Correspondence Response to Letters Regarding Article, “Vascular Reactivity and Flow Characteristics of Radial Artery and Long Saphenous Vein Coronary

Our study showed that 5 years after aortocoronary bypass graft surgery, radial artery grafts had preserved flow-mediated dilatation, whereas saphenous vein (SV) grafts had not.1 In agreement with Brugaletta et al, we feel it would be ideal to know the preexisting vasomotor response of the study grafts in all patients. Unfortunately, not all the patients who were studied at 3 months agreed to participate at 5 years.1,2 Four patients participated in Doppler studies at both follow-ups (radial artery2 and SV2), and we believe that the numbers are too small to make any conclusions from these data. Although not ideal, we consider these small numbers do not invalidate the findings of our study. We agree with Dr Doraiswamy’s suggestion that the structural changes that take place in SVs when placed in an arterial system may explain the lack of effect of nitrates in our study. In the Radial artery versus Saphenous Vein Patency (RSVP) trial at 3 months,2 SV graft