Cardiac troponin-I as a predictor of mortality in patients with first episode acute atrial fibrillation

Background: Recent-onset atrial fibrillation (AF) is a frequent cause for presentation to the emergency department. Recent studies proposed that the addition of biomarker information might improve the prediction of clinical outcomes by enabling identification of patients at high risk. Aim: We aimed to examine the role of cardiac troponin I as a predictor of clinical outcome in patients with first episode acute AF. Design: Patients, 18 years or older, presenting to our hospital with a primary diagnosis of first episode acute AF were included in this retrospective study. Methods: The association between elevated cTnI with mortality or the composite endpoint (mortality, stroke or heart failure) was examined in a univariate Cox regression model. Results: Of the 274 study patients, 111 had elevated cTnI levels (41%). Increased cTnI was associated with older age, history of myocardial infarction, higher creatinine levels and higher heart rate (All P < 0.01). Elevated cTnI was associated with an adjusted hazard ratio of 1.86 [95% confidence interval (CI) 1.17-2.96; P = 0.009] for mortality and 1.89 (95% CI 1.27-2.84; P = 0.002) for the combined endpoint. Conclusions: Elevated cardiac Troponin I is a significant predictor of mortality and a composite endpoint of mortality, stroke or heart failure in patients presenting with first episode acute AF.