Abstract 16370: Coronary Microvascular Endothelial Dysfunction is an Independent Predictor of Larger Epicardial Plaque Area and Higher Plaque Burden.

Background: Larger epicardial plaque burden (PB) and coronary microvascular endothelial dysfunction (CMED) have both been associated with major adverse cardiovascular events (MACE). However, the relationship between PB and CMED remains unknown. Methods: 148 patients with chest pain, referred for evaluation of coronary vasomotion and found to have angiographically normal coronary arteries or mild coronary artery disease (CAD) [<40% stenosis], underwent acetylcholine (Ach) assessment of CMED (defined as coronary blood flow [CBF] change <50% post ACh) and gray-scale intravascular ultrasound (IVUS) imaging of the left anterior descending artery for evaluation of vessel-averaged epicardial plaque area (PA) and PB (PB: PA/vessel area x 100). Results: Baseline clinical characteristics were not significantly different between patients with (n=87, 58.8%) vs. those without CMED (n=61, 41.2%). We observed a significant inverse linear relationship between both IVUS segment-level PA and PB with CBF (Figure). Patients with CMED had significantly higher averaged epicardial PA and PB (Figure). Hypertension (β=0.179, p=0.027 for PA and β=0.166, p=0.036 for PB), hyperlipidemia (β=0.26, p=0.001 for PA and β=0.311, p<0.001 for PB), and CMED (β=0.189, p=0.017 for PA and β=0.20, p=0.01 for PB) were independent predictors of larger PA and higher PB after adjusting for age, sex, hypertension, hyperlipidemia, diabetes mellitus, smoking and CMED. Conclusion: Coronary microvascular endothelial dysfunction is an independent predictor of larger epicardial PA and higher PB in patients with non-obstructive CAD. [ABSTRACT FROM AUTHOR]