A randomized trial of deferred stenting versus immediate stenting to prevent no-or slow reflow in acute ST-elevation myocardial infarction(DEFER-STEMI)

Objectives To assess whether deferred stenting might reduce no-reflow and salvage myocardium in primary percutaneous coronary intervention(PCI) for ST-elevation myocardial infarction(STEMI). Background Noreflow is associated with adverse outcomes in STEMI. Methods A prospective single center randomized controlled proof-of-concept trial in reperfused STEMI patients with ≥ 1 risk factors for no-reflow. Randomization was to deferred stenting with an intention-to-stent 4-16 hours later or conventional treatment with immediate stenting. The primary outcome was the incidence of no / slow-reflow(TIMI ≤ 2). Cardiac magnetic resonance imaging(MRI) was performed 2 days and 6 months post-MI. Myocardial salvage was the final infarct size indexed to the initial area-at-risk. Results Of 411 STEMI patients(11 March 2012-21 November 2012), 101patients(mean age 60 years, 69% male) were randomized(n = 52 deferred group, n = 49 immediate stenting). The median(IQR) time to the second procedure in the deferred group was 9(6, 12) hours. Fewer patients in the deferred stenting group had no / slow-reflow [14(29%) vs. 3(6%); P = 0.006], no-reflow[7(14%) vs. 1(2%); P = 0.052] and intra-procedural thrombotic events [16(33%) vs. 5(10%); P =0.010]. TIMI coronary flow grades at the end of PCI were higher in the deferred stenting group(P = 0.018).Recurrent STEMI occurred in 2 patients in the deferred group before the second procedure. Myocardial salvage index at 6 months was greater in the deferred group [68(54, 82%) vs. 56(31, 72%); P = 0.031].Conclusion In high risk STEMI patients, deferred stenting in primary PCI reduced no-reflow and increased myocardial salvage.