LO076: Remote ischemic conditioning to reduce reperfusion injury during acute STEMI: a systematic review and meta-analysis

Introduction: Remote ischemic conditioning (RIC) is a non-invasive therapeutic strategy that uses brief cycles of inflation and deflation of a blood pressure cuff to reduce ischemia-reperfusion injury during acute ST-elevation myocardial infarction (STEMI). The primary objective of this systematic review was to determine if RIC initiated prior to catheterization increases myocardial salvage index, defined as the proportion of area at risk of the left ventricle salvaged by treatment following emergent percutaneous coronary intervention (PCI) for STEMI. Secondary outcomes included infarct size and major adverse cardiovascular events. Methods: Electronic searches of PubMed, Ovid MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials were conducted and reference lists were hand-searched. Randomized controlled trials comparing PCI with and without RIC for patients with STEMI published in English were included. Two reviewers independently screened abstracts, assessed quality of the studies, and extracted data. Data were pooled using random-effects models and reported as risk ratios (RR) with 95% confidence intervals (CIs). Results: Nine RCTs were included with a combined total of 999 patients (RIC+PCI = 534, PCI = 465). The myocardial salvage index was higher in the RIC+PCI group at 3 and 30 days; mean difference 0.09 (95% CI: 0.04, 0.15) and 0.12 (95% CI: 0.03, 0.21), respectively. Infarct size was reduced in the RIC+PCI group at 3 and 30 days; mean difference -3.82 (95% CI: -8.15, 0.51) and -4.00 (95% CI: -7.07, -0.93), respectively. There was no statistical difference with respect to death and re-infarction, however there was a reduction in heart failure with RIC+PCI at 6 months; RR: 0.43 (95% CI: 0.19, 0.99). Conclusion: RIC is emerging as a promising adjunctive treatment to PCI for the prevention of reperfusion injury in STEMI patients. Ongoing, multicenter clinical trials will help elucidate the effect of RIC on clinical outcomes such a hospitalization, heart failure and mortality.