Determinants of postoperative atrial fibrillation and associated resource utilization in cardiac surgery.

Introduction And Objectives: Atrial arrhythmias occur after cardiac surgery in 10-65% of patients. The most common postoperative arrhythmia is atrial fibrillation (AF).

Methods: The Tehran Heart Center Cardiovascular Research database (of 15 580 patients) was used to identify all patients who developed any form of AF as a postoperative complication following their first cardiac surgery (e.g. for coronary artery bypass grafting [CABG], valve surgery or both), with and without cardiopulmonary bypass, between June 2002 and March 2008.

Results: Of the 15 580 patients who underwent a first cardiac surgery, 11 435 (73.4%) were male and their mean age was 58.16+/-10.11 years. New-onset AF developed postoperatively in 1129 (7.2%). New-onset AF occurred most frequently in patients who were aged > or =60 years and who had no history of beta-blocker use. In addition, patients were more likely to develop new-onset AF if they had valve surgery alone (16.5%) or CABG plus valve surgery combined (9.6%), needed intra-aortic balloon counterpulsation (IABC), or had a long cardiopulmonary bypass time. Multivariate analysis identified the following predictors of postoperative AF: older age, history of renal failure, congestive heart disease, operation type, longer perfusion time, and use of IABC. The incidence of early readmission (4.4%) was significantly higher in patients with postoperative AF, as was the duration of hospitalization, both overall and postoperatively. The short-term postoperative mortality rate was 3.8%.

Conclusions: Atrial fibrillation frequently develops after cardiac surgery and is associated not only with increased morbidity and mortality, but also with increased use of health-care resources.