A previous study reported that highly sensitive cardiac troponin I (cTnI; >1.5 pg/mL) was an independent predictor of occult coronary plaque burden and composition on coronary computed tomography angiography (CTA) in patients with established rheumatoid arthritis (RA). The current study examines whether high cTnI also predicts incident long-term cardiovascular (CV) events and optimizes CV risk stratification in the Prospective Evaluation of Lateral Coronary Atherosclerosis in RA (PROTECT-RA) trial after 5 years of follow-up.
Eligible patients with RA (n = 159) without symptoms or prior diagnosis of CV disease underwent a baseline 64-slice CTA for plaque evaluation; blood was also collected for laboratory evaluations, including for biomarker assessments. Patients were followed for a mean of 60 ± 26 months for incident CV events. Using Cox regression analysis, the association between high cTnI (>1.5 pg/mL) and CV events was evaluated.
During the 5-year follow-up period, 11 patients suffered incident events (1.54/100 patient-years). Of these, 8 were ischemic CV events, including 1 cardiac death, 3 myocardial infarctions, 2 strokes, and 2 peripheral arterial ischemic events requiring emergent revascularizations; and 3 were nonischemic events, including new onset, hospitalization, and systolic heart failure.
The CV cohort showed an increased number of traditional CV risk factors, including diabetes (4/11 patients), hypertension (8/11 patients), and D’Agostino Framingham score (15.6). The CV cohort also showed unfavorable coronary plaque burden and associated biomarkers, including coronary artery calcium, segment involvement score, segment stenosis score, plaque burden score, and mixed plaque score.
Patients who experienced CV events had higher levels of highly sensitive cTnI compared with those who did not (2.6 [2.1-4.4] pg/mL vs 1.5 [1.0-2.6] pg/mL; P <.01). Measurement of highly sensitive cTnI was higher in patients with plaque versus those without. Coronary plaque presence, burden, and complexity were enriched in patients with higher levels of highly sensitive cTnI. Importantly, higher levels of highly sensitive cTnI predicted the risk for incident CV events independently of demographic and traditional cardiac risk factors, including age, sex, hypertension, diabetes, dyslipidemia, smoking, body mass index, and prednisone use. Moreover, patients with low cTnI (<1.5 pg/mL) were found to be 82% less likely to suffer a CV event.
Source: Karpouzas G, Estis J, Pham L, et al. Highly sensitive cardiac troponin-I in peripheral blood predicts cardiovascular events in patients with rheumatoid arthritis. Arthritis Rheumatol. 2017;69(suppl 10). Abstract 867.