title: CMR-verified diffuse myocardial fibrosis is associated with diastolic dysfunction in HFpEF.
abstract: OBJECTIVE
  The purpose of this study was to investigate diffuse myocardial fibrosis in patients with systolic heart failure (SHF) and in patients with heart failure with preserved ejection fraction (HFpEF) and the association with diastolic dysfunction of the left ventricle (LV).
  
  
  BACKGROUND
  Increased diffuse myocardial fibrosis may impair LV diastolic function. However, no study has verified the association between the degree of diffuse myocardial fibrosis and the severity of impaired diastolic function in SHF and HFpEF.
  
  
  METHODS
  Forty patients with SHF, 62 patients with HFpEF, and 22 patients without HF underwent cardiac magnetic resonance (CMR), including T1 mapping and cine CMR on a 3-T system. Extracellular volume fraction (ECV), a measure of diffuse myocardial fibrosis, was quantified from T1 mapping. Systolic and diastolic functions of the LV were assessed by cine CMR. The ECV values and LV functional indexes were compared among the 3 groups. Associations between ECV and LV diastolic function were also investigated.
  
  
  RESULTS
  Compared with patients without HF, significantly higher ECV was found in patients with SHF (31.2% [interquartile range (IQR): 29.0% to 34.1%] vs. 27.9% [IQR: 26.2% to 29.4%], p < 0.001) and HFpEF (28.9% [IQR: 27.8% to 31.3%] vs. 27.9% [IQR: 26.2% to 29.4%], p = 0.006). Peak filling rate, a diastolic functional index assessed by cine CMR, was significantly decreased in patients with SHF (1.00 s(-1) [IQR: 0.79 to 1.49 s(-1)] vs. 3.86 s(-1) [IQR: 3.34 to 4.48 s(-1)], p < 0.001) and HFpEF (2.89 s(-1) [IQR: 2.13 to 3.50 s(-1)] vs. 3.86 s(-1) [IQR: 3.34 to 4.48 s(-1)], p < 0.001). Myocardial ECV was significantly correlated with peak filling rate in the HFpEF group (r = -0.385, p = 0.002), but no correlation was found in the SHF and non-HF groups (r = 0.030, p = 0.856 and r = -0.238, p = 0.285, respectively).
  
  
  CONCLUSIONS
  In patients with HF, only those with HFpEF show a significant correlation between increased diffuse myocardial fibrosis and impaired diastolic function. Diffuse myocardial fibrosis plays a unique role in the pathogenesis of HFpEF.
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Mao-Yuan M
authors.initials: MY
authors.lastname: Su
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Lian-Yu
authors.initials: LY
authors.lastname: Lin
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yao-Hui E
authors.initials: YH
authors.lastname: Tseng
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chin-Chen
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Cho-Kai
authors.initials: CK
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: jiunnlee@ntu.edu.tw.
authors.forename: Jiunn-Lee
authors.initials: JL
authors.lastname: Lin
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan; Center for Optoelectronic Medicine, National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: wytseng@ntu.edu.tw.
authors.forename: Wen-Yih I
authors.initials: WY
authors.lastname: Tseng
mesh_terms: D000368:Aged; D005260:Female; D005355:Fibrosis; D054143:Heart Failure, Systolic / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D013318:Stroke Volume / Q000502:physiology; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000473:pathology / Q000503:physiopathology
keywords: cardiac magnetic resonance; extracellular volume fraction; heart failure with preserved ejection fraction