| Abstract: |
Background: Risk factors for post-CABG atrial fibrillation (AF) beyond older age are not well defined. Controversy exists as to which preoperative clinical and/or electrocardiographic characteristics distinguish patients who develop AF after cardiac surgery from those who do not. Our goal was to study the predictability of easily available preoperative clinical information. Methods: We retrospectively studied 1056 patients who had standard CABG without concurrent valvular surgery. Continuous telemetry was used to detect AF. Based on an extensive literature review of preoperative risk factors that were independently associated with AF, five were selected: age, male gender, heart rate, P wave duration > 120 ms and PR-interval. The standard preoperative 12-lead ECG was used and data were examined with univariate and multivariate methods. Results: AF occurred in 324/1056 (31%) patients. AF patients were older and had a longer PR-interval (Table). Multivariate analysis showed that older age (P<0.0001) and increasing PR-interval (P=0.04) were indpendently associated with AF risk. The rate of increase in risk with age appeared to decline after age 70, possibly due to patient selection bias. Conclusions: In the current study older age and evidence of prolonged intraatrial conduction were significant risk factors for postoperative AF. These easily obtainable preoperative variables can help risk-stratify CABG patients who may be at the highest risk for postoperative AF and also require more aggressive prevention or treatment strategies.. |
