Abstract 14566: Combining High Sensitivity Troponin I and T Measurements Improves Prediction of Long-Term Clinical Outcomes in Patients With Atrial Fibrillation - An Aristotle Substudy
Background: Cardiac troponin levels predict clinical outcomes in patients with atrial fibrillation (AF). However, it is not known whether cardiac troponin I (cTnI) and cardiac troponin T (cTnT) provide complementary prognostic information. In this study we investigated if the combined use of cTnI and cTnT improves the prognostication in AF patients.
Methods: At randomization plasma cTnI and cTnT were analyzed in 14,806 AF patients in the ARISTOTLE trial using high sensitivity assays. Patients were grouped according to median levels of troponin: group 1 with both troponins lower than median, group 2 with low cTnI and high cTnT, group 3 high cTnI and low cTnT, and group 4 with both troponins above median. The associations between troponin concentrations and stroke or systemic embolism, cardiac death, and myocardial infarction were evaluated using Cox models.
Results: Both troponins were measurable in almost all subjects, 98.5% with cTnI (median 5.4 ng/L) and 99.4% with cTnT (median 10.9 ng/L). The correlation between the cTnI and cTnT was, however, moderate (Spearman 0.70). During median 1.9 years follow-up, patients with high values of both troponins had a significantly higher risk for all outcomes as compared to those with low levels of both cTnI and cTnT (Table). Importantly, patients having low levels according to only one troponin subtype but not the other presented a significantly higher risk with a hazard ratio (95% confidence intervals) up to 1.49 (1.04-2.12) for stroke/systemic embolism, HR 2.82 (1.97-4.05) for cardiac death, and HR 3.04 (1.65-5.62) for myocardial infarction.
Conclusions: Cardiac troponin I and T are detectable in almost all AF patients, although their correlation is moderate. The risk of stroke, cardiac death, and myocardial infarction is highest in patients with elevated levels of both troponins. Our findings show that different cardiac troponins provide complementary and additive information and may lead to improved risk stratification in AF.
- © 2013 by American Heart Association, Inc.