Magnesium for aneurysmal subarachnoid haemorrhage (MASH-2): a randomised placebo-controlled trial.
BACKGROUND
Magnesium sulphate is a neuroprotective agent that might improve outcome after aneurysmal subarachnoid haemorrhage by reducing the occurrence or improving the outcome of delayed cerebral ischaemia. We did a trial to test whether magnesium therapy improves outcome after aneurysmal subarachnoid haemorrhage.


METHODS
We did this phase 3 randomised, placebo-controlled trial in eight centres in Europe and South America. We randomly assigned (with computer-generated random numbers, with permuted blocks of four, stratified by centre) patients aged 18 years or older with an aneurysmal pattern of subarachnoid haemorrhage on brain imaging who were admitted to hospital within 4 days of haemorrhage, to receive intravenous magnesium sulphate, 64 mmol/day, or placebo. We excluded patients with renal failure or bodyweight lower than 50 kg. Patients, treating physicians, and investigators assessing outcomes and analysing data were masked to the allocation. The primary outcome was poor outcome-defined as a score of 4-5 on the modified Rankin Scale-3 months after subarachnoid haemorrhage, or death. We analysed results by intention to treat. We also updated a previous meta-analysis of trials of magnesium treatment for aneurysmal subarachnoid haemorrhage. This study is registered with controlled-trials.com (ISRCTN 68742385) and the EU Clinical Trials Register (EudraCT 2006-003523-36).


RESULTS
1204 patients were enrolled, one of whom had his treatment allocation lost. 606 patients were assigned to the magnesium group (two lost to follow-up), 597 to the placebo (one lost to follow-up). 158 patients (26·2%) had poor outcome in the magnesium group compared with 151 (25·3%) in the placebo group (risk ratio [RR] 1·03, 95% CI 0·85-1·25). Our updated meta-analysis of seven randomised trials involving 2047 patients shows that magnesium is not superior to placebo for reduction of poor outcome after aneurysmal subarachnoid haemorrhage (RR 0·96, 95% CI 0·86-1·08).


CONCLUSIONS
Intravenous magnesium sulphate does not improve clinical outcome after aneurysmal subarachnoid haemorrhage, therefore routine administration of magnesium cannot be recommended.


BACKGROUND
Netherlands Heart Foundation, UK Medical Research Council.
Utrecht Stroke Center, Department of Neurology and Neurosurgery, Rudolf Magnus Institute of Neurosciences, University Medical Center Utrecht, Utrecht, The Netherlands. s.m.dorhoutmees@umcutrecht.nl
Sanne M
SM
Dorhout Mees
Ale
A
Algra
W Peter
WP
Vandertop
Fop
F
van Kooten
Hans A J M
HA
Kuijsten
Jelis
J
Boiten
Robert J
RJ
van Oostenbrugge
Rustam
R
Al-Shahi Salman
Pablo M
PM
Lavados
Gabriel J E
GJ
Rinkel
Walter M
WM
van den Bergh
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008278:Magnesium Sulfate / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000008:administration & dosage*; D010865:Pilot Projects; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy*; D016896:Treatment Outcome; D055815:Young Adult
D018696:Neuroprotective Agents; D008278:Magnesium Sulfate