Rationale and Design of the ILIAS ANOCA Clinical Trial: a blinded-arm controlled trial for routine ad-hoc coronary function testing.

Angina with non-obstructive coronary arteries (ANOCA) is a major cause of chronic coronary syndromes, affecting nearly half of patients with anginal symptoms who undergo invasive coronary angiography. ANOCA may lead to substantial symptom burden, increased risk of adverse cardiac events, increased healthcare utilization due to ongoing symptoms, repeat hospitalizations, and invasive testing. The pathophysiology of ANOCA often involves a variety of coronary disorders, such as coronary microvascular dysfunction, epicardial or microvascular vasospasm and endothelial dysfunction. While coronary function testing (CFT) can identify each of these specific endotypes, in current practice it is used as a second- or third-line diagnostic tool, delaying diagnosis which contributes to persistent symptoms and diminished quality of life. The ILIAS ANOCA clinical trial aims to enhance understanding and management of ANOCA through early routine CFT-guided management. After exclusion of obstructive coronary artery disease, eligible patients undergo comprehensive CFT, and will be randomized to blinding of the CFT results (control group) or disclosure of the CFT results combined with a tailored medical therapy escalation plan (intervention group). The control group will be unblinded after one year. The primary outcome is the mean difference in the within-subject change in Seattle Angina Questionnaire (SAQ) summary score between the groups at 6 months from baseline. Secondary outcomes include differences in SAQ-summary score and additional health-status and quality of life questionnaires at 12 and 24 months from baseline. Trial registration: International Clinical Trials Registry Platform identifier NL-OMON20739.