Post coronary artery bypass graft surgery

Diabetes mellitus role in impeding prophylactic effects of
magnesium on postcoronary artery bypass grafting atrial
fibrillation
Najafi M and Salehi Omran A
Tehran Heart Center, Medical Sciences/University of Tehran, Tehran, Iran
Abstract
Background: Hypomagnesemia is a well known issue in diabetics. Recent studies have
suggested the promising role of supplemental magnesium (Mg) administration in
preventing post-surgical atrial fibrillation (AF); however, there is no evidence on
differences between diabetic and non-diabetic patients in response to prophylactic
administration of Mg supplements.
Methods: Three hundred forty-five patients (115 diabetic; 230 non-diabetic), candidates
for isolated coronary artery bypass grafting (CABG) with normal renal function, were
randomly divided into two groups. Group A (case; 48.1%) received 2 g of Mg after
induction of anesthesia until cardiopulmonary bypass (CPB) onset and 8 g following CPB
to 24 h thereafter. In group B (control; 51.9%), no supplemental Mg was administered.
Mg serum levels was measured in all the patients four times (at the onset of induction,
and hours 0, 24, and 48 after ICU admission).Patients were then followed for developing
AF after the end of surgery until their discharge.
Results: Thirty-four patients (9.9%) developed AF: 12 in group A and 22 in group B.
Of 12 patients in group A, 8 (67%) were diabetic, whereas there were just 6 diabetic ones
(27.3%) in group B (p=0.026). Serum Mg level were not statistically different between
the groups. There was no significant difference statistically for the rate of DM in nonarrhythmic
patients between the two groups (31% in group A vs. 34% in group B).
Conclusions: DM has a major role in impeding prophylactic effects of Mg infusion on
developing AF. This effect has no correlation with perioperative serum Mg levels.
Keywords: magnesium, diabetes mellitus, atrial fibrillation
5