Determining the Cause of Coronary Vasomotor Disorders in Patients With Ischemia and Nonobstructive Coronary Arteries: Design and Rationale of the DISCOVER INOCA Prospective, Multicenter Registry

Approximately 30% to 50% of patients who are referred for diagnostic coronary angiography are found to have no obstructive coronary artery disease (CAD). Ischemia and nonobstructive coronary arteries (INOCA) is increasingly recognized and encompasses coronary microvascular dysfunction, vasospastic angina, symptomatic myocardial bridging, and other vasomotor disorders. However, the prevalence of these disorders and whether underlying atherosclerotic plaque burden and morphology affect the long-term outcomes of each physiologic phenotype is unknown.