Deferred or immediate stent implantation for primary percutaneous coronary intervention: A meta-analysis of randomized trials

Objectives: To perform a meta-analysis of randomized trials comparing a deferred versus immediate stenting strategy for primary percutaneous coronary intervention (PCI). Background: Deferred stent implantation has emerged as a potential strategy aiming to reduce the thrombus burden and improve micro-vascular reperfusion during primary PCI. Methods: Electronic databases were searched for randomized trials that compared a deferred stent implantation versus immediate stent implantation strategy in patients undergoing primary PCI. Random effects risk ratios (RR) were estimated for the outcomes of interest. Results: Four trials with 1,570 patients were included. A deferred stent implantation strategy was associated with a lower incidence of no-/slow reflow (RR 0.49, 95% confidence interval [CI] 0.24-0.96), and improved myocardial blush grade 3 (RR 1.42, 95% CI 1.14–1.77). At a mean follow up of 34 ± 15 months, both strategies were associated with a similar risk of all-cause mortality (RR 0.85, 95% CI 0.58–1.24), cardiovascular mortality (RR 0.84, 95% CI 0.48–1.45), reinfarction (RR 1.54, 95% CI 0.43–5.49), and stent thrombosis (RR = 0.35, 95% CI 0.04–3.35, P = 0.36). Conclusion: In patients undergoing primary PCI, deferred stent implantation is associated with improvement in surrogate outcomes, but does not appear to improve clinical outcomes. Future randomized trials are encouraged to identify the patient population who might benefit from a deferred stent implantation strategy (e.g., high thrombus burden).