title: Non-invasive estimation of pulmonary vascular resistance with cardiac magnetic resonance.
abstract: OBJECTIVE
  To develop a cardiac magnetic resonance (CMR) method for non-invasive estimation of pulmonary vascular resistance (PVR).
  
  
  RESULTS
  The study comprised 100 consecutive patients with known or suspected pulmonary hypertension (PH; 53 ± 16 years, 73% women) who underwent same-day right heart catheterization (RHC) and CMR. Increased PVR was defined from RHC as >3 WU (n = 66, 66%). From CMR cine and phase-contrast images, right ventricular (RV) volumes and ejection fraction (RVEF), pulmonary artery (PA) flow velocities and areas, and cardiac output were quantified. The best statistical model to estimate PVR was obtained from a derivation cohort (n = 80) based on physiological plausibility and statistical criteria. Validity of the model was assessed in the remaining 20 patients (validation cohort). The CMR-derived model was: estimated PVR (in WU) = 19.38 - [4.62 × Ln PA average velocity (in cm/s)] - [0.08 × RVEF (in %)]. In the validation cohort, the correlation between invasively quantified and CMR-estimated PVR was 0.84 (P < 0.001). The mean bias between the RHC-derived and CMR-estimated PVR was -0.54 (agreement interval -6.02 to 4.94 WU). The CMR model correctly classified 18 (90%) of patients as having normal or increased PVR (area under the receiver operator characteristics curve 0.97; 95% confidence interval: 0.89-1.00). CONCLUSIONS Non-invasive estimation of PVR using CMR is feasible and may be valuable for PH diagnosis and/or follow-up.
authors.affiliation: The Zena and Michael A. Wiener Cardiovascular Institute and Marie-Josee and Henry R. Kravis Center for Cardiovascular Health, Mount Sinai School of Medicine, New York 10029, USA.
authors.forename: Ana
authors.initials: A
authors.lastname: García-Alvarez
authors.forename: Leticia
authors.initials: L
authors.lastname: Fernández-Friera
authors.forename: Jesús G
authors.initials: JG
authors.lastname: Mirelis
authors.forename: Simonette
authors.initials: S
authors.lastname: Sawit
authors.forename: Ajith
authors.initials: A
authors.lastname: Nair
authors.forename: Jill
authors.initials: J
authors.lastname: Kallman
authors.forename: Valentin
authors.initials: V
authors.lastname: Fuster
authors.forename: Javier
authors.initials: J
authors.lastname: Sanz
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology*