Choosing the Appropriate Antithrombotic Agent for the Prevention and Treatment of VTE: A Case-Based Approach

The importance of appropriate prophylaxis for the prevention of venous thromboembolism in at-risk medical patients

BACKGROUND

Venous thromboembolism (VTE), which encompasses both deep-vein thrombosis and pulmonary embolism, is a significant healthcare problem, leading to considerable morbidity, mortality and resource utilisation.

AIMS

This review discusses the adherence to VTE guideline recommendations and the available clinical evidence on the appropriate type, dose and duration of VTE prophylaxis.

METHODS

A literature survey was conducted using Pub Med and EMBASE to identify publications related to appropriate thromboprophylaxis in medically ill patients at risk of VTE.

RESULTS

Despite evidence from clinical trials and national guidelines, VTE prophylaxis in medically ill patients remains underutilised. The use of unfractionated heparin three-times-daily, low-molecular-weight heparin once-daily and fondaparinux once-daily has demonstrated effectiveness in clinical trials of medically ill patients. However, controversy exists about the use of unfractionated heparin twice-daily, and fondaparinux has not yet received US Food and Drug Administration approval for VTE prophylaxis in medically ill patients.

CONCLUSION

It is important for clinicians to have an understanding of the evidence-based literature when selecting an appropriate drug, at the appropriate dose, for the appropriate duration for VTE prophylaxis in medically ill patients. VTE prophylaxis in medically ill patients is cost-effective, and drugs that are expensive may still be cost-effective when considering improved efficacy and/or safety. Recently, the underutilisation of VTE prophylaxis has led to the involvement of government and other regulatory agencies in an attempt to increase appropriate VTE prophylaxis in US hospitals and improve the clinical and economic outcomes in medical patients at risk of VTE.

Economic burden of venous thromboembolism in hospitalized patients

Venous thromboembolism, a condition that includes deep vein thrombosis and pulmonary embolism, is a significant medical problem that affects more than 1 million patients each year. In addition to the immense impact of venous thromboembolism on morbidity and mortality, the economic burden of the disease is considerable, costing the health care system in the United States more than $1.5 billion/year. The cost of managing an initial episode of deep vein thrombosis is estimated at $7712-10,804, and for an initial pulmonary embolism event $9566-16,644. Management of acute venous thromboembolism in patients with cancer costs more than $20,000. Although much of the costs of venous thromboembolism are associated with managing the acute event, there are also significant costs associated with its long-term complications such as recurrent venous thromboembolism, postthrombotic syndrome, and pulmonary hypertension. Data from numerous robust clinical trials have demonstrated that with appropriate prophylaxis, many of these venous thromboembolism events can be prevented in both surgical and medical patients. Even though the strong evidence supporting venous thromboembolism prophylaxis spans several decades, a number of large American and global registries have documented very poor use of appropriate venous thromboprophylaxis. Because of increasing regulatory requirements, hospitals nationwide are developing necessary documentation of appropriate venous thromboembolism prophylaxis programs for both surgical and medical patients. Hospitals and clinicians must have a firm understanding of not only the clinical impact but also the economic impact of failing to use appropriate prophylaxis and of the cost-effectiveness of different venous thromboprophylaxis methods.

Treatment of thrombosis with fondaparinux (Arixtra) in a patient with end-stage renal disease receiving hemodialysis therapy

Treatment of thrombosis in children with end-stage renal disease (ESRD) is extremely challenging owing to the underlying risk of bleeding. Fondaparinux (Arixtra, Sanofi-Synthélabo), a synthetic pentasaccharide, is contraindicated in patients with compromised renal function as it is excreted via kidneys. We describe a unique case with ESRD and pulmonary embolism who was treated with fondaparinux owing to the toxicity and poor compliance with low-molecular-weight heparin. Despite regular hemodialysis, a gradual rise in drug levels was observed without significant bleeding complications. This report implies that although low dose fondaparinux can be an option in patients with ESRD under special circumstances, guidelines for laboratory monitoring and appropriate dose adjustments are urgently required to ensure the safety of the patient.