Drug-eluting stent malapposition and its relationship to drug-eluting stent thrombosis

Stent malapposition (whether acute and persistent, or late and acquired) is common, occurring in 10–20% of drug-eluting stent implantations in stable patients and 30–40% of ST-elevated myocardial infarction patients. Acute stent malapposition is not a predictor of early stent thrombosis. Conversely, late stent malapposition, especially the large late stent malapposition area, might be a cause of late stent thrombosis and very late stent thrombosis in some patients. Other causes such as vessel wall inflammation, positive vessel wall remodeling, in-stent neoatherosclerosis with plaque rupture, stent fracture and delayed re-endothelialization with uncovered stent struts may also contribute to late and very late stent thrombosis.