Reversibility of chronic kidney disease and outcomes following aortic valve replacement

OBJECTIVES: Chronic kidney disease (CKD) is prevalent in patients undergoing aortic valve replacement (AVR). We sought to evaluate the impact of AVR on estimated glomerular filtration rate (eGFR) levels and determine the impact of reversibility of CKD on postoperative outcomes. METHODS: We retrospectively reviewed 2169 patients who underwent isolated AVR between 2000 and 2012. eGFR was calculated using the CKD-EPI formula. Based on preoperative eGFR, patients were divided into three groups: NoCKD (eGFR >60, n= 1417), ModCKD (eGFR = 30–60, n= 619) and SevCKD (eGFR = 15–30, n= 86). End-stage renal disease patients (eGFR <15 and/or dialysis, n= 47) were excluded from the study. RESULTS: Before AVR, eGFR in the NoCKD, ModCKD and SevCKD groups was 81.3 ± 14.2, 48.9 ± 8.10 and 25.3 ± 4.12 ml/min/1.73 m 2 , respectively. NoCKD patients showed a decline in eGFR during the first month postoperatively; thereafter, eGFR remained stable over 1 year. ModCKD and SevCKD patients demonstrated an initial improvement in eGFR, which peaked at 1 week postoperatively. In ModCKD, eGFR stabilized at a slightly lower level thereafter out to 1-year follow-up. In SevCKD, eGFR declined slightly out to 6 months postoperatively. Regardlessly, eGFR in ModCKD at 1 year and in SevCKD at 6 months postoperatively demonstrated sustained improvement over baseline eGFR. Reversibility of CKD was associated with a better long-term survival in the ModCKD group (P< 0.001) and short-term survival in the SevCKD group (P= 0.018). CONCLUSIONS: AVR confers a marked initial improvement in eGFR, which is sustained in patients with ModCKD and SevCKD, and is associated with a better survival. The reversible nature of CKD in certain patients warrants careful consideration during preoperative risk scoring and stratification.