Pulmonary Thromboembolism Follow Up

Monitoring

Patients with acute pulmonary embolism have a high frequency (20-50%) of symptomatic extension of thrombus and/or recurrent venous thromboembolism and therefore require long-term anticoagulant treatment. Treatment with oral anticoagulant is the preferred method of long-term management of most pulmonary embolism patients. Adjusted doses of UFH or LMWH may be indicated for selected patients in whom oral anticoagulants are contraindicated or impractical.  

Low-Molecular-Weight Heparin (LMWH)  

LMWHs are the preferred drug for patients with pulmonary embolism and cancer. It should be used for the first 3-6 months of long-term anticoagulant therapy, then continued as oral therapy indefinitely or until the cancer has resolved.  

Oral Anticoagulant  

The duration of anticoagulation is dependent on the type of event and the coexistence of prolonged risk factors which are as follows:

• Pulmonary embolism due to transient or reversible risk factor: Oral anticoagulation is recommended for at least 3 months
• Unprovoked pulmonary embolism: Oral anticoagulation is recommended for at least 3 months
• Unprovoked pulmonary embolism (first episode), with low-risk of bleeding and in whom stable anticoagulation can be achieved: Consider long-term oral anticoagulation 
• Unprovoked pulmonary embolism (second episode): Long-term treatment is recommended

Risk Factors for Major Bleeding During Anticoagulation  

The following are the risk factors for major bleeding during anticoagulation:

• Age >75 years
• Previous gastrointestinal bleeding
• Previous noncardioembolic stroke
• Chronic hepatic and renal disease
• Concomitant antiplatelet therapy
• Poor anticoagulant control 
• Suboptimal monitoring of therapy 
• Comorbid illness

Monitoring During Anticoagulation  

INR should be checked at least weekly during the first several weeks of Warfarin therapy. If stable, monitor every 2 weeks then every 4 weeks, but not >4 weeks. The target INR is 2.5 for most patients and 3.0 for patients with recurrent venous thromboembolism.