Background: The radial artery is proposed as an alternative conduit in coronary revascularization. During the last years the transradial approach has, in many centers, emerged as the preferred technique in percutaneous diagnostic and interventional coronary procedures. This induces a trauma to the radial artery that possibly could influence its suitability as a bypass graft. In this study we assessed by ultrasound the long-term effects of transradial coronary angiography on the radial artery diameter and vasodilatory properties.
Methods: Thirty patients were examined with high resolution ultrasound 10 to 14 months after a transradial coronary angiography. Radial artery baseline diameter and response to flow-mediated (FMD) and nitroglycerin-mediated vasodilation (NMD) were examined in the right radial artery with the unexposed left radial artery as control.
Results: Right radial artery diameter was reduced compared with the left radial artery (2.58 +/- 0.38 vs 2.71 +/- 0.32 mm, p < 0.01). Both FMD and NMD were preserved in the exposed artery (FMD 8.4 +/- 8.0 vs 8.0 +/- 6.1%, NMD 15.5 +/- 6.8 vs 16.7 +/- 6.6%, both ns). Due to the reduced baseline diameter, the right radial lumen diameter remained significantly smaller after vasodilatory stimuli. Large interindividual differences were demonstrated.
Conclusions: The radial artery diameter is diminished one year after transradial coronary angiography while vasodilatory properties are preserved. The preserved vasodilatory capacity could favorably influence the suitability of the artery as bypass graft. However, with the long-term structural changes induced by transradial angiography, use of a catheter-exposed radial artery as a conduit in coronary artery revascularization should not be strongly recommended. With ultrasound, both structure and vasodilatory properties of a catheterization-exposed radial artery may be assessed in case the artery is considered as bypass material.