Age- and gender-specific values of estimated glomerular filtration rate among 6232 patients undergoing cardiac surgery

Abstract

Impaired preoperative renal function as estimated by glomerular filtration rate (GFR) is an independent risk factor for mortality after cardiac surgery. Little is known about the actual prevalence of renal dysfunction among patients undergoing cardiac surgery in Germany. We performed a retrospective analysis of 6232 patients from 20 to 80 years. GFR was estimated with the modification of diet in renal disease (MDRD) formula. There was an age-dependent decrease in estimated glomerular filtration rates (eGFR) among both men and women. There is a stepwise age-dependent increase of chronic kidney disease (CKD) stages 3-5 (<60 ml/min/1.73 m(2)). The lower the eGFR the higher the risk for mortality [odds ratio 2.93 95%-confidence interval (CI) 1.92-4.53] for eGFR<30 ml/min/1.73 m(2); odds ratio 1.93 (95%-CI 1.56-2.39) for eGFR 30-60 ml/min/1.73 m(2) compared to patients with an eGFR>60 ml/min/1.73 m(2). The actual mortality rates varied between 6.3% (307/4869) for patients with an eGFR>60 ml/min/1.73 m(2), 11.3% (137/1051) for patients with an eGFR of 30-60 ml/min/1.73 m(2) and 16.6% (27/163) for patients with an eGFR<30 ml/min/1.73 m(2). Estimated GFR declines are age- and gender-dependent. Preoperative renal dysfunction is an important predictor of in-hospital mortality after cardiac surgery.