Dorhout Mees SM, Algra A, Wong GKC, Poon WS, Bradford CM, Saver JL, et al. Early Magnesium Treatment After Aneurysmal Subarachnoid Hemorrhage: Individual Patient Data Meta-Analysis. Stroke. 2015
Five trials comprising 1981 patients were included, and the patients were binned according to how long after symptom onset they received magnesium (<6 hours, 6-12 hours, 12-24 hours, >24 hours). FAST-MAG included 5 patients with SAH (as the criteria were clinical stroke symptoms), so these 5 patients were incorporated into this meta-analysis. The primary endpoint was poor clinical outcome (mrs 4-5) or death at 3-6 months, with a secondary endpoint of delayed cerebral ischemia (which was determined differently by each trial).
Unfortunately, no benefit was seen with early magnesium treatment after SAH with respect to either functional outcome or delayed cerebral ischemia. A possible criticism is that only 83 patients (of a total 1981) were in the <6 hour group. However, if there were a strong effect in this early group, we would expect to at least detect a trend in improved outcome, which there was not. So long, magnesium; on to the next!