Immediate vs. delayed stenting in acute myocardial infarction: a systematic review and meta-analysis.

AIMS To conduct a meta-analysis of studies comparing immediate versus delayed stenting in populations where primary percutaneous coronary intervention (PCI) or early invasive revascularisation was the initial mode of reperfusion. METHODS AND RESULTS We identified five non-randomised studies and one randomised trial for a total of 590 patients in studies comparing immediate to delayed stenting in populations where primary PCI or early invasive revascularisation was the initial mode of reperfusion. In non-randomised studies, delayed stenting was associated with a reduction of procedure-related angiographic events (OR=0.13, 95% credible interval [CrI]: 0.03- 0.36). No differences were observed in the rates of major bleeding (OR=0.81, 95% CrI: 0.01-13.42) and major adverse cardiac events (OR=0.40, 95% CrI: 0.09-1.91), between delayed and immediate stenting. In one randomised trial, delayed stenting was associated with a reduction in myocardial infarction during hospitalisation (39% vs. 60%; relative risk [RR]=0.55, 95% confidence interval [CI]: 0.39-0.80). None of the patients assigned to delayed stenting experienced a major adverse cardiac event in the interval between the initial angiogram and the stenting. CONCLUSIONS Delayed stent implantation is associated with better angiographic outcomes. Randomised trials are required to assess whether delayed stenting translates into better long-term cardiac outcomes.