Morphological and functional consequences of transradial coronary angiography on the radial artery: implications for its use as a bypass conduit

OBJECTIVES: To assess the degree of damage to the radial artery (RA) in coronary artery bypass grafting (CABG) patients who underwent preoperative transradial coronary angiography (RA-CA). METHODS: From May 2012 to October 2013, 50 consecutive CABG patients who underwent RA-CA were prospectively enrolled in the study. All patients underwent echo-Doppler evaluation of the RA of the catheterized arm; the contralateral RA was used as control. The distal segment of the RA was submitted to immunohistochemical assessment of endothelial integrity. Patients were divided in three groups according to the time interval from angiography to evaluation: <= 24 h, >24 h to <7 days and >= 7 days. RESULTS: Baseline RA median diameters were 0.25 +/- 0.04 cm in the cannulated arm and 0.22 +/- 0.04 cm in the non-cannulated arm (P = 0.01). The flow-mediated dilatation (FMD) in the RA in the catheterized arm and in the control arm were 11.6 +/- 7.9 and 14.2 +/- 8.9 (P = 0.01), respectively. A statistically significant correlation was found between FMD of the catheterized RA and the time from RA-CA (Pearson's r = 0.348). Linear regression analysis confirmed that the FMD of the catheterized RA was dependent on days elapsed from the procedure (P = 0.032; OR 1.11, CI 0.009-0.203). Immunohistochemical evaluation showed extensive endothelial lesion in all examined RAs, with a trend towards reduction of the damage with time. Endothelial function and integrity of the cannulated arm did not reach those of the control arm in any of the study patients. CONCLUSIONS: RA-CA produces extensive damage to the RA. The lesions tend to heal with time but incomplete recovery of endothelial integrity and function is still present more than 30 days after the procedure. After RA-CA, the cannulated RA should not be used for CABG.