Copeptin: a novel, independent prognostic marker in patients with ischemic stroke.

OBJECTIVE: Early prediction of outcome in patients with ischemic stroke is important. Vasopressin is a stress hormone. Its production rate is mirrored in circulating levels of copeptin, a fragment of provasopressin. We evaluated the prognostic value of copeptin in acute stroke patients.
METHODS: In a prospective observational study, copeptin was measured using a new sandwich immunoassay on admission in plasma of 362 consecutive patients with an acute ischemic stroke. The prognostic value of copeptin to predict the functional outcome (defined as a modified Rankin Scale score of <or=2 or >or=3), mortality within 90 days, was compared with the National Institutes of Health Stroke Scale score and with other known outcome predictors.
RESULTS: Patients with an unfavorable outcomes and nonsurvivors had significantly increased copeptin levels on admission (p <0.0001 and p <0.0001). Receiver operating characteristics to predict functional outcome and mortality demonstrated areas under the curve of copeptin of 0.73 (95% confidence interval [CI], 0.67-0.78) and 0.82 (95% CI, 0.76-0.89), which was comparable with the National Institutes of Health Stroke Scale score but superior to C-reactive protein and glucose (p <0.01). In multivariate logistic regression analysis, copeptin was an independent predictor of functional outcome and mortality, and improved the prognostic accuracy of the National Institutes of Health Stroke Scale to predict functional outcome (combined areas under the curve, 0.79; 95% CI, 0.74-0.84; p <0.01) and mortality (combined areas under the curve, 0.89; 95% CI, 0.84-0.94; p <0.01).
INTERPRETATION: Copeptin is a novel, independent prognostic marker improving currently used risk stratification of stroke patients. Ann Neurol 2009;66:799-808.