The outcomes in STEMI patients with high thrombus burden treated by deferred versus immediate stent implantation in primary percutaneous coronary intervention: a prospective cohort study

Background: No-/slow-reflow indicates worse outcomes in ST-elevation myocardial infarction (STEMI) patients with high thrombus burden. We examined whether deferred stenting (DS) strategy reduces no-/slow-reflow or major adverse cardiovascular events (MACEs) in primary percutaneous coronary intervention (pPCI) for patients with acute STEMI and high thrombus burden.Methods: We performed an open-label, multi-center, prospective cohort study among eligible patients with acute STEMI and high thrombus burden who further received pPCI. All participants received PCI with DS (second procedure performed within 48–72 h) or immediate-stenting (IS) strategy. The primary outcome was the incidence of no-/slow-reflow. We evaluated MACEs and bleeding events during hospitalization and at 30- and 90-day follow-ups.Results: We recruited 245 patients to this study, including 51 with DS and 194 with IS. Baseline clinical characters were comparable between the 2 strategies. Incidence of no-/slow-reflow defined by thrombolysis in myocardial infarction (TIMI) flow grade was not significantly different between the 2 strategies [DS: 5 (9.8%), IS: 33 (17.0%), P=0.21]. No-/slow-reflow by TIMI myocardial perfusion grade (TMPG) was less prevalent in DS [20 (39.2%) vs. 107 (55.2%), P=0.04]. No significant differences were found in recurrence of myocardial infarction (P=0.56), cardiac death (P=0.37), all-cause mortality (P=0.37), heart failure-induced readmission (P=0.35), or bleeding (P=0.61) between the 2 strategies in-hospital, and at 30- and 90-day follow-up.Conclusions: In STEMI patients with high thrombus burden who underwent pPCI, DS strategy reduced no-/slow-reflow of microcirculation. However, DS strategy did not reduce incidence of MACEs or bleeding.