Bay-8040 is a potent, selective human neutrophil elastase (HNE) inhibitor with IC50 of 28 nM; displays no significant inhibition toward 68 other pharmacologically relevant targets (>10 uM), and a panel of related serine proteases; shows in vivo efficacy with regard to decreasing cardiac remodeling and amelioration of cardiac function in monocrotaline-induced rat model for pulmonary arterial hypertension.