Vasomotor dysfunction in patients with angina and nonobstructive coronary artery disease is dominated by vasospasm

Coronary vasomotor dysfunction, comprising endotypes of coronary spasm and/or impaired microvascular dilatation (IMD), is common in patients with angina and no obstructive coronary arteries (ANOCA). However, there are discrepant reports regarding the prevalence of these endotypes. The objective of this study was to determine the prevalence of coronary vasomotor dysfunction in patients with ANOCA, underlying endotypes, and differences in clinical characteristics. Prospective registry of patients with ANOCA that underwent clinically indicated invasive coronary function testing (CFT), including acetylcholine spasm testing (2–200 μg) to diagnose coronary spasm, and adenosine testing (140 μg/kg/min) to diagnose IMD, defined as an index of microvascular resistance ≥25 and/or coronary flow reserve