Surrogate and clinical outcomes following ischemic postconditioning during primary percutaneous coronary intervention of ST-segment elevation myocardial infarction: A meta-analysis of 15 randomized trials

Objectives: To conduct a meta-analysis on surrogate and clinical outcomes with myocardial ischemic postconditioning (IPoC) following revascularization with primary percutaneous intervention (PPCI) for ST-segment myocardial infarction (STEMI) compared with PPCI alone. Background: Reperfusion injury remains an important problem following PPCI for STEMI. Trials of IPoC have mainly focused on cardiac biomarkers; the impact on clinical outcomes is unknown. Methods: Clinical trials that randomized STEMI patients to IPoC as compared with conventional PPCI were included for analysis. Results: A total of 15 randomized trials with 1,545 patients met our selection criteria (785 underwent IPoC1PPCI, 760 PPCI alone). Mean follow-up for clinical outcomes was 4.7 months. The mean ischemic time was 225 min. ST-segment resolution (Relative Risk [RR]50.98; 95% Confidence Intervals [CI] 0.85-1.13; P50.75) and infarct size (Weighted mean difference [WMD]522.53%, 95% CI 26.10 to 1.05; P50.17) were similar between the IPoC1PPCI vs. PPCI arms. Left ventricular ejection fraction at followup was marginally higher in the IPoC (WMD54.15%, 95% CI 0.19-8.12%, P50.04). No differences were noted in any of the clinical outcomes studied, including mortality (RR51.52; 95% CI 0.77-2.99; P50.23), recurrent MI (RR53.04; 95% CI 0.74-12.54; P50.12); stent thrombosis (RR51.24, 95% CI 0.51-3.04; P50.83) or the composite MACE outcome (RR51.53; 95% CI 0.89-2.63; P50.13). Conclusions: IPoC following PPCI is not associated with improvements in surrogate or clinical outcomes at 5 months as compared with PPCI alone. Our findings indicate no role for IPoC in the routine management of patients with STEMI.