CorMicA) study which is a randomized controlled trial evaluating the effect of diagnostic strategy and linked therapy on symptoms and quality of life in INOCA. 13 The Rose–Angina questionnaire was administered on the day of the angiogram and only patients with definite or possible angina were eligible for the study. 14 Exclusion criteria included a non-coronary indication for invasive angiography e.g.…”

“…The CorMicA study design paper describes the coronary artery function testing procedure. 13 A total of 11 control subjects were recruited: 9 from the CorMicA study (NCT03193294) and 2 from a contemporaneous related study (CorCTCA: NCT03477890). Control subjects had stable chest pain syndromes investigated with the same diagnostic protocols but coronary microvascular dysfunction was not found during invasive interrogation.…”

Assessment of Vascular Dysfunction in Patients Without Obstructive Coronary Artery Disease

“…Historically, there was no randomized evidence that a diagnostic strategy linked to therapy improves patient well-being. The CorMicA (Coronary Microvascular Angina) trial was undertaken to address this evidence gap ( 11 , 38 ). Patients with INOCA were randomized 1:1 to the intervention group (stratified medical therapy, interventional or functional diagnostic procedure disclosed) or the control group (standard care, IDP performed, results not disclosed).…”

Coronary microvascular dysfunction: Filling the research gaps with careful patient selection

“…This study will provide the first randomized assessment of whether routine testing for CMD translates into clinical benefits. 17 In summary, the study by Monroy-Gonzalez et al is significant for demonstrating the long-term prognostic implications for patients with CMD and the confirmed absence of obstructive epicardial CAD. These results further indicate the need to fill the research gap with larger prognostic studies looking at long-term outcomes, assessing whether routine testing for CMD affects outcomes, and evaluating CMD treatments.…”