Oral Anticoagulation in Clinical Medicine for Venous and Arterial Thrombotic Indications

Oral anticoagulant therapy is used increasingly for the prevention and treatment of thromboembolic complications from vascular disease on the basis of accumulating evidence of its effectiveness in many clinical indications. In the last few decades important developments have been achieved in laboratory and clinical monitoring of treated patients, leading to more appropriate therapy and improved safety. As a result, the number of patients on chronic oral anticoagulation has increased dramatically in recent years. However, the underutilization of this effective therapy is still a pervasive problem. Both fear of complications, especially bleeding, and the practical difficulties associated with this demanding therapy are frequent concerns of physicians, preventing wider use of this treatment in many patients who would benefit from it.

Promising new antithrombotic drugs have now been developed for clinical use. Evidence suggests that these news drugs are potentially safer than the vitamin K antagonists and easier to administer. This notwithstanding, many patients are presently treated with oral anticoagulants, and a further increase in the number of treated patients should be expected in the next few years. It seems worthy, therefore, to review the baseline aspects of oral anticoagulants and their monitoring, use, and risks in clinical practice and to review the current status of clinical research in the various fields of vascular disease in which prevention and/or treatment of thrombosis is requested. Thus, this issue of Seminars in Vascular Medicine has been dedicated to “Oral Anticoagulation in Clinical Medicine for Venous and Arterial Thrombotic Indications.”

Leading authorities in the field accepted our invitation to contribute to this issue, giving a wide, complete, and up-to-date overview of the most important topics involved. Ann Wittkowsky discusses the pharmacokinetic and pharmacodynamic aspects of warfarin, focusing on the practical issue of drug interactions. Ann Daly and Guruprasad Aithal provide an update on the effects of genetic characteristics of subjects on the metabolism of warfarin and the different response to anticoagulants. Rebecca Beyth analyzes the issues involved in the quality of life of treated patients, an aspect of paramount importance for individuals who often are on lifelong treatment. Armando Tripodi, Mimi Breukink-Egbers, and Anton van den Besselaar tackle the difficult topic of the laboratory control of anticoagulated patients, and especially the relatively new use of portable monitors. It is well known that the period of initiation of oral anticoagulation is particularly associated with a high risk of both bleeding and thrombotic complications. Mark Crowther has investigated this topic in depth and reviews it in his article. Jack Ansell analyzes in detail the importance of high-quality management of anticoagulated patients, especially through dedicated anticoagulant clinics, as an essential condition to optimize the efficacy and safety of treatment. Bleeding is the most important complication of oral anticoagulation and represents a limiting factor for the wider use of this treatment. Elaine Hylek analyzes the complications of anticoagulation and especially the rates and risk factors for bleeding. Michael Makris, on the other hand, describes how to manage excessive anticoagulation or overt bleeding. Commonly, anticoagulated patients, especially the elderly, have to undergo surgery or invasive diagnostic/ therapeutic procedures. This condition is often a source of uncertainty for doctors. Clive Kearon analyzes this challenging topic. Alan Jacobson reports on patient self-testing of the INR in North America with the increasingly popular portable prothrombin time monitors. Benilde Cosmi and Gualtiero Palareti have reviewed the use of oral anticoagulant therapy in venous thromboembolism with a focus on the optimal duration of antithrombotic treatment in this condition. Trevor Baglin has tackled the controversial topic of treatment in subjects with congenital or acquired thrombophilia. Daniel Hackam, Sonia Anand, and Salim Yusuf have analyzed in depth the use of oral anticoagulant therapy in patients with coronary artery disease. The number of patients with atrial fibrillation is increasing with the increasing number of elderly subjects, and Vittorio Pengo analyzes oral anticoagulant therapy in this condition. Finally, the use of oral anticoagulation in patients with peripheral artery disease is reviewed by Frank Visseren and Bert Eikelboom.

As guest editors, we are proud of this effort and thank warmly all of the authors for their contributions. We hope that you will enjoy reading these articles and find them informative and practical, as we have.