Pulmonary embolism (PE) occurs in 600,000 to 1 million patients each year. It is the 3rd leading cause of cardiovascular mortality in the United States.  Following a PE, about one third of patients will develop persistent symptoms of shortness of breath.  The reason for these persistent symptoms is not fully understood.
“Post-PE syndrome” is now a term used to describe the persistent shortness of breath, exercise limitation, and impaired quality of life that occurs for longer than 3 months after effective anticoagulation treatment of a PE.  There are three recognized causes of the “Post-PE syndrome” which include: thromboembolic pulmonary hypertension (CTEPH); chronic thromboembolic disease (CTED); or functional limitations due to shortness of breath without identifiable cause.
In patients with CTEPH, the blood clots have not resolved in the pulmonary arteries and have caused the pressures in these vessels to raise affecting heart function.  Removal of the clot is potentially curable.  In CTED, the patient may have had multiple small clots over time.  The patients show a reduce exercise capacity, but usually no effect on heart function. No treatment other than life- long anticoagulation is available for this group.  Patients cannot be considered for Post-PE syndrome until the patient has completed at least 3 months of effective anticoagulation therapy.  The work-up must rule out CTEPH and CTED, which at times can be challenging.  It is possible that the Post-PE syndrome is simply a continuation of CTEPH to CTED to Post-PE syndrome.  At this point, no specific treatment is available.