The study is published Online First in The Lancet. Sanne Dorhout Mees from the University Medical Center Utrecht, Netherlands, who conducted the study, explained: "The findings from MASH 2 have important implications for clinical practice. Administration of magnesium is standard practice in many centers."
Aneurysmal subarachnoid hemorrhage (SAH; the bursting of a blood vessel on the surface of the brain), is the most lethal form of stroke - killing almost a third of patients within the first month. In addition, 20% of those who survive are left disabled. Delayed cerebral ischemia is an important cause of poor outcome and can occur 4-10 days after SAH.
Although earlier studies suggested that intravenous magnesium sulphate benefits SAH patients, recent studies have reported conflicting results.
In this study, the researchers reveal the results of a randomized trial comparing magnesium with placebo. The trial included adults with SAH from the Netherlands, Scotland and Chile.
606 participants were randomly assigned to receive magnesium treatment and 597 were assigned to receive placebo.
The trials primary outcome measure was poor outcome, or death, three months after hemorrhage. Poor outcome was defined as a score of 4 to 5 on the modified Rankin Scale.
At three months the researchers found no difference in poor outcome between the two groups -158 patients (26.2%) given magnesium versus 151 (25.3%) given placebo.
Results from an additional meta-analysis of 7 randomized trials found that magnesium was no more beneficial than placebo.
The researchers conclude:
"Results from MASH 2 alone, and in combination with the other trial data, show that intravenous magnesium does not affect outcome after aneurysmal subarachnoid hemorrhage. Subgroup analyses did not identify a subgroup of patients who might benefit from magnesium treatment...therefore routine administration of magnesium cannot be recommended."
In a joint comment, Chethan Venkatasubba Rao and Jose Suarez from Baylor College of Medicine, Texas, USA, said:
"The results, although disappointing, are nonetheless very pertinent to the management of patients with aneurysmal subarachnoid hemorrhage. We agree with the researchers, and previous findings, that routine intravenous magnesium sulphate infusion cannot be recommended for patients with aneurysmal subarachnoid hemorrhage."
Written By Grace Rattue