Remote Ischemic Preconditioning for Renal and Cardiac Protection During Endovascular Aneurysm Repair: A Randomized Controlled Trial

Abstract

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). 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. 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. 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.