Pathology of Chronic Total Occlusion in Bare-Metal Versus Drug-Eluting Stents: Implications for Revascularization.
The aim of this study was to explore the pathology of in-stent chronic total occlusion (IS-CTO) in bare-metal (BMS) versus drug-eluting stents (DES).



Despite a relatively high prevalence of IS-CTO, little is known about the underlying etiology and histopathologic characteristics of the occlusion.



From CVPath Institute's stent registry of human native coronary arteries, the authors identified 56 lesions (32 BMS and 24 DES) from 54 patients with IS-CTO. Sections of stented coronary arteries were examined for histological features of IS-CTO. The underlying mechanisms of IS-CTO were determined along with the histopathological characteristics.



The pathological prevalence of IS-CTO was significantly higher in BMS versus DES cases at autopsy (11.7% vs. 5.9%; p = 0.01). The most frequent etiology of IS-CTO was acute thrombotic occlusion (51% in BMS vs. 67% in DES), followed by restenosis (31% vs. 8%) and neoatherosclerotic rupture (9% vs. 4%). The proximal lumen pattern was abrupt in 67% of BMS and in 57% of DES, whereas the distal lumen was tapered in 68% of BMS and in 74% of DES. BMS showed longer fibrous cap of IS-CTO than DES in both proximal (4.6 mm vs. 1.6 mm; p = 0.06) and distal (5.3 mm vs. 2.0 mm; p = 0.06).



At autopsy, IS-CTO was observed more frequently in BMS versus DES, with acute thrombotic occlusion being the most frequent cause, followed by restenosis (especially in BMS) and neoatherosclerotic rupture. Our findings shed new light upon the frequency, mechanisms, and pathology of IS-CTO.
CVPath Institute, Gaithersburg, Maryland.
Hiroyoshi
H
Mori
CVPath Institute, Gaithersburg, Maryland.
Christoph
C
Lutter
CVPath Institute, Gaithersburg, Maryland.
Kazuyuki
K
Yahagi
CVPath Institute, Gaithersburg, Maryland.
Emanuel
E
Harari
CVPath Institute, Gaithersburg, Maryland.
Robert
R
Kutys
Office of the Chief Medical Examiner, Baltimore, Maryland.
David R
DR
Fowler
CVPath Institute, Gaithersburg, Maryland.
Elena
E
Ladich
CVPath Institute, Gaithersburg, Maryland.
Michael
M
Joner
CVPath Institute, Gaithersburg, Maryland.
Renu
R
Virmani
CVPath Institute, Gaithersburg, Maryland; University of Maryland, School of Medicine, Baltimore, Maryland. Electronic address: afinn@cvpath.org.
Aloke V
AV
Finn
D000368:Aged; D001344:Autopsy; D002908:Chronic Disease; D054059:Coronary Occlusion / Q000453:epidemiology / Q000473:pathology*; D023903:Coronary Restenosis / Q000453:epidemiology / Q000473:pathology*; D003328:Coronary Thrombosis / Q000453:epidemiology / Q000473:pathology*; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008670:Metals; D008875:Middle Aged; D058426:Neointima; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects* / Q000295:instrumentation*; D058226:Plaque, Atherosclerotic; D015995:Prevalence; D011474:Prosthesis Design; D012042:Registries; D012307:Risk Factors; D012422:Rupture, Spontaneous; D015607:Stents; D016896:Treatment Outcome
D008670:Metals
chronic total occlusion; in-stent chronic total occlusion; neoatherosclerosis; restenosis; stent thrombosis