Intravenous Magnesium Sulphate and Its Combination with Oral Vitamin C for AF Prophylaxis in Patients Undergoing Coronary Artery Bypass Surgery: A Randomized Double Blind Controlled Trial

Abstract

Atrial fibrillation (AF) is one of the most commonly encountered complications following coronary artery bypass grafting, whose treatment modalities are still not definite. In this prospective randomized double blind controlled trial we evaluated the adjuvant role of oral vitamin C with intravenous magnesium sulphate for the prevention of postoperative AF among the patients who underwent CABG under cardiopulmonary bypass. Group M (n=90) received4gm of intravenous magnesium sulphate just after anesthesia induction followed by 2gm daily till the 3rd postoperative day. Group MC (n=91) received a similar dose of magnesium sulphate along with oral vitamin C 2gm on the night before surgery and their after 1 gm daily till the 3 rd postoperative day. We noticed a significant number of patients from Group M suffered from AF while compared to Group MC (25.56% vs 13.9%,p=0.035).Moreover, the onset of this incidence was earlier in the former group (27.92±3.65 vs 30.55±3.24 hr, p=0.04) and lasted for a longer duration. More patients from Group M while compared with Group MC (21.11% vs 7.60%, p=0.01) needed rescue drug therapy for AF management. The incidence of AF was found to be more in male sex (71.42% vs 28.58, p=0.05), diabetic patients (28.06% vs 41.71%, p=0.02), patients with ventricular dysfunction (p=0.003) and those with poor sized vessels (p=0.004).The patients with AF had a longer duration of hospital stay (p=0.01) indicating a load on hospital resources. We conclude with an appropriate dosage and regime of intravenous magnesium, incidence of AF following CABG can be reduced but its administration alone may not be sufficient for the prophylaxis. Vitamin C as an adjuvant therapy is effective in reducing the incidence of AF.