Individuals with chronic thromboembolic pulmonary hypertension (CTEPH, World Health Organization Group 4 PH) who have surgery to remove blood clots from the lungs could have a better five-year survival rate compared to those individuals who do not have surgery, according to the results of a study of 550 people with CTEPH in the U.K.
CTEPH is primarily caused by physical blockage of the pulmonary arteries by old, organized blood clots. It is also the only form of pulmonary hypertension (PH) that can potentially be cured by surgically removing the clots through a surgery called pulmonary thromboendarterectomy (PTE) or pulmonary endarterectomy (PEA). Not all people with CTEPH have blood clots that can be removed and have what is called inoperable disease. Even in people with CTEPH who have blood clots that can be surgically removed (called operable disease), not all of them undergo PEA. This can happen for several reasons, such as not being healthy enough for surgery or choosing not to have surgery.
Syed Rehan Quadery and fellow researchers from the U.K. conducted a study to investigate the outcomes of people with CTEPH who had PEA surgery, those who had operable disease but did not have PEA surgery and those who had inoperable disease.
Patients in the study visited the Pulmonary Vascular Disease Unit of the Royal Hallamshire Hospital in Sheffield, U.K. between 2001 and 2014 and had not yet received treatment for CTEPH. Their common symptoms included breathlessness (98%), ankle swelling (38%), dizziness or nearly fainting (27%) and chest pain (19%). The authors found no significant difference in symptoms or how long patients had symptoms prior to diagnosis between those with operable disease, those electing not to complete surgery and those who were inoperable.
The authors found that five-year survival rates were better for patients who had PEA surgery compared to those who did not, confirming the results of previous studies. The five-year survival rate for patients undergoing PEA was 83% compared to 53% for those who had operable disease but did not undergo surgery. The survival rate for those with inoperable disease was 59%.
Among the 550 patients studied, 81% of patients had operable disease, and 19% had inoperable disease due to the location of the blood clots in their lungs; 49% of the total cohort had surgery. Out of the 81% of patients who had operable disease, 39.5% elected not to have surgery, some due to health reasons or personal choice. Those declining surgery due to patient choice had a survival rate of just 55%, prompting the authors to note that additional study is necessary to understand the factors that may lead to the decision to decline surgery and its impact on outcomes.
The researchers did note, however, that the study was conducted before the availability of riociguat (PH-targeted medication approved for use in people with inoperable CTEPH) or balloon pulmonary angioplasty (BPA, a type of procedure researchers are learning more about that uses a balloon that is inflated in the pulmonary arteries to move blood clots to the edges of a blood vessel to allow blood to flow more easily), so the potential benefits of these treatments cannot be assessed.
Overall, the authors found that survival in patients who had PEA was better than in those who did not have surgery, and eligible patients should be counseled and supported to make an informed decision regarding PEA.