Early vs. delayed invasive strategy in patients with acute coronary syndromes without ST-segment elevation: a meta-analysis of randomized studies

Although early percutaneous coronary intervention has been demonstrated to reduce the risk of mortality in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS), there are emerging conflicting data as to whether the catheterization needs to be done very early or whether it could be delayed while the patient receives medical therapy. The aim of the current study was to perform a meta-analysis of randomized controlled trials (RCTs) comparing early vs. delayed invasive strategies for NSTE-ACS patients. Medline/CENTRAL and the Web were searched for RCTs comparing early vs. delayed invasive strategies for NSTE-ACS patients. The primary endpoint was all cause mortality, whereas myocardial infarction (MI), coronary revascularizations and 30-day major bleeding complications were secondary end points. Fixed or random effects models were used based on statistical heterogeneity. As a sensitivity analysis, Bayesian random effects meta-analysis was performed in addition to the classical random effects meta-analysis. A total of 5 RCTs were finally included, enrolling 4155 patients. As compared with a delayed strategy, an early invasive approach did not significantly reduce the rates of death [odds ratio (OR) 95% confidence interval (95% CI) = 0.81 (95% CI 0.60-1.09), P = 0.17], MI [OR = 1.18 (95% CI 0.68-2.05), P = 0.55] or revascularizations [OR = 0.97 (0.77-1.24), P = 0.82]. There was a not significant trend toward fewer major bleeding complications for the early invasive approach [OR (95% CI) = 0.76 (0.55-1.04), P = 0.08]. The present meta-analysis shows that for NSTE-ACS patients a routine early invasive strategy does not significantly improve survival nor reduce MI and revascularization rates as compared with a delayed approach.