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.