Effects of Remote Ischemic Preconditioning With Postconditioning in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery

Abstract

BACKGROUND: Myocardial injury is associated with an adverse outcome after off-pump coronary artery bypass graft surgery (OPCAB). The authors conducted a randomized controlled trial to evaluate whether remote ischemic preconditioning (RIPC) with remote ischemic postconditioning (RIPostC) reduces myocardial injury in patients undergoing OPCAB. METHODS AND RESULTS: Seventy patients scheduled for OPCAB were randomly assigned to an RIPC+RIPostC group (n=35) or a control group (n=35). In the RIPC+RIPostC group, 4 cycles of 5-min ischemia and 5-min reperfusion were done on a lower limb before anastomoses (RIPC) and after anastomoses (RIPostC). RIPC+RIPostC significantly reduced postoperative serum troponin I levels (P=0.001). The area under the curve for postoperative troponin I was 48.7% lower in the RIPC+RIPostC group (median [interquartile range], 21.3 h·ng⁻¹·ml⁻¹, 16.5-53.1 h·ng⁻¹·ml⁻¹ vs. 41.5 h·ng⁻¹·ml⁻¹, 24.6-90.2 h·ng⁻¹·ml⁻¹, P=0.020). There was no significant difference in creatinine levels and PaO₂/F(i)O₂ ratios between the 2 groups. CONCLUSIONS: RIPC+RIPostC by lower limb ischemia decreased postoperative myocardial enzyme elevation by almost half postoperatively in patients undergoing OPCAB.