title: Predictors of diastolic-to-wedge gradient in patients evaluated for pulmonary hypertension.
abstract: BACKGROUND
  Differentiation of pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PVH) often requires right heart catheterization (RHC). We sought to determine whether a combination of clinical and echocardiographic variables could predict the pulmonary diastolic to wedge (PAd-PWP) gradient and thus differentiate patients with PAH and PVH.
  
  
  METHODS
  We prospectively enrolled 108 patients presenting for PH evaluation. We developed a multivariate model to predict PAd-PWP gradient and validated this model using bootstrapping technique.
  
  
  RESULTS
  PAH patients had worse hemodynamics and were more likely to have evidence of right ventricular dilation and dysfunction whereas patients with PVH were older and more likely to have features of the metabolic syndrome. PAd-PWP gradient of ≥ 6 mm Hg accurately discriminated patients with PAH compared to PVH. Our model including clinical and echocardiographic variables was highly accurate for the prediction of PAd-PWP gradient with a slope 0.89 (slope of 1 represents perfect prediction).
  
  
  CONCLUSIONS
  In this prospective study of patients referred for PH evaluation, a model of readily available clinical parameters and simple echocardiographic measurements accurately predicted the PAd-PWP gradient, allowing discrimination of patients with PAH and PVH. This model requires validation in a larger cohort, but may afford clinicians more parsimony with referral for invasive testing in the evaluation of PH.
authors.affiliation: Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America.
authors.forename: Evan L
authors.initials: EL
authors.lastname: Brittain
authors.forename: Meredith E
authors.initials: ME
authors.lastname: Pugh
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Alex L
authors.initials: AL
authors.lastname: Newman
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Robbins
authors.forename: John H
authors.initials: JH
authors.lastname: Newman
authors.forename: Anna R
authors.initials: AR
authors.lastname: Hemnes
mesh_terms: D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization; D004452:Echocardiography; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011446:Prospective Studies; D011669:Pulmonary Wedge Pressure; D012307:Risk Factors