HIV positive (HIV+) people today experience an increasing burden of coronary artery disease (CAD). Although it has been postulated that increased inflammation interacts with traditional risk factors to accelerate atherosclerosis in HIV+ people, the importance of inflammation per se in the pathogenesis of CAD in HIV+ people is not known. This critical gap in knowledge about CAD pathogenesis was identified by the NHLBI Working Group on Advancing HIV/AIDS Research in Heart, Lung, and Blood Diseases last year and addressing it is important not only for our understanding of in vivo vascular biology in the setting of HIV but also for defining the role, if any, for anti-inflammatory approaches in altering CAD in HIV+ people. Anti-inflammatory strategies are associated with lower cardiovascular event rates in individuals with inflammatory autoimmune disease and are appealing in HIV+ populations but are not currently used in practice because of the lack of an established and easily obtained measure of the effect of inflammation on the processes which result in coronary atherosclerosis and because no clinical trial has established whether an anti-inflammatory strategy alone alters these processes. One such process is coronary endothelial dysfunction, which plays a pivotal role in the development, progression, and clinical manifestations of CAD, and is a marker for sub-clinical disease, an independent predictor of adverse cardiovascular events, and a potential target for medical interventions. We recently developed noninvasive, reproducible MRI-based methods to measure coronary endothelial function (CEF). We propose a placebo-controlled, double blind, single-center mechanistic trial to test the hypothesis that the anti-inflammatory approach, low dose colchicine (LDC), improves impaired local CEF in HIV+ people with subclinical CAD. The studies will provide novel much-needed mechanistic insight into the potential of anti-inflammatory strategies to reduce coronary endothelial dysfunction, which inflammatory biomarkers herald the CEF response, the relationship of CAD and CEF with epicardial adipose tissue (a purported local paracrine source of pro-inflammatory mediators), and whether a heterogeneous CEF response occurs with differential effects in more severely than mildly diseased coronary vessels, suggesting local anti-inflammatory effects. In addition to this novel mechanistic information, the findings will provide critical safety data on LDC in HIV+ people to guide larger multicenter outcomes trials on this clinically available pharmaceutical. (End of Abstract)