ABSTRACT
Pulmonary arterial hypertension (PAH) is a rare disease that affects 15 to 50 subjects/ million inhabitants in the Western world (1). PAH corresponds to a group of pulmonary vascular diseases characterized by remodeling of the small pulmonary arteries leading to progressive vascular obstruction, causing breathlessness, loss of exercise capacity, and death due to elevated pulmonary artery pressure and subsequent right-heart failure (2-4). A definite diagnosis of PAH requires strict right-heart catheter criteria (2,3). PAH is defined by an elevation of the mean pulmonary artery pressure above 25 mmHg at rest without elevation of the pulmonary capillary wedge pressure (less than 15 mmHg), and elimination of frequent causes of so-called “secondary” pulmonary hypertension due to left-heart diseases, chronic hypoxia, obstructive and restrictive respiratory diseases, and chronic thromboembolic pulmonary disease (2,3).
