Cardiac involvement in patients with acute neurologic disease: Confirmation with cardiac troponin I

Background: Patients with acute neurologic illness often manifest findings suggestive of cardiac injury. Their proper interpretation is unclear. Accordingly, we conducted a blinded evaluation to assess the incidence of cardiac injury determined by elevations of cardiac troponin I (cTnI) in patients presenting within 24 hours of a neurologic event and to determine their short- and long-term prognostic effect. Methods: Blood samples for measurement of cTnI levels were obtained on hospital admission and daily for 3 days and were run by immunoassay. Extensive clinical evaluations including electrocardiograms and echocardiograms were obtained from all patients; daily follow-up evaluations were performed. The clinical electrocardiographic, echocardiographic, and biochemical data were analyzed independently by blinded observers. Results: Peak levels of cTnI were elevated (≥0.4 μg/L) in 17 patients (19%) (mean ± SD, 2.5 ± 2.7 μg/L). All patients with elevated cTnI levels had clinical, electrocardiographic, or echocardiographic evidence of cardiac injury except those (n=5) with minor elevations. One-year mortality was 29% (23/80). Early death (≤30 days) accounted for 44% of total mortality (n= 10) and was significantly higher in patients with elevated cTnI levels (Wilcoxon P=.01; odds ratio, 6.4). This difference was less marked by 1 year (Wilcoxon P=.07). Conclusions: There is a substantial prevalence of myocardial injury in patients with acute neurologic illness. Cardiac injury in this population, as in others, seems to adversely affect prognosis.