Ahmad A, Corban MT, Toya T, et al. - Researchers investigated if serum homocysteine concentrations and coronary microvascular endothelial dysfunction (CMED) are associated. Participants were 1,418 patients experiencing chest pain or with an abnormal functional stress test and having nonobstructive coronary artery disease (< 40% angiographic stenosis). These individuals underwent CMED assessment with functional angiography and had serum homocysteine concentrations recorded. Two groups of patients were defined: those having normal microvascular function vs CMED. Findings demonstrated the presence of significantly higher levels of serum homocysteine in patients with CMED. A significantly increased odds of an invasive diagnosis of CMED was observed in relation to raised serum homocysteine concentrations. Experts suggested that homocysteine has a potential role in the diagnosis as well as target treatment in patients with early coronary atherosclerosis.