Author + information
- Received August 10, 2011
- Revision received December 7, 2011
- Accepted December 22, 2011
- Published online June 1, 2012.
- Saami K. Yazdani, PhD⁎,
- Andrew Farb, MD†,
- Masataka Nakano, MD⁎,
- Marc Vorpahl, MD⁎,
- Elena Ladich, MD⁎,
- Aloke V. Finn, MD‡,
- Frank D. Kolodgie, PhD⁎ and
- Renu Virmani, MD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Renu Virmani, CVPath Institute Inc., 19 Firstfield Road, Gaithersburg, Maryland 20878
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.
Dr. Finn is supported by National Institutes of Health 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. Dr. Virmani is a consultant for Medtronic AVE, Abbott Vascular, W.L. Gore, Atrium Medical, Arsenal Medical, and Lutonix. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received August 10, 2011.
- Revision received December 7, 2011.
- Accepted December 22, 2011.
- American College of Cardiology Foundation