Title: Studies of the Vascular Properties of Arterial Bypass Grafts in the Arterial Revascularisation Trial
The Arterial Revascularisation Trial (ART) compares coronary artery bypass grafting with a single internal mammary artery (IMA) to surgery with bilateral internal mammary arteries. In this study the radial artery was mainly used as the additional graft. While the IMA has patency rates of up to 95% at 10 years there is conflicting data on the success of radial artery grafts. Chief investigator of the ART trial is Professor David Taggart.
ART-Vascular is a sub-study of ART that invited 258 Oxford based patients undergoing cardiac surgery, to undergo further investigations that aims to explore whether biological factors might also have an important influence on the success of their bypass grafts after surgery.
The inner lining of arteries are made up of endothelial cells which release substances that cause your artery to dilate. The measure of how well this mechanism works is called endothelial function and is potentially modifiable.
Pre-operative tests were carried out to investigate endothelial function in the radial artery by non-invasive ultrasound (by flow mediated dilation) in combination with laboratory tests of vessel physiology to test the hypothesis that endothelial dysfunction is a key factor in early radial artery graft failure.
-To investigate why some bypass grafts work better than others in the ART study.
-To test the hypotheses that pre-operative measures of endothelial function of the radial artery predict early radial artery graft failure and cardiovascular outcome following coronary artery bypass grafting surgery.
258 patients undergoing coronary artery bypass grafting surgery at the John Radcliffe Hospital, Oxford were enrolled to the study. The study is no longer recruiting. Data collection continues through access to patient’s medical records, extracting data from both the local Hospital archive and the NHS Digital records. Samples are still being analysed, and new scientific results continue to be presented in scientific meetings and published in scientific publications.
As this study is part of the Oxford Heart Vessels Fat (Ox-HVF) cohort, its results are interpreted together with the findings of other Ox-HVF projects. Ox-HVF is a cluster of clinical studies that provide synergistic results allowing the deployment of a multi-level strategy to understand the mechanisms of cardiovascular disease. This adds value to the research results and potentially may allow translation of the findings into clinical applications.
Study Visits: Study participants had non-invasive, ultrasound assessment of the radial artery’s endothelial function before surgery and surplus segments of the vessels used for bypass grafting were collected for laboratory tests. 60 patients were invited back 9 months after surgery for a follow up angiography to assess the grafts’ patency.
Prof Charalambos Antoniades (CI of sub-study), Prof David Taggart, Prof Keith Channon, Prof Paul Leeson, Dr David Adlam and Miss Laura Herdman
Organising and Research Funding: The study is organised by the Department of Cardiothoracic Surgery and Department of Cardiology at the John Radcliffe hospital and the University of Oxford. The study is funded by the British Heart Foundation and the Medical Research Council.
Study Approval: Ethical Approval was provided following review by the Division of Cardiovascular Medicine (University of Oxford) and the Northern and Yorkshire Multi-Centre Research Ethics Committee (Reference MREC/04/3/006).