http://www.thrombosisadviser.com 2010-03-11T15:02:32Z

ROCKET AF is a randomized, double-blind, double-dummy, event-driven trial, which aims to establish the noninferiority of rivaroxaban compared with warfarin in patients with nonvalvular AF who have a history of stroke or at least 2 additional independent risk factors for future stroke. Patients are randomly assigned to receive rivaroxaban, 20 mg once daily (od), or dose-adjusted warfarin titrated to a target international normalized ratio (INR) of 2.5 (range 2.0-3.0, inclusive) using point-of-care INR devices to receive true or sham INR values, depending on the study drug allocation.

Two classes of agent currently being researched as new oral anticoagulants are direct thrombin inhibitors and Factor Xa inhibitors. The one that may be closest to regulatory approval in the United States is rivaroxaban (Xarelto, Bayer), an oral Factor Xa inhibitor already approved for hip and knee replacement thromboprophylaxis in Europe and Canada. The RECORD series of clinical trials compared rivaroxaban to subcutaneous enoxaparin for the prevention of venous thromboembolism after orthopedic surgery. All four trials showed the new drug’s efficacy and safety.

Despite an international normalized ratio less than 1.7, warfarin-treated patients are more likely than those not taking warfarin to experience symptomatic intracerebral hemorrhage following treatment with intravenous tissue plasminogen activator. Larger studies in this subgroup are warranted.

A group of representatives from federal health agencies and patient groups, as well as experts from the medical and public health communities — convened by the American Society of Hematology — has drafted three recommendations to address the growing problem of deep vein thrombosis and pulmonary embolism.

As compared with placebo or aspirin, OAC with or without aspirin does not reduce mortality or reinfarction, reduces stroke, but is associated with significantly more major bleeding.

The purpose of this study was to evaluate the long-term effects of distal protection during percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI).

Although a family history of venous thromboembolism is associated with factor V Leiden mutation in thrombosis-free gravid women, the sensitivity and positive predictive values are too low to recommend screening women for the factor V Leiden mutation based solely on a family history.

An IVC filter should be considered in patients with a DVT who have a contraindication to anticoagulation. Other indications for IVC filter use are not supported by the current literature.

Low-molecular-weight heparins such as enoxaparin are preferred for prevention of venous thromboembolism after major joint replacement. Apixaban, an orally active factor Xa inhibitor, might be as effective, have lower bleeding risk, and be easier to use than is enoxaparin.

More than 17,000 Americans have already died in 2010 from blood clots in the lungs. The Vascular Disease Foundation’s Venous Disease Coalition, reminds us of this sobering fact on its homepage with a new counting widget at www.venousdiseasecoalition.org, and urges Americans to learn the risks of venous blood clots to help prevent these deaths.

March is deep vein thrombosis awareness month in the United States. To mark this event, this issue of Arteriosclerosis, Thrombosis, and Vascular Biology contains a series of reviews on new anticoagulants that either are in development or have been approved for clinical use. Particularly exciting are the new oral inhibitors of thrombin (dabigatran etexilate) and factor Xa (rivaroxaban).

"These findings suggest that the risk of venous thromboembolism after surgery is greater and lasts for longer than previously thought," the authors wrote. "Overall, we found increased relative risks of venous thromboembolism during the [first] 17 postoperative weeks that were much larger than those reported previously."

Antiplatelet drug resistance is one of the urgent issues in current cardiovascular medicine. Many platelet function tests have been used to define responsiveness of patients with cardiovascular disease to aspirin and clopidogrel.

Less than half of patients who were at risk of venous thromboembolism (VTE) received pharmacological prophylaxis during hospitalization, and less than 10% received postdischarge medication to prevent VTE, according to the results of a data analysis reported at Chest 2009. In a related study presented at the same meeting, lead author Alpesh N. Amin, MD, MBA, and colleagues also reported that inadequate VTE prophylaxis resulted in longer hospital stays and increased costs.

Treatment regimens for preventing thromboembolism in AF patients range from vitamin K antagonists such as warfarin or coumadins, antiplatelet drugs like aspirin or clopidogrel, to newly developed orally available antithrombotics like the direct thrombin inhibitor dabigatran, or the Factor Xa-inhibitor rivaroxaban. The available anticoagulant and antiplatelet drugs have different advantages and disadvantages. This review attempts to delineate the specific role of clopidogrel in patients with AF and at risk of stroke, taking into consideration new and ongoing trials in this important field of medical practice.

Venous thromboembolism, comprising deep vein thrombosis and pulmonary embolism, is a common disorder with at least 250 000 new events occurring each year in the United States alone. Treatment of venous thromboembolism includes anticoagulation, which is achieved initially with the use of a parenterally administered agent followed by a more prolonged course of treatment with an oral vitamin K antagonist. The duration of treatment depends on the clinical assessment of the benefit-to-risk ratio of prolonged anticoagulation versus the risk of recurrent events. In this review, we discuss some of the issues that we believe are among the most critical unanswered questions in the management of venous thromboembolism in the present era.

Perceptions of DVT risk factors and prophylaxis practices vary by both physician specialty and attending/resident status. Prophylaxis practice differences may result from these perceptions.

No recommendations can be drawn from the two studies. One study showed a reduction in PE rates but not mortality, but was subject to significant biases. The PREPIC study lacked statistical power to detect a reduction in PE over shorter and more clinically significant time periods. However, the trial demonstrated that permanent VCFs were associated with an increased risk of long term lower limb DVT.There is a paucity of VCFs outcome evidence when used within currently approved indications and a lack of trials on retrievable filters. Further trials are needed to assess vena caval filter safety and effectiveness.

We describe the results of a systematic literature review and an explicit approach to consensus techniques which resulted in recommendations for the key therapeutic issues in cancer patients with VTE.

The anticoagulant market has been very active recently with the development of new compounds including injectable anti-Xa such as fondaparinux, already available, and idraparinux, already replaced by its new biotynilateed form, and new oral drugs which can be divided into anti-IIa with dabigatran already available, and anti-Xa, such as the recently marketed rivaroxaban and apixaban still in the development stage. Others are coming forward.