---
title: Chronic thromboembolic pulmonary hypertension
description: What CTEPH is, why clots sometimes do not dissolve after a pulmonary embolism, who is tested and how, and which treatment approaches clinical guidelines describe.
type: disease
aliases:
  - CTEPH
  - chronic thrombo-embolic pulmonary hypertension
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Легочная гипертензия, в том числе хроническая тромбоэмболическая легочная гипертензия
    year: 2024
    doi: 10.15829/1560-4071-2024-6161
    url: https://cr.minzdrav.gov.ru/view-cr/159_2
  - tier: guideline
    org: esc
    title: 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension
    year: 2022
    doi: 10.1183/13993003.00879-2022
    url: https://doi.org/10.1183/13993003.00879-2022
  - tier: guideline
    org: esc
    title: 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism
    year: 2019
    doi: 10.1093/eurheartj/ehz405
    url: https://doi.org/10.1093/eurheartj/ehz405
  - tier: reference
    org: msd-manuals
    title: Pulmonary Hypertension (consumer version)
    year: 2024
    url: https://www.msdmanuals.com/home/lung-and-airway-disorders/pulmonary-hypertension/pulmonary-hypertension
  - tier: reference
    org: msd-manuals
    title: Pulmonary Embolism (PE)
    year: 2024
    url: https://www.msdmanuals.com/professional/pulmonary-disorders/pulmonary-embolism-pe/pulmonary-embolism-pe
sources_checked: 2026-10-13
review: null
---

Chronic thromboembolic pulmonary hypertension (CTEPH) is a form of [pulmonary hypertension](../pulmonary-hypertension/) in which branches of the <Structure id="pulmonary-trunk">pulmonary artery</Structure> stay narrowed or blocked by organised clots after a thromboembolism, and the small lung vessels then change as well.<Cite n={[1, 3]} /> CTEPH is a rare late complication of [pulmonary embolism](../pulmonary-embolism/) (PE) and is often recognised late.<Cite n={[1, 2]} /> It is important not to miss it: for some patients there is an operation after which most of those operated on have much milder symptoms.<Cite n={3} />

<Diagram name="chronic-thromboembolic-pulmonary-hypertension">
  <p slot="normal">
    Blood from the right side of the heart travels through the pulmonary arteries to the small
    vessels of the lungs. Normally the pressure in the pulmonary arteries is low, so the wall of
    the right ventricle is thinner than that of the left.<Cite n={4} /> In the diagram all branches
    of the pulmonary artery are open and the right ventricle is of normal size.
  </p>
  <p slot="disease">
    In CTEPH a clot turns into dense fibrotic tissue that permanently blocks the
    artery.<Cite n={3} /> It is attached to the vessel wall and forms ring-like narrowings and webs
    across the lumen, and it closes some branches completely.<Cite n={[1, 2]} /> Blood is
    redirected into the remaining open branches and overfills them, while the parts of the lung
    beyond the blocked branches get less blood.<Cite n={[2, 3]} /> The right ventricle works
    against a pressure overload: over time its wall thickens and its cavity
    enlarges.<Cite n={[1, 4]} /> The small lung vessels also change in CTEPH, but the diagram does
    not show them.<Cite n={[1, 2]} />
  </p>
</Diagram>

## Why it happens

<Patient>

In PE, clots, most often from the deep veins of the legs, travel to the pulmonary arteries ([deep vein thrombosis](../deep-vein-thrombosis/)).<Cite n={4} /> In most people the arteries become open again within the first few months after PE.<Cite n={3} /> In some people, however, the clots do not dissolve but become "organised", turning into dense fibrotic tissue, and in rare cases this leads to CTEPH.<Cite n={[3, 5]} /> The resistance to blood flow in the lungs gradually rises and the <Structure id="right-ventricle">right ventricle</Structure> works under an overload: over time it thickens and enlarges, and right-sided [heart failure](../heart-failure/) can develop.<Cite n={[1, 3, 4]} />

