Using a radial artery instead of a saphenous vein for multivessel coronary artery bypass grafting (CABG) improved outcomes, according to the RADIAL meta-analysis of patient-level trial data.
At a mean follow-up of 60 months, the composite outcome of death, myocardial infarction or repeat revascularization was reduced by the multi-artery strategy instead of vein conduit as a supplement to left internal-thoracic-artery grafting during isolated CABG surgery (HR 0.67, P=0.01).
Radial grafts were also associated with:
- Lower risk of occlusion (HR 0.44, P<0.001)
- "Nominally lower" incidence of myocardial infarction (6 versus 9 per 1,000 patient-years, HR 0.72, P=0.04)
- Less repeat revascularization (HR 0.50, P<0.001)
Death from any cause numerically went in the same direction but with a wide confidence interval (15 versus 17 per 1,000 patient-years, HR 0.90, P=0.68), Mario Gaudino, MD, of NewYork-Presbyterian and Weill Cornell Medicine in New York City, reported at the American Association for Thoracic Surgery (AATS) meeting in San Diego.
RADIAL looked at outcomes from 1,036 patients across six trials (534 received radial-artery grafts and 502 received saphenous-vein grafts).
The findings "should guide a genuine change" in how CABG is done, argued study co-author John Puskas, MD, of Icahn School of Medicine at Mount Sinai in New York City and chair of the adult cardiac program for the conference. "Surgeons in North America and Europe presently use the radial artery in less than 8% of all coronary bypass procedures."
Thoralf Sundt, MD, chief of cardiac surgery at Massachusetts General Hospital in Boston, commented: "It is enough to make me question whether I should use more radial arteries."
However, whether it will move overall practice is unclear, he told ľֱ. "The strange thing is that it has proven very, very hard to get surgeons in this country to move their practice towards multiple arterial grafting. If cardiologists see this though they may demand it."
Puskas called RADIAL a landmark study -- and not only for being the first late-breaking study in AATS's more than 100-year history to get a release in the New England Journal of Medicine.
"While retrospective observational studies have suggested that this [benefit of radial conduit] might be the case, several randomized controlled trials of radial artery versus saphenous vein grafts as the second conduit in coronary bypass operations have failed to prove a statistically significant improvement in clinical outcomes with the radial artery, because these individual trials have had too few patients enrolled to reach statistical significance," he told ľֱ.
The pooled data from RADIAL provided "an adequate number of patients to perform more powerful statistical analyses, conclusively proving" the advantage, Puskas said.
Disclosures
The study was funded by Weill Cornell Medicine and the National Institute for Health Research Bristol Biomedical Research Centre.
Gaudino and Puskas disclosed no relevant conflicts of interest; co-authors reported relationship with industry outside of the current study.
Primary Source
New England Journal of Medicine
Gaudino M, et al "Radial-artery or saphenous-vein grafts in coronary-artery bypass surgery" N Engl J Med 2018; DOI: 10.1056/NEJMoa1716026.