Author + information
- David Adlam, DPhil,
- Charalambos Antoniades, MD, PhD,
- Regent Lee, MD,
- Johnathan Diesch, BA,
- Cheerag Shirodaria, MD,
- David Taggart, PhD,
- Paul Leeson, PhD and
- Keith M. Channon, MD⁎ ()
- ↵⁎Address for Correspondence:
Prof. Keith M. Channon, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, United Kingdom
CORONARY ARTERY BYPASS GRAFTING (CABG) REMAINS A FIRST-LINE TREATMENT FOR CORONARY ARTERY DISEASE, with good long-term clinical outcomes. Although left internal mammary grafts have high long-term patency rates, in current CABG practice the overwhelming majority of patients also require saphenous vein grafts (SVG) as bypass conduits. SVG occlusion following surgery remains a significant limitation of CABG. Serial angiographic follow-up studies demonstrate that approximately 10% of SVG occlude in the first year after which there is a continued attrition which accelerates as grafts age. However, the relationship between angiographic stenosis and SVG occlusion is less clear, since the majority of graft occlusions occur in grafts previously characterized as angiographically normal (1).
We performed elective angiography (n = 42) with optical coherence tomography (OCT) (n = 16) and intravascular ultrasound (IVUS) (n = 21) assessment of patent SVG in asymptomatic patients 3 years after surgery. All aspects of the study were approved by local and national ethical committee. Patients gave written informed consent prior to the procedure. Fifty-five percent of SVGs were occluded (patency rates: 93% left internal mammary artery, 73% right internal mammary artery, 36% radial conduit patency). All patent grafts imaged had variable fibrocellular neointima but no significant stenotic disease. OCT but not IVUS demonstrated findings consistent with thin-cap fibroatheroma (2) in 6 of 16 SVGs and luminal adherent thrombus in 4 of 16 SVGs. These novel features may be important markers of vein grafts vulnerable to future occlusion.
This analysis of SVGs assessed by angiography and endoluminal imaging with IVUS and OCT suggests that following contemporary surgery with appropriate concomitant secondary prevention therapy there remains significant loss of SVG conduits following CABG but with little development of stenotic disease in patent vein grafts after 3 years. OCT, but not IVUS, identifies clear features of atherosclerosis, including circumferential fibrous caps and adherent thrombus. Our findings suggest that high resolution imaging techniques such as OCT may begin to allow us insights into the causes of vein graft failure (Figs. 1, 2, and 3)⇓⇓
This work was supported by the NIHR Biomedical Research Centre, Oxford, and by grants from the British Heart Foundation (RG/02/006 to K.M.C., FS/03/105/16340 to C.S. PG/05/040 and FS/06/024 to P.L.) and a Marie Curie Re-Integration Grant, within the 7th European Community Framework Programme (to C.A.).
All authors have reported that they have no relationships to disclose.
- American College of Cardiology Foundation