Background: Neuroprotective can be administered soon after symptom onset may preserve brain tissue potentially leading to better outcomes after endovascular treatment. We describe prehospital treatment with magnesium sulfate among endovascular treated cases.
Methods: Subjects enrolled in the NIH Phase 3 Field Administration of Stroke Therapy Magnesium (FAST-MAG) clinical trial of prehospital treatment with magnesium or placebo initiated <2 hours from symptom onset who underwent endovascular treatment. Timing and exposure to treatment prior to procedure and the effects of magnesium compared to placebo are described.
Results: Of 1235 subjects with cerebral ischemia, 76 (6%) underwent endovascular therapy (38 magnesium, 38 placebo), mean age 69 (SD13), 50% women, median NIHSS 17 (IQR 11-23). Median (IQR) time from onset to study drug initiation was 39 (33-46) minutes, to TPA (N=49) 135 (114-175) and to groin puncture was 247 (169-287) minutes. There were no significant differences in baseline demographics or times. Assignment to Mg was not associated with improved NIHSS at 24 hours (12 vs.13.5, p=0.904) or disability at 3-months (mRS 3 vs. 3, p=0.867).
Conclusions: Although treatment with magnesium was neutral, the strategy of prehospital Neuroprotection initiation strategy exposed subjects to 3 hours and 28 minutes of potential brain stabilizing therapy prior to groin puncture. With more recent groin puncture times prehospital Neuroprotection could provide 3 hours of stabilization prior to endovascular therapy initiation.