The impact of new-onset atrial fibrillation on in-hospital mortality following cardiac surgery

Background: The impact of new-onset postoperative atrial fibrillation (NAF) on in-hospital mortality (IHM) following cardiac surgery is unknown. Methods: All patients without preoperative atrial fibrillation undergoing isolated coronary artery bypass graft surgery (CABG) and concomitant CABG and valve surgery were identified (n = 7,347). The association between NAF and IHM was determined using logistic regression modeling. Also, propensity score analysis was used to create two matched subgroups of patients with and without NAF (n = 2,015 in each group). The secondary outcomes examined were stroke, myccardial infarction (MI), intra-aortic balloon pump use, GI complications, deep sternal wound infection (DSWI), septicemia, renal failure, and length of stay. Results: NAF developed in 2,047 patients (27.9%). NAF was not an independent predictor of IHM (odds ratio, 0.8; 95% confidence interval, 0.6 to 1.2; p = 0.3). In multivariate analysis, NAF was associated with age ≥ 60 years, combined procedures, preoperative MI within 7 days of surgery, COPD, cerebrovascular disease, and male gender. Propensity-adjusted results revealed no difference in IHM between NAF vs no-NAF patients (2.9% vs 3.5%, respectively; Bonferroni-corrected p = 0.99). However, GI complications (4.2% vs 2.1%), DSWI (1.3% vs 0.4%), septicemia (4.0% vs 1.1%), renal failure (7.6% vs 4.3%), and length of stay (8 days vs 6 days) were significantly increased in patients with NAF. Conclusion: NAF following cardiac surgery is not associated with increased IHM.