Survival in patients with acute kidney injury requiring dialysis after coronary artery bypass grafting

Abstract

OBJECTIVES: The aim was a nationwide analysis of need for dialysis and survival in all patients who had coronary artery bypass grafting (CABG) in Sweden during 2002 up to 2008. METHODS: Primary isolated CABG was performed in 28 220 patients without preoperative need for dialysis. Survival was analysed in patients suffering postoperative acute kidney injury requiring dialysis. RESULTS: Postoperative dialysis was needed in 162 patients (0.6%). Old age, female gender, reduced glomerular filtration rate (GFR), diabetes mellitus, peripheral vascular disease, chronic obstructive pulmonary disease, prior myocardial infarction, prior stroke and reduced left ventricular function were associated with need for dialysis. Only 0.3% of the patients with GFR >60 ml/min/1.73 m2 needed postoperative dialysis compared with 9.5% if GFR was <30 ml/min/1.73 m2. Sixteen of 54 patients (27%) with GFR <30 l/min/1.73 m2 and a =50% increase in postoperative serum creatinine needed dialysis. There were 42 deaths (26%) within 30 days in patients who needed dialysis and 1% if dialysis was not required. Early mortality was markedly higher in patients who required dialysis than in those without dialysis after multivariable adjustment for age, sex, diabetes mellitus, left ventricular function and GFR (odds ratio 19, 95% confidence interval 13-29). The corresponding risk of late death was 2-fold higher in patients who survived for 90 days and had required dialysis compared with those who did not (hazard ratio 2.4, 95% confidence interval 1.7-3.3). Five-year survival was 43 and 89%, respectively. The risk of death increased with age. Five-year survival after dialysis was 66% in patients younger than 65 years, but 32% in those aged over 70 years. Fifty-one per cent (14 of 27) of patients 80 years of age or older who required dialysis died early compared with 3% (68 of 2426) of those who did not (P < 0.001). Nine survivors who needed dialysis developed end-stage renal disease. CONCLUSIONS: Need for dialysis after non-emergency was an uncommon serious complication associated with high early mortality and an increased risk of late death. Old age and impaired preoperative renal function were strong predictors of need for dialysis after CABG. Postoperative dialysis after CABG was a marker of poor outcome but could, in some patients, be life-saving. © The Author 2013. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.