Copeptin for Risk Stratification in Acute Stroke Patients: the CoRisk Study (CoRisk)

Background

The investigators in the Prolyse in Acute Cerebral Thromboembolism (PROACT) II study found that intra-arterial thrombolysis (IAT) with prourokinase within 6 hours after onset of symptoms was beneficial in patients with middle cerebral artery (MCA) occlusion. Intra-arterial thrombolysis (IAT) thus is an option for treatment of selected patients who have major stroke of <6 hours' duration due to occlusions of the MCA. Recently observational study showed that IAT was more beneficial than intra-venous thrombolysis (IVT) in the specific group of stroke patients presenting with hyperdense middle cerebral artery sign on CT, even though IAT was started later.

However complications after both reperfusion treatment modalities such as symptomatic intracerebral hemorrhage, malignant brain oedema, re-occlusion, infection, and seizures may occur. Unfortunately few clinical signs provide prognostic information for clear risk stratification. The guidelines for reperfusion therapies in Switzerland, Europe and the US do not include -for the time being- biomarkers in the decision-making-process. However there might be powerful biomarkers, which can serve as point of care tools for the risk stratification of candidates to receive thrombolysis. Plasma copeptin concentration has recently been shown to be an easy to determine, steady parameter which independently predicts functional outcome and death in patients with an acute ischemic stroke. Copeptin derives from a larger precursor peptide (pre-provasopressin) along with two other peptides, Vasopressin (AVP) and neurophysin II. Released in an equimolar ratio, the amount of copeptin mirrors the production of AVP. AVP plays an important role in the regulation of the hypothalamo-pituitary-adrenal (HPA) axis and, thus, reflecting the individual stress response. "Stressors" such as stroke are strong stimulators of the release of AVP. The close and reproducible relation of copeptin levels to the degree of activation of the stress axis is the basis of its usefulness as a biomarker. Early prognostic factors to predict mortality and outcome in stroke patients are important to guide and tailor early decision on treatment. In this context, copeptin may be helpful tool in the early risk stratification of stroke patients to guide the decision for reperfusion therapies.

Objective

To evaluate copeptin as prognostic tool to predict outcome in a well-defined cohort of stroke patients.

Methods

Step 1. All eligible patients in the emergency department or the neurological ward will be evaluated for enrollment into the study. On admission, 2 x 7.5ml- EDTA-blood tubes will be drawn during the first routine blood sampling, and 2 x 7.5ml-EDTA-blood tubes on the following routine blood-sampling. Copeptin levels will be assessed in a blinded batch analysis upon completion of the plasma asservation. Measurement will be performed with a new chemiluminescence sandwich immunoassay.

Step 2. All baseline data will be collected. CT or MRI will be performed 22 to 36 hours after IAT. All complications including death after the reperfusion therapies will be assessed until discharge.

Step 3. A telephone follow-up regarding morbidity and mortality will be obtained after 3 months. An unfavorable outcome will be defined as a mRs of 3 to 6