title: Extracellular Volume Fraction for Characterization of Patients With Heart Failure and Preserved Ejection Fraction.
abstract: BACKGROUND
  Optimal patient characterization in heart failure with preserved ejection fraction (HFpEF) is essential to tailor successful treatment strategies. Cardiac magnetic resonance (CMR)-derived T1 mapping can noninvasively quantify diffuse myocardial fibrosis as extracellular volume fraction (ECV).
  
  
  OBJECTIVE
  This study aimed to elucidate the diagnostic performance of T1 mapping in HFpEF by examining the relationship between ECV and invasively measured parameters of diastolic function. It also investigated the potential of ECV to differentiate among pathomechanisms in HFpEF.
  
  
  METHODS
  We performed T1 mapping in 24 patients with HFpEF and 12 patients without heart failure symptoms. Pressure-volume loops were obtained with a conductance catheter during basal conditions and handgrip exercise. Transient pre-load reduction was used to extrapolate the diastolic stiffness constant.
  
  
  RESULTS
  Patients with HFpEF showed higher ECV (p < 0.01), elevated load-independent passive left ventricular (LV) stiffness constant (beta) (p < 0.001), and a longer time constant of active LV relaxation (p = 0.02). ECV correlated highly with beta (r = 0.75; p < 0.001). Within the HFpEF cohort, patients with ECV greater than the median showed a higher beta (p = 0.05), whereas ECV below the median identified patients with prolonged active LV relaxation (p = 0.01) and a marked hypertensive reaction to exercise due to pathologic arterial elastance (p = 0.04). On multiple linear regression analyses, ECV independently predicted intrinsic LV stiffness (β = 0.75; p < 0.01).
  
  
  CONCLUSIONS
  Diffuse myocardial fibrosis, assessed by CMR-derived T1 mapping, independently predicts invasively measured LV stiffness in HFpEF. Additionally, ECV helps to noninvasively distinguish the role of passive stiffness and hypertensive exercise response with impaired active relaxation. (Left Ventricular Stiffness vs. Fibrosis Quantification by T1 Mapping in Heart Failure With Preserved Ejection Fraction [STIFFMAP]; NCT02459626).
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Karl-Philipp
authors.initials: KP
authors.lastname: Rommel
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: von Roeder
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Latuscynski
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Oberueck
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Blazek
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Fengler
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Besler
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Sandri
authors.affiliation: Department of Radiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lücke
authors.affiliation: Department of Radiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Gutberlet
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Linke
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schuler
authors.affiliation: Department of Internal Medicine/Cardiology, Leipzig University, Heart Center, Leipzig, Germany. Electronic address: Philipp.Lurz@gmx.de.
authors.forename: Philipp
authors.initials: P
authors.lastname: Lurz
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods; D005260:Female; D005355:Fibrosis / Q000473:pathology / Q000503:physiopathology; D018737:Hand Strength / Q000502:physiology; D006321:Heart / Q000503:physiopathology; D006333:Heart Failure / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology*
keywords: diastolic dysfunction; heart failure with preserved ejection fraction; magnetic resonance imaging