New targets for pulmonary arterial hypertension: going beyond the currently targeted three pathways

Purpose of review Pulmonary arterial hypertension (PAH) is a hemodynamic state defined by a resting mean pulmonary arterial pressure at or above 25 mmHg with a normal pulmonary capillary wedge pressure, ultimately leading to right heart failure and premature death. Although considerable progress has been made in the development of drug therapies for PAH targeting abnormalities found in the three main pathobiologic pathways (nitric oxide, prostacyclin, and endothelin-1), there is no drug available to specifically stop the progressive cellular accumulation into the pulmonary artery vessel wall. Indeed, this pulmonary vascular remodeling is a key pathological feature in PAH, contributing to the progressive narrowing of the lumen responsible to the functional decline and to the right ventricle hypertrophy and dysfunction. Recent findings Because numerous important discoveries in the PAH pathogenesis have been recently made, our improved understanding of additional pathways in this condition will presumably lead to the development of novel and more powerful therapeutic strategies in the near future. Summary In this review, we highlight some recent biological findings and discuss the opportunities that could lead to the identification of new promising targets in PAH paving the way for future therapeutic strategies.