Remote ischemic preconditioning reduces myocardial and renal injury after elective abdominal aortic aneurysm repair - A randomized controlled trial

Background - Myocardial and renal injury commonly contribute to perioperative morbidity and mortality after abdominal aortic aneurysm repair. Remote ischemic preconditioning (RIPC) is a phenomenon whereby brief periods of ischemia followed by reperfusion in one organ provide systemic protection from prolonged ischemia. To investigate whether remote preconditioning reduces the incidence of myocardial and renal injury in patients undergoing elective open abdominal aortic aneurysm repair, we performed a randomized trial. Method and Results - Eighty-two patients were randomized to abdominal aortic aneurysm repair with RIPC or conventional abdominal aortic aneurysm repair (control). Two cycles of intermittent crossclamping of the common iliac artery with 10 minutes ischemia followed by 10 minutes reperfusion served as the RIPC stimulus. Myocardial injury was assessed by cardiac troponin I (>0.40 ng/mL), myocardial infarction by the American College of Cardiology/American Heart Association definition and renal injury by serum creatinine (>177 mu mol/L) according to American Heart Association guidelines for risk stratification in major vascular surgery. The groups were well matched for baseline characteristics. RIPC reduced the incidence of myocardial injury by 27% (39% versus 12% [ 95% CI: 8.8% to 45%]; P = 0.005), myocardial infarction by 22% (27% versus 5% [ 95% CI: 7.3% to 38%]; P = 0.006), and renal impairment by 23% (30% versus 7%; [ 95% CI: 6.4 to 39]; P = 0.009). Multivariable analysis revealed the protective effect of RIPC on myocardial injury (OR: 0.22, 95% CI: 0.07 to 0.67; P = 0.008), myocardial infarction (OR: 0.18, 95% CI: 0.04 to 0.75; P = 0.006) and renal impairment were independent of other covariables. Conclusions - In patients undergoing elective open abdominal aortic aneurysm repair, RIPC reduces the incidence of postoperative myocardial injury, myocardial infarction, and renal impairment.