KEY CLINICAL UPDATES IN PULMONARY VENOUS THROMBOEMBOLISM
Direct-acting oral anticoagulants are recommended as first-line anticoagulation for most patients.
Discontinuation of anticoagulation may be considered after 3 months for patients
– With major transient/reversible risk factors (such as fracture of lower limb; hip or knee surgery)
– Who were hospitalized because of heart failure, atrial fibrillation, or myocardial infarction.
Guidelines support systemic thrombolysis for high-risk or massive PE (hemodynamically unstable) with low risk of bleeding.
Intermediate-risk or submassive PE patients have a significant decrease in incidence of hemodynamic collapse but do not have a mortality benefit with thrombolytic therapy.
They do, however, have an increase in major hemorrhagic complications, including intracranial hemorrhage.
ESSENTIALS OF DIAGNOSIS
Third most common cardiovascular cause of death in the United States.
May present with one or more of the following: dyspnea, pleuritic chest pain, hemoptysis, syncope.
Tachypnea, tachycardia, hypoxia (alone or in any combination).
Risk stratification with clinical scores, cardiac biomarkers, and right ventricular imaging is key for management.
Pulmonary venous thromboembolism (VTE), often referred to as pulmonary embolism (PE), is a common, serious, and potentially fatal complication of thrombus formation within the deep venous circulation. PE is the third leading cause of death among hospitalized patients. Despite this prevalence, most cases are not recognized antemortem, and less than 10% of patients with fatal emboli have received specific treatment for the condition. Management demands a vigilant systematic approach to diagnosis and an understanding of risk factors so that appropriate therapy can be initiated.
Many substances can embolize to the pulmonary circulation, including air (during neurosurgery, from central venous catheters), amniotic fluid (during active labor), fat (long bone fractures), foreign bodies (talc in injection drug users), parasite eggs (schistosomiasis), septic emboli (acute infective endocarditis), and tumor cells (renal cell carcinoma). The most common embolus is thrombus, which may arise anywhere in the venous circulation or right heart but most often originates in the deep veins of the lower extremities. Thrombi confined to the calf rarely embolize to the pulmonary circulation. However, about 20% of calf vein thrombi propagate proximally to the popliteal and iliofemoral veins, at which point they may break off and embolize to the pulmonary circulation. Pulmonary emboli will develop in 50–60% of patients with proximal deep venous thrombosis (DVT); half of these embolic events will be asymptomatic. Approximately 50–70% of patients who have symptomatic pulmonary emboli will have lower extremity DVT when evaluated.
PE and DVT are two manifestations of the same disease. The risk factors for PE are the risk factors for thrombus formation within the venous circulation: venous stasis, injury to the vessel wall, and hypercoagulability (Virchow triad). Venous stasis increases with immobility (obesity, stroke, bed rest—especially postoperative), hyperviscosity (polycythemia), and increased central venous pressures (low cardiac output states, pregnancy). Vessels may be damaged by prior episodes of thrombosis, orthopedic surgery, or trauma. Hypercoagulability can be caused by medications (oral ...