OBJECTIVES:We conducted a meta-analysis of randomized controlled trials (RCTs) to compare the efficacy and safety of early versus delayed invasive management of non-ST-elevation acute coronary syndrome (NSTE-ACS). BACKGROUND:Coronary angiography is recommended for patients with NSTE-ACS, however, the optimal timing for this remains controversial. METHODS:Literature search of Pubmed/MEDLINE, Cochrane Library, and Embase for all RCTs that compared early with delayed invasive approaches in treating NSTE-ACS was conducted by two independent authors. Primary outcome was major adverse cardiovascular events (MACE), while the secondary outcomes included cardiovascular mortality, all-cause mortality, myocardial infarction (MI), and bleeding events. The Mantel-Haenszel random-effects model was used to calculate risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS:We included 14 RCTs (9,637 patients, mean age 65.4, 67% males). The early invasive strategy was associated with a lower incidence of MACE compared with the delayed invasive strategy (RR 0.65, 95%CI 0.49-0.87; p = .003). Subgroup analysis according to GRACE score showed a lower incidence of MACE with early invasive strategies in GRACE >140 patients (p for interaction = .002). Furthermore, recurrent ischemia was lower in patients with an early invasive strategy (RR 0.42, 95%CI 0.26-0.69; p < .0005). In contrast, there were no significant differences in all-cause mortality, cardiovascular mortality, MI, or bleeding events between groups (all p > .05). CONCLUSIONS:Among patients with NSTE-ACS, an early invasive strategy was associated with lower incidence of MACE and recurrent ischemia compared with delayed invasive strategy. There were no significant differences in all-cause mortality, cardiovascular mortality, MI, or bleeding events between groups.