title: E/e' Ratio in Patients With Unexplained Dyspnea: Lack of Accuracy in Estimating Left Ventricular Filling Pressure.
abstract: BACKGROUND
  Elevated left ventricular filling pressure is a cardinal feature of heart failure with preserved ejection fraction. Mitral E/e' ratio has been proposed as a noninvasive measure of left ventricular filling pressure. We studied the accuracy of E/e' to estimate and track changes of left ventricular filling pressure in patients with unexplained dyspnea.
  
  
  RESULTS
  We performed supine and upright transthoracic echocardiography in 118 patients with unexplained dyspnea who underwent right heart catheterization. Supine E/e' ratio modestly but significantly correlated with supine pulmonary arterial wedge pressure (PAWP; r=0.36; P<0.001) and demonstrated poor agreement with PAWP values (Bland-Altman limits of agreement of -8.3 to 8.3 mm Hg; range, 6.5-21.2 mm Hg). Similarly, E/e' ratio cut off of 13 performed poorly in identifying patients with elevated left ventricular filling pressure (sensitivity 6%, specificity 90%). The receiver-operating characteristic area of E/e' was 0.65 (95% confidencce interval, 0.50-0.79). With change from the supine to upright position, PAWP decreased (-5±4 mm Hg; P<0.001) as did both E wave (-17±15 cm/s; P<0.001) and e' (-2.7±2.7 cm/s; P<0.001) velocities, whereas E/e' remained stable (+0.2±2.6; P=0.57). Positional change in PAWP correlated modestly with change in E-wave (r=0.37; P<0.001) velocity. There was no appreciable relationship between change in PAWP and change in average E/e' (r=-0.04; P=0.77) and in half the patients the change in PAWP and E/e' were directionally opposite.
  
  
  CONCLUSIONS
  In patients with unexplained dyspnea, E/e' ratio neither accurately estimates PAWP nor identifies patients with elevated PAWP consistent with heart failure with preserved ejection fraction. Positional changes in E/e' ratio do not reflect changes in PAWP.
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: Mário
authors.initials: M
authors.lastname: Santos
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: Jose
authors.initials: J
authors.lastname: Rivero
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: Shane D
authors.initials: SD
authors.lastname: McCullough
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: Erin
authors.initials: E
authors.lastname: West
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Opotowsky
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Waxman
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.).
authors.forename: David M
authors.initials: DM
authors.lastname: Systrom
authors.affiliation: From the Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Portugal (M.S.); Divisions of Cardiovascular Medicine (J.R., S.D.M., E.W., A.R.O., A.M.S.) and Pulmonary and Critical Care Medicine (A.B.W., D.M.S.), Brigham and Women's Hospital, Boston, MA; and Department of Cardiology, Boston Children's Hospital, MA (A.R.O.). ashah11@partners.org.
authors.forename: Amil M
authors.initials: AM
authors.lastname: Shah
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D006328:Cardiac Catheterization; D004417:Dyspnea / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D056888:Patient Positioning; D011237:Predictive Value of Tests; D011669:Pulmonary Wedge Pressure; D012372:ROC Curve; D015203:Reproducibility of Results; D012307:Risk Factors; D013318:Stroke Volume; D016683:Supine Position; D013997:Time Factors; D014463:Ultrasonography; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
keywords: dyspnea; echocardiography; heart failure; hemodynamics; pulmonary wedge pressure