Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Im Neuenheimer Feld 410, Heidelberg 69120, Germany
Eur Heart J Cardiovasc Imaging. 2015 Feb;16(2):210-6. doi: 10.1093/ehjci/jeu183. Epub 2014 Sep 22.
The aim of this study was to determine the value of extracellular volume fraction (ECV) for the non-invasive assessment of diffuse myocardial fibrosis (MF) in different stages of systolic left ventricular (LV) dysfunction in dilated cardiomyopathy (DCM) in comparison with endomyocardial biopsy.
Non-invasive ECV assessment using cardiovascular magnetic resonance (CMR) T1 mapping reflects diffuse MF in patients with severe DCM, but earlier stages of DCM with mild LV functional impairment have not been investigated yet.
Forty-five subjects with mild functional impairment and LV dilation ['early DCM', ejection fraction (EF) 45-55%], 29 with LV dysfunction and volume dilatation ('DCM', EF <45%) and 56 healthy volunteers (controls) underwent standard CMR imaging, late gadolinium enhancement (LGE) and T1 mapping for the calculation of ECV. The collagen volume fraction (CVF) was quantified histologically from endomyocardial biopsies of 24 DCM patients out of the study cohort.
The ECV between 'early DCM' (25 ± 4%), 'DCM' (27 ± 4%), and controls (23 ± 3; P < 0.05 for all) differed significantly. There was a weak inverse correlation between ECV and EF (r = -0.35; P < 0.01). A strong correlation between ECV and CVF could be detected (r = 0.85; P = 0.01). The cut-off value for ECV to differentiate between healthy myocardium and DCM was 26% (specificity 91.1%, sensitivity 62.1%, area under the curve 0.8, P < 0.0001). ECV is already elevated at early stages of functional impairment, whereby an overlap between early DCM and controls is present. But 31% of the early DCM patients had an ECV fraction above the mean ±2 SD ECV of controls.
ECV measurement with CMR reflects myocardial collagen content in DCM. Therefore, CMR-based assessment of ECV may have the potential to serve as a non-invasive tool for the quantification of diffuse MF in order to monitor therapy response and aid risk stratification in different stages of DCM.
本研究旨在通过心血管磁共振（CMR）T1 映射技术评估细胞外容积分数（ECV），以评估扩张型心肌病（DCM）不同收缩性左心室（LV）功能障碍阶段弥漫性心肌纤维化（MF）的无创性，并与心内膜心肌活检进行比较。
使用心脏磁共振（CMR）T1 映射技术评估细胞外容积分数（ECV）可反映严重 DCM 患者的弥漫性 MF，但尚未研究早期 DCM 阶段（LV 功能轻度受损）。
45 例轻度 LV 功能障碍和 LV 扩张的患者（早期 DCM，射血分数[EF]为 45%-55%）、29 例 LV 功能障碍和容量扩张的患者（DCM，EF<45%）和 56 例健康志愿者（对照组）接受标准 CMR 成像、钆延迟增强（LGE）和 T1 映射以计算 ECV。对研究队列中的 24 例 DCM 患者的心内膜心肌活检进行组织学检测，以量化胶原容积分数（CVF）。
早期 DCM（25±4%）、DCM（27±4%）和对照组（23±3%）之间的 ECV 差异有统计学意义（均 P<0.05）。ECV 与 EF 呈弱负相关（r=-0.35，P<0.01）。ECV 与 CVF 呈强相关（r=0.85，P=0.01）。ECV 区分健康心肌和 DCM 的截断值为 26%（特异性 91.1%，敏感性 62.1%，曲线下面积 0.8，P<0.0001）。在 LV 功能障碍的早期阶段，ECV 已经升高，早期 DCM 和对照组之间存在重叠。但 31%的早期 DCM 患者的 ECV 分数高于对照组 ECV 均值±2SD。
CMR 测量 ECV 可反映 DCM 中的心肌胶原含量。因此，CMR 评估 ECV 可能具有作为一种无创工具的潜力，用于量化不同 DCM 阶段弥漫性 MF，以监测治疗反应和辅助风险分层。
