Abstract 19739: Decreased Resting Coronary Flow and Impaired Endothelial Function in Patients With Vasospastic Angina

Introduction: Intracoronary acetylcholine (ACh) provocation test is useful to diagnose vasospastic angina (VSA). Endothelial and vascular smooth muscle dysfunction of epicardial coronary arteries play an important role in the pathogenesis of VSA. However, entire coronary circulation in patients with VSA is not fully understood. Hypothesis: We assessed the hypothesis that patients with VSA have coronary circulation dysfunction. Methods: A total of 25 patients without obstructive coronary artery disease in the left descending coronary artery undergoing ACh provocation test, were prospectively enrolled. Coronary circulation was invasively assessed with a thermodilution method by obtaining coronary flow reserve, index of microcirculatory resistance, and mean transit time (Tmn) at rest and hyperemia in the left descending coronary artery. Endothelial function was evaluated by reactive hyperemia index. The positive diagnosis of ACh provocation test was defined as total or subtotal coronary artery narrowing acco...