Inflammation and Disease Activity are Associated with High Circulating Cardiac Markers in Rheumatoid Arthritis Independently of Traditional Cardiovascular Risk Factors

Objective. To measure concentration S of high-sensitivity cardiac troponin (HS-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with rheumatoid arthritis (RA) and to examine correlates. Methods. The plasma concentrations of HS-cTnT and NT-proBNP were measured in consecutive patients with RA and compared to values obtained from age-matched and sex-matched healthy controls. Results. We included 236 unrelated patients with RA (192 females, 57 +/- 13 yrs) and 213 controls (170 females, 55 +/- 15 yrs). Seventy-one patients with RA were free of cardiovascular (CV) risk factors. HS-cTnT and NT-proBNP concentrations were significantly higher in the total cohort of patients with RA (p = 0.03 and p < 0.0001, respectively) and in the subgroup free of CV risk factors (p = 0.02 and p <0.0001, respectively) compared to controls. In addition, both the total cohort of patients with RA and the subgroup free of CV risk factors were more likely to have levels above the cutoff concentrations of HS-cTnT (p = 0.003 and p = 0.007, respectively) and NT-proBNP (p = 0.0001 and p < 0.0001, respectively) than controls. Patients with RA and increased C-reactive protein (CRP) levels had higher HS-cTnT (p = 0.03) and NT-proBNP (p = 0.02) concentrations. HS-cTnT levels positively correlated with the 28-joint Disease Activity Score (DAS28-CRP; r = 0.2, p = 0.020). Multivariate logistic regression analysis indicated that increased HS-cTnT levels were independently associated with a DAS28-CRP > 5.1 (OR 11.8; 95% CI 1.6-35.5) and a body mass index > 30 kg/m(2) (OR 2.7; 95% CI 1.3-5.5). Conclusion. HS-cTnT and NTproBNP are increased in patients with RA, independent of CV risk factors. The association between HS-cTnT, NT-proBNP, and CRP, together with the correlation between HS-cTnT and disease activity, support the link between myocardial injury/dysfunction and inflammation.