Impact of estimated glomerular filtration rate on the 15-year outcome after coronary artery bypass surgery

Abstract

Objective: The aim of the present study was to evaluate the impact of estimated glomerular filtration rate (eGFR) on the 15-year outcome after coronary artery bypass surgery (CABG) in a community-wide population study.

Methods: Eight hundred and eighty-two patients who underwent CABG were included in this study. eGFR was estimated by the modified Modification of Diet in Renal Disease study equation.

Results: Among 30-day operative survivors, patients with eGFR<60 ml/min/1.73 m(2) had significantly poorer overall survival (at 5, 10 and 15 year, 84.7%, 63.5% and 43.8% vs 92.8%, 77.6% and 58.3%, respectively, p<0.0001). eGFR (HR 0.989, 95% CI 0.981-0.997, as well as eGFR<60 ml/min/1.73 m(2): HR 1.470, 95% CI 1.092-1.979) was an independent predictor of late all-cause mortality only when patients' age was excluded from the regression model. This was probably due to strong impact of age on eGFR. eGFR (HR 0.987, 95% CI 0.975-0.998, as well as eGFR<60 ml/min/1.73 m(2); HR 1.612, 95% CI 1.086-2.395) was an independent predictor of cardiovascular mortality secondary to ischemic heart disease or ischemic stroke. eGFR (HR 0.991, 95% CI 0.983-0.999, as well as eGFR<60 ml/min/1.73 m(2): HR 1.396 95% CI 1.031-1.891) was an independent predictor of cardiovascular mortality and morbidity (myocardial infarction, stroke, need for redo CABG or PCI). When both preoperative serum creatinine and eGFR were included in the regression model, only eGFR was predictive of all-cause mortality, cardiovascular mortality and combined cardiovascular mortality and morbidity.

Conclusions: This study showed that an eGFR<60 ml/min/1.73 m(2) is an important determinant of long-term outcome after isolated CABG. Since its predictive value seems to be superior to serum creatinine, eGFR may be useful to identify those patients undergoing CABG with subclinical chronic kidney disease.