Abstract 20782: Incidence and Predictors of Postoperative Atrial Fibrillation in Patients Undergoing Elective Noncardiac Surgery in a large cohort of patients
Background: Postoperative atrial fibrillation (AF) after cardiothoracic surgery has been well described. However, the incidence and predictors of AF after noncardiac surgery (NCS) have not been well defined.
Methods: Patients undergoing elective NCS in 2005-2007 requiring at least an overnight stay were identified through a surgery scheduling system. Demographics, diagnoses, labs, medications and postoperative AF were obtained from the electronic medical record. AF was validated by individual chart analysis and data was collected regarding use of Intravenous medications and /or cardioversion for rate and rhythm control. Missing values in the predictor variables were multiply imputed by chained equations in order to effectively utilize the sample size. A stepwise selection method was used to identify significant predictive variables of postoperative AF in a multivariable logistic regression analysis. A concordance index was calculated for the final model including the selected predictors.
Results: Postoperative AF developed in 946 of 34,793 patients (2.7%), of which 690 (73%) had new onset AF, 594 (63%) needed intravenous medications for rate and rhythm control and 68 (7%) needed urgent cardioversion. Multivariable logistic analysis identified older age, male sex, surgeries with increased bleeding risk, vascular surgery, prior history of pulmonary embolism or AF, insulin dependent diabetes and sodium as significant independent predictors of postoperative AF (p<0.05) (Table).Hyperlipidemia, hypertension, normal calcium values and statin use were associated with a lower incidence of postoperative AF. The reduced model achieved a concordance index of 0.833 after internal cross-validation.
Conclusions: Similar to cardiac surgery, older age, prior AF, and higher risk vascular surgeries were associated with postoperative AF after NCS. Statin use was associated with a lower incidence suggesting that future studies of statins for NCS may be of interest.
- © 2010 by American Heart Association, Inc.