Acute Kidney Injury After Coronary Artery Bypass Grafting and Long-Term Risk of End-Stage Renal Disease
Background—Acute kidney injury (AKI) is a common complication after coronary artery bypass grafting (CABG), and is associated with adverse outcomes. However, the relationship between AKI after CABG and the long-term risk of end-stage renal disease (ESRD) is unknown.
Methods and Results—This study included 29 330 patients who underwent primary isolated CABG in Sweden between 2000 and 2008. AKI was classified according to the Acute Kidney Injury Network (AKIN) classification: stage 1, >0.3 mg/dL (>26 µmol/L) or 50-100% increase; stage 2, 100-200% increase; stage 3, >200% increase between pre- and postoperative serum creatinine levels. Cox proportional hazards regression analysis was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for ESRD in AKIN stage 1 and stage 2-3. Postoperative AKI occurred in 13% of patients. During a mean follow-up period of 4.3±2.4 years, 123 (0.4%) patients developed ESRD, including 50 (1.6%) with AKIN stage 1, 29 (5.2%) with AKIN stage 2-3, and 44 (0.2%) without AKI after CABG. After multivariable adjustment, the HR (95% CI) for ESRD was 2.92 (1.87-4.55) for AKIN stage 1 and 3.81 (2.14-6.79) for AKIN stage 2-3.
Conclusions—This nationwide study of patients who underwent CABG found that a small increase in the postoperative serum creatinine level was associated with an almost 3-fold increase in the long-term risk of ESRD after adjustment for a number of confounders including preoperative renal function.
- Acute kidney injury
- long-term outcome
- coronary artery bypass graft surgery
- end-stage renal disease
- Received April 16, 2014.
- Revision received September 6, 2014.
- Accepted September 12, 2014.