Remote ischaemic preconditioning for coronary artery bypass grafting (with or without valve surgery)

Background Despite substantial improvements in myocardial preservation strategies, coronary artery bypass grafting (CABG) is still associated with severe complications. It has been reported that remote ischaemic preconditioning (RIPC) reduces reperfusion injury in people undergoing cardiac surgery and improves clinical outcome. However, there is a lack of synthesised information and a need to review the current evidence from randomised controlled trials (RCTs). Objectives To assess the benefits and harms of remote ischaemic preconditioning in people undergoing coronary artery bypass grafting, with or without valve surgery. Search methods In May 2016 we searched CENTRAL, MEDLINE, Embase and Web of Science. We also conducted a search of ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP). We also checked reference lists of included studies. We did not apply any language restrictions. Selection criteria We included RCTs in which people scheduled for CABG (with or without valve surgery) were randomly assigned to receive RIPC or sham intervention before surgery. Data collection and analysis Two review authors independently assessed trials for inclusion, extracted data and checked them for accuracy. We calculated mean differences (MDs), standardised mean differences (SMDs) and risk ratios (RR) using a random-effects model. We assessed quality of the trial evidence for all primary outcomes using the GRADE methodology. We completed a 'Risk of bias' assessment for all studies and performed sensitivity analysis by excluding studies judged at high or unclear risk of bias for sequence generation, allocation concealment and incomplete outcome data. We contacted authors for missing data. Our primary endpoints were 1) composite endpoint (including all-cause mortality, non-fatal myocardial infarction or any new stroke, or both) assessed at 30 days after surgery, 2) cardiac troponin T (cTnT, ng/L) at 48 hours and 72 hours, and as area under the curve (