title: Characterization of patients with borderline pulmonary arterial pressure.
abstract: BACKGROUND
  Resting mean pulmonary artery pressure (mPAP) values between 20 and 25 mm Hg are above normal but do not fulfill the criteria for pulmonary hypertension (PH). The clinical relevance of such borderline hemodynamics is a matter of discussion.
  
  
  METHODS
  We focused on patients who underwent right-sided heart catheterization during rest and exercise for symptoms indicative of PH or due to underlying disease associated with an increased risk for pulmonary arterial hypertension and characterized the patients according to their resting mPAP. Patients with manifest PH (mPAP ≥ 25 mm Hg) were excluded.
  
  
  RESULTS
  We included 141 patients, 32 of whom presented with borderline hemodynamics (20 < mPAP < 25 mm Hg). Borderline patients were older (65.8 ± 12.5 years vs 57.3 ± 12.5 years, P = .001) and more often had cardiac comorbidities (53% vs 15%, P < .001) or decreased lung function (47% vs 16%, P < .001) as compared with patients with resting mPAP < 21 mm Hg. After correction for age, borderline patients had significantly increased pulmonary vascular resistance (2.7 ± 0.7 Wood units vs 1.8 ± 0.8 Wood units, P < .001) and mPAP/cardiac output (CO) and transpulmonary gradient/CO slopes (both P < .001) as well as lower peak oxygen uptake (16.9 ± 4.6 mL/min/kg vs 20.9 ± 4.7 mL/min/kg, P = .009) and 6-min walk distance (383 ± 120 m vs 448 ± 92 m, P = .001). During follow-up (4.4 ± 1.4 years), the mortality rate of borderline patients vs patients with resting mPAP < 21 mm Hg was 19% vs 4%.
  
  
  CONCLUSIONS
  In patients undergoing right-sided heart catheterization with exclusion of manifest PH, borderline elevation of pulmonary arterial pressure is associated with cardiac and pulmonary comorbidities, decreased exercise capacity, and a poor prognosis.
authors.affiliation: Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria. Electronic address: gabor.kovacs@klinikum-graz.at.
authors.forename: Gabor
authors.initials: G
authors.lastname: Kovacs
authors.affiliation: Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Avian
authors.affiliation: Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: Tscherner
authors.affiliation: Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.
authors.forename: Vasile
authors.initials: V
authors.lastname: Foris
authors.affiliation: Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Bachmaier
authors.affiliation: Department of Experimental Anesthesiology, Medical University of Graz.
authors.forename: Andrea
authors.initials: A
authors.lastname: Olschewski
authors.affiliation: Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.
authors.forename: Horst
authors.initials: H
authors.lastname: Olschewski
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D062186:Arterial Pressure / Q000502:physiology; D006328:Cardiac Catheterization; D002318:Cardiovascular Diseases / Q000401:mortality / Q000503:physiopathology*; D016022:Case-Control Studies; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D014655:Vascular Resistance