Some patients (in registries, about a quarter) have no known history of PE, and their breathlessness builds up gradually.<Cite n={[1, 3]} /> The risk of CTEPH is higher with repeated venous thrombosis, with a PE that affected large branches and overloaded the right ventricle, and with certain diseases and conditions: antiphospholipid syndrome, removal of the spleen, permanent devices in the blood vessels or heart such as a pacemaker, inflammatory bowel disease and cancer.<Cite n={[1, 2]} />

</Patient>

<Student>

The Russian Ministry of Health guideline describes CTEPH (group 4 PH) as post-thromboembolic obstructive remodelling of the pulmonary artery branches combined with secondary distal vasculopathy, leading to pre-capillary PH.<Cite n={1} /> Its hallmark is fibrotic transformation of the thrombus: fixed mechanical obstruction leads to overflow of the open pulmonary arterial bed, microvascular remodelling and a progressive increase in pulmonary vascular resistance (PVR).<Cite n={3} /> PH in CTEPH is therefore a consequence not only of obstruction by organised fibrotic clots but also of the associated microvasculopathy.<Cite n={[1, 2]} />

The median age at diagnosis is 63 years, both sexes are equally affected, and paediatric cases are rare.<Cite n={3} />

</Student>

<HeartModel highlight={['pulmonary-trunk', 'right-ventricle']} />

## Symptoms

<Patient>

The symptoms of CTEPH are non-specific and may be absent early on.<Cite n={[1, 3]} /> The main symptom is breathlessness on exertion that builds up gradually.<Cite n={[1, 2]} /> Tiredness and swelling of the legs, developing over months to years, also occur.<Cite n={5} /> Signs of right-sided heart failure only become obvious at a late stage.<Cite n={3} />

Breathlessness after PE is common, and studies suggest it is mostly explained by loss of muscle fitness, especially with excess weight and other heart and lung diseases, rather than by CTEPH.<Cite n={3} /> But if breathlessness or poor exercise tolerance persists or newly appears after PE, further tests are recommended.<Cite n={[1, 2, 3]} />

</Patient>

<Student>

The clinical picture of CTEPH may resemble acute PE or pulmonary arterial hypertension (PAH); oedema and haemoptysis are more frequent in CTEPH, and syncope in PAH.<Cite n={3} /> In a patient presenting with acute PE, CT signs of CTEPH and right ventricular hypertrophy point to a chronic process.<Cite n={2} />

</Student>

## How it is diagnosed

<Patient>

The first test when CTEPH is suspected is a heart ultrasound, [echocardiography](../../diagnostic/echocardiography/), which shows how likely pulmonary hypertension is.<Cite n={[1, 2]} /> The main way to rule out CTEPH is a ventilation/perfusion lung scan: if the blood supply to the lungs on the scan is normal, CTEPH is very unlikely.<Cite n={[1, 2]} />

If symptoms remain after three months of treatment with anticoagulants (medicines that reduce blood clotting) and parts of the lungs still have a poor blood supply, the person is referred to a pulmonary hypertension expert centre.<Cite n={[1, 2, 3]} /> There, CT angiography of the pulmonary arteries is done, and the diagnosis is confirmed by right heart catheterisation with pressure measurement together with angiography of the pulmonary arteries.<Cite n={[1, 2]} />

</Patient>

<Student>

CTEPH is diagnosed by a work-up done after at least three months of anticoagulation: it requires criteria of pre-capillary PH at right heart catheterisation (see the [PH article](../pulmonary-hypertension/)) plus imaging of post-thromboembolic pulmonary artery lesions on CT angiography, pulmonary angiography and/or perfusion scintigraphy.<Cite n={1} /> Signs of chronic, organised, fibrotic clots are ring-like stenoses, webs/slits and chronic total occlusions; the Russian Ministry of Health guideline lists intravascular bands, membranes, webs and strictures as direct CT signs.<Cite n={[1, 2]} /> When such lesions are present without pre-capillary PH, chronic thromboembolic pulmonary disease (CTEPD) is diagnosed; ESC/ERS 2022 keeps the term CTEPH for patients with PH.<Cite n={[1, 2]} />

