Purpose: The syndromes of myocardial infarction/myocardial ischemia with No Obstructive Coronary Artery Disease (MINOCA/INOCA) are seen more and more often. Endothelial dysfunction (ED) leading to ischemic events has been reported in many of these patients. We aimed to compare patients with MINOCA and INOCA regarding brachial artery flow-mediated endothelium-dependent vasodilation (flowmediated dilation [FMD]) and plasma concentration of cardiotrophin-1 (CT-1).Methods: We included 42 patients with MINOCA and 38 patients with INOCA.Endothelial function was assessed by measuring FMD% and nitroglycerin-mediated dilatation (NMD%) in the brachial artery. The plasma level of CT-1 was determined by solid-phase enzyme-linked immunosorbent assay.Results: FMD% was significantly lower in MINOCA than in INOCA patients (6.45