One Type of Pulmonary Hypertension Is Under-diagnosed, Study Suggests

A form of pulmonary hypertension known as chronic thromboembolic pulmonary hypertension may be under-diagnosed and under-treated, a review of research articles suggests.

The study, “An epidemiological analysis of the burden of chronic thromboembolic pulmonary hypertension in the USA, Europe and Japan,” was published in the European Respiratory Review.

Chronic thromboembolic pulmonary hypertension, or CTEPH, is a rare condition that occurs when thromboembolic material, such as a blood clot, collects in pulmonary arteries. The clot, which scientists call a pulmonary embolism, can obstruct arteries, preventing blood flow. This can lead to pulmonary hypertension and failure of the right side of the heart.

Other factors that are believed to contribute to the risk of CTEPH include splenectomy, or surgical removal of the spleen; infections in cardiac shunts, or holes that allow fluids to pass; thyroid replacement therapy; lupus; cancer; infected heart pacemaker lines; and chronic inflammatory conditions such as inflammatory bowel disease.

Determining how many people actually have CTEPH is difficult, starting with the fact that early signs and symptoms are often non-specific. In addition, not all patients with CTEPH are at risk of developing a pulmonary embolism or another type of blood clot known as a venous thromboembolism (VTE). This can lead to a delayed or missed diagnosis, increasing the challenge of quantifying the prevalence of the disease.

To try to get a better handle on the prevalence of CTEPH, researchers reviewed articles in more than 25 scientific publications as well as multiple databases and science registries in the United States, Europe and Japan. The team used the information to create country-specific estimates of the future incidence and future diagnosis rates of CTEPH.

The annual incidence of CTEPH in the United States and Europe was 3-5 cases per 100,000 people, they calculated. In Japan, the rate was lower: 1.9 per 100,000 people.

Researchers also found that in 2013 doctors had diagnosed only 7-29 percent of CTEPH cases in the United States and Europe. This finding is what prompted the team to contend that CTEPH is under-diagnosed and under-treated.

There is an urgent need to increase awareness of CTEPH, the team said. Additional researche is needed to better diagnose and treat the disease, it added.

“CTEPH is under-diagnosed and under-treated, and there is an urgent need to increase awareness of CTEPH,” the researchers wrote. “High-quality epidemiological studies are required to increase understanding of CTEPH.”