Bare Metal Stent Thrombosis and In-Stent Neoatherosclerosis

Abstract

Background-Very late stent thrombosis (VLST) was reported to occur even in patients with bare metal stent (BMS) implantation, although the annual incidence of VLST after BMS was much lower than that after drug-eluting stent implantation. Pathophysiologic mechanisms of VLST after BMS implantation remain largely unknown. . Evidence for fragments of atherosclerotic plaques, such as foamy macrophages, cholesterol crystals, and thin fibrous cap, was more commonly seen in patients with EST (23%) and VLST (31%), whereas these findings were rarely observed in patients with LST (10%). Atherosclerotic fragments were predominantly seen in patients who had EST within 7 days or VLST beyond 3 years. The aspirated thrombi harvested from patients with ST and those with ACS were histologically indistinguishable from each other. Eosinophils were very rarely observed. Plasma level of total cholesterol and triglyceride were significantly higher in VLST cases with atherosclerotic fragments as compared with those without. Conclusions-Fragments of atherosclerotic plaque were highly prevalent in patients with VLST beyond 3 years. Methods and Results-FromDisruption of in-stent neoatherosclerosis could play an important role in the pathogenesis of VLST of BMS occurring beyond 3 years after implantation. (Circ Cardiovasc Interv. 2012;5:47-54.)

Failure Mechanisms and Neoatherosclerosis Patterns in Very Late Drug-Eluting and Bare-Metal Stent Thrombosis

“…7,16,[21][22][23] One pathological study demonstrated that in-stent neoatherosclerosis accounts for 15% of VLST in DES and 83% of VLST in BMS. 11 We observed a trend toward more neoatherosclerosis in BMS than in DES (40.5% in DES and 68.4% in BMS; P=0.056).…”

Increased Thin-Cap Neoatheroma and Periprocedural Myocardial Infarction in Drug-Eluting Stent Restenosis

“…4 However, although systematic in vivo imaging data are not available for BMS, it is reported that more than one third of these patients present with acute coronary syndromes 5 and have evidence of atherosclerotic plaque within aspirates of definite stent thrombosis. 6 Taken together, there remains a need to characterizeBackground-Re-endothelialization is delayed after drug-eluting stent (DES) implantation. In this setting, neointima is more prone to become lipid laden and develop neoatherosclerosis (NA), potentially increasing plaque vulnerability.…”

“…4 However, although systematic in vivo imaging data are not available for BMS, it is reported that more than one third of these patients present with acute coronary syndromes 5 and have evidence of atherosclerotic plaque within aspirates of definite stent thrombosis. 6 Taken together, there remains a need to characterize…”

Very Late Stent Thrombosis and Late Target Lesion Revascularization

“…23 Recently, Yamaji showed that aspiration of the thrombus in 42 patients with very late ST after bare-metal-stent thrombosis showed fragments of atherosclerotic plaques and suggested that disruption of in-stent neoatherosclerosis could play a role in VLST. 24 These observations suggest that neoatherosclerosis may be responsible for VLST in some patients. How often neoatheroscleosis occurs and how often it leads to plaque rupture and thrombosis versus restenosis is not known, and further serial studies are needed.…”