HYPERVOLEMIC HEMODILUTION IN ACUTE ISCHEMIC STROKE - THE MULTICENTER AUSTRIAN HEMODILUTION STROKE TRIAL (MAHST)

Background and Purpose-Experimental studies suggest a beneficial effec t of hemodilution on acute ischemic stroke. This was not proven by pre vious multicenter trials in the clinical setting. Various reasons have been suggested for the failure of these studies, which we attempted t o consider in the Multicenter Austrian Hemodilution Stroke Trial (MAHS T). Methods-MAHST is a randomized, double-blind, placebo-controlled st udy of hypervolemic hemodilution (HHD) within 6 hours of a clinically first ischemic stroke localized in the middle cerebral artery territor y, The treatment consisted of 10% hydroxyethyl starch 200/0.5 (HES) an d was tested against pure rehydration with Ringer's lactate over a per iod of 5 days, Our primary outcome measure was clinical improvement wi thin 7 days as measured by the Graded Neurologic Scale (GNS). We perfo rmed an adaptive interim analysis to reevaluate the study goal after e ntering half of the projected number of patients (n=200). At least 600 patients per group would have been required for significant results, and therefore we decided to terminate the trial. Results-Ninety-eight patients received HHD and 102 patients placebo. The baseline character istics were comparable between both groups. In the HHD group the absol ute reduction of the hematocrit was 2.5% on day 2 with a maximum of 3. 7% on day 5, which compares with a reduction in the placebo group of 1 % and 1.9%, respectively, Intention-to-treat analysis showed no signif icant difference of the change of the GNS scores between HHD-treated ( median, -8.5; 95% confidence interval, -14.2 to -4.0) and placebo-trea ted patients (median, -6.0; 95% confidence interval, -11.0 to 0.0) on day 7, and GNS scores remained similar in both treatment groups throug hout the trial. At 3 months, slightly more HHD patients showed complet e independence on the Barthel Index (28 versus 24), and fewer HHD than placebo patients had died (13 versus 17), but these differences were not statistically significant. HHD treatment was not associated with a ny specific adverse event. Conclusions-Mild HHD is safe but failed to demonstrate a significant beneficial effect over the pure rehydration regimen in patients with acute ischemic stroke.