The Recanalization After Thrombolysis as Surrogate for Clinical Outcomes in Patients with ST-segment Elevation Acute Myocardial Infarction: A Systematic Review and Meta-Regression Analysis of Data from Randomized Controlled Trials

AIMS Thrombolytic therapy has been known to be effective in reducing clinical outcomes and increasing recanalization rate among patients with ST-segment elevation acute myocardial infarction (STEMI). However, whether post-thrombolysis recanalization could be used as a surrogate for clinical outcomes is unknown. METHODS We systematically searched PubMed, EMBASE and the Cochrane Library database to identify randomized controlled trials (RCT) that examined effects of thrombolytic agents in STEMI. Recanalization was defined as TIMI grade 2 or 3 flow. The primary outcome was in-hospital all-cause mortality. Secondary outcomes included in-hospital and 30-day recurrent myocardial infarction (re-MI), composite of death and re-MI, major bleeding and all bleeding. Random-effects meta-regression was used for analysis. RESULTS We identified 111 eligible study arms and 52 eligible comparisons from 58 RCTs involving 16 536 patients. Our analyses showed that among study arms recanalization rate was significantly inversely associated with the incidence of in-hospital all-cause mortality (β: -0.07, 95% confidence interval [CI]: -0.13 to -0.02), re-MI (β: -0.09, 95%CI: -0.18 to -0.01) and the composite of death and re-MI (β: -0.17, 95%CI: -0.28 to -0.05), and positively associated with in-hospital all bleeding but not with major bleeding. Among paired comparisons, the difference in recanalization rate was associated with the corresponding difference in incidence of in-hospital all-cause mortality (β: -0.15, 95%CI: -0.28 to -0.01) but the relationship was not significant for any other outcome. CONCLUSION Pooled evidence from RCTs suggest the potential use of recanalization as a surrogate for clinical outcomes in evaluating the efficacy of thrombolysis among patients with STEMI.