Phenotyping of patients with pulmonary hypertension and mean pulmonary arterial pressure between 21 and 24 MMHG

Background In the healthy population, the mean pulmonary artery pressure (mPAP) does not exceed 20 mmHg at rest, and pulmonary vascular resistance (PVR) is <2 W.U. Recent studies have shown an increasing mortality for mPAP values >20 mmHg and PVR > 2 W.U. Based on these findings, the European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines were updated, lowering the mPAP cut-off from 25 to 20 mmHg and the PVR cut-off from 3 to 2 W.U. for the diagnosis of pre-capillary pulmonary hypertension (PH). However, there is limited data on the newly identified populations of patients with mPAP 21-24 mmHg and PVR 2-3 W.U. Purpose to phenotype the population of patients with mild increases in mPAP (21-24 mmHg), assessing their demographic, hemodynamic characteristics, and burden of cardio-pulmonary comorbidities, as well as evaluating their prognosis. Methods Between January 2002 and January 2024, we enrolled patients with mPAP 21-24 mmHg at baseline right heart catheterization. We assessed clinical characteristics (age, gender), WHO functional class, comorbidities (previous pulmonary embolism, HIV infection, portal hypertension, anemia, renal insufficiency), presence of left heart or pulmonary diseases, and haemodynamic variables. We also evaluated the predictors of prognosis in the entire mPAP 21-24 mmHg population and in the subgroup of patients with PVR >2 W.U. Results 259 patients were included (39% with PVR ≤2 W.U., 39% with PVR between 2-3 W.U., and 22% with PVR >3 W.U.). The baseline characteristics of these patients are shown in Table 1. Independent predictors of prognosis are shown in Table 2. During follow-up, 19 patients (11 with baseline PVR 2-3 W.U. and 8 with baseline PVR > 3 W.U.) developed a form of pre-capillary pulmonary hypertension according to 2015 ESC/ERS Guidelines (mPAP > 25 mmHg and PVR > 3 W.U.), of which only 2 developed PAH. Conclusions Patients with mPAP values between 21 and 24 mmHg represent a heterogeneous population with a high burden of cardiac and/or pulmonary comorbidities, many of which have an independent negative prognostic impact, and often are the main cause of death. The development of a clinically defined diagnosis of pulmonary arterial hypertension, with a progressive pulmonary vasculopathy that affects the prognosis of these patients, is extremely rare.Baseline characteristics Multivariate analysis