Atrial fibrillation after coronary artery bypass grafting: does the type of procedure influence the early postoperative incidence?

Objective: Atrial fibrillation (AF), the common postoperative complication, has been observed after coronary artery bypass grafting (CABG) in 7-40% of patients. Cardiopulmonary bypass (CPB), eliminated in off-pump operations (OPCABG) may decrease the incidence of AF, whereas the combination of CABG with heart valve replacement may result in more frequent postoperative atri al fibrillation. The aim of our study was to compare the early postoperativ e AF incidence rate during ICU stay in three groups of patients: after CABG , OPCABG, and CABG combined with valve replacement. Material and methods: A prospective study of 906 consecutive patients was carried out between Janu ary 1999 and January 2000. Clinical profile of 906 patients, including fact ors having potential influence on postoperative AF did not showed any signi ficant differences between the groups. The presence of arrhythmia history w as the reason of excluding 85 patients from the statistical analysis. The o bservation was performed in each case during ICU-stay, using a HP system fo r continuos automated arrhythmia analysis, Early postoperative incidence of AF. was recorded and compared between three groups of patients: 650 after conventional CABG, 118 after OPCABG, and 53 after CABG combined with valve replacement. Chi-square and a Mann-Whitney tests, Statistica 5.0 PL were us ed for the statistical analysis. Results: Atrial fibrillation occurred duri ng the postoperative ICU stay in 9.8% of patients after CABG, in 10.2% afte r OPCABG, and in 21% after CABG combined with valve replacement. There was no significant difference between CABG and OPCABG groups (P = 0.965). The c onfidence interval of the odds ratio ranges from 0.5 to 1.85. Consequently, an increased risk would be possible for both methods. We observed a statis tically significant increase of the early postoperative atrial fibrillation incidence rate in patients after CABG combined with valve replacement, whe n compared with both CABG + OPCABG groups (P = 0.005). Conclusions: (1) Atr ial fibrillation is a common postoperative complication after myocardial re vascularization procedures which prolongs ICU stay. (2) The study did not s how that the incidence of postoperative AF is influenced by the technique o f coronary artery bypass grafting: with or without CPB. (3) The prevalence of postoperative AF increase when CABG is combined with valve replacement. (C) 2001 Elsevier Science B.V. All rights reserved.