New Magnesium Regimen Reduces Incidence of Atrial Fibrillation After CABG

The incidence of atrial fibrillation, a common and dreaded complication of coronary artery bypass grafting (CABG), is reduced when a novel magnesium regimen is administered, according to study findings presented Tuesday at the 37th annual meeting of The Society of Thoracic Surgeons.

Dr. Huseyin Cem Alhan and colleagues, from Acybadem Hospital, in Istanbul, Turkey, assessed the ability of magnesium to prevent postoperative atrial fibrillation by randomizing 200 patients undergoing CABG to receive 1.5 g of magnesium sulfate in 100 mL 0.9% saline or saline alone, 1 day before, during, and 4 days after surgery. Patient demographics were similar between the groups.

The researchers found that 2% of magnesium-treated patients experienced postoperative atrial fibrillation, significantly fewer than the 21% of untreated patients who manifested this arrhythmia.

“Many other studies have shown that magnesium has an effect on atrial fibrillation, but the appropriate dose and timing of infusion was not clear,” Dr. Alhan told Reuters Health. “While many patients are hospitalized prior to their surgery, we found that even patients who do not receive the preoperative dose still have lower rates of atrial fibrillation.”

“There are no contraindications to magnesium therapy, we give it to patients with normal as well as low magnesium levels,” Dr. Alhan stated. “In the elderly it has been shown that patients may be total body magnesium deficient, but have normal serum levels,” he explained. “We are not sure if the therapeutic mechanism is replenishment of a deficiency or a pharmacologic effect of the drug.”

“Atrial fibrillation is not the most serious complication after cardiac surgery, but it is the most common,” Dr. Alhan pointed out. “It has a strong impact on the hospital length of stay and therefore on the cost associated with cardiac surgery,” he noted. “The patients who received magnesium in this study went home earlier,” Dr. Alhan emphasized.