In the absence of parenchymal lung disease, a normal perfusion scan excludes CTEPH with a negative predictive value of 98%.<Cite n={2} /> A negative CT pulmonary angiogram does not exclude CTEPD, as distal disease can be missed.<Cite n={2} /> Testing for antiphospholipid syndrome is recommended in all patients with CTEPH.<Cite n={[1, 2]} />

</Student>

## How it is treated

<Patient>

Treatment is chosen by the team of an expert centre: surgeons, interventional specialists, specialists in imaging of the lung vessels and cardiologists experienced in pulmonary hypertension.<Cite n={[1, 2, 3]} /> The methods are often combined.<Cite n={2} />

- **Pulmonary endarterectomy** is the main method. It is not the removal of a fresh clot as in acute PE: the surgeon frees the organised fibrotic material from the wall and removes it from the branches of both pulmonary arteries, down to small branches, while the body is deeply cooled and the circulation is temporarily stopped.<Cite n={[1, 2, 3]} /> Age by itself is not a reason to refuse surgery.<Cite n={[1, 3]} /> The operation is done in specialised centres.<Cite n={3} />
- **Balloon pulmonary angioplasty** is used if the lesions cannot be reached by surgery or pulmonary hypertension remains after the operation. A guide wire is passed through a catheter into the narrowed branch and a balloon is inflated, tearing the web; the procedure is done in several stages.<Cite n={[1, 2]} /> It improves the circulation in the lungs, the work of the right ventricle and exercise capacity, but it can cause serious complications, so it is done in experienced centres.<Cite n={2} />
- **Medicines for pulmonary hypertension** that act on the small vessels are used for inoperable CTEPH or when pulmonary hypertension remains after surgery.<Cite n={[1, 2]} />
- **Lifelong anticoagulants** are recommended for everyone with CTEPH, including after a successful operation or angioplasty.<Cite n={[1, 2, 3]} /> The doctor chooses the medicine.

Supervised exercise training helps; for swelling and low blood oxygen, diuretics and oxygen are used.<Cite n={[2, 3]} /> Long-term follow-up is needed after treatment, because pulmonary hypertension can come back.<Cite n={2} /> Which treatment is needed is decided by the doctor together with the patient.

</Patient>

<Student>

Treatment is multimodal: pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and medical therapy target proximal lesions, distal lesions and microvasculopathy, respectively; all patients should be reviewed by a CTEPH team.<Cite n={2} /> According to the Russian Ministry of Health guideline, a patient is considered inoperable only if at least two independent expert centres decide so.<Cite n={1} />

PEA is the treatment of choice for fibrotic obstructions accessible by surgery: a complete bilateral endarterectomy down to segmental and subsegmental levels in phases of deep hypothermic circulatory arrest.<Cite n={[1, 2]} /> The long-term prognosis of operated patients is better than that of non-operated patients; some patients have residual PH after surgery.<Cite n={[1, 2, 3]} />

BPA is recommended for technically inoperable patients and for residual PH after PEA with distal obstructions; a staged approach with a limited number of segments per session is preferred.<Cite n={2} /> The most frequent complications are vessel perforation and severe reperfusion lung injury.<Cite n={1} /> PAH-specific therapy is used for the microvascular component.<Cite n={[1, 2]} /> Drugs and doses are not given here. Lifelong anticoagulation is recommended for all patients with CTEPH, as recurrent thromboembolism with insufficient clot resolution is a key feature of the disease.<Cite n={[1, 2]} />

</Student>

## When to call an ambulance

CTEPH develops gradually, but dangerous complications are possible: a new acute PE can occur on top of it.<Cite n={[1, 2]} /> The complications for which the Russian Ministry of Health guideline on pulmonary hypertension advises emergency hospital admission are listed in the article on [pulmonary hypertension](../pulmonary-hypertension/).<Cite n={1} />

Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) for fainting, coughing up blood, rapidly worsening breathlessness, or palpitations with feeling faint.<Cite n={[1, 2]} /> Sudden breathlessness and chest pain can be signs of a new PE: see the article on [pulmonary embolism](../pulmonary-embolism/). As with any heart condition, call an ambulance for fainting, chest pain or severe breathlessness: this is the site's general safety rule, repeated at the bottom of every page.

<Quiz />