The Effect of Riociguat on Gas Exchange, Exercise Performance, and Pulmonary Artery Pressure During Acute Altitude Exposure

Impairment of exercise performance during altitude exposure results in hypoxemia and decreased oxygen delivery to exercising muscles. Hypoxic pulmonary vasoconstriction (HPV) and ventilation/perfusion (VA/Q) mismatch further contribute to hypoxemia. Therefore, if pharmacologic blockade could attenuate HPV, then VA/Q matching, arterial PO2, and exercise performance might improve. The nitric oxide (NO) pathway has been targeted in this context with sildenafil, but NO is limited at high altitude, which may explain the variable effectiveness of this approach.