Remote Ischemic Preconditioning Reduces Myocardial and Renal Injury After Elective Abdominal Aortic Aneurysm Repair: A Randomized Controlled Trial

Abstract

Conclusion: Remote ischemic preconditioning (RIPC) reduces postoperative myocardial injury, myocardial infarction, and renal impairment in patients undergoing elective open abdominal aortic aneurysm (AAA) repair. Summary: Remote ischemic preconditioning is a phenomenon where brief periods of ischemia, followed by reperfusion, can provide systemic protection from prolonged ischemia. The authors sought to investigate whether RIPC could reduce the incidence of myocardial and renal injury in patients undergoing elective AAA repair. This was a randomized trial, and 82 patients were randomized to undergo AAA repair with RIPC or AAA repair without RIPC. Remote ischemic preconditioning was performed using two cycles of intermittent cross-clamping of the common iliac arteries with 10 minutes of ischemia, followed by 10 minutes of reperfusion. Cardiac troponin levels were used to assess postoperative myocardial injury and myocardial infarction. Renal injury was assessed by serum creatinine level. Baseline characteristics were well matched in both groups. The incidence of myocardial injury was reduced 27% by RIPC (39% vs 12%; 95% confidence interval [CI], 8.8%-45%; P = .005). Also reduced in the RIPC patients were myocardial infarction (27% vs 5%; 95% CI, 7.3%-38%; P = .006) and renal impairment (30% vs 7%; 95% CI, 6.4%-39%; P = .009. The effect of covariables was assessed with multivariable analysis. The protective effect of RIPC on myocardial injury (odds ratio, 0.22; 95% CI, 0.07-0.67; P = .008), myocardial infarction (odds ratio, 0.18; 95% CI, 0.04-0.75; P = .006) was independent of the covariables. Comment: Studies suggest that ischemia at a site distal from the heart can confer ischemic protection at remote sites. This must occur through some sort of neural mechanism or a circulating humoral mechanism. It is intriguing to think that a simple maneuver that is feasible in most AAA open repairs could reduce cardiac and renal impairment after open AAA repair.