Remote ischaemic conditioning for myocardial infarction or elective PCI: systematic review and meta-analyses of randomised trials

Background:The efficacy of remote ischaemic conditioning in clinical trials of ST-segment elevation myocardial infarction (STEMI) or elective percutaneous coronary intervention is controversial. We aimed to systematically review and meta-analyse whether remote ischaemic conditioning reduces myocardial damage in those patients.Methods:We searched PubMed, Embase and Web of Science from inception until December 2017 for randomised clinical trials evaluating remote ischaemic conditioning versus a control group. Two independent reviewers extracted data of 23 trials (2118 patients with STEMI; 2048 patients undergoing elective percutaneous coronary intervention) which were meta-analysed using random-effects models.Results:Remote ischaemic conditioning reduced infarct size in STEMI patients when assessed by imaging (mean difference of infarct size as percentage of left ventricle −2.43, 95% confidence interval (CI) –4.37 to −0.48; P=0.01; I2=44%; n=925) or biomarkers related to myocardial injury (peak values of ca...