A 72-year-old man with a history of DVT 2 years ago (treated with 6 months of warfarin) presents with acute dyspnea. Clinical pretest probability for PE is high. D-dimer is 3.2 mcg/mL, and CTPA confirms PE. He is started on IV unfractionated heparin. Which of the following represents the mechanism of action of heparin in this case?
- A)Direct inhibition of thrombin and factor Xa through antithrombin III activationGABARITO
- B)Direct conversion of plasminogen to plasmin for clot dissolution
- C)Inhibition of von Willebrand factor binding to glycoprotein Ib
- D)Irreversible inhibition of platelet aggregation via COX-1 blockade
- E)Vitamin K-dependent inhibition of factors II, VII, IX, and X
Explicação
Unfractionated heparin (UFH) is an indirect thrombin inhibitor that binds to antithrombin III and potentiates its inhibition of thrombin (factor IIa) and factor Xa. This is its primary anticoagulant mechanism. UFH is the drug of choice for acute PE, especially... Ver explicação completa e trilha adaptativa →