Predictive factors of new onset postoperative atrial fibrillation in cardiac surgery

Abstract

Atrial fibrillation is the most frequently encountered arrhythmia and is a well recognized complication of cardiac surgery with a reported incidence of 30% after coronary artery bypass grafting (CABG). The study's purpose was to evaluate postoperative atrial fibrillation (POAF)’s incidence after CABG and to determine its potential predictive factors. It was a retrospective study which included 100 patients who underwent non emergent CABG, from January until December 2017. Non-inclusion criteria were: preoperative atrial fibrillation, more than mild valvular heart disease or a concomitant valvular surgery, and postoperative shock. The sex ratio was 0,19 with 16 women and 84 men. The average age was 60.4 ± 9.5 years. POAF was observed in 18 patients. The average body mass index (BMI) was 26,8 ± 5.5 kg/m 2 . There was no significant correlation between BMI and POAF ( P = 0.29). Only 11 patients (61%) in the POAF group were taking Beta Blockers (BB) in the preoperative period, while 87,8% of the second group with no POAF, were receiving it, with a statistically significant difference ( P = 0.012). The time limit for resuming BBs in the postoperative period was significantly correlated with POAF occurrence ( P = 0.02). After analysing ROC curve we found that resuming BBs beyond the second postoperative day was associated with a significantly higher rate of POAF ( P = 0.001). The biological assessment revealed that 39% among POAF group had chronic renal failure (Cl < 60 ml/min), while 13,4% of the remaining patients had renal impairment ( P = 0.018). Multivariate logistic regression analysis revealed that only renal impairment ( P = 0.041; OR = 4.2) and BB resuming beyond the second postoperative day P = 0.006; OR = 7.5) were independent predictive factors of POAF. There is strong evidence that a delayed postoperative taking of BBs and preoperative renal impairment are associated with a higher risk of POAF.