Pulmonary Arterial Hypertension (PAH), [WHO Class I] is a rare, chronic, and progressive form of Pulmonary Hypertension, which is characterized by the elevated pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) in blood vessels carrying the blood from right side of heart through lungs. It occurs due to the tightening and stiffening of the small pulmonary arteries leading to the right ventricular dysfunction and vessel obstruction.
Prevalence of PAH varies according to the geographical distribution, environmental factors, sex, age and socioeconomic factors. Despite the advancement and improvement in treatment owing to the unmet need of Pulmonary Arterial Hypertension the number of patients suffering from this rare disease is constantly increasing over the years. Amongst the major sub-types of PAH i.e., Idiopathic PAH, heritable PAH, and disease associated PAH, atleast more than 30% prevalent population suffers from idiopathic PAH. Unlike the previous studies, which underestimated the prevalence of PAH, the latest research findings have exhibited significant increment in the patient population, almost in tunes of approximately 70,000 patients in the 7MM. It was estimated that United States has higher prevalence of PAH as compared to EU5 and Japan. Among the EU5 countries, Germany accounts for the highest prevalence of PAH whereas Spain accounts for the lowest prevalence of PAH.