The effects of remote ischemic conditioning in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention: a meta-analysis.

INTRODUCTION: Timely and successful reperfusion is effective at improving outcome in patients presenting with ST elevation myocardial infarction (STEMI). However, abrupt restoration of blood flow may cause detrimental myocardial reperfusion injury. Remote ischemic conditioning (RIC) is a potent activator of innate protection against ischemia-reperfusion injury. This study assessed remote ischemic conditioning in patients presenting with STEMI treated with primary percutaneous coronary intervention (PCI).

EVIDENCE ACQUISITION: Relevant studies were identified through electronic literature search from PubMed, Medline, EMBASE, CNKI, WANFANG, and VIP. Studies published up to December 2015 were eligible for inclusion. RIC was performed by applying consecutive cycles of reocclusion/reperfusion through intermittent upper or lower limb ischemia before, during, or after reperfusion. The outcomes included creatine kinase-MB (CK-MB), ST resolution (STR), and left ventricular ejection fraction (LVEF).

EVIDENCE SYNTHESIS: The 9 trials allocated 540 patients to perform RIC cycles before, during, or after reperfusion and 533 patients to usual PCI. Statistical analysis indicated that the peak of CK-MB and CK-MB AUC in RIC groups decrease significantly during the first 72 hours after PCI compared with controls (P=0.02 and P<0.01). The STR was significantly improved in RIC patients than in control subjects (P<0.001). LVEF is also improved 7 days after myocardial infarction (P=0.001). However, LVEF was not significantly different between study groups over 1 month (P=0.65).

CONCLUSIONS: There may be a cardioprotective effect of RIC before, during, or after reperfusion, in the setting of acute STEMI.