Pulmonary Arterial Hypertension (PAH) is a debilitating, life-threatening disease in which arteries in the lungs become narrowed or blocked, thereby limiting blood flow. This raises the blood pressure in the lungs arteries, and as a result the patient’s heart has to work harder to pump blood through affected arteries. Eventually, the heart muscles weaken, and heart failure can develop. PAH can be inherited, secondary to a systemic disease or infection with the human immunodeficiency virus (HIV) or due to cocaine abuse or appetite suppressant drug use. In some cases, the cause is unknown (idiopathic PAH).
Although pharmacological treatments are available such as prostanoids, phosphodiesterase 5 inhibitors and endothelin receptor antagonists, they are often complex, have negative side effects, or require extensive follow-up care and PAH still remains a progressive and fatal disease. When medications are unsuccessful, lung transplantation can be required.