Background:
Renal dysfunction is independently associated with both short-term and long-term mortality after coronary artery bypass grafting (CABG). The estimated glomerular filtration rate (eGFR) is a convenient and effective indicator of renal function. However, the ability of eGFR calculated by various equations to predict the outcomes of patients undergoing off-pump CABG (OPCABG) is still unclear. This study was aimed to compare the predictive ability of in-hospital and long-term mortality in three equations of estimating renal functions after OPCABG.
Methods:
Totally, 1362 patients undergoing OPCABG were retrospectively reviewed. Preoperative and postoperative serum creatinine (Scr) levels were detected. The renal function was evaluated by the Cockcroft-Gault (CG) equation, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, and the full-age spectrum (FAS) equation. The endpoints were in-hospital and long-term all-cause mortality rates. Receiver operating characteristic curves, net reclassification index, decision curve analysis (DCA), multivariable logistic model, and ﻿Cox regression model were used for comparisons.
Results:
The CG equation had the significantly highest discriminatory power to predict in-hospital mortality (area under the curve=0.815). Valuable clinical net benefits of the CG equation were greater than the other two equations regardless of before or after operation by DCA. Multivariable logistic and ﻿Cox regression analysis illustrated that the eGFR calculated by the CG equation was a significant independent risk factor of both in-hospital mortality (odds ratio=3.390) and long-term mortality (hazard ratio=1.553).
Conclusion:
The CG equation outperformed the FAS and CKD-EPI equations in predicting the mortality of patients after OPCABG. Postoperative renal function was more efficiently predicted compared with the preoperative one.