This study is a phase II randomized, double-blind, placebo-controlled parallel trial of 20 subjects with hepatopulmonary syndrome designed to assess the effect of letrozole 2.5 mg orally daily or placebo for 6 months on the alveolar-arterial oxygen gradient (AaPO2).~Subjects at each site will be screened at outpatient clinic visit appointments and interested qualified subjects will be consented and offered participation in this trial. Once consent has been obtained baseline values will be established and subjects will begin letrozole with follow-up clinic visits and testing at 3 months, and 6 months.
The purpose of this study is to assess the safety, tolerability and possible benefit of letrozole compared to placebo in patients with Hepatopulmonary Syndrome.