Myocardial infarction: magnesium therapy has no effect on mortality.

Clinical bottom line (level 1a-)

  1. Patients who have had an acute myocardial infarction and are given magnesium therapy, have no difference in mortality than those given a control.
  2. There is no difference in arrhythmia rates either..
Visser et al: Netherlands Journal of Medicine 1995; 46: 156-165
Expires March 2003

The study

Systematic review of clinical trials of
  • Patients: acute myocardial infarction
  • Intervention: intravenous magnesium therapy (sulphate or chloride) compared with placebo
  • Outcome: mortality and arrhythmias



Articles found in ? langauge using ? databases, ? dates (search terms: none given )

Selection criteria: randomised trials
Appraisal criteria: "all trials in the last 13 years" were included
Articles excluded if: none detailed

Ten trials (nine double blind and one single blind) were included.

  • All patients were admitted within 12 hours after onset of chest pain.
  • The mean age varied between 50 and 68 years.

The evidence

Outcome Time to outcome CEREERRRR
(95% CI)		ARR
(95% CI)		NNT
(95% CI)
mortality unknown 2069
(7.13%)		 2112
(7.28%)		 -2%
(-8% to 4%)		 -0.15%
(-0.57% to 0.27%)		 -666
(NNT = 370 to infinity;
NNH = 175 to infinity)
arrhythmias unknown 576
(1.98%)		 525
(1.80%)		 9%
(-3% to 19%)		 0.17%
(-0.05% to 0.40%)		 573
(NNT = 253 to infinity;
NNH = 2140 to infinity)

  • Follow-up was anywhere between 24 hours and 28 days.

Comments

  1. Methods of the review are not given. Results are thus very much weakened (hence the '-' level).
  2. The authors noted that in two of the studies, differences existed in baseline characteristics between the groups which might have influenced the outcome.

Citation

  1. Visser PJ, Bredero AC, Hoekstra JBL: Magnesium therapy in acute myocardial infarction. Netherlands Journal of Medicine 1995; 46: 156-165
Contributor: Clare Wotton and Chris Ball, February 2000
Reviewer:

Clinical Question.
Patient myocardial infarction
Intervention or Exposure magnesium therapy
Comparison control
Outcome mortality and arrhythmias