A-priori Versus Provisional Heparin on Radial Artery Occlusion After Transradial Coronary Angiography and Patent Hemostasis

The Provisional Heparin TherApy on Radial Artery Occlusion after transradial coronary angiography and patent Hemostasis (PHARAOH) study compares the strategy of standard a-priori heparin use in patients undergoing transradial coronary angiography to a strategy of provisional heparin administration only if patent hemostasis is not achievable.

Transradial access use for coronary angiography and intervention is increasing. Its efficacy in lowering access site complications, as well as increased patient comfort, has been proven unequivocally. One of the complications of transradial access is radial artery occlusion (RAO) that occurs with a variable incidence. It is population specific, with a higher prevalence in subsets, such as women, and patient's with small radial arteries. RAO is also known to be higher at hospital discharge and radial recanalization may spontaneously occur at later times. It is usually asymptomatic. Its main adverse impact is by limiting future transradial access from that radial artery. Since most of the patient's with atherosclerotic vascular disease may undergo several invasive procedures during their lifetime, prevention of RAO is of paramount importance. Heparinization, during the procedure, has been shown to be of benefit in lowering the incidence of RAO. Maintaining patency of the radial artery during hemostasis, has also been shown to be effective in prevention of RAO following transradial access. As maintenance of flow has potent antithrombotic effect, it is unclear whether systemic anticoagulation is still required in all cases. In some cases, it would be preferable to avoid heparin administration prior to coronary angiography. It is currently unknown whether it would be safe to refrain from heparin administration in case of transradial catheterization and patent hemostasis technique.