Remote ischemic preconditioning for prevention of acute kidney injury: a meta-analysis of randomized controlled trials

Background: Remote ischemic preconditioning (RIPC) to prevent acute kidney injury (AKI) following cardiac and vascular interventions is a controversial practice.

Study design: We conducted a systematic review and meta-analysis using the MEDLINE database (1966 through November 2013), EMBASE (1988 through November 2013), and Cochrane Library database.

Setting & population: Patients undergoing cardiac and vascular interventions.

Selection criteria for studies: Randomized controlled trials comparing patient outcome with or without RIPC for prevention of AKI following cardiac and vascular interventions.

Intervention: RIPC using an inflatable tourniquet around the limb or cross-clamping the iliac arteries versus non-RIPC.

Outcomes: AKI, need for renal replacement therapy, postoperative kidney biomarkers, in-hospital mortality, and length of intensive care unit and hospital stay.

Results: 13 trials (1,334 participants) were included. RIPC decreased the risk of AKI for patients undergoing cardiac and vascular interventions compared with the control group (11 trials; 1,216 participants; risk ratio [RR], 0.70; 95% CI, 0.48-1.02; P = 0.06; I(2) = 45%) with marginal statistical significance. There were no differences in levels of postoperative kidney biomarkers (serum creatinine and glomerular filtration rate), incidence of renal replacement therapy, in-hospital mortality, hospital stay, or intensive care unit stay between the 2 groups. Metaregression analysis indicated that contrast intervention was not a covariate contributing significantly to heterogeneity on the risk estimate for AKI incidence; also, there was no dose effect of RIPC using tourniquet cuff around the limb on AKI prevention based on different ischemia duration.

Limitations: Different AKI definitions adopted in the trials included.

Conclusions: RIPC might be beneficial for the prevention of AKI following cardiac and vascular interventions, but the current evidence is not robust enough to make a recommendation. Adequately powered trials are needed to provide more evidence in the future.