Postoperative Atrial Fibrillation is Associated with Higher Euroscore, but not with Hospital Mortality after Coronary Artery Bypass Graft Surgery

Carol Chen Scarabelli,Giuseppe Faggian

doi:10.4172/2155-9880.s9-002

Abstract

Background: Postoperative atrial fibrillation (POAF) is the most common arrhythmia after coronary artery bypass surgery (CABG) and is associated with an increased morbidity. Recently, it has been suggested that POAF is also associated with increased postoperative mortality. Aim: To investigate whether POAF after isolated CABG was associated with a higher EuroSCORE, indicating greater in-hospital mortality risk. Methods: We reviewed data from our prospective cardiac surgery database of all patients (n=2791) undergoing isolated CABG from January 2003 through December 2006 at a large university medical center. The Mann-Whitney test was used to test for differences in continuous variables between the POAF and non-POAF groups, while the Chi-square test was used for categorical variables. Cox proportional-hazards regression analysis was used to identify independent predictors of in-hospital mortality. Results: The mean age was 68 ± 9.1yrs, and mean EuroSCORE was 6.91 ± 3.18. The overall incidence of POAF was 32.3%. The POAF group was older (70.5 ± 7.8 vs. 66.8 ± 9.5yrs non-POAF: p<0.0001), but there was no significant difference in ejection fraction (EF) between the two groups (p=0.13). There was a significant difference in the mean EuroSCORE (POAF, 7.6 ± 3.2 vs non-POAF, 6.6 ± 3.1, p<0.0001), indicating that the POAF group was at greater risk for postoperative mortality. Although, there was a significant association between EuroSCORE and POAF (p<0.0001), there was no significant difference in hospital mortality between the POAF and non-POAF groups. The overall hospital mortality was 1.9%, with no difference between the two groups (p=0.91). Furthermore, POAF was not predictive of hospital mortality after CABG. Conclusion: POAF is associated with a higher EuroSCORE, but it is neither associated with, nor predictive of increased hospital mortality after CABG

Highlights

Atrial fibrillation (AF), is the most common arrhythmia after cardiac surgery [1,2,3], occurring in as much as, forty to sixty-five percent of the patients [2,4,5,6,7]
With regards to the incidence of diabetes mellitus (DM), emphysema, hypercholesterolemia, and cerebrovascular accident (CVA), there was no significant difference between the Postoperative atrial fibrillation (POAF) and non-POAF groups
There was no significant difference in myocardial infarction (MI), left main disease, or surgical priority, the POAF group exhibited an increased pre-operative risk as evidenced by a greater need for preoperative intra-aortic balloon pump (IABP) support (8.1% vs 5.7%, p=0.02), as well as risk for increased postoperative mortality, as demonstrated by a higher EuroSCORE (AF: 7.6 ± 3.2 vs 6.6 ± 3.1, p

Summary

Introduction

Atrial fibrillation (AF), is the most common arrhythmia after cardiac surgery [1,2,3], occurring in as much as, forty to sixty-five percent of the patients [2,4,5,6,7]. POAF has been increasingly associated with greater hospital and 6-month mortality rates [4], as well as late mortality [2,8,9,10] Many of those studies documenting such an association between POAF and mortality utilized earlier cardiac surgery databases from the 1990s. Subsequent studies utilizing more recent databases from 20032007 found that new-onset POAF was not associated with increased hospital mortality [18] and was not an independent predictor of early mortality after coronary artery bypass graft [CABG] surgery [19]. Postoperative atrial fibrillation (POAF) is the most common arrhythmia after coronary artery bypass surgery (CABG) and is associated with an increased morbidity. It has been suggested that POAF is associated with increased postoperative mortality

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