Thrombotic Complications of Antithrombotic Therapy: A Paradox with Implications for Clinical Practice

Heparin and warfarin have been the standard therapy for thromboembolic disease for more than 50 years. During this time, the clinical indica-tions for their use have expanded. Heparin is the standard initial therapy for acute venous thrombosis or pulmonary embolism; it is also widely used to treat acute coronary syndromes and prevent throm-bosis during vascular surgery or angioplasty, ex vivo thrombi during cardiopulmonary bypass surgery and hemodialysis, and postoperative venous thromboem-bolism in high-risk patients. The use of warfarin has also expanded in recent years to include prevention of thromboembolic stroke in patients with atrial fibrillation, a condition that affects many thousands of elderly patients each year in the United States. The wider use of warfarin has been facilitated b