Low magnesium is not a significant predictor of hard events in acute myocardial infarction

Although magnesium (Mg) has recognized cardioprotective properties and hypomagnesemia is common in patients with acute myocardial infarction (AMI), data regarding the role of Mg as prognostic factor for adverse events are scarce, as well as there are conflicting results on the use of Mg as adjuvant therapy in AMI.

To evaluate the role of Mg as predictor for hard events (HE, all cause death, and nonfatal myocardial infarction) in AMI patients.

We studied 406 AMI patients (306 males, age: 67 ± 12 years, mean ± SD). Patient data were collected from the Institute electronic databank which saves demographic, clinical, instrumental, therapeutical and follow-up data of all patients admitted to our Coronary Unit.

During a mean follow-up period of 21 ± 18 months, the combined endpoint accounted for 63 HE, 44 (11%) deaths (35 cardiac deaths), 19 (5%) nonfatal MI. The multiple regression model identified glycemia as the only independent determinant of Mg in AMI pts. (T value = - 2.8, standard coefficient = - 0.15, p < 0.01). The Kaplan-Meier survival estimates failed to show a significantly worst outcome in patients presenting low Mg (< 0.783 mmol/L, 25th percentile). Aging (> 67 years-50th percentile), and ejection fraction (< 40%) remained as prognostic factors for HE in the adjusted Cox multivariate proportional hazard model (HR = 2.8, 95% CI = 1.6-5, p < 0.001; HR = 3.2, 95% CI = 1.9-5.3 p < 0.001, respectively).

The present findings do not support a significant role of low Mg as predictor for HE in AMI.