Understanding Chronic Thromboembolic Pulmonary Hypertension (CTEPH)
Chronic thromboembolic pulmonary hypertension arises from repeated or unresolved pulmonary embolism – or clots in the pulmonary arteries.
The pulmonary arteries bring deoxygenated blood from the right side of the heart to each lung in order to be oxygenated. When the blood is oxygenated, the pulmonary veins bring the blood back to the left side of the heart which pumps the oxygenated blood through the body. Pulmonary means relating to the lungs.
A thrombus is a solid mass of platelets and proteins in the bloodstream. An embolus is a piece of a thrombus that breaks free, travels and lodges downstream in a blood vessel. When thrombi detach and float downstream to occlude (block) a blood vessel like a pulmonary artery, this is referred to as a pulmonary embolism.
Pulmonary embolism is a fairly common cardiovascular condition. Usually a pulmonary embolism either resolves without treatment or can be successfully treated with medication that breaks up the clot. However, when the clot does not dissipate with medication or there is frequent recurrence of clots, the lungs undergo harmful vascular changes and can result in pulmonary hypertension. Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of severe pulmonary hypertension and right sided heart failure.
Pulmonary hypertension is abnormally high blood pressure in the pulmonary arteries. It makes the right side of the heart work harder than normal to pump blood to the lungs to be oxygenated. Certain types of pulmonary hypertension, such as CTEPH, can be deadly. Read more about the different types of pulmonary hypertension.
Until the development of PTE at UC San Diego Health System, the treatment for CTEPH was lung transplantation. PTE is now saving thousands of lives worldwide.
Getting the Right Diagnosis
Angiograms showing a healthy pulmonary artery (left) and a pulmonary artery with numerous blockages (right).
CTEPH is much more prevalent than recognized. This condition is often misdiagnosed or left undiagnosed, as the primary symptom – shortness of breath – is unspecific. Primary care physicians frequently treat these patients for asthma or COPD, or other more common conditions, as they may not be familiar with CTEPH. There is also a trend of physicians treating such patients with medications designed and approved for a specific and different form of pulmonary hypertension without properly considering or ruling out CTEPH.
It has been reported that as high as 3.8 percent of individuals with first time pulmonary embolism may develop CTEPH. That suggests there may be over 12,000 new cases of CTEPH in the United States annually. Even if that represents an overestimation of true incidence, we appear to be under diagnosing this treatable condition.
In many cases, our team of specialists will correct a diagnosis – finding CTEPH when another form of pulmonary hypertension has been assumed, or when the patient has been living with a misdiagnosis. A correct diagnosis is critical for successful outcomes.