Effects of DHEA in Pulmonary Hypertension

Pulmonary hypertension (PH) is a heterogenous clinical disease characterized foremost by an abnormal increase in pulmonary artery pressure. Pulmonary vasculopathy, characterized by pathologic remodeling and vasoconstriction of the pulmonary arterioles, results in progressive dyspnea, exercise intolerance, right ventricular (RV) failure, and death. Female sex is the strongest clinical risk factor for PAH, with a 4:1 female-to-male ratio reported from the largest registry. Despite the increased risk of PAH in women, women with PAH have better survival than men. RV function is an important cause of morbidity and mortality in PAH as well as highly prevalent heart and lung diseases, but determinants of the RV response are entirely unknown. We and others have shown that female sex is associated with better RV systolic function in both health and disease, including PAH and left heart failure. Targeted PAH therapy leads to greater improvements in RVEF (demonstrated after just several months of treatment) in women as compared to men and partially explains better outcomes in women. Demonstration that DHEA has direct RV and sex-based effects will support the hypothesis that sex hormones play an important role in disease pathogenesis and provide insight into sex hormone manipulation as a treatment strategy in PAH. The goal of this crossover trial is to correlate sex and sex hormones (particularly DHEA) to pulmonary vascular and RV phenotype differences in men and women with PAH. The study seeks to leverage a safe and available hormone treatment to gain further insight into 1) RV effects (a novel and critical end point in PH and PAH), 2) effects on two key PAH pathways in vivo and in vitro as a means for understanding sex-based differences in PAH, and 3) efficiency planning for a future Phase II parallel trial of DHEA as a novel treatment strategy in PAH.