Chronic thromboembolic pulmonary hypertension (CTEPH) is high blood pressure in the lungs. This happens when the blood vessels in the lungs are blocked by a clot that prevents normal blood flow and causes pressure in the vessels builds. Normally, CTEPH occurs after a pulmonary embolism (PE) — a sudden blockage in one of the pulmonary arteries in the lung. Over half of patients with CTEPH are not aware they have had a PE.
Most PE are absorbed by the body or easily treated with medications. However, about 3-5% of patients who have had a PE do not respond to these medications and develop CTEPH. Blood thinners are NOT effective in treating CTEPH.
Because the arteries are clogged, the heart must work harder to pump blood through the constricted pulmonary blood vessels. Eventually the heart will become weak. If CTEPH is not treated, it will ultimately result in heart failure.