Abstract 15603: Does Repeat Measurement of High Sensitivity Troponin I Improve Prediction of Cardiovascular Events in Atrial Fibrillation?
BACKGROUND: Troponin levels predict stroke and other cardiovascular events in patients with atrial fibrillation (AF). This study investigates if repeat measurement using a high-sensitivity cardiac troponin I (cTnI) assay improve the prognostication of outcomes in patients with AF treated with anticoagulation.
METHODS: Levels of cTnI were measured in samples obtained at study entry and after 2 months with the Abbott ARCHITECT high sensitivity assay in 4 648 patients in the ARISTOTLE trial. Repeated measures ANOVA were used to assess intraclass correlation. Patients were grouped according to ±20% change at follow-up relative to baseline levels. The associations between cTnI levels and outcomes were evaluated with Cox and C index adjusted for baseline levels.
RESULTS: Median cTnI level at entry was 5.1 ng/L. Intraclass correlation was 0.87 and within subject variance 19%. The proportions with decreasing and increasing cTnI levels were 21.6% and 29.2%, respectively. During follow-up, median 1.9 years, the group with increasing levels at 2 months indicated an elevated risk for cardiovascular events with hazard ratio (HR) (95% CI) up to 1.93 (1.04-3.59) for stroke/systemic embolism, and HR 2.53 (1.49-4.31) for cardiovascular death as compared with patients with decreasing cTnI levels at follow-up. Based on continuous levels repeated measurements significantly improved C index for cardiovascular mortality (0.738 to 0.754, p<0.0005) but not for stroke/systemic embolism on top of established risk factors.
CONCLUSIONS: In patients with AF, increasing troponin levels are associated with a raised risk of adverse cardiovascular outcomes. The variability of troponin levels during 2 months is limited. Thus, repeat measurement may contribute to refining cardiovascular risk assessment at an individual level.
Author Disclosures: The Disclosure Block has exceeded its maximum limit. Please call Tech support at (217) 398-1792 for more information.
- © 2014 by American Heart Association, Inc.