Thrombus and embolus

Thrombi and emboli are pathological intravascular solid masses that disrupt normal blood flow and are central to the pathogenesis of major cardiovascular events. A thrombus is a blood clot formed in situ within the vascular system, typically triggered by the components of Virchow's triad: endothelial injury, stasis or turbulent blood flow, and hypercoagulability (StatPearls, 2023). An embolus is a detached intravascular mass—most commonly a dislodged thrombus—that is carried by the blood to a site distant from its point of origin, where it can cause sudden tissue infarction (NIH, 2022). These structures are primarily composed of a fibrin meshwork, aggregated platelets, and interspersed red and white blood cells. Therapeutic strategies do not target the thrombus as a single molecule but rather its constituent pathways; anticoagulants like heparin and rivaroxaban inhibit the coagulation cascade to prevent fibrin formation, while antiplatelet agents like aspirin target platelet activation (Merck Manual, 2023). Thrombolytic drugs, such as alteplase, act as plasminogen activators to enzymatically dissolve the fibrin matrix of an established clot, though this carries a significant risk of systemic bleeding (PubMed, 2021).

Other names

Thrombi and emboliBlood clotIntravascular coagulationThromboembolismVenous thromboembolism (VTE)

Drugs act by inhibiting the formation of fibrin (anticoagulants), preventing platelet activation and aggregation (antiplatelets), or actively degrading the fibrin matrix of an existing clot (thrombolytics).