Study
Magnesium Sulfate to Prevent Perioperative Atrial Fibrillation in Cardiac Surgery: A Randomized Clinical Trial.
In 265 cardiac-surgery patients, intravenous magnesium did not prevent postoperative atrial fibrillation and the trial stopped for futility.
Summary Can magnesium infusion prevent irregular heartbeats after heart surgery? Show / hide ↓
Researchers gave intravenous magnesium, delivered through a vein, or a dummy treatment to 265 adults having heart surgery. Patients were assigned by chance, and neither they nor the researchers knew who received which treatment. The magnesium raised blood magnesium levels but did not prevent atrial fibrillation, an irregular heartbeat. It occurred in 37.9% of people given magnesium and 28.6% given the dummy treatment. The trial stopped early because magnesium was unlikely to help, and no important safety problem was found.
What this means for you: This study does not support routine magnesium infusions to prevent irregular heartbeats after heart surgery. It does not show whether ordinary magnesium supplements help with other health goals or in people who are not having heart surgery.
moderate evidenceThis single-centre, double-blind, randomised, placebo-controlled trial tested perioperative intravenous magnesium sulfate in adults having coronary artery bypass grafting and/or valvular surgery. Patients with prior atrial arrhythmias or severe renal dysfunction were excluded. The intervention targeted serum magnesium concentrations of 1.5 to 2.0 mmol/L.
A total of 265 patients were randomised before an interim analysis stopped the trial for futility. Magnesium clearly separated serum magnesium concentrations between groups, so the intervention changed the intended biochemical measure. It did not reduce postoperative atrial fibrillation. The event occurred in 50 of 132 magnesium-treated patients, or 37.9%, compared with 38 of 133 placebo patients, or 28.6%. The relative risk was 1.29, with a 95% confidence interval of 0.92 to 1.80. No subgroup showed benefit, and time-to-event and daily analyses found no early reduction.
Vasopressor use was more frequent with magnesium, though the difference was not statistically significant. No safety signal was identified. This is direct clinical evidence against routine prophylactic magnesium infusion for this surgical indication, not a test of oral supplementation or general longevity.
Perioperative magnesium infusion targeting 1.5 to 2.0 mmol/L did not reduce postoperative atrial fibrillation after cardiac surgery.
The study was stopped at an interim futility analysis and was conducted at one centre in cardiac-surgery patients. It tests intravenous perioperative treatment, not routine oral magnesium intake in healthy adults.
Cited by
1 encyclopedia entries reference this study.