Pathology of Drug-Eluting Versus Bare-Metal Stents in Saphenous Vein Bypass Graft Lesions

• Type of Material: Article
• Authors: Saami K. Yazdani, CVPath Institute, Inc.; Andrew Farb, U.S. Food and Drug Administration; Masataka Nakano, CVPath Institute, Inc.; Marc Vorpahl, CVPath Institute, Inc.; Elena Ladich, CVPath Institute, Inc.; Aloke Finn, Emory University; Frank D. Kolodgie, CVPath Institute, Inc.; Renu Virmani, CVPath Institute, Inc.
• Language: English
• Date: 2012-06-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2012 American College of Cardiology Foundation.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jcin.2011.12.017
• Title of Journal or Parent Work: JACC: Cardiovascular Interventions
• ISSN: 1936-8798
• Volume: 5
• Issue: 6
• Start Page: 666
• End Page: 674
• Grant/Funding Information: Dr. Finn is supported by the NIH grant HL096970-01A1, the Carlyle Fraser Heart Center at Emory University, sponsored research agreement with Medtronic and St. Jude Medical, and is a consultant for Abbott Vascular and Cordis.
• Keywords: FOLLOW-UP; saphenous vein bypass graft; INTERVENTION; IMPLANTATION; THROMBOSIS; drug-eluting stent(s); Cardiovascular System & Cardiology; Science & Technology; SIROLIMUS; pathology; PREDICTORS; PLACEMENT; BALLOON ANGIOPLASTY; CORONARY-ARTERY-DISEASE; RESTENOSIS; bare-metal stent(s); Life Sciences & Biomedicine; Cardiac & Cardiovascular Systems
• Research Categories: Health Sciences, Radiology; Health Sciences, Pathology

Abstract

Objectives: The purpose of this study was to assess the pathological responses of atherosclerotic saphenous vein bypass grafts (SVBGs) to drug-eluting stents (DES) versus bare-metal stents (BMS). Background: Repeat bypass surgery is typically associated with a high rate of morbidity and mortality. Percutaneous coronary interventions have emerged as the preferred treatment; however, only limited data are available on SVBGs pathological responses to DES and BMS. Methods: Formalin-fixed SVBG of > 2 years duration (n = 31) were collected to histologically characterize advanced atherosclerotic lesions in native SVBG. In a separate group, SVBGs treated with DES (n = 9) and BMS (n = 9) for > 30 days duration were assessed for morphological and morphometric changes. Results: Necrotic core lesions were identified in 25% of SVBG sections, and plaque rupture with luminal thrombosis was observed in 6.3% of histological sections (32% [10 of 31] vein grafts examined). Morphometry of DES demonstrated reduction in neointimal thickening versus BMS (0.13 mm [interquartile range: 0.06 to 0.16 mm] vs. 0.30 mm [interquartile range: 0.20 to 0.48 mm], p = 0.004). DES lesions also showed greater delayed healing characterized by increased peristrut fibrin deposition, higher percentage of uncovered struts, and less endothelialization compared with BMS. Stent fractures (DES 56% vs. BMS 11%, p = 0.045) and late stent thrombosis (DES 44% vs. BMS 0%, p = 0.023) were more common in DES versus BMS. Conclusions: Advanced SVBG atherosclerotic lesions are characterized by large hemorrhagic necrotic cores. Stenting of such lesions is associated with delayed vascular healing and late thrombosis particularly following DES implantation, which may help explain the higher rates of cardiovascular events observed in SVBG stenting as compared with native coronary arteries.