Pulmonary artery wedge pressure (PAWP) >15 mm Hg is typically used to indicate left heart dysfunction; however, some adjudicated group 1 pulmonary hypertension (PH) patients exhibit elevated PAWP. In this analysis of 325 adjudicated group 1 PH patients from PVDOMICS (2016–2019; 73% women; mean age 53.0±14.3 years), 15% (n=48) had PAWP >15 mm Hg. The analysis was published in the Circulation.

Compared with group 1 PH with normal PAWP, those with high PAWP demonstrated greater obesity, left ventricular hypertrophy (P<0.0002), impaired left ventricular strain (P<0.0001), and reduced left ventricular compliance (P<0.0001), similar to combined pre- and postcapillary PH related to HFpEF (n=75). However, compared with Cpc-PH HFpEF, group 1 PH with high PAWP had better left atrial function, including lower PAWP V wave and higher left atrial compliance and ejection fraction (P<0.0001 for all). Metabolomics revealed minimal differences between group 1 PH with high versus normal PAWP, but 100 metabolites differed versus Cpc-PH HFpEF (false discovery rate P<0.05).

Validation cohorts showed elevated PAWP in 18% (n=402), 22% (n=55), and 19% (n=787) of group 1 PH patients. Exercise responses were intermediate between normal PAWP group 1 PH and Cpc-PH HFpEF (interaction P<0.0001).

Limitations include subjective probabilistic adjudication without a gold-standard distinction between entities.

Approximately one in five group 1 PH patients had elevated resting PAWP. Findings suggest resting PAWP alone may not fully distinguish group 1 PH from Cpc-PH HFpEF and highlight need for integrated diagnostic criteria.