Usefulness of urine output criteria for early detection of acute kidney injury after transcatheter aortic valve implantation

Background: Previous studies demonstrated that acute kidney injury (AKI) following transcatheter aortic valve implantation (TAVI) is frequent and associated with adverse outcomes. However, these studies only applied the serum creatinine (sCr) criteria while ignoring the urine output criteria. We hypothesized that adding the urine output criteria might contribute to an earlier diagnosis of AKI. Methods: We included 143 patients with severe aortic stenosis who underwent transfemoral TAVI between December 2012 and April 2014. Urine output was assessed hourly for at least 24 h following TAVI, and sCr was assessed at least daily until discharge. Based on the Valve Academic Research Consortium-2 (VARC-2), AKI was determined using both sCr and urine output criteria. We compared the incidence of AKI and time to AKI diagnosis based on these two methods. Results: The mean age was 81 ± 6 years (range 61-94) and 56% were male. AKI occurred in 27 (19%) patients, 13 (9%) of whom had AKI defined by sCr criteria. Twenty (14%) patients had AKI defined by urine output criteria, only 6 of whom had AKI also defined by sCr criteria. The use of urine output criteria resulted in earlier identification of AKI (18 ± 4 vs. 64 ± 57 h, p = 0.02) and was associated with lower sCr elevation in patients having AKI defined by only urine output criteria (0.03 ± 0.12 vs. 0.37 ± 0.06 mg/dl, p < 0.001). Conclusion: The use of the VARC-2 urine output criteria significantly increased the incidence of AKI and shortened the time to AKI diagnosis.