Austin Health Professors Part of Multi-National CABG Study
Professor Jai Raman and Professor David Hare, Austin Health are part of a multi-national study reporting the 10 year outcomes of a patient-data pooled analysis of randomised trials comparing the radial artery versus sephenous vein as a CABG conduit.
Association of Radial Artery Graft vs Saphenous Vein Graft With Long-term Cardiovascular Outcomes Among Patients Undergoing Coronary Artery Bypass Grafting
A Systematic Review and Meta-analysis
Impact of this article:-
CABG is still the most commonly performed cardiac surgical procedure worldwide, with growing numbers in emerging economies and underdeveloped countries also. The left internal mammary artery, grafted to the left anterior descending coronary artery, is the cornerstone of this procedure with good long-standing durability. Grafts to the other vessels of the heart have conventionally utilised saphenous vein as aorto-coronary bypass grafts. In general, vein grafts are predisposed to develop atherosclerotic disease and tend to start blocking off beyond the first 5 years post-operatively.
Professor Brian Buxton was a pioneer 30 year ago in the evaluation, propagation and study of arterial grafts with hope of better long-term patency – the use of the radial artery and the right internal mammary artery were popularised by him, resulting in him having an international impact on surgical practice. This appeared transformational in achieving better long-term outcomes and survival in patients with coronary artery disease. Numbers of observational studies suggested the significant benefits for arterial grafts.
Of course, the only way to avoid the potential confounding issues of case selection of observational studies is to undertake randomised control trials (RCTs). One of the pioneering and most largest studies was undertaken at the Austin Hospital with patients randomised between 1995 and 2005: RAPCO (Radial Artery Patency & Clinical Outcomes) and then closely followed for the subsequent 10 years for both graft patency and clinical outcomes. A study of this kind has required a large team of investigators over a 25 year period. Professor Brian Buxton was always the energy behind the trial. He and Professor Jai Raman, as well as being involved in the original protocol development, were the trial surgeons responsible for the largest numbers of patients enrolled and implanted with randomised grafts. Professor David Hare has been a co-investigator from the start, ensuring scientific precision, rigorous follow up, event adjudication, data analysis and publications over the subsequent 25 years.
To get more power to analyse clinical outcomes, we linked the primary patient data from the 5 most rigorous RCTs that had compared the radial artery with saphenous vein grafts in a format that allowed differential analysis of the subsequent clinical outcomes. We called this the “RADIAL” collaboration.
The publication of our 5-year outcome data in the New England Journal of Medicine in 2018 demonstrated important clinical differences but without enough time elapsed for the differential rate of graft disease vein and arterial conduits to have had such a profound effect.
This recent publication in JAMA (Impact Factor 45.5) reports the 10-year clinical outcomes, demonstrating a marked advantage in favour of the radial artery grafts. Whilst not an a priori outcome, there was also a potentially significant all-cause mortality advantage (p<0.01). The accompanying editorial comment by Steven Nissen is also very enlightening. This paper should have a major impact on the international practice of coronary artery surgery.
Professor Jai Raman (L) and Professor David Hare (R)
Association of Radial Artery Graft vs Saphenous Vein Graft With Long-term Cardiovascular Outcomes Among Patients Undergoing Coronary Artery
A Systematic Review and Meta-analysis