The Effect of Magnesium on Reperfusion Arrhythmias in STEMI Patients, Treated With PPCI. A Systematic Review With a Meta-Analysis and Trial Sequential Analysis

Abstract

Aims: The restoration of coronary circulation plays a crucial role in treating ST-segment elevation myocardial infarction (STEMI), however successful reperfusion with primary percutaneous coronary intervention (PPCI) may induce life-threatening arrhythmias. The relation between myocardial electrical instability, as a background factor in reperfusion arrhythmia, and magnesium administered periprocedurally is still questionable. Several randomized clinical trials have been conducted predominantly in the thrombolysis era. Due to the contradictory results of these studies, there is little evidence of the potential preventive effect of magnesium on reperfusion arrhythmias. The aim of our study is to review and meta-analytically analyze data from all studies published so far in the PPCI era, comparing STEMI patients who have undergone primary PCI and received either magnesium or a placebo before the reperfusion procedure. Methods and Results: Our meta-analysis follows the points in the PRISMA protocol and, meets all of their criteria. We conducted a search in five scientific databases using the following keyword combination: (myocardial infarction OR myocardial injury OR acute coronary syndrome OR acs OR stemi) AND magnesium. The 7,295 collected publications were filtered with the Endnote program by title, abstract and full-text based on predefined criteria. A statistical analysis was performed on three randomized-controlled trials using three common parameters, involving 336 patients Trial sequential analysis (TSA) was applied to assess the risk of random error associated with sparse data and multiple testing which can affect cumulative meta-analysis. The incidence of ventricular tachycardias (VTs) was not significantly increased in the non-magnesium control group. (OR: 1.36; CI: 0.619; -2.986, P = 0.263). For the ejection fraction (EF), a non-significant decrease was observed in the magnesium group by weighted mean difference calculation. (WMD: 7.262, 95% CI: -0.238; 0.053; P = 0.057). There was significant decrease in the infarct zone wall motion index (IZWMSI) in the magnesium treatment group. (WMD: 0.384, 95% CI: -0.042; 0.811, P = 0.015). Based on the TSA assessments, the results of all parameters are not significant, objectively demonstrating the lack of reasonable data pertaining to our question. Conclusions: The preventive effect of magnesium on reperfusion arrhythmia associated with primary PCI can still be considered contradictory based on previous studies. In our study, we found, that magnesium is ineffective with a very weak evidence, due to the small number of patients and the biases of the included studies, and a well-designed clinical trial is needed in this area, based on the TSA.

Keywords: PCI; STEMI; magnesium; percutaneous coronary intervention; reperfusion arrhythmia.

Figure 1

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) study selection flow diagram.

Figure 2

(A) Forest plot with the odds ratio method, of the 3 studies concerning the number of reperfusion associated ventricular tachycardias (VT) showing a non-significant increase in the magnesium group. (B) Trial sequential analysis shows that the number of VTs is non-significantly lower in the placebo group. More importantly, the Z curve does not intersect either the conventional boundary or the futility area, therefore, the result is not significant and may be strongly influenced by additional data in the future.

Figure 3

(A) Forest plot with weighted mean difference method, of the 3 studies concerning the ejection fraction (EF) during hospitalization, showing a non-significant decrease in the magnesium group. (B) Trial sequential analysis shows that EF is non-significantly decreased in the magnesium group. More importantly, the Z curve does not intersect either the conventional boundary or the futility area, therefore, the result is not significant and may be strongly influenced by additional data in the future.

Figure 4

(A) Forest plot with weighted mean difference method, of the 3 studies concerning the infact zone wall motion severity index (IZWMSI) during the hospitalization, showing a significant decrease in the magnesium group. (B) Trial sequential analysis shows that IZWMSI, in contrast to the weighted mean difference method, is non-significantly decreased in the magnesium group. More importantly, the Z curve does not intersect either the conventional boundary or the futility area, therefore, the result is not significant and may be strongly influenced by additional data in the future.