Elevated Troponin Levels in Acute Stroke Patients Predict Long-term Mortality

Abstract

Background: Elevated plasma levels of troponin in acute stroke patients are common and have in several studies been shown to predict in-hospital and short-term mortality. Little is, however, known about the long-term prognosis of these patients. The aim of this study was to determine patient characteristics and 5-year mortality in patients with acute stroke and troponin elevation on admission.

Methods: A retrospective cohort study of all consecutive patients with acute stroke and a plasma troponin I (TnI) analyzed on admission to Danderyd Hospital between January 1, 2005, and January 1, 2006 (n = 247). Patient characteristics were obtained from the Swedish National Stroke Register, Riksstroke, as well as hospital records. Mortality data were obtained from the Swedish Cause of Death Register.

Results: There were 133 patients (54%) with TnI less than .03 μg/L (normal), 74 patients (30%) with TnI .03-.11 μg/L (low elevation), and 40 patients (16%) with TnI greater than .11 μg/L (high elevation). TnI elevations were associated with a higher age, prior ischemic stroke, chronic heart failure, renal insufficiency, stroke severity, and ST segment elevation or depression on admission. The rate of hyperlipidemia decreased with increasing TnI. Adjusted for age and comorbidity, elevated TnI values on admission had a significantly and sustained increased mortality over the 5-year follow-up, with a hazard ratio of 1.90 (95% confidence interval, 1.33-2.70).

Conclusions: Troponin elevation in patients with acute stroke, even when adjusted for several possible confounders, is associated with an almost 2-fold increased risk of 5-year mortality.

Keywords: Acute stroke; long-term prognosis; myocardial damage; troponin elevation.