Postoperative Atrial Fibrillation Significantly Increases Mortality, Hospital Readmission, and Hospital Costs

Background. New-onset postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. However, the magnitude of POAF on length of stay, resource utilization, and readmission rates remains an area of clinical interest. The purpose of this study was to examine the risk-adjusted impact of POAF on measures of mortality, hospital resources, and costs among multiple centers. Methods. A total of 49,264 patient records from a multiinstitutional Society of Thoracic Surgeons (STS) certified database for cardiac operations (2001 to 2012) were extracted and stratified by the presence of POAF (19%) versus non-POAF (81%). The influence of POAF on outcomes was assessed by hierarchic regression modeling, adjusted for calculated STS predictive risk indices. Results. Mean age was 64 +/- 11 years, and median STS predicted risk of mortality for patients who developed POAF were incrementally higher (2% vs 1%, p < 0.001) compared with non-POAF patients. The rate of POAF was highest among those undergoing aortic valve replacement D coronary artery bypass grafting, aortic valve, and mitral valve replacement operations. The POAF patients had a higher unadjusted incidence of mortality, morbidity, hospital readmission, longer intensive care unit (ICU) and postoperative length of stay, and higher hospital costs. After risk adjustment, POAF was associated with a twofold increase in the odds of mortality (adjusted odds ratio = 2.04, p < 0.001), greater hospital resource utilization, and increased costs; POAF was associated with 48 additional ICU hours (p < 0.001), 3 additional hospital days (p < 0.001), and $3,000 (p < 0.001) and $9,000 (p < 0.001) of increased ICU and total hospitalrelated costs, respectively. Conclusions. New onset POAF is associated with increased risk-adjusted mortality, hospital costs, and readmission rates. Protocols to reduce the incidence of POAF have the potential to significantly impact patient outcomes and the delivery of high-quality, cost-effective patient care. (C) 2014 by The Society of Thoracic Surgeons