Thromboembolism is a condition in which a blood clot (thrombus) breaks off from its original site and travels through the bloodstream (as an embolus) to obstruct a blood vessel, causing tissue ischemia and organ damage. Thromboembolism can affect both the venous and arterial systems, with different clinical manifestations and management strategies.

Venous thromboembolism (VTE) BD72 comprises the following conditions:

VTE is a common cardiovascular disorder with significant morbidity and mortality.

VTE can present with various symptoms, such as painful leg swelling, chest pain, dyspnea, hemoptysis, syncope, and even death, depending on the location and extent of the thrombus. VTE can also cause long-term complications, such as recurrent VTE, post-PE syndrome, chronic thromboembolic pulmonary hypertension (CTEPH), and post-thrombotic syndrome (PTS).

The mainstay of VTE management is anticoagulation therapy, which prevents thrombus propagation and embolization. Such treatment reduces the risk of recurrence. The choice and duration of anticoagulation depend on the individual patient's risk factors, bleeding risk, and preferences.

Direct oral anticoagulants (DOACs) have emerged as an essential alternative to conventional anticoagulants, such as vitamin K antagonists (VKAs) and low-molecular-weight heparins (LMWHs), due to their rapid onset of action, predictable pharmacokinetics, fixed dosing, and lower risk of bleeding. DOACs can also facilitate home treatment and extended therapy for selected patients.

In addition to anticoagulation, some patients with VTE may benefit from adjunctive therapies, such as thrombolysis, catheter-directed interventions, or inferior vena cava (IVC) filters, to remove or prevent thrombus migration. However, these therapies are associated with higher risks of bleeding and complications. These therapies are not routinely recommended by the current guidelines except for specific indications, such as massive PE, iliofemoral DVT, or contraindications to anticoagulation.

The optimal duration of anticoagulation for VTE is determined by the balance between the risk of recurrence and the risk of bleeding, and should be individualized for each patient. In general, VTE provoked by a transient or reversible risk factor, such as surgery, trauma, or immobilization, should be treated for three months, while VTE provoked by a persistent or progressive risk factor, such as cancer, should be treated indefinitely. Unprovoked VTE, which occurs in the absence of any identifiable risk factor, has a high risk of recurrence and may require indefinite anticoagulation, depending on the patient's characteristics and preferences. The risk of recurrence of thrombosis also plays a role in treatment duration. In general, patients who experience a major reversible risk factor such as major trauma or surgery, have a lower incidence of recurrence and require less treatment time. Those whose thrombosis is brought on by a minor reversible risk factor have a higher change of recurrent thrombus and require longer treatment time. These events include long flights, estrogen therapy, pregnancy and peripartum, and minor leg traumas.  It should also be noted that all patients with a first time VTE, regardless of what brought on the initial thrombosis, have a 50% chance of recurrence in the first 8-10 years after anticoagulation is discontinued.