Recent advances in the management of venous thromboembolism / 대한혈액학회지

Venous thromboembolism (VTE) is a spectrum of diseases that includes deep vein thrombosis (DVT) and pulmonary embolism (PE). Anticoagulant treatment is the mainstay of therapy for VTE. Unfractionated heparin (UFH) or low molecular weight heparin (LMWH) followed by vitamin K antagonists have been the treatment of choice for most patients with VTE, with the aim to prevent thrombus extension or embolization and recurrent VTE. Fondaparinux, a selective, indirect, parenteral factor Xa inhibitor, is now also approved for the initial treatment of VTE and represents an important alternative to UFH or LMWH. Secondary prevention of VTE with vitamin K antagonists is usually prescribed for a minimum of three months, with the duration of treatment based on the presence or absence of major identifiable risk factors for the index event. Patients with permanent risk factors or patients with recurrent DVT or PE require life long secondary prevention. Over the last years, new oral anticoagulant agents have been developed and are now undergoing extensive clinical evaluation in several settings, including the treatment of VTE. New oral anticoagulants include selective, direct thrombin inhibitors, such as dabigatran etexilate, and selective, direct factor Xa inhibitos, such as rivaroxaban, apixaban or edoxaban. All these drugs are admistered at fixed daily doses and do not require laboratory monitoring. The positive results of the first completed clinical trials suggest that a new era in the management of VTE is about to begin.

Perioperative Anticoagulation in Patients with Mechanical Heart Valves Undergoing Elective Surgery: Results of a Survey Conducted among Korean Physicians

The optimal perioperative anticoagulation management in patients on warfarin therapy is poorly defined due to the lack of randomized trials. Because guidelines are heterogeneous, it was hypothesized that "treatment strategies are not uniform in clinical practice". Between February 2003 and May 2003, a questionnaire with 4 different clinical scenarios was distributed to physicians by e-mail, or direct contact was made by a survey monitor. Two scenarios described the cases of patients with a mechanical heart valve (MHV) in the mitral position, with additional risk factors for a systemic embolism; one undergoing major (scenario 1) and the other minor surgery (scenario 3). Two scenarios described patients with an aortic MHV; one undergoing major (scenario 2) and the other minor (scenario 4) surgery. Different preoperative and postoperative management options were offered. The treatment options for all scenarios were the same. Of the 90 questionnaires distributed, 52 (57.8%) were returned. Hospitalization for full-dose intravenous unfractionated heparin (IV UH) was the most commonly selected strategy in the preoperative phase for scenarios 1 (59%), 2 (42%) and 3 (44%). In scenario 4, 34% chose IV UH. Outpatient, full- dose, subcutaneous UH or low-molecular-weight heparin (LMWH) was the most selected option in the postoperative phase for all scenarios, with the exception of number 4 (52.9% in scenario 1, 34% in scenario 2, 32%, in scenario 3 and 28% in scenario 4). Even among expert clinicians, the management of perioperative anticoagulation is heterogeneous. In particular, the definition of risk categories and the optimal intensity of antithrombotic drugs need to be defined by well-designed prospective studies.