Outpatient treatment of patients with pulmonary embolism.

Very few treatment studies have included patients with pulmonary embolism (PE) but there have been many enrolling patients with deep vein thrombosis (DVT). Should treatment for PE be different from treatment for DVT? Post-mortem and clinical studies have shown a strong association between PE and the presence of venous thrombosis in the lower limbs but some recent data suggest that certain clinical factors will predict patients at higher risk of death from PE. Unfortunately, it is not clear that identifying patients as high risk will affect outcome. Two large studies recently compared treatment with unfractionated heparin to treatment with low-molecular-weight heparin in patients with PE. Combining the two studies, the rates of recurrent DVT or PE were 2.9% (13/442) in the low-molecular-weight heparin group and 3.2% (14/441) in the unfractionated heparin group, and major hemorrhage occurred in fewer than 3% of patients. The feasibility of providing outpatient care to many patients presenting to tertiary care hospitals with acute PE has become evident. In our institutions, the data suggest about 50% of patients with PE could be treated as outpatients. Until further knowledge is available, it is not unreasonable to perform echocardiography and cardiac troponin T on patients with PE if they are not completely stable or if concern over concomitant cardiopulmonary disease exists. If they meet criteria demonstrated to result in early death, it is of course reasonable not to treat such patients on a solely outpatient basis. Evidence is accumulating that patients with PE as their initial symptom complex of their venous thromboembolic disease have a worse prognosis, specifically, higher risk of recurrence and higher risk of death, but there are no data to suggest outpatient therapy will affect their prognosis. Low-molecular-weight heparin or intravenous unfractionated heparin, followed by oral anticoagulant therapy, provide adequate therapy in most patients with PE, and many can be treated as outpatients.