New markers for early detection of acute kidney injury after transcatheter aortic valve implantation

Acute kidney injury (AKI) is a frequent complication after a transcatheter aortic valve implantation (TAVI). Biomarkers such as urinary G1 cell cycle arrest proteins (TIMP-2 and IGFBP7) and sonographic evaluation (Doppler Renal Resistive Index [RRI]) have been advocated to predict AKI at an early stage after a TAVI-procedure. The primary aim was to determine the predictive value of these markers to detect AKI after a TAVI-procedure at an early phase. In a prospective observational study, 62 consecutive patients were scheduled for a TAVI. AKI was assessed based on the KDIGO criteria. Biomarkers and RRI were measured concomitantly before TAVI, at the first micturition post-implantation and the first micturition on the morning after the procedure. Twenty-two patients (35%) developed AKI. On the first day after the TAVI-procedure, urinary TIMP-2 and IGFBP7 concentrations increased significantly in patients who developed AKI (0.1, [interquartile] [0.1–0.35] to 0.40 [0.10–1.00] vs. 0.2 [0.1–0.5] to 0.10 [0.10–0.20], P=0.012) with an area under the receiver-operating characteristic curve of 0.71 [0.55–0.83]. Sensitivity was 0.57 and specificity was 0.83 for a cut-off value of 0.35. No significant increases in RRI were found in patients who developed AKI. Based on the current guidelines for the diagnosis of AKI, the urinary proteins TIMP-2 and IGFBP7 do not detect AKI at an early stage accurately in patients undergoing a TAVI-procedure.