Effect of remote ischaemic preconditioning on myocardial injury in patients undergoing coronary artery bypass graft surgery: a randomised controlled trial

SummaryBackgroundWhether remote ischaemic preconditioning, an intervention in which brief ischaemia of one tissue or organ protects remote organs from a sustained episode of ischaemia, is beneficial for patients undergoing coronary artery bypass graft surgery is unknown. We did a single-blinded randomised controlled study to establish whether remote ischaemic preconditioning reduces myocardial injury in these patients.Methods57 adult patients undergoing elective coronary artery bypass graft surgery were randomly assigned to either a remote ischaemic preconditioning group (n=27) or to a control group (n=30) after induction of anaesthesia. Remote ischaemic preconditioning consisted of three 5-min cycles of right upper limb ischaemia, induced by an automated cuff-inflator placed on the upper arm and inflated to 200 mm Hg, with an intervening 5 min of reperfusion during which the cuff was deflated. Serum troponin-T concentration was measured before surgery and at 6, 12, 24, 48, and 72 h after surgery. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00397163.FindingsRemote ischaemic preconditioning significantly reduced overall serum troponin-T release at 6, 12, 24, and 48 h after surgery. The total area under the curve was reduced by 43%, from 36·12 μg/L (SD 26·08) in the control group to 20·58 μg/L (9·58) in the remote ischaemic preconditioning group (mean difference 15·55 [SD 5·32]; 95% CI 4·88–26·21; p=0·005).InterpretationWe have shown that adult patients undergoing elective coronary artery bypass graft surgery at a single tertiary centre could benefit from remote ischaemic preconditioning, using transient upper limb ischaemia.