Impact of atrial fibrillation on in-hospital outcomes of coronary artery bypass graft surgery: an analysis by propensity score matching

Abstract

Abstract Background/Introduction Many patients referred for coronary artery bypass graft (CABG) surgery have persistent or permanent atrial fibrillation (AF). Despite the significant occurrence, the impact of this arrythmia on surgical outcomes remains uncertain. Purpose To assess the impact of persistent or permanent AF on post-CABG in-hospital outcomes. Methods A cohort of 3,124 patients undergoing to isolated CABG between 2010 and 2020 was evaluated. A propensity score pairing was applied, considering persistent or permanent AF as a dependent variable and another 19 baseline characteristics as independent variables in the regression model used to build the propensity score. Pairing was performed at a ratio of 3:1 – Group 1: 324 patients without persistent or permanent AF; Group 2: 108 patients with the documented diagnosis of persistent or permanent AF. The statistical plan also included normality analyses, descriptive and univariate analyses, binary logistic regression, ROC curves and DeLong test to compare de curves. The significance level adopted was 5%. The analyses were performed by the programming language Python. Results None of the baseline characteristics evaluated showed a significant difference between the groups, including the EuroScore II (Group 1: 1.54±1.45 vs Group 2: 1.49±1.59; p=0.990). Likewise, none of the analysed surgical characteristics showed a significant difference, indicating a very approximate pattern of complexity of the surgeries. The absence of differences demonstrated a high degree of homogeneity between the groups. The use of pairing by propensity score aimed to form two extremely similar study groups, which differed only in relation to the diagnosis of the arrhythmia under study. Among the outcomes evaluated, AMI (1.5 vs 6.5; p=0.013), MACCE (7.1% vs 14.8%; p=0.015) and death (1.5% vs 6.5%; p=0.013) had significantly higher incidences in Group 2, formed by patients with persistent or permanent AF. From the multivariate analysis, it can be identified that permanent AF was an independent risk predictor for the occurrence of in-hospital death (OR: 5.009; 95% CI 1.433–17.507; p=0.012). Finally, it was also possible to verify that the association of EuroScore II with persistent or permanent AF showed higher predictive accuracy than EuroScore II alone (ESII+FA = AUC 0.852 vs ESII alone = AUC 0.775, p<0,05). Conclusion(s) Patients with persistent or permanent AF had significantly higher incidences of AMI, MACCE and in-hospital death. Persistent or permanent AF was characterized as an independent predictor for the occurrence of death and the association with the EuroScore II resulted in a 9.9% increase in the predictive accuracy of the surgical risk score. Funding Acknowledgement Type of funding sources: None.