One‐year death rate in 270 patients with suspected acute myocardial infarction, initially treated with intravenous magnesium or placebo

Abstract

Summary:In a double-blind, placebo-controlled study, 273 patients with suspected acute myocardial infarction (AMI) were randomized to receive either 48-h magnesium (Mg) or placebo therapy intravenously, initiated immediately on admission to hospital. We describe the results from a 1-year survey in 270 of the patients, who were available for follow-up. Patients were equally divided: 135 received Mg and 135 received placebo. Mg treatment was associated with a marked reduction in 1-year death rate from 32% in the placebo group to 20% in the Mg group (p=O.O18). If only death from ischemic heart disease is considered, the figures were 28% in the placebo group as opposed to 15% in the Mg group (p=0.006). This reduction was mainly due to a reduction in mortality during the initial 30 days after inclusion in the study (17% vs. 7%), after which the difference in mortality between the two groups did not reach statistical significance (1 8 % vs. 15%, p=0.56). The beneficial effect of Mg on mortality was partly linked to a reduced incidence of arrhythmias (27% vs. 16%), and partly to a reduced incidence of infarction (63% vs. 48%) during the initial hospitalization. However, factors unknown to us were also involved, as revealed by a remaining statistically significant partial regression coefficient, when sex, age, cardiovascular history, development of AMI, and development of arrhythmias were considered. It is concluded that intravenous Mg treatment is beneficial to patients with acute ischemic heart disease and should be adopted as part of the routine treatment of these patients.

Long-Term Outcome of Intravenous Magnesium Therapy in Thrombolysis-Ineligible Acute Myocardial Infarction Patients

“…Our results are concordant with Rasmussen et al [29]who reported on a one-year death rate in 270 patients with suspected AMI, initially treated with intravenous magnesium or placebo. All-cause mortality was 20% in patients who received magnesium, compared with 32% in patients who received placebo (p = 0.018), and mortality from ischemic heart disease was 15% compared with 28% (p = 0.006), respectively.…”

“…Our study not only confirms the findings of Rasmussen et al [29]who state that the beneficial effect of magnesium on mortality in a high-risk population (patients ineligible for thrombolysis and the elderly) is mainly during the first month after AMI, but continues to demonstrate an extended beneficial effect up to 4.8 years after AMI, concomitantly with a higher LVEF. However, it should be noted that the added beneficial effects of intravenous magnesium therapy observed in the current study could also be due to statistical bias or chance.…”

Possible pharmacological actions of magnesium in acute myocardial infarction.

“…Five of them (Abraham et al, 1987;Ceremuzynski et al, 1989;Rasmussen et al, 1986Rasmussen et al, , 1987Rasmussen et al, , 1988aSchechter et al, 1990;Smith et al, 1986) reported a reduction in mortality, in frequency of arrhythmias or both in those patients who received magnesium. Two (Feldstedt et al, 1988;Morton et al, 1984) were negative; the first of these included only 76 patients.…”

“…Two (Feldstedt et al, 1988;Morton et al, 1984) were negative; the first of these included only 76 patients. Rasmussen et al (1986Rasmussen et al ( , 1988a randomised 273 patients with suspected acute myocardial infarction to receive 62 mmol magnesium chloride or saline over 48 h. Significantly fewer patients had infarction confirmed in the magnesium group and mortality at 1 year was 32% in the placebo group and 20% in the magnesium group (P < 0.02). Although none of the trials had sufficient statistical power to be conclusive, collectively they strongly suggest a beneficial effect of intravenous magnesium and this interpretation is supported by a formal metaanalysis of all the available data (Teo et al, 1990).…”

Acute and Chronic Oral Magnesium Supplementation: Effects on Endothelial Function, Exercise Capacity, and Quality of Life in Patients With Symptomatic Heart Failure

“…Multiple studies show the advantage of Mg 2+ therapy in coronary artery disease. For coronary artery disease, at least ten prospective, randomized, double‐blind, controlled trials report supportive results comparing Mg 2+ supplementation with placebo 28–34 . These studies have demonstrated a decrease in myocardial damage and reduced mortality rate in subsets of high‐risk patients when Mg 2+ therapy was administered before reperfusion occurred.…”