Renal function-based contrast dosing predicts acute kidney injury following transcatheter aortic valve implantation.

OBJECTIVES: This study sought to assess whether the volume of contrast media (CM) influences the occurrence of acute kidney injury (AKI) following transcatheter aortic valve implantation (TAVI).

BACKGROUND: The volume of CM has been shown to be associated with increasing risk of AKI; however, in a high-risk elderly TAVI population, the predictive value and optimal threshold of CM dose on AKI remain uncertain.

METHODS: Data of 415 consecutive transfemoral TAVI patients (age 83.6 ± 6.8 years, logistic EuroSCORE 23.0 ± 12.2%) were analyzed. AKI was defined by Valve Academic Research Consortium criteria. Based on a previous formula, the ratio of CM to serum creatinine (SCr) and body weight (BW) (CM × SCr/BW) was calculated as defining the degree of CM use. The association between CM dose and incidence of AKI, as well as predictive factors and prognosis of AKI, were investigated.

RESULTS: AKI occurred in 63 patients (15.2%). Cumulative 1-year mortality showed significant differences between the AKI and non-AKI groups (47.9% vs. 15.7%, p < 0.001). Mean CM × SCr/BW ratio was higher in the AKI group than in the non-AKI group (4.1 ± 2.9 vs. 2.9 ± 1.6, p < 0.001). By multivariate analysis, CM × SCr/BW per 1.0 increase, ejection fraction <40%, and transfusion were associated with the occurrence of AKI (odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.03 to 1.20; p = 0.017, OR: 3.01; 95% CI: 1.49 to 5.00; p = 0.001, OR: 2.73; 95% CI: 1.54 to 6.15; p = 0.001, respectively). A threshold value of CM × SCr/BW for predicting AKI was statistically identified as 2.7.

CONCLUSIONS: Although mechanisms of AKI following TAVI are multifactorial, the present study identified a relationship between CM dose increment and high prevalence of AKI. Therapeutic efforts not to exceed the threshold value may reduce the risk of AKI.