Atrial Fibrillation after Off-Pump versus On-Pump Coronary Artery Bypass Graft Surgery

Background- Atrial fibrillation (AF) is the most common postoperative arrhythmic complication after coronary artery bypass graft surgery (CABG). The aim of the present study was to compare AF prevalence after off- pump versus on-pump CABG. Methods- In this prospective study, performed between September 2008 and September 2009, 128 consecutive patients in our local cardiovascular surgery ward were allocated into two groups of offpump (95 patients) and on-pump CABG (33 cases). We compared preoperative risk factors such as left ventricular ejection fraction (LVEF)<% 40, hypertension (HTN), and Cr>2mg/dl, site of grafting such as the left coronary descending artery (LAD), right coronary artery (RCA), and left circumflex artery (LCX) in the two groups of surgery techniques (on-pump versus off-pump CABG) with/without postoperative AF after 24 hours of surgery in the Intensive Care Unit. Statistical power of the study was 80%, and a P-value less than 0.05 was considered significant. Results- The prevalence of AF was 15 (15.8%) in the off-pump group versus 7 (21.2%) in the onpump group (p=0.67) 24 hours after CABG. In the on-pump group, there was no difference between age categories (p=0.11). In the on-pump group, as opposed to the off-pump CABG group, there was no relationship between the surgery techniques with or without AF, LVEF<% 40, and HTN. There was a significant relation with Cr more than 2 mg/dl in the on-pump CABG group (p=0.001) versus the off-pump CABG group (p= 0.057). There was no statistical relation between the type of vascular graft (LAD, RCA, and LCX) between the on-pump and off-pump CABG patients attributed to with or without AF. Conclusion- There was no reduction in the AF rate in the on-pump CABG versus off-pump CABG. It seems that there was another predictive factor for AF in the off and on-pump CABG groups, so further prospective trials with larger sample sizes are recommended.