NEW YORK – Patients with rheumatoid arthritis had significantly greater aortic wall inflammation than did control patients with coronary artery disease but without autoimmune disease in an 18- fluorodeoxyglucose PET imaging study. No differences in carotid artery wall inflammation were found between the groups.
"These results suggest that part of the risk of cardiovascular disease in rheumatoid arthritis patients may not only be from systemic inflammation but truly localized inflammation that is causing plaques to become more vulnerable, less stable, and more likely to rupture," said Dr. Jeffrey D. Greenberg, who presented the results of the cross-sectional comparison at the NYU Seminar in Advanced Rheumatology, sponsored by New York University.
It has been known for some time that rheumatoid arthritis (RA) patients have systemic inflammation as well as vascular inflammation and have an increased risk of cardiovascular-related death, according to Dr. Greenberg, associate director of clinical translational sciences in the division of rheumatology at New York University Langone Medical Center and the NYU Hospital for Joint Diseases. He cited multifactorial mechanisms by which RA patients may incur heightened cardiovascular risk, including traditional cardiovascular risk factors (altered lipid balance, impaired insulin sensitivity), abnormal endothelial function, and increased plaque vulnerability. He said that the results of this study demonstrate another factor – localized inflammation causing subclinical vasculitis in the aorta and perhaps coronary vessels.
Dr. Greenberg and his associates used a 10 mCi injection of 18-fluorodeoxyglucose (18-FDG) and PET imaging in two separate cohorts of patients, one consisting of 27 RA patients (aged 35-64 years) and another of 70 controls with coronary artery disease but without autoimmune disease (aged 41-76 years). The investigators determined vascular 18-FDG uptake by calculating target to background ratios (TBRs) that served as proxies for macrophage activity and inflammation in the vessel walls.
RA patients had significantly higher TBR scores than did controls for the aorta mean TBR (1.46 vs. 1.25; P less than .0001), aorta maximum TBR (2.08 vs. 1.75; P less than .0001) and the TBR of the most diseased segment of aorta (2.23 vs. 1.87; P = .0004). These values were adjusted for differences in age, gender, and body mass index between the groups in multivariate regression models. RA patients had mean disease duration of about 11 years and mean DAS28 of 4.6, with no history of coronary artery disease, myocardial infarction, or stroke.
The results of the study were presented previously at the 2012 ACR Annual Meeting.
Dr. Greenberg serves as a consultant to the Consortium of Rheumatology Researchers of North America Inc. (CORRONA) and Pfizer and holds an ownership interest in CORRONA. He also receives grant support from the American College of Rheumatology, the Arthritis National Research Foundation, the Agency for Healthcare Research and Quality, the National Institute for Arthritis, and Musculoskeletal and Skin Diseases, and the NYU Clinical and Translational Science Institute.