Prognostic Significance of Troponin Elevation for Long-Term Mortality after Ischemic Stroke

Background and Purpose Troponin, a marker of myocardial injury, frequently increases and is related with poor outcome in ischemic stroke patients. However, the long-term outcome of this elevation remains uncertain. We, therefore, investigated the prognostic significance of troponin elevation for long-term mortality, and explored factors affecting troponin elevation after ischemic stroke. Methods We retrospectively analyzed the medical data of stroke patients who were admitted within 24 hours of symptom onset and underwent a serum cardiac troponin I test at admission during a five-year period. Information on mortality as the outcome was obtained from the National Death Certificate system. Results A total of 1,692 patients were eligible for inclusion with 33 months of median follow-up. Troponin elevation that exceeded the 99th percentile (> 0.04 ng/mL) of values was detected in 166 patients (9.8%). After adjusting for baseline characteristics, troponin elevation was associated with previous ischemic heart disease and congestive heart failure, comorbid atrial fibrillation and active cancer, and increased National Institutes of Health Stroke Scale score. Patients with troponin elevation had a high risk of overall death (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.40-2.40), including stroke-related (HR 1.71, 95% CI 1.14-2.55), cardiac-related (HR 3.17, 95% CI 1.49-6.74), and cancer-related (HR 1.98, 95% CI 1.14-3.45) death than those without troponin elevation. Conclusions Troponin elevation in the acute stage of ischemic stroke was associated with long-term mortality, mainly due to increased stroke-and cancer-related death in the first year and cardiac-related death in the later period.