CHADS2 score predicts atrial fibrillation following cardiac surgery

Background: Atrial fibrillation (AF) following cardiac surgery portends higher morbidity and increased health expenditure. Although many anatomic and patient risk factors have been identified, a simple clinical scoring system to identify high-risk patients is lacking. The CHADS2 score is widely used to predict the risk of stroke in patients with AF. We assessed the utility of this scoring algorithm in predicting the development of de novo postoperative atrial fibrillation (POAF) in cardiac surgery patients.

Material and methods: A total of 2120 patients from 2008 to 2013 were identified for inclusion in our analysis. CHADS2 scores were calculated, and patients grouped into low- (0), intermediate- (1) and high-risk (≥2) categories. A multivariate regression model was developed to account for known risk factors of AF.

Results: Of the 2120 patients, 344 (16.2%) patients developed de novo POAF during their primary hospitalization. Mean CHADS2 scores for POAF patients and no POAF patients were 2.1 ± 1.2 and 1.7 ± 1.3 (P < 0.0001), respectively. CHADS2 score was a significant predictor of AF on multivariate regression analysis (adjusted odds ratio, 1.26; 95% confidence interval, 1.14-1.40). As CHADS2 score increased from 0 to 6, the probability of POAF increased from 11.1% to 32.7% (P < 0.0001). Compared with the low-risk group, the intermediate-risk and high-risk groups had a 1.73- and 2.58-fold increase in odds of developing POAF, respectively (P < 0.02 and P < 0.0001).

Conclusions: CHADS2 score is a powerful and convenient predictor of developing POAF. We recommend its utilization in identifying high-risk patients that may benefit from pharmacologic prophylaxis.