Despite the impressive, but marginally significant, reduction in mortality with intravenous magnesium which was seen in the LIMIT and earlier small trials, the 60 000-patient ISIS-4 trial showed a non-significant trend to harm. There is still controversy over these discrepant results, with some alleging that the magnesium in ISIS-4 should have been started earlier and before thrombolysis in those patients (approximately 90 per cent) who received non-trial thrombolytics. A new United States trial (MAGIC) will attempt to resolve this. Meanwhile, magnesium cannot at present be recommended as routine therapy for myocardial infarction. There were fewer arrhythmias in ISIS-4 in those patients allocated magnesium, but this expected benefit was offset by more shock and heart failure.
Was this article helpful?