Effect of remote ischemic preconditioning in patients with STEMI during primary percutaneous coronary intervention: a meta-analysis of randomized controlled trials

Remote ischemic conditioning is usually associated with cardioprotective intervention against ischemia-reperfusion. However, the effect of remote ischemic preconditioning (RIC-pre) completed before myocardial reperfusion with intermittent limb ischemia-reperfusion in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI) is unclear. PubMed, EMBASE, and the Cochrane Library were fully searched from the beginning of each database up to September 2019 to find seven RCTs, a total of 2796 patients with STEMI undergoing PPCI with RIC-pre and 2818 patients with STEMI undergoing PPCI alone. No significant discrepancy in cardiac death was observed between RIC-pre and control groups (RR 1.03, 95% CI [0.76-1.41], P = 0.83, I² = 40%). The incidences of hospitalization for heart failure (RR 1.03, 95% CI [0.85-1.25], P = 0.77, I² = 0%), myocardial infarction (RR 0.86, 95% CI [0.59-1.26], P = 0.44, I² = 0%), and stroke (RR 1.04, 95% CI [0.62-1.77], P = 0.87, I² = 0%) were not decreased in RIC-pre group when compared with control group. Subgroup analysis revealed similar risk in clinical adverse events at long- and short-term follow-up between two groups. However, peak of creatine kinase-myocardial band (CK-MB) was reduced in RIC-pre group (SWD -0.42, 95% CI [-0.77, -0.07], P = 0.02, I² = 34%). RIC-pre tended to a low peak of CK-MB in patients with STEMI undergoing PPCI, but lacked significant beneficial effects on improving clinical outcomes at long- and short-term follow-up.