Treatment of idiopathic/hereditary pulmonary arterial hypertension.

Treatment of pulmonary hypertension has progressed by recently developed pulmonary arterial hypertension-targeted drugs. However, long-term survival of the patients with idiopathic/heritable pulmonary arterial hypertension is still suboptimal. To improve the outcomes, treatment goals of pulmonary hypertension were proposed at the 5th World Symposium on Pulmonary Hypertension held at Nice, France in 2013; parameters were obtained from cardiopulmonary exercise test, blood tests, echocardiography, and magnetic resonance imaging. In particular, parameters evaluating right ventricular function have been highlighted because survival of the patients with pulmonary arterial hypertension is closely related to right ventricular function. However, treatment specifically targeted to improve right ventricular function in pulmonary hypertension is not yet established. In this setting, we need to maintain or improve right ventricular function with available vasodilators. In this review, we focus on the following two points: (1) Why can pulmonary arterial hypertension-targeted drugs improve right ventricular function without an apparent decrease in pulmonary artery pressure? (2) Are proposed goals sufficient to improve long-term prognosis of the patients? Further, we will discuss what would be the appropriate goal in treating patients with pulmonary arterial hypertension.