Stiffness Parameters of the Radial Artery in Patients Undergoing Distal Transradial Coronary Angiography: A Duplex Ultrasonography Investigation

Background: Distal radial artery (DRA) is a feasible access in coronary angiography. Aims: We aimed to determine the stiffness parameters of DRA and main radial artery (MRA) in pre and post-transradial catheterization by using ultrasonography. Methods: Patients admitted for elective distal transradial coronary angiography were consecutively enrolled from September to December 2020. Overall, Duplex analysis was assessed in 100 patients on admission and 24 h post-catheterization. Emerging two MRA occlusion and four DRA occlusion cases were excluded from statistical analysis. As a result, we had 98 measurements in MRA and 96 in the DRA adjusted for statistical analysis. Results: Systolic diameter of the DRA was smaller than the MRA as 2.21 +/- 0.38 versus 2.38 +/- 0.38 mm (p group < 0.001). These increased to 2.4 +/- 0.46 and 2.75 +/- 0.47 mm, respectively, following catheterization (p group-time = 0.006). Stiffness index of the DRA was higher than the MRA (30.3 +/- 26.3 vs. 22.7 +/- 25.1 p = 0.601). After catheterization, this parameter significantly increased in the MRA while being preserved in the DRA (p time-group 0.032). Inversely, distensibility showed a decrease in the MRA (p time-group = 0.001) with preservation in the DRA after catheterization (p = 0.422). Conclusion: DRA is smaller and shows higher stiffness index with lower distensibility than the MRA. Following catheterization, these parameters show preservation in the DRA, despite an impairment in the MRA.