Chronic thromboembolic pulmonary hypertension (CTEPH), similarly to other types of pulmonary hypertension (PH), reduces blood flow and increases pressure in the blood vessels of the lung.1
Breaking its name down helps us to understand what CTEPH is.
- ‘Chronic’ means a long-lasting illness.
- ‘Thromboembolic’ refers to the complete or partial blockage of a blood vessel by a blood clot that has broken away from where it was formed.
- ‘Pulmonary’ relates to the lungs.
- ‘Hypertension’ is the medical term for high blood pressure.
What causes CTEPH?
CTEPH can be the result of blood clots that travel to the lungs (called a pulmonary embolism – PE) and block the pulmonary arteries. It is thought that sometimes these blood clots do not disappear completely after treatment with blood thinners (anticoagulants), and a portion may remain stuck to the wall of the arteries in the lungs. Over time, tissue forms within the clot and it becomes more fibrous, creating a blockage that stops blood flowing easily through the lungs.
These fibrous clots are characteristic of CTEPH. They are very different from blood clots and cannot be dissolved with blood thinners. The presence of a number of these fibrous clots causes high blood pressure and places strain on the right side of the heart, causing it to enlarge and weaken. If left untreated, this may eventually lead to right heart failure.
CTEPH is the only type of PH that can potentially be cured without the need for a lung transplant. A diagnostic test called a ventilation-perfusion scan should be carried out on all patients with PH to assess whether or not they may have CTEPH.
Surgery for CTEPH
An operation called a pulmonary endarterectomy (PEA) can be performed to remove the fibrous blockage(s) from the lung.2 PEA surgery is only carried out by a small number of highly skilled surgeons. Quality of life and life expectancy improve for many people with CTEPH after the PEA operation.
Before deciding if someone with CTEPH is suitable for PEA surgery, they need to be thoroughly assessed by an expert team at a specialist CTEPH center.3 After PEA surgery, patients still need to have regular medical tests and will need blood-thinning medication for the rest of their lives. Even after surgery, CTEPH may persist or return at a later date, and so further treatment may be required.
Medical treatment for CTEPH
Surgery should always be considered first for someone with CTEPH.3 If surgery is not an option, the soluble guanylate cyclase stimulator riociguat is the first approved treatment specifically for patients with CTEPH. It can be used for patients who have inoperable CTEPH and those with persistent or recurrent CTEPH following PEA.
How many people are affected by CTEPH?
CTEPH is estimated to affect 8–40 individuals per million people worldwide.4
CTEPH is defined as ‘Group 4’ in the World Health Organization (WHO) clinical classification of PH5 (see classification for further information).
The future for CTEPH
In recent years, advances in technology have led to improvements in the diagnosis of CTEPH. Moreover, riociguat is the first medical treatment approved specifically for the treatment of adult patients in WHO functional class II to III with inoperable CTEPH or persistent/recurrent CTEPH after surgical treatment, to improve exercise capacity. Clinical trials show that riociguat is effective at improving the symptoms of CTEPH. A new surgical technique called balloon pulmonary angioplasty may also offer an alternative treatment for some CTEPH patients, although it requires further investigation.6
Further information and educational materials on CTEPH can be found in the section PH. It’s personal.
- Lang IM, Pesavento R, Bonderman D et al. Risk factors and basic mechanisms of chronic thromboembolic pulmonary hypertension: a current understanding. Eur Respir J 2013;41:462–8.
- Mayer E. Surgical treatment of chronic thromboembolic pulmonary hypertension. Swiss Med Wkly 2006;136:491–7.
- Jenkins D, Mayer E, Screaton N et al. State-of-the-art chronic thromboembolic pulmonary hypertension diagnosis and management. Eur Respir Rev 2012;21:32–9.
- UK National Health Service. Service Specification and Standards – Pulmonary Thromboendarterectom. Available from: http://www.webarchive.org.uk/wayback/archive/20130325152542/http:/www.specialisedservices.nhs.uk/document/service-specification-standards-pulmonary-endarterectomy/search:true (accessed August 2014).
- Simonneau G, Gatzoulis MA, Adatia I et al. Updated clinical classification of pulmonary hypertension. J Am Coll Cardiol 2013;62:D34–41.
- Andreassen AK, Ragnarsson A, Gude E et al. Balloon pulmonary angioplasty in patients with inoperable chronic thromboembolic pulmonary hypertension. Heart 2013;99:1415–20.