The prognostic significance of troponin I elevation in acute ischemic stroke

Background The significance of cardiac troponin I (TnI) levels in patients with acute ischemic stroke remains unclear. Methods Data were prospectively collected on 1718 patients with acute ischemic stroke (2009-2010). Patients with positive TnI (peak TnI ≥ 0.1 μg/L) were assigned to the myocardial infarction (MI) group if they met diagnostic criteria. The remaining patients with positive TnI were assigned to the no-MI group. Patients were followed up for 1.4 ± 1.1 years. Primary outcome was inhospital and long-term all-cause mortality. Results Positive TnI was present in 309 patients (18%), 119 of whom (39%) were classified as having MI. Positive TnI was independently associated with older age, hypertension, smoking, peripheral arterial disease, heart failure, higher systolic blood pressure, higher serum creatinine, and lower heart rate (P <.01). Patients with MI had the highest inpatient mortality (P <.001) and the lowest survival rate by Kaplan-Meier analysis (P <.0001). Peak TnI greater than or equal to 0.5 μg/L, particularly if satisfying criteria for MI, was independently associated with long-term mortality (P <.0001); peak TnI less than 0.5 μg/L alone was not when adjusted for covariates. Conclusion Positive TnI greater than or equal to 0.5 μg/L in patients with acute ischemic stroke was independently associated with worse outcomes. Patients with diagnosis of MI represent a particularly high-risk subgroup.