Venous thromboembolism: classification, risk factors, diagnosis, and management

Abstract

Venous thromboembolism (VTE) is categorised as deep venous thrombosis (DVT) and pulmonary embolism (PE). VTE is associated with high morbidity and causes a huge financial burden on patients, hospitals, and governments. Both acquired and hereditary risks factors contribute to VTE. To diagnose VTE, noninvasive cost-effective diagnostic algorithms including clinical probability assessment and D-dimer measurement may be employed followup by compression ultrasonography for suspected DVT patients and multidetector computed tomography angiography for suspected PE patients. There are pharmacological and mechanical interventions to manage and prevent VTE. The pharmacological approaches mainly target pathways in coagulation cascade nonspecifically: conventional anticoagulants or specifically: new generation of anticoagulants. Excess bleeding is one of the major risk factors for pharmacological interventions. Hence, nonpharmacological or mechanical approaches such as inferior vena cava filters, graduated compression stockings, and intermittent pneumatic compression devices in combination with pharmacological interventions or alone may be a good approach to manage VTE.

Figure 1

Different pharmaceutical interventions for VTE target various steps in coagulation cascade. Traditional anticoagulants including unfractionated heparin, low-molecular-weight heparin, and vitamin K antagonists target different steps. Despite, new generation of anticoagulants; rNAPc2 (recombinant nematode anticoagulant protein c2), fondaparinux, rivaroxaban, apixaban, and dabigatran etexilate, have specific targets in coagulation pathways.