Effects of Abatacept on Myocarditis in Rheumatoid Arthritis

Study Summary

This study aims to evaluate the effects of abatacept, a CTLA4-Ig fusion protein that binds cluster of differentiation antigen 80 (CD80)/86 (B7-1/B7-2), on subclinical myocarditis in rheumatoid arthritis (RA) through its effect on T cell subpopulations. RA patients without clinical CVD, biologic naïve, and with inadequate response to methotrexate (MTX), will undergo cardiac fluorodeoxyglucose (FDG) positron emission tomography (PET)/computerized tomography (CT) imaging to assess myocardial inflammation. Studies that investigate the impact of treatment on subclinical myocarditis in RA, a possible contributor to heart failure, while exploring potential underlying mechanisms (i.e., different T cell subpopulations), are needed for a better understanding of their relevance in the pathogenesis of heart failure in RA and survival improvement in these patients with excess risk for cardiovascular death. If the investigator hypothesis is confirmed and treatment with abatacept decreases and/or suppresses or prevents myocardial inflammation in RA, this will have multidisciplinary implications that could lead to changes in the current management of RA patients at high risk for cardiovascular events. Similarly, identification of T cell subpopulations in RA patients with myocardial FDG uptake will shed light into the underlying cellular mechanisms of myocardial injury and serve to guide the use of therapies that prevent their pathogenicity. The objectives of this study are to compare the change in myocardial FDG uptake in RA patients treated with abatacept vs adalimumab, and identify T cell subpopulations associated with myocardial FDG uptake in each treatment arm. RA patients will be randomized in an unblinded, 1:1 ratio to treatment with abatacept vs adalimumab. A cardiac FDG PET/CT will be performed at baseline and 16 weeks post-biologic treatment. T cell subpopulations associated with myocardial FDG uptake will be evaluated at both points in time with their transcriptional phen

Primary Outcome

Using FDG PET cardiac imaging to identify myocardial inflammation at baseline and post-treatment, the study will quantitatively compare the change in myocardial FDG uptake in biologic naïve RA patients without clinical CVD and with inadequate methotrexate response, following randomization to 16-week treatment with abatacept vs the TNF-inhibitor adalimumab. Conventional cardiovascular disease (CVD) risk factors and measures of RA disease activity and severity will be ascertained.

Interventions

• DRUG Abatacept
• DRUG Adalimumab