Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
JACC Cardiovasc Imaging. 2014 Oct;7(10):991-7. doi: 10.1016/j.jcmg.2014.04.022. Epub 2014 Sep 17.
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).
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.
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.
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).
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.
本研究旨在探讨收缩性心力衰竭（SHF）和射血分数保留的心力衰竭（HFpEF）患者的弥漫性心肌纤维化，并研究其与左心室（LV）舒张功能障碍的关系。
弥漫性心肌纤维化可能会损害 LV 舒张功能。然而，尚无研究证实 SHF 和 HFpEF 患者弥漫性心肌纤维化程度与舒张功能障碍严重程度之间的关系。
40 例 SHF 患者、62 例 HFpEF 患者和 22 例非 HF 患者接受心脏磁共振（CMR）检查，包括 3T 系统上的 T1 映射和电影 CMR。通过 T1 映射量化细胞外容积分数（ECV），这是弥漫性心肌纤维化的一个指标。通过电影 CMR 评估 LV 的收缩和舒张功能。比较 3 组之间的 ECV 值和 LV 功能指标。还研究了 ECV 与 LV 舒张功能之间的关系。
与非 HF 患者相比，SHF 患者（31.2% [四分位距（IQR）：29.0%至 34.1%]）和 HFpEF 患者（28.9% [IQR：27.8%至 31.3%]）的 ECV 值明显更高（均 p<0.001）。HFpEF 患者（28.9% [IQR：27.8%至 31.3%]）和非 HF 患者（27.9% [IQR：26.2%至 29.4%]）之间的 ECV 值无显著差异（p=0.006）。由电影 CMR 评估的舒张功能指标，峰值充盈率在 SHF 患者（1.00 s(-1) [IQR：0.79 至 1.49 s(-1)]）和 HFpEF 患者（2.89 s(-1) [IQR：2.13 至 3.50 s(-1)]）中明显降低（均 p<0.001）。HFpEF 患者（2.89 s(-1) [IQR：2.13 至 3.50 s(-1)]）和非 HF 患者（3.86 s(-1) [IQR：3.34 至 4.48 s(-1)]）之间的峰值充盈率无显著差异（p=0.006）。HFpEF 患者的心肌 ECV 值与峰值充盈率呈显著负相关（r=-0.385，p=0.002），但在 SHF 患者和非 HF 患者中无相关性（r=0.030，p=0.856 和 r=-0.238，p=0.285）。
在 HF 患者中，只有 HFpEF 患者弥漫性心肌纤维化与舒张功能障碍之间存在显著相关性。弥漫性心肌纤维化在 HFpEF 的发病机制中起独特作用。
