Remote ischemic preconditioning for renal and cardiac protection during endovascular aneurysm repair: a randomized controlled trial.

Purpose: To report a randomized clinical trial designed to determine if remote ischemic preconditioning (IP) has the ability to reduce renal and cardiac damage following endovascular aneurysm repair (EVAR).
Methods: Forty patients (all men; mean age 76+/-7 years) with abdominal aortic aneurysms averaging 6.3+/-0.8 cm in diameter were enrolled in the trial from November 2006 to January 2008. Eighteen patients (mean age 74 years, range 72-81) were randomized to preconditioning and completed the full remote IP protocol; there were no withdrawals. Twenty-two patients (mean age 76 years, range 66-80) were assigned to the control group. Remote IP was induced using sequential lower limb ischemia. Serum and urinary markers of renal and cardiac injury were compared between the groups.
Results: Urinary retinol binding protein (RBP) levels increased 10-fold from a median of 235 micromol/L to 2356 micromol/L at 24 hours (p = 0.0001). There was a lower increase in the preconditioned group, from 167 micromol/L to 413 micromol/L at 24 hours (p = 0.04). The median urinary albumin:creatinine ratio was significantly lower in the preconditioned group at 24 hours (5 versus 8.8, p = 0.06). There were no differences in the rates of renal impairment or major adverse cardiac events.
Conclusion: Remote preconditioning reduces urinary biomarkers of renal injury in patients undergoing elective EVAR. This small pilot trial was unable to detect an effect on clinical endpoints; further trials are warranted.