Radial Artery and Saphenous Vein Patency More Than 5 Years After Coronary Artery Bypass Surgery: Results From RAPS (Radial Artery Patency Study)

Study Questions:

What is the incidence of radial and saphenous vein graft (SVG) occlusion more than 5 years following coronary artery bypass surgery?


A total of 510 patients <80 years of age undergoing primary isolated nonemergent coronary artery bypass grafting with three-vessel disease were initially enrolled in nine Canadian centers. Target vessels for the radial artery and study SVG were the right and circumflex coronary arteries, which had >70% proximal stenosis. Within-patient randomization was performed; the radial artery was randomized to either the right or circumflex territory and the study SVG was used for the other territory. The primary endpoint was functional graft occlusion by invasive angiography at least 5 years following surgery. Complete graft occlusion by invasive angiography or computed tomography angiography was a secondary endpoint.


A total of 269 patients underwent late angiography (234 invasive angiography, 35 computed tomography angiography) at a mean of 7.7 ± 1.5 years after surgery. The frequency of functional graft occlusion was lower in radial arteries compared with SVGs (28 of 234 [12.0%] vs. 46 of 234 [19.7%]; p = 0.03 by McNemar’s test). The frequency of complete graft occlusion was also significantly lower in radial compared with SVGs (24 of 269 [8.9%] vs. 50 of 269 [18.6%]; p = 0.002).


The authors concluded that radial arteries are associated with reduced rates of functional and complete graft occlusion compared with SVGs more than 5 years following surgery.


This study suggests that radial arteries used as conduits are associated with reduced rates of graft occlusion compared with SVGs more than 5 years following surgery. The data support the use of the radial artery as a second arterial conduit, or as a third arterial conduit in association with both internal thoracic artery grafts, particularly for patients with high-grade target vessel proximal stenoses. The benefit of the radial artery compared with a vein graft persists over 7.5 years and appears to be the preferred conduit compared to vein grafts.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Incidence, Vascular Patency, Epoxy Compounds, Radial Artery, Coronary Angiography, Tomography, Hypothermia, Saphenous Vein, Mammary Arteries, Canada, Coronary Artery Bypass

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