Characteristics of Earlier Versus Delayed Presentation of Very Late Drug-Eluting Stent Thrombosis: An Optical Coherence Tomographic Study

Background: the pathophysiology underlying very late drug-eluting stent (des) thrombosis is not sufficiently understood. using optical coherence tomography,we investigated characteristics of very late stent thrombosis (vlst) according to different onset times.methods and results: a total of 98 patients from 10 south korean hospitals who underwent optical coherence tomography for evaluation of very late des thrombosis were retrospectively included in analyses. vlst occurred at a median of 55.1 months after des implantation. all patients were divided into 2 equal groups of earlier versus delayed presentation of vlst,according to median onset time. in total,27 patients were treated with next-generation des and 71 with first-generation des. based on optical coherence tomography findings at thrombotic sites,main vlst mechanisms were as follows,in descending order: neoatherosclerosis (34.7%),stent malapposition (33.7%),and uncovered struts without stent malapposition or evagination (24.5%). compared with patients with earlier vlst,patients with delayed vlst had lower frequency of uncovered struts without stent malapposition or evagination (34.7% versus 14.3%,respectively; p=0.019). conversely,the frequency of neoatherosclerosis was higher in patients with delayed versus earlier vlst (44.9% versus 24.5%,respectively; p=0.034). the frequency of stent malapposition was not different between patients with earlier and delayed vlst (34.7% versus 32.7%,respectively; p=0.831). the frequency of stent malapposition,evagination,and uncovered struts was still half of delayed vlst.conclusions: the pathological mechanisms of very late des thrombosis changed over time. delayed neointimal healing remained a substantial substrate for vlst,even long after des implantation. © 2017 the authors. published on behalf of the american heart association,inc.,by wiley.