Patients undergoing diagnostic cardiac catheterization via the trans-radial approach will be randomly allocated (1:1:1) to receive either low-dose UFH (25 IU/Kg -maximal dose 3,000 IU), high-dose UFH 50 IU/kg -maximal dose 5,000 IU) or N/S 0.9%. After 30 minutes, patients will undergo a gradual wrist band release. Hematoma and radial artery occlusion will be assessed.
Patients undergoing cardiac catheterization will be randomized to 3 groups: no anticoagulant, low dose anticoagulant and high dose anticoagulant.