The purpose of this study is to evaluate coronary artery and peripheral vein vascular endothelial profiles in patients with ischemia with non-obstructive coronary arteries (INOCA) who undergo coronary function testing (CFT). The aims are: (1) Evaluate coronary artery endothelial profiles and associations with coronary microvascular dysfunction (CMD) in INOCA. (2) Assess brachial vein endothelial cell profiles in patients with INOCA and associations with CMD, and (3) Characterize relationships between endothelial signatures and anginal symptoms, functional status, and physical activity at baseline and 1-year follow-up.