A prospective and randomized comparison of the safety and effects of therapeutic levels of enoxaparin versus unfractionated heparin in chronically anticoagulated patients undergoing elective cardiac catheterization.

Consecutive patients with atrial fibrillation and/or prosthetic heart valves, receiving chronic anticoagulation with phenprocoumon and scheduled to undergo cardiac catheterization, were randomized to subcutaneous enoxaparin twice daily (n = 32) or intravenous UFH (n = 36). Cardiac catheterization was performed at an international normalized ratio <1.5.