Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension, or CTEPH, is group 4 pulmonary hypertension according to the ESC/ERS 2022 guidelines. It occurs when a blood clot in the pulmonary arteries does not fully dissolve after a pulmonary embolism and instead turns into scar tissue that sticks to the artery wall. This tissue forms webs, bands, or blockages that obstruct blood flow, so the pressure in the pulmonary arteries rises and the right ventricle of the heart has to work harder. Pulmonary embolism is covered on the Pulmonary Embolism page, while an overview of pulmonary hypertension is covered on the Pulmonary Hypertension page.

How Common It Is

In most people, the clot dissolves within a few weeks to months with blood thinners. Only a small proportion of pulmonary embolism survivors, about two to three in every hundred people, develop CTEPH within two years. However, up to a quarter of people with CTEPH never knew they had a pulmonary embolism, because the initial episode had no clear symptoms or was not diagnosed.

Symptoms That Are Easily Missed

The main symptom of CTEPH is shortness of breath during activity that does not improve, or even gets worse, after the pulmonary embolism has been treated. Because it resembles being out of shape, asthma, or heart failure, the diagnosis is often delayed. Guidelines recommend an evaluation if shortness of breath or limited ability to be active is still present three to six months after a pulmonary embolism.

It Can Be Treated

Unlike the majority of pulmonary hypertension types, CTEPH can often be improved. If the blockages can be reached, pulmonary endarterectomy surgery removes the scar tissue from inside the pulmonary arteries. This surgery can lower lung pressure substantially, even close to normal in some patients. If surgery is not possible, the options are balloon pulmonary angioplasty and specific medicines. Everyone with CTEPH needs long-term blood thinners. Guidelines recommend that treatment decisions be made by a multidisciplinary team experienced in treating CTEPH.

After Treatment

After surgery or balloon angioplasty, regular follow-up is still needed to assess lung pressure and right ventricular function, usually with echocardiography, a six-minute walk test, and sometimes right heart catheterization. Blood thinners are continued, and supervised exercise training helps gradually restore your ability to be active.

Suspicion usually arises in people who are still short of breath after a pulmonary embolism, or whose shortness of breath has no explanation. Echocardiography assesses the likelihood of pulmonary hypertension and the strain on the right ventricle. A ventilation-perfusion (V/Q) scan is the screening test recommended by guidelines: a normal result nearly rules out CTEPH, while areas of the lung that receive air but no blood flow point to long-standing blockages.

The diagnosis is made after you have been on blood thinners for at least three months. CT pulmonary angiography, catheter-based pulmonary angiography, or MRI shows the typical webs, bands, and blockages. Right heart catheterization confirms the pulmonary artery pressure and pulmonary vascular resistance. Blood tests, including antiphospholipid antibodies, look for clotting disorders. The results of all tests are discussed by the CTEPH team to decide whether the blockages can be treated with surgery.

If you have had a pulmonary embolism, get checked if shortness of breath or limited ability to be active is still present three to six months later, or is getting worse. Go to the emergency room right away if you have sudden shortness of breath, sharp chest pain, cough up a large amount of blood, or faint. Make an appointment for a checkup if you have:

• Shortness of breath when climbing stairs or walking that does not improve
• Tiring more quickly than before the pulmonary embolism
• Swelling in the ankles
• Dizziness or nearly fainting during activity
• Unexplained shortness of breath and a history of deep vein thrombosis