Postoperative atrial fibrillation after thoracic aortic surgery.

Background: Postoperative atrial fibrillation (POAF) increases considerably the chances of morbidity and mortality after cardiac surgery. The objective of this study was to identify the major risk factors responsible for POAF after thoracic aortic surgery in order to define preventive measures.

Methods: We analyzed 12,260 records (between January 1, 2004, and December 31, 2008) obtained from the Japan Adult Cardiovascular Surgery Database. Patients with history of AF were excluded. Data were collected for 12 preoperative and 10 operative risk factors that had been proven or believed to influence POAF. The relationship between the risk factors and outcome was assessed by the Fisher exact test, Student t test, and multiple logistic regression analysis.

Results: The patients' mean age (± standard deviation) was 67.5 ± 12.7 years, and 27% of the subjects were women. The incidence of POAF was 17.1%. The following risk factors were associated with increased POAF: age (p < 0.0001), history of smoking (p < = 0.020), hypertension (p = 0.020), congestive heart failure (p < 0.0001), urgent operation (p = 0.023), and concomitant with nonelective coronary artery bypass (p = 0.022). Postoperative mortality and postoperative stroke were significantly increased in patients with POAF (p < 0.0001 in both cases). The odds ratios for the POAF risk factors were as follows: replacement of the ascending aorta, 1.67; aortic arch, 1.62; aortic root, 1.42; concomitant with valve operation, 1.35; age, 1.27; and urgent operation, 1.22.

Conclusions: Several risk factors contribute to the incidence of POAF after thoracic aortic surgery. We found that POAF significantly increased 30-day operative mortality (p < 0.0001). Our findings can be used to develop a risk stratification system for the prediction of POAF.