Ischemic Preconditioning for Prevention of Contrast Medium–Induced Nephropathy Randomized Pilot RenPro Trial (Renal Protection Trial)

Background —Contrast-medium-induced acute kidney injury is associated with substantial morbidity and mortality. The underlying mechanism has been partially attributed to ischemic kidney injury. The aim of this randomized, double-blind, sham-controlled trial was to assess the impact of remote ischemic preconditioning on contrast-medium-induced acute kidney injury. Methods and Results —Patients with impaired renal function (serum creatinine >1.4 mg/dL and/or estimated glomerular filtration rate <60 mL/min/1.73 m2) undergoing elective coronary angiography were randomized in a 1:1 ratio to standard care with (n=50) or without ischemic preconditioning (n=50; intermittent arm ischemia through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff). Overall, both study groups were at high risk to develop contrast-medium-induced acute kidney injury using Mehran risk score. The primary endpoint was the incidence of contrast-medium-induced kidney injury, defined as an increase of serum creatinine ≥ 25 % and/or ≥ 0.5 mg/dL above baseline at 48 hours after contrast-medium exposure. Contrast-medium-induced acute kidney injury occurred in 26 patients (26%), 20 (40%) in the control group and 6 (12%) in the remote ischemic preconditioning group (OR 0.21; 95% CI 0.07-0.57; P=0.002). No major adverse events were related to remote ischemic preconditioning. Conclusions —Remote ischemic preconditioning before contrast-medium use prevents contrast-medium-induced acute kidney injury in high risk patients. Our findings merit a larger trial to establish remote ischemic preconditioning on clinical outcomes. Clinical Trial Registration Information —www.germanctr.de; Identifier: U1111-1118-8098.