Postoperative radial artery angiography for coronary artery bypass surgery

Objective: To compare radial artery (RA) patency with internal mammary arte ry (IMA) patency for coronary artery bypass surgery in our early experience . Methods: Symptomatic as well as asymptomatic patients with greater than o r equal to 1 RA coronary graft underwent postoperative angiography. Each an astomosis was considered separately. A string sign referred to a diffusely narrowed conduit, which did not fill the grafted coronary artery, as well a s all occluded conduits. The raw value of P was adjusted fur the testing of multiple hypotheses (P). The patency data for each conduit was divided int o two parts. 'Cut-off' stenosis for a conduit was the lowest dividing coron ary stenosis at which a difference in patency rare with P less than or equa l to 0.05 occurred. Results: One-hundred-and-twenty-nine patients had 137 r adial arteries anti 157 angiograms. Only the most recent angiogram was anal yzed for each patient at 13 +/- 0.7 months (n = 129). Overall patency for a rterial conduit 91% (n = 404) was not different from venous conduit 91% (n = 42) and patency for RA 90%;; (n = 226) was not different from TMA 92% (n = 178), (P' = 0.999). Cut-off stenosis for RA was 70% and IMA was 40%. pate nt arterial conduit had a mean coronary stenosis of 85% and non-patent cond uit 64%. (P' < 0.001). Right coronary territory patency was 82 vs. 94% fur other territories (P' = 0.012). No overall differences in patency were note d for patients with sequential anastomoses, symptoms or coronary disease at the anastomosis at the time of surgery. Reversible ischaemia was detected in the distribution of only two of I 1 string signs in patients undergoing sestamibi exercise protocol following angiogram. Conclusion : There were no differences in patency between radial artery and internal mammary artery a t 13 months post-operative. Lower coronary stenosis and right coronary terr itory predicted lower patency, The clinical importance of a string sign rem ains to be determined. (C) 2000 Elsevier Science B.V. All rights reserved,