Letter by Spence et al Regarding Article, “Impact of Patient and Target-Vessel Characteristics on Arterial and Venous Bypass Graft Patency: Insight From a Randomized Trial”
To the Editor:
In their recent article1 based on the 440 patients who underwent angiographic follow-up, Desai et al have proposed factors that may explain the superior radial artery compared with saphenous vein graft patency observed in their well-designed Radial Artery Patency Study.2 We are interested in the model predictors chosen a priori on the basis of their presumed clinical relevance.
Radial artery access for both diagnostic coronary angiography and intervention has become increasingly common owing to the almost negligible access-site complications and early patient mobilization with this approach.3 Nevertheless, concerns exist that previous radial artery instrumentation, including transradial catheterization, may render the radial artery unsuitable as a bypass graft.4 It is unclear from the published inclusion and exclusion criteria whether such patients were included in this trial.5
Although severe peripheral vascular disease limiting vascular access was an exclusion criterion for the study, interestingly, 64 patients (15%) in this analysis had peripheral vascular disease, and its presence was detrimental to radial artery compared with saphenous vein graft patency.1 As the authors state, a history of peripheral vascular disease is associated with an increased risk of radial artery atherosclerosis at the time of harvest, but it is also conceivable that these patients were more likely to have undergone previous transradial catheterization that injured the artery, causing the observed reduced patency.
Given the potential for confounding, determining whether any of the radial artery grafts were previously instrumented is therefore vital in accurately interpreting these data. As advocates of transradial coronary catheterization, we hope that this excellent trial can also shed light on the vexatious issue of the suitability of the radial artery as a graft after instrumentation.4
Desai ND, Naylor CD, Kiss A, Cohen EA, Feder-Elituv R, Miwa S, Radhakrishnan S, Dubbin J, Schwartz L, Fremes SE; Radial Artery Patency Study Investigators. Impact of patient and target-vessel characteristics on arterial and venous bypass graft patency: insight from a randomized trial. Circulation. 2007; 115: 684–691.
Agostoni P, Biondi-Zoccai GG, de Benedictis ML, Rigattieri S, Turri M, Anselmi M, Vassanelli C, Zardini P, Louvard Y, Hamon M. Radial versus femoral approach for percutaneous coronary diagnostic and interventional procedures: systematic overview and meta-analysis of randomized trials. J Am Coll Cardiol. 2004; 44: 349–356.