Clinical Pearls & Morning Reports
Published July 6, 2022
Initial treatment of pulmonary embolism is guided by risk stratification of the pulmonary embolism as high, intermediate, or low risk on the basis of the patient’s clinical presentation. Read the NEJM Clinical Practicle Article here.
Q: How are patients with low-risk pulmonary embolism managed?
A: Patients with pulmonary embolism whose conditions are hemodynamically stable and who have no right ventricular strain and normal cardiac biomarkers are considered to have low-risk pulmonary embolism. Most of these patients can be treated with a direct oral anticoagulant (on the basis of high-quality trial data) and assessed for outpatient treatment.
Q: What about the management of those with intermediate-risk pulmonary embolism?
A: Patients with echocardiographic or CT evidence of right heart strain, elevated cardiac biomarkers (such as troponin or brain natriuretic peptide), or both are considered to have intermediate-risk pulmonary embolism. Patients with intermediate-risk pulmonary embolism should receive anticoagulant therapy and be closely monitored to identify the 1 patient in 20 in whom shock may subsequently develop (at which point reperfusion therapy may be administered). On the basis of expert opinion, low-molecular-weight heparin is the preferred immediate anticoagulant for patients with intermediate-risk pulmonary embolism.
A: Approximately 5% of patients present with high-risk pulmonary embolism, involving shock, end-organ hypoperfusion, hypotension (systolic blood pressure of <90 mm Hg or a decrease in systolic blood pressure of >40 mm Hg that is not caused by sepsis, arrhythmia, or hypovolemia), or cardiac arrest. Observational data support the evaluation of patients with high-risk pulmonary embolism for immediate reperfusion therapy by ruling out contraindications (e.g., brain metastases, bleeding disorders, and recent surgery). Intravenous systemic thrombolysis is the most readily available option for reperfusion, and protocols include a weight-based dose of tenecteplase, alteplase at a dose of 0.6 mg per kilogram of body weight, or alteplase at a dose of 100 mg administered over a period of 1 to 2 hours. There is insufficient evidence to support one of these agents over the other; however, tenecteplase can be administered as a bolus in an emergency, and weight-based dosing may be preferable in elderly patients or patients with low body weight.
A: Patients with acute pulmonary embolism should receive anticoagulant therapy for at least 3 months to reduce the risks of further embolization, thrombus extension, early recurrence of venous thromboembolism, and death. Among patients who have pulmonary embolism that was provoked by a major transient (i.e., reversible) risk factor, the long-term risk of venous thromboembolism recurrence is low and anticoagulation therapy can be stopped after 3 months. If the pulmonary embolism was very large or was associated with moderate dysfunction of the right ventricle or if the patient has persistent residual symptoms, some experts recommend that treatment extend to 6 months. In patients with persistent provoking factors such as active cancer, the long-term risk of recurrence is high and indefinite anticoagulation therapy is recommended. Decision making is more nuanced in patients with a first pulmonary embolism that was unprovoked or weakly provoked (i.e., associated with a minor transient risk factor, such as estrogen therapy, pregnancy, minor surgery, or minor leg injury).