Clinical Review

Decision Making in Venous Thromboembolism


 

References

From the Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Boston, MA.

Abstract

  • Objective: To review the diagnosis and management of venous thromboembolism (VTE).
  • Methods: Review of the literature.
  • Results: VTE and its associated complications account for significant morbidity and mortality. Various imaging modalities can be employed to support a diagnosis of a VTE and are used based on clinical suspicion arising from the presence of signs and symptoms. Clinical decision rules have been developed that can help determine which patients warrant further testing. Anticoagulation, the mainstay of VTE treatment, increases bleeding risk, necessitating tailored treatment strategies that must incorporate etiology, risk, benefit, cost, and patient preference.
  • Conclusion: Further study is needed to understand individual patient risks and to identify treatments that will lead to improved patient outcomes.

Venous thromboembolism (VTE) and its associated complications account for significant morbidity and mortality. Each year between 100 and 180 persons per 100,000 in Western countries develop VTE. The majority of VTEs are classified as either pulmonary embolism (PE), which accounts for one third of the events, or deep vein thrombosis (DVT), which is responsible for the remaining two thirds. Between 20% and 30% of those patients diagnosed with thrombotic events will die within the first month after diagnosis [1].PE is a common consequence of DVT; 40% of patients who are diagnosed with DVT will be subsequently found to have PE upon further imaging. This high rate of association is also seen in those who present with PE, 70% of whom will also be found to have concomitant DVT [2,3].

There are many risk factors for VTE, including patient-specific demographic factors, environmental factors, and pharmacologic factors ( Table 1 ). One of the main demographic factors associated with development of VTE is age. It is rare for children to suffer a thrombotic event, whereas older persons have a risk of 450 to 600 events per 100,000 [1]. Other demographic risk factors, both inherited and acquired, have been associated with increased risk of VTE. Inherited risk factors include factor V leiden mutation, prothrombin gene mutation, protein C and protein S deficiencies, antithrombin deficiency, and dysfibrinogenemia. The prevalence of these inherited thrombophilias in patients with VTE is about 25% to 35% compared to 10% in controls without VTE [4,5].Acquired risk factors include prior VTE, malignancy, surgery, trauma, obesity, smoking, pregnancy, and immobilization [6–9].Additionally, multiple medical conditions, including the antiphospholipid antibody syndrome, myeloproliferative neoplasms, paroxysmal nocturnal hemoglobinuria, renal disease (particularly nephritic syndrome), liver disease, and inflammatory bowel disease have been shown to increase risk of VTE [10–13].

Anatomic risk factors include Paget-Schroetter syndrome (compression of upper extremity veins due to abnormalities at the thoracic outlet), May-Thurner syndrome (significant compression of the left common iliac vein by the right common iliac artery), and abnormalities of the inferior vena cava [14–16].Medications that are associated with increased risk of VTE include but are not limited to estrogen (both in oral contraceptives as well as hormone replacement therapy) [17,18],the selective estrogen receptor modulator tamoxifen [19],testosterone [20],and glucocorticoids [21].It is important to note that many patients with VTE have more than one acquired risk factor for thrombosis [22],and also that acquired risk factors are more likely to lead to VTE in the setting of underlying inherited thrombophilic conditions [23].

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