The ratio of contrast volume to glomerular filtration rate predicts acute kidney injury and mortality after transcatheter aortic valve implantation

Objective The aim of this study was to assess the impact of the ratio of volume of contrast medium to the glomerular filtration rate (V/GFR) on acute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI) and its impact on long-term mortality. Methods We retrospectively calculated V/GFR in 397 patients undergoing TAVI. AKI was defined as VARC-modified Risk, Injury, Failure, Loss and End-stage (RIFLE) kidney disease score ≥ 2. Results The incidence of AKI was 17.9%. The mean V/GFR ratio was 3.0 ± 2.7 in patients without AKI and 7.8 ± 8.8 in patients with AKI (p < 0.001). The receiver–operator characteristic curve analysis showed fair discrimination between patients with and without AKI (C-statistic 0.85) at a V/GFR ratio of 3.2. Multivariable regression analysis indicated that V/GFR > 3.2 was an independent predictor of both AKI (OR 3.4, 95% CI 1.0–6.1, p < 0.001) and long-term mortality (OR 3.3, 95% CI 2.0–5.2, p < 0.001). Conclusions A V/GFR > 3.2 was found to be correlated with a higher incidence of AKI and mortality after TAVI. Therefore, this ratio could potentially be used to calculate the maximum volume of contrast medium that can be administered without significantly increasing the risk of AKI and mortality. Further larger studies are needed to validate these findings.