Meta-analysis of randomized controlled trials on magnesium in addition to beta-blocker for prevention of postoperative atrial arrhythmias after coronary artery bypass grafting.
BACKGROUND
Atrial arrhythmia (AA) is the most common complication after coronary artery bypass grafting (CABG). Only beta-blockers and amiodarone have been convincingly shown to decrease its incidence. The effectiveness of magnesium on this complication is still controversial. This meta-analysis was performed to evaluate the effect of magnesium as a sole or adjuvant agent in addition to beta-blocker on suppressing postoperative AA after CABG.


METHODS
We searched the PubMed, Medline, ISI Web of Knowledge, Cochrane library databases and online clinical trial database up to May 2012. We used random effects model when there was significant heterogeneity between trials and fixed effects model when heterogeneity was negligible.


RESULTS
Five randomized controlled trials were identified, enrolling a total of 1251 patients. The combination of magnesium and beta-blocker did not significantly decrease the incidence of postoperative AA after CABG versus beta-blocker alone (odds ratio (OR) 1.12, 95% confidence interval (CI) 0.86-1.47, P = 0.40). Magnesium in addition to beta-blocker did not significantly affect LOS (weighted mean difference -0.14 days of stay, 95% CI -0.58 to 0.29, P = 0.24) or the overall mortality (OR 0.59, 95% CI 0.08-4.56, P = 0.62). However the risk of postoperative adverse events was higher in the combination of magnesium and beta-blocker group than beta-blocker alone (OR 2.80, 95% CI 1.66-4.71, P = 0.0001).


CONCLUSIONS
This meta-analysis offers the more definitive evidence against the prophylactic administration of intravenous magnesium for prevention of AA after CABG when beta-blockers are routinely administered, and shows an association with more adverse events in those people who received magnesium.
Department of Cardiovascular Medicine, the Second Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, Shaanxi, PR China.
Xiaosan
X
Wu
Congxia
C
Wang
Jinyun
J
Zhu
Chunyan
C
Zhang
Yan
Y
Zhang
Yanhua
Y
Gao
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D015636:Magnesium Chloride / Q000009:adverse effects / Q000627:therapeutic use*; D008278:Magnesium Sulfate / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013617:Tachycardia, Supraventricular / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D015636:Magnesium Chloride; D008278:Magnesium Sulfate