Copeptin is a strong and independent predictor of outcome in cardiogenic shock

Introduction

As a stress hormone, arginine vasopressin (AVP) is significantly increased in acute hemodynamic instability. AVP is released in response to osmotic and haemodynamic changes aiming to maintain fluid volume and vascular tone. Copeptin is a stable fragment of pre-pro-vasopressin that is synthesised and released in equimolar quantities as AVP. Unlike AVP, copeptin is highly stable ex vivo. We aimed to test the prognostic potency of an elevation of copeptin in patients with cardiogenic shock.

Methods

In this prospective observational study we included consecutive patients with cardiogenic shock admitted to the ICU of the Department of Cardiology/Medical University of Vienna between November 2004 and March 2006. In all patients, blood samples for determination of routine laboratory tests and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and copeptin plasma levels were obtained on admission. Copeptin was assessed using an immunoassay in the chemiluminescence/coated tube format. Copeptin, NT-pro-BNP, age, gender, presence of acute renal failure and mechanical ventilation were analysed for prediction of ICU survival.

Results

We included 91 consecutive patients (66 male (72%), age 66.5 ± 11.4 years) with diagnosis of cardiogenic shock on ICU admission. All patients required intravenous inotropic support, 19 patients (21%) were treated with an intraaortic balloon counter-pulsation and nine patients (9%) were on extracorporeal circulatory support (eight patients (8%) had an extracorporeal membrane oxygenation, one patient (1%) was on novacor support). Fifty-six patients (62%) survived and 35 patients (38%) died. Copeptin plasma levels were significantly higher in ICU nonsurvivors than in ICU survivors (164.4 ± 117.8 vs. 248.2 ± 256.6 pg/ml, P = 0.034). In a logistic regression model, copeptin was the best predictor of ICU survival, with only NT-pro-BNP providing independent additional information (copeptin OR = 1.002; P = 0.001 and NT-pro-BNP OR = 1.001; P = 0.05).

Conclusion

Elevated plasma levels of copeptin are a strong and independent predictor of adverse outcome in patients with cardiogenic shock.