Letters Regarding Article by Khot et al, “Radial Artery Bypass Grafts Have an Increased Occurrence of Angiographically Severe Stenosis and Occlusion Compared With Left Internal Mammary Arteries and Saphenous Vein Grafts”

Abstract

To the Editor: Since its first clinical use by Carpentier in 1971,1 the radial artery (RA) has become one of the grafts of choice in coronary surgery. The article by Khot et al2 claims that the patency of RA grafts is lower than that of internal mammary artery (IMA) as well as venous grafts. We believe that their methodology is flawed, primarily because the sample studied is composed almost exclusively of patients presenting with angina, ECG changes, or both. In most other published reports, only ≈20% of patients have recurrent angina at 5 years. Therefore, we believe that the denominator used to calculate the rates of patency is incorrect, and the results obtained by the authors may be misleading. Furthermore, it would appear that the RA was often used in high–occlusion-risk situations, which could account for the low observed patency rate in this highly selected population. For example, 22% of the patients underwent redo surgery, a substantially high proportion of patients in a daily practice, and a situation in which target vessels are often suboptimal. In one third of the cases, the RA was anastomosed to the right coronary artery, which is known to be at high risk for occlusion, whereas the number of right IMA grafts constructed in this area was so small that it did not allow a statistical comparison. Therefore, we believe that it is dangerous to extrapolate the patency data observed in this series to a homogeneous cohort of patients. These results are at variance with previously published series, which established that the patency of the RA graft was 92% and 83% at 1 and 5 years, respectively. These rates are comparable to those of the right IMA graft. Several studies have reported that use of the RA as opposed to vein grafts improved …