Highly-Sensitive Cardiac Troponin-I and Beta-2-Glycoprotein-I IgA Antibodies May Guide Atherosclerosis Screening and Surveillance in Rheumatoid Arthritis

Abstract

Methods. The sample included 144 patients with complete biomarker data who underwent plaque evaluation with coronary computed tomography angiography; 95 were re-imaged within 6.9±0.3 years. Presence of >5 segments with plaque or coronary artery calcium >100 constituted extensive disease; lesions rendering >50% stenosis were considered obstructive. The Framingham 2008 cardiovascular risk score was included in all models. Results. Hs-cTnI added to the cardiovascular risk score increased area-under-the curve (AUC) from 0.710 to 0.729 and improved prediction accuracy for baseline plaque presence [Net Reclassification Improvement =0.538 (95% confidence interval 0.143-0.895)] and Integrated Discrimination Improvement (IDI) =0.035 (0.001-0.128). In contrast, a-b2GPI-IgA did not, and the combination offered no added benefit over hs-cTnI alone. While hs-cTnI alone did not predict plaque progression, a-b2GPI-IgA presence did (p=0.005), especially in patients with >median hs-cTnI (p=0.015). In patients with >median hs-cTnI, adding a-b2GPI-IgA to a cardiovascular risk score model predicting progression from non-extensive/non-obstructive to extensive/obstructive plaque increased AUC from 0.796 to 0.878 and improved model precision [IDI=0.277 (0.011-0.946)]. Conclusion. High hs-cTnI significantly improved prediction of baseline plaque presence and may trigger an initial non-invasive coronary atherosclerosis evaluation. A-b2GPI-IgA presence may justify a follow-up interrogation in patients with non-extensive, non-obstructive plaque at baseline.