Bioimpedance-Guided Hydration for the Prevention of Contrast-Induced Kidney Injury: The HYDRA Study.

Background: Intravascular volume expansion plays a major role in the prevention of contrast-induced acute kidney injury (CI-AKI). Recommended standard amounts of fluid infusion before procedures do not produce homogeneous responses in subjects with different initial hydration status.

Objectives: The goal of this study was to compare the effect of standard and double intravenous (IV) infusion volumes in patients with low body fluid level, assessed by using bioimpedance vector analysis (BIVA), on the incidence of CI-AKI after elective coronary angiographic procedures.

Methods: A total of 303 patients with low BIVA level on admission were randomized to receive standard volume saline (1 ml/kg/h for 12 h before and after the procedure) or double volume saline (2 ml/kg/h). Patients (n = 715) with an optimal BIVA level received standard volume saline and were included in a prospective registry. The saline infusion was halved in all patients with an ejection fraction <40%. BIVA was repeated immediately before the angiographic procedure in all patients. CI-AKI was defined as an increase in levels of cystatin C ≥10% above baseline at 24 h after contrast administration.

Results: The incidence of CI-AKI was significantly lower (11.5% vs. 22.3%; p = 0.015) in patients receiving double volume saline than in those receiving standard volume saline, respectively. Before the angiographic procedure, 50% of the double volume patients achieved the optimal BIVA level compared with only 27.7% in the standard group (p = 0.0001). The findings were consistent in all the pre-specified subgroups excluding patients with a left ventricular ejection fraction <40% (p for interaction = 0.01).

Conclusions: Evaluation of BIVA levels on admission in patients with stable coronary artery disease allows adjustment of intravascular volume expansion, resulting in lower CI-AKI occurrence after angiographic procedures. (Personalized Versus Standard Hydration for Prevention of CI-AKI: A Randomized Trial With Bioimpedance Analysis; NCT02225431).