Liao KP, Huang J, He Z, et al. - Researchers undertook this retrospective cohort study to compare the prevalence of coronary microvascular dysfunction (CMD) in rheumatoid arthritis (RA) to diabetes mellitus (DM), as well as to assess the link with all-cause mortality, using data from a registry including all patients undergoing stress myocardial perfusion positron emission tomography as component of routine clinical care from 2006-2017. A normal perfusion scan was the inclusion criteria. This study included 73 patients with RA and 441 with DM. They found a similar prevalence of CMD in RA and in DM, among patients with a normal perfusion scan. Findings are indicative of a crucial role for CMD as a potential contributor to excess cardiovascular risk and death in RA, as earlier seen in DM. A mechanistic connection between inflammation and CVD was also evident.