title: Addressing the Controversy of Estimating Pulmonary Arterial Pressure by Echocardiography.
abstract: BACKGROUND
  There is currently controversy over whether echocardiography provides reliable estimations of pulmonary pressures. The objective of this study was to determine the factors influencing the accuracy and reliability of estimating right ventricular systolic pressure (RVSP) using echocardiography in patients with advanced lung disease or pulmonary arterial hypertension.
  
  
  METHODS
  Between January 2001 and December 2012, 667 patients with advanced lung disease or pulmonary arterial hypertension underwent right heart catheterization and transthoracic echocardiography. Of those, 307 had both studies within 5 days of each other. The correlation and bias in estimating RVSP according to tricuspid regurgitation (TR) signal quality and reader expertise were retrospectively determined. Reasons for under- and overestimation were analyzed. The diagnostic performance of estimated RVSP, relative right ventricular size, eccentricity index, and tricuspid annular plane systolic excursion was compared for classifying patients with pulmonary hypertension (mean pulmonary artery pressure ≥ 25 mm Hg).
  
  
  RESULTS
  Invasive mean and systolic pulmonary artery pressures were strongly correlated (R(2) = 0.95, P < .001), with mean pulmonary artery pressure = 0.60 × systolic pulmonary artery pressure + 2.1 mm Hg. Among patients undergoing right heart catheterization and transthoracic echocardiography within 5 days, level 3 readers considered only 61% of TR signals interpretable, compared with 72% in clinical reports. Overestimation in the clinical report was related mainly to not assigning peak TR velocity at the modal frequency and underestimation to overreading of uninterpretable signals. When the TR signal was interpretable, the areas under the curve for classifying pulmonary hypertension were 0.97 for RVSP and 0.98 for RVSP and eccentricity index (P > .05). When TR signals were uninterpretable, eccentricity index and right ventricular size were independently associated with pulmonary hypertension (area under the curve, 0.77).
  
  
  CONCLUSIONS
  Echocardiography reliably estimates RVSP when attention is given to simple quality metrics.
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California. Electronic address: mamsalle@stanford.edu.
authors.forename: Myriam
authors.initials: M
authors.lastname: Amsallem
authors.affiliation: Division of Pulmonary and Critical Care, Stanford University School of Medicine, Stanford, California.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Sternbach
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Sasikanth
authors.initials: S
authors.lastname: Adigopula
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Thu A
authors.initials: TA
authors.lastname: Vu
authors.affiliation: Division of Pulmonary and Critical Care, Stanford University School of Medicine, Stanford, California.
authors.forename: Roham
authors.initials: R
authors.lastname: Zamanian
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: David
authors.initials: D
authors.lastname: Liang
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Gundeep
authors.initials: G
authors.lastname: Dhillon
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Ingela
authors.initials: I
authors.lastname: Schnittger
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Michael V
authors.initials: MV
authors.lastname: McConnell
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: François
authors.initials: F
authors.lastname: Haddad
mesh_terms: D062186:Arterial Pressure; D006328:Cardiac Catheterization; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008171:Lung Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012189:Retrospective Studies
keywords: Advanced lung disease; Echocardiography; Pulmonary hypertension; Right heart catheterization; Right ventricular systolic pressure