Background: Although remote ischemic preconditioning (RIPC) is shown to preserve kidney function in patients at high risk of contrast-induced acute kidney injury (CI-AKI), the effect in patients at low-moderate risk remains unknown. The preventive effects of RIPC in patients not at high risk of CI-AKI were examined, and biomarkers with anticipated roles in renal protection via RIPC investigated.
Methods and results: Sixty patients who had moderate chronic kidney disease and who underwent angiography were randomly assigned to the control (n=30) or RIPC (intermittent arm ischemia, n=30) group. The baseline characteristics in the 2 groups did not differ significantly. CI-AKI was evaluated by measuring urinary liver-type fatty acid-binding protein (L-FABP). Biomarkers were measured before and 24 and 48 h after angiography. Twenty-four hours after angiography, the percent change in urinary L-FABP level in the RIPC group was significantly smaller than in the control group (41.3±15.6 vs. 159±34.1%, P=0.003). L-FABP-based CI-AKI developed in 8 control patients (26.9%) vs. only 2 patients in the RIPC group (7.7%), suggesting that RIPC prevents CI-AKI. Factors contributing to CI-AKI were analyzed. Neither high-sensitivity C-reactive protein nor pentraxine-3 level differed significantly between the 2 groups, while the percent change in asymmetrical dimethy larginine (ADMA) level and blood derivatives of reactive oxidative metabolite levels were significantly smaller in the RIPC group.
Conclusions: RIPC alleviates CI-AKI in patients at low-moderate risk. This effect might be mediated partly by decreasing oxidative stress and plasma ADMA level.