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

Thromb Haemost. 2003 Aug;90(2):267-71. doi: 10.1160/TH02-10-0159.


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. Activated partial thromboplastin times and levels of anti-Factor Xa activity were measured daily. The time until effective anticoagulation (primary endpoint) was significantly shorter for enoxaparin than for UFH (1.1 +/- 0.4 days versus 3.7 +/- 2.5 days, p<0.0001). The percentage of days of effective anticoagulation was significantly higher in the enoxaparin group than in the UFH group (93.3 +/- 9.5% versus 53.7 +/- 26.6%, p <0.0001). In conclusion, enoxaparin achieves therapeutic levels of anticoagulation more rapidly and consistently than UFH in chronically anticoagulated patients with prosthetic heart valves and/or atrial fibrillation undergoing cardiac catheterization.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anticoagulants / therapeutic use*
  • Antithrombin III / metabolism
  • Atrial Fibrillation
  • Cardiac Catheterization*
  • Enoxaparin / therapeutic use*
  • Female
  • Heart Valve Prosthesis
  • Heparin / therapeutic use*
  • Humans
  • International Normalized Ratio
  • Male
  • Middle Aged
  • Partial Thromboplastin Time
  • Time Factors
  • Treatment Outcome


  • Anticoagulants
  • Enoxaparin
  • Antithrombin III
  • Heparin