Similar to transfemoral percutaneous coronary interventions (PCI), anticoagulation is indicated during transradial PCI in order to minimize the risk of acute coronary thrombosis. However, unlike procedures utilizing femoral artery access, anticoagulation is also administered for diagnostic transradial cases in order to prevent radial artery occlusion (RAO), regardless of whether PCI will be attempted. Transfemoral access, in contrast, does not pose an analogous risk of femoral artery occlusion due to the relatively large diameter of the vessel.
RAO is a well-documented complication of transradial cardiac catheterization that can result in chronic obstruction of radial artery flow. Although patients who develop RAO are generally asymptomatic, it may prevent future use of transradial access in the affected arm. The reported incidence of RAO in contemporary practice varies, but most studies report a rate ≤5% (Figure 1),1-9 with variation attributable to differences in sheath size, anticoagulation dosing, strategies for achieving hemostasis, methods for assessing radial artery patency, and the timing of radial artery patency assessment. Risk factors that predispose patients to RAO are listed in Table 1. This chapter will focus primarily on anticoagulation strategies for the prevention of RAO, but will also briefly discuss prevention of coronary thrombosis during transradial PCI.