Magnesium Sulfate to Prevent Perioperative Atrial Fibrillation in Cardiac Surgery: A Randomized Clinical Trial.

Denna enkelcentrerade dubbelblinda randomiserade placebokontrollerade studie testade perioperativt intravenöst magnesiumsulfat hos vuxna som genomgick kranskärlsoperation och/eller klaffkirurgi. Patienter med tidigare förmaksarytmier eller svår njurdysfunktion exkluderades. 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.