Magnesium Helps Prevent Arrhythmia After Cardiac Surgery
Magnesium administration helps prevent postoperative atrial fibrillation in patients undergoing cardiac surgery, researchers reported here on March 9th at the American College of Cardiology 53rd Annual Scientific Session.
Eugene Crystal, MD, Schulich Heart Center, University of Toronto, Toronto, Ontario, McMaster University, Hamilton, Ontario, Canada, and colleagues, who conducted the study, also found that the magnitude of the effect is comparable to that of proposed anti-arrhythmic drugs.
To evaluate the effect of magnesium for preventing post-operative atrial fibrillation and to evaluate the influence of magnesium administration on length of postoperative hospital stay, mortality, and stroke, Dr. Crystal and colleagues systematically reviewed the evidence from 18 randomized, controlled trials including 2,040 patients.
Results revealed that the rate of postoperative atrial fibrillation was 28% in the control group and 17% in the magnesium group (odds ratio 0.51; 95% confidence interval ÄCIÅ, 0.34 to 0.76).
Data on length of hospital stay drawn from 827 patients enrolled in 6 trials showed that magnesium did not have a significant impact (weighted mean difference -0.07 days of stay, 95% CI -0.78, 0.63). Overall mortality was 0.7% and was not affected by magnesium administration (odds ratio 0.90, 95% CI 0.24, 3.32).
The extent of magnesium’s effect on postoperative atrial fibrillation was similar to that of beta-blockers or amiodarone, Dr. Crystal said.
He cautioned, however, that this study is limited by a lack of relevant data, particularly on length of hospital stay, rates of stroke, and mortality. Also, some studies excluded groups of patients with high-risk but commonly encountered cardiac diseases. Finally, a meta-analysis itself is associated with a publication bias where studies with a positive result are more likely to be published than negative studies, he said.
He emphasized that questions remain about the optimal regimen of administration and its efficacy in combination with other drugs.
