Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp BVS as compared with metallic platform DES may include: decrease in late adverse events through complete biodegradation of stent struts preventing the risk of thrombus formation at the site of impaired endothelialization; normalization of vasomotion and compensatory remodeling during follow-up, thus suggesting restoration of normal vessel physiology after complete biodegradation of the stent struts; no interference with diagnostic or therapeutic measures (eg, coronary artery bypass graft) in case of disease progression; improved vascular healing; and discontinuation of long-term antiplatelet therapy in patients with single-vessel coronary artery disease. In particular, some crucial points in STEMI patients have to be emphasized. First of all, culprit lesions are frequently localized in the proximal segments of the coronary artery tree; restoration of physiological vasomotion may therefore have a greater effect in patients with STEMI as compared with patients with stable coronary artery disease. Secondly, vulnerable plaque of STEMI lesions, often characterized by necrotic core, interferes with vascular healing after metallic stent implantation, thus leading to coronary evagination or late acquired malapposition, both of which have been correlated with adverse ischemic outcomes. 14 Recent study suggests that BVS may eventually decrease the incidence of angina during follow-up, by reducing fixed and dynamic restenoses and by improving vasomotor responses. 15 Finally, the potential advantages of implanting BVS (vs. other DES) in STEMI may be mostly related to the young age of these patients. Indeed, they usually have less extensive coronary artery disease (compared with non-STrimary percutaneous coronary intervention (PCI) currently represents the first choice of treatment in experienced centers for patients presenting with ST-segment elevation myocardial infarction (STEMI) with limited time delay. 1 In this context, first-generation drug-eluting stents (DES) have reduced the need for repeat revascularization compared with bare metal stents (BMS). 2-4 However, the 1st-generation DES have been associated with late complications, such as neo-atherosclerosis, late restenosis, and stent thrombosis. 5 In particular, in the acute thrombotic setting, the antiproliferative drug elution used in DES has been shown to interfere with vascular healing processes, creating the background for delayed strut coverage, and persistent or acquired malapposition. 6,7 Possible explanations for this phenomenon are thrombus sequestration behind the struts, which subsequently resolves with acquired malapposition, and vasoconstriction during the acute phase. 8 The newer-generation DES with improved biocompatibility of polymers have also shown a lower rate of clinical events in acute patients as compared with either 1st-generation DES or BMS. 9-12 The clinical introduction of bioresorbable scaffolds resulted in a revolutionary change among local c...