A total of 600 patients undergoing coronary procedures via transradial access using 6F sheath were randomized at the end of the procedure to receive either 250-µg nicardipine or 500-µg nitroglycerin administered to the radial artery through the radial sheath before sheath removal. A continuous patent hemostasis was applied in each patient with the use of an oximetry to maintain an oxygen saturation of >95%, measured in the finger of the accessed arm until compression device was totally removed. The primary outcome is early RAO which was evaluated by color duplex ultrasonography of the accessed arteries at the day after the radial procedure. Secondary outcome was the change of blood pressure at 2-3 minutes after drug administration. Radial artery angiogram was performed after radial sheath insertion and doppler ultrasound of the accesed radial artery was examined at the day after the procedure.

Doppler ultrasound of the accessed artery was performed at the day after the radial procedure in all patients. The absence or presence of antegrade flow in the radial artery will be examined while compressing the ulnar artery as previously described.

The internal lumen radial artery diameter was evaluated by doppler ultrasound as the distance between the inner walls of the artery by personnel that are blinded to the study protocol.

Radial artery angiogram was performed soon after radial sheath insertion and the radial artery diameter was measured in AP projection in all patients.

Inclusion Criteria:

• All patients undergoing transradial catheterization

Exclusion Criteria:

• Systolic blood pressure < 100 mmHg

Double blind