EDN1 and pulmonary arterial hypertension: We employed a cutoff of ≥ 30 mmHg to screen subjects for PAH because 1) our group recently found that using the lower threshold resulted in less missed cases of PAH among HIV-infected individuals, and 2) a PASP ≥ 30 mmHg on TTE has been shown to predict mortality in certain patient populations who are at risk for PAH.[31,32] Next, Feijoo et al. reported an overall median level of ET-1 of 1.16 pg/ml (IQR 0.86–2.37) among 23 HIV patients with elevated PASP on TTE.