Simplified prediction of postoperative cardiac surgery outcomes with a novel score: R2CHADS2

Abstract

Objective: To compare the accuracy of R2CHADS2, CHADS2, and CHA2DS2-VASc scores vs the Society of Thoracic Surgeons (STS) score as predictors of morbidity and mortality after cardiovascular surgery.

Methods: All patients who underwent cardiothoracic surgery at our institution from January 2008 to July 2013 were analyzed. Only those patients who fulfilled the criteria for STS score calculation were included. The R2CHADS2 score was computed as follows: 2 points for GFR < 60 mL/min/1.73 m(2) (R2), prior stroke or TIA (S2); 1 point for history of congestive heart failure (C), hypertension (H), age ≥75 years (A), or diabetes (D). Area under the curve (AUC) analysis was used to estimate the accuracy of the different scores. The end point variables included operative mortality, permanent stroke, and renal failure as defined by the STS database system.

Results: Of the 3,492 patients screened, 2,263 met the inclusion criteria. These included 1,160 (51%) isolated valve surgery, 859 (38%) coronary artery bypass graft surgery, and 245 (11%) combined procedures. There were 147 postoperative events: 75 (3%) patients had postoperative renal failure, 48 (2%) had operative mortality, and 24 (1%) had permanent stroke. AUC analysis revealed that STS, R2CHADS2, CHADS2, and CHA2DS2-VASc reliably estimated all postoperative outcomes. STS and R2CHADS2 scores had the best accuracy overall, with no significant difference in AUC values between them.

Conclusion: The R2CHADS2 score estimates postoperative events with acceptable accuracy and if further validated may be used as a simple preoperative risk tool calculator.