Prognostic value of copeptin in patients with acute ischemic stroke

Stroke is the second leading cause of mortality in the Chinaand one of the leading causes of severe morbidity. An earlyrisk assessment with estimate of the severity of disease andprognosis is pivotal for optimized care and allocation ofhealthcare resources. Reliable prognostic markers availableduring the initial phase after acute stroke may aid clinicaldecision-making.Vasopressin (AVP) is a potent synergistic factor ofcorticotropin-releasing hormone as hypothalamic stimulator ofthe hypothalamo-pituitary-adrenal axis.1 Some studies foundincreased AVP levels in patients with ischemic stroke werecorrelated with stroke severity2 and outcome.3 Copeptin isreleased in an equimolar ratio to AVP, and is more stable inthe circulation and easy to measure.4We designed a preliminary prospective cohort study toevaluate the prognostic value of copeptin in acute strokepatients. Adult patients with a persistent neurological deficitdue to ischemic stroke were eligible. Sixty-ninenonconsecutive patients admitted at 3 hospitals with adiagnosis of acute ischemic stroke confirmed by CT scanningwere evaluated. All patients provided informed consent. Inpatients who died within 24 hours after admission or inpatients who were discharged, data from admission or untildischarge were collected. The National Institute of HealthStroke Scale (NIHSS) score was assessed on admission.Functional outcome was obtained on days 90 according to themodified Rankin Scale (mRS) blinded to copeptin levels. Poorfunctional outcome at 3 months was considered as a mRSscore > 2. Blood samples were collected on admission andimmediately centrifuged and sera stored at –70°C. Copeptinwas measured with a sandwich immunoluminometricassay.1 Discrete variables are summarized as counts(percentage), and continuous variables as medians andinterquartile ranges (IQRs). Two-group comparison of notnormally distributed data was performed using Mann–Whitney U test, and a Kruskal–Wallis one-way analysis ofvariance was used for multi-group comparisons.The median age of the 69 patients was 62 years (IQR,55 to 84), 61% were men and the median NIHSS score onadmission was 7 points (IQR, 3 to 12). In 38 patients(55%) with a poor functional outcome (13 patients died),copeptin levels were higher compared with those inpatients with a favorable outcome (23.5; IQR, 10.6 to 64.3pmol/L vs. 7.5; IQR, 3.8 to 13.6 pmol/L; P < 0.0001).Multivariate logistic regression analysis adjusted for ageand NIHSS score showed that copeptin was anindependent predictor of poor functional outcome (oddsratio = 3.12; 95%CI, 1.54–6.46). The area under the