{
  "abstract": "Background Revised haemodynamic criteria for pulmonary hypertension (PH)—mean pulmonary artery pressure (mPAP) >20 mm Hg and pulmonary vascular resistance (PVR) >2 Wood Units (WU)—have defined new subsets of patients with mild PH. We aimed to characterise their clinical profile and prognosis.Methods We included consecutive incident, treatment-naïve patients undergoing right heart catheterisation at a PH referral centre. Patients with mPAP 21–24 mm Hg and pulmonary artery wedge pressure (PAWP) ≤15 mm Hg were stratified by PVR values to identify those with unclassified PH (PVR≤2 WU) and mild precapillary PH (PVR>2 WU). Patients with mild precapillary PH were compared with matched controls with normal haemodynamics and with patients meeting previous pulmonary arterial hypertension (PAH) haemodynamic criteria (mPAP≥25 mm Hg, PAWP≤15 mm Hg, PVR>3 WU).Results Among 259 patients with mPAP 21–24 mm Hg and PAWP≤15 mm Hg, 76% had left heart or lung disease. In unclassified PH, mPAP elevation was mainly due to high stroke volume index (SVI) or backward transmission from borderline PAWP. In mild precapillary PH, SVI was the only independent haemodynamic predictor of survival. Survival was similar between mild precapillary PH and PAH patients. A limited number of patients with PAH risk factors progressed to overt PAH and, in the absence of comorbidities, appeared to benefit from PAH therapies.Conclusions Unclassified PH is mainly related to pulmonary overflow or backward transmission from borderline PAWP. Mild precapillary PH is typically associated with comorbidities and not necessarily an early PAH stage. SVI is a key prognostic marker. Careful clinical phenotyping is essential to identify the small subset who may benefit from targeted therapies.",
  "authors": [
    {
      "affiliations": [
        "Cardiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy"
      ],
      "name": "Fabio Dardi"
    },
    {
      "affiliations": [
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Riccardo Bertozzi"
    },
    {
      "affiliations": [
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Alberto Ballerini"
    },
    {
      "affiliations": [
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Francesco Cennerazzo"
    },
    {
      "affiliations": [
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Federico Donato"
    },
    {
      "affiliations": [
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Daniele Guarino"
    },
    {
      "affiliations": [
        "Cardiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy"
      ],
      "name": "Alessandra Manes"
    },
    {
      "affiliations": [
        "IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy"
      ],
      "name": "Elena Nardi"
    },
    {
      "affiliations": [
        "Cardiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy",
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Massimiliano Palazzini"
    },
    {
      "affiliations": [
        "Cardiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy",
        "Dipartimento DIMEC (Dipartimento di scienze mediche e chirurgiche), Alma Mater Studiorum University of Bologna, Bologna, Italy"
      ],
      "name": "Nazzareno Galié"
    }
  ],
  "title": "Phenotyping of patients with mild pulmonary hypertension",
  "uid": "e7f975c3-5e6f-56c5-8a2c-fff7e9861c24"
}