Radial artery graft in coronary artery bypass surgery 1 week to 1 year postoperation

Background: The actual patency rate of the radial artery (RA) grafts 1 week and 1 year after coronary artery bypass grafting (CABG) has not been extensively reported on. We used coronary computed tomography angiography (CCTA) to evaluate the patency rate of RA grafts and compared it with that of saphenous vein (SV) grafts.Methods: In this observational cohort study, 80 patients who underwent urgent or elective CABG with RA and SV grafts at Ruijin Hospital from August 2019 to June 2021 were included. Follow-up CCTA scans were completed about 1 year postoperation in the out-patient clinic. We graded the grafts into four classes: A, excellent; B, graft diameter <50% of target coronary artery; O, occluded; and S, string sign. Both S and O were defined as graft failure.Results: The patients' mean age was 58.48 +/- 8.06 years, and 87.5% (70/80) of the patients were male. The 1-week patency rate of the left internal mammary artery (LIMA), RA, and SV grafts were 98.7% (75/76), 76.3% (61/80), and 93.8% (75/80), respectively. At 1 year, the patency rate of the LIMA, RA, and SV grafts were 97.4% (74/76), 80.0% (64/80), and 81.3% (65/80), respectively. The RA graft patency rate was lower than was the SV graft patency rate perioperatively [relative risk (RR): 0.918; 95% confidence interval (CI): 0.852-0.990; P=0.007]. Moreover, 63.6% (7/11) of RA grafts graded S and 25.0% (2/8) of RA grafts graded O were defined as patent (graded A or B) at 1 year postoperation. Compared with SV grafts, more RA grafts improved (RA: 12/80, 15.0%; SV: 0%) and fewer RA grafts deteriorated (RV: 10/80, 12.5%; SV: 19/80, 23.8%) from 1 week to 1 year (P=0.001). The patency rate of the 2 types of grafts became similar at 1 year postoperation (RR: 0.560; 95% CI: 0.113-2.781; P>0.99). Conclusions: RA grafts had a lower patency rate than did SV grafts 1week after operation. However, because of the "revival" phenomena and lower attrition rate, the patency rate of the two kinds of grafts did not show any significant difference at 1 year.