Plasma endothelin-1 levels neither increase nor correlate with neurological scores, stroke risk factors, or outcome in patients with ischemic stroke

Background and Purpose-Endothelins (ETs) are potent vasoconstrictors and ma y play a role in the pathophysiology of several diseases. Limited and contr oversial data exist on their role in human ischemic stroke. We planned a pr ospective, observational, and longitudinal clinical study to test whether E T-I levels increase in various phases of ischemic stroke and whether the ET -1 levels correlate with neurological scores, stroke etiology, stroke risk factors, or final outcome. Methods-We measured plasma ET-1 levels with a sandwich-enzyme immunoassay m ethod in 101 consecutive patients with ischemic stroke on admission and 1 w eek, 1 month, and 3 months after stroke and in 101 sex- and age-matched con trol subjects. At each sampling, the patients underwent a complete neurolog ical evaluation. All stroke risk factors were recorded, an array of laborat ory tests were performed, and the subtype of ischemic stroke was determined . The patients were contacted 3 years later for prognostic determination. Results-ET-1 levels in patients (2.4+/-1.3 pg/mL on admission, 2.2+/-1.4 pg /mL at 1 week, 2.1+/-1.4 pg/mL at 1 month, and 2.1+/-1.2 pg/mL at 3 months) were not different from those of the control subjects (2.2+/-0.9 pg/mL) at any time point. No correlation was found between the ET-1 levels and strok e etiology, stroke risk factors, stroke recurrence risk, age, sex, or neuro logical scores, except that ET-I levels correlated with the use of warfarin and with body mass index. Conclusions-Plasma ET-1 levels were normal in patients with ischemic stroke . Our findings cannot exclude a role of ETs in the pathophysiology of ische mic stroke because plasma levels might not accurately reflect intracerebral concentrations, but they also do not support the occurrence of a major pla sma ET-I level increase at any phase of stroke, Our patient population is t he largest ever reported in whom ET-1 levels were measured, but it consiste d of mild and moderately ill patients with stroke due to the study design, of which the aim was long-term observation, which excludes severely ill pat ients.