Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
Department of Diagnostic and Interventional Radiology, University of Leipzig-Heart Center, Leipzig, Germany.
JACC Cardiovasc Imaging. 2018 Jan;11(1):38-45. doi: 10.1016/j.jcmg.2017.01.025. Epub 2017 Apr 12.
The aim of the present study was to evaluate whether extracellular volume fraction (ECV) can reliably inform on the extent of diffuse fibrosis in the simultaneous presence of myocardial inflammation, which has not been verified to date.
Diffuse myocardial fibrosis is associated with unfavorable outcome in patients with cardiomyopathy, and is of prognostic relevance. Assessment of ECV bears promise for being a noninvasive surrogate parameter, but it may be altered by other pathologies.
In this prospective study, 107 consecutive patients with clinical suspicion of inflammatory cardiomyopathy were included. All patients underwent left ventricular (LV) endomyocardial biopsy (EMB) and cardiac magnetic resonance imaging on a 1.5-T scanner. T1 mapping was obtained with the modified Look-Locker inversion recovery sequence, and ECV was calculated.
Myocardial inflammation was present in 66 patients. Patients with and without inflammation were of similar age and had comparable LV ejection fraction (37 ± 17% vs. 36 ± 18%; p = 0.9) and symptom duration (median 14 days [interquartile range: 5 to 36 days] vs. median 14 days [interquartile range: 7 to 30 days]; p = 0.73). Although LV collagen volume percentage was comparable between groups (inflammation 12.3 ± 17.8% vs. noninflammation 11.4 ± 7.9%; p = 0.577), ECV was significantly higher in patients with inflammation (0.37 ± 0.06%) than in those without inflammation (0.33 ± 0.08%; p = 0.02). Importantly, ECV adequately estimated the degree of LV fibrosis percentage only in patients without inflammation (r = 0.72; p < 0.0001) and not in those with inflammation (r = 0.24; p = 0.06).
These findings prove the theoretical concept of ECV as an estimate for diffuse myocardial fibrosis, but only in the absence of significant myocardial inflammation. Assuming that various degrees of myocardial inflammation and fibrosis coexist in such a scenario, the measured ECV will reflect a sum of these different pathologies but will not inform solely on the extent of diffuse fibrosis.
本研究旨在评估细胞外容积分数（ECV）是否能可靠地反映心肌炎症同时存在时弥漫性纤维化的程度，这一点迄今尚未得到验证。
弥漫性心肌纤维化与心肌病患者的不良预后相关，具有预后相关性。ECV 评估有望成为一种无创替代参数，但它可能会被其他病理改变所改变。
在这项前瞻性研究中，纳入了 107 例临床疑似炎症性心肌病的连续患者。所有患者均在 1.5-T 扫描仪上接受左心室（LV）心内膜心肌活检（EMB）和心脏磁共振成像。采用改良 Look-Locker 反转恢复序列获得 T1 映射，并计算 ECV。
66 例患者存在心肌炎症。有和没有炎症的患者年龄相似，LV 射血分数（37 ± 17% vs. 36 ± 18%；p = 0.9）和症状持续时间（中位数 14 天[四分位距：5 至 36 天] vs. 中位数 14 天[四分位距：7 至 30 天]；p = 0.73）也相似。尽管两组的 LV 胶原容积百分比相似（炎症组 12.3 ± 17.8% vs. 非炎症组 11.4 ± 7.9%；p = 0.577），但炎症组的 ECV 明显更高（0.37 ± 0.06%）高于非炎症组（0.33 ± 0.08%；p = 0.02）。重要的是，ECV 仅能在无炎症患者中充分估计 LV 纤维化程度（r = 0.72；p < 0.0001），而在有炎症患者中则不能（r = 0.24；p = 0.06）。
这些发现证明了 ECV 作为弥漫性心肌纤维化估计值的理论概念，但仅在没有明显心肌炎症的情况下成立。假设在这种情况下存在不同程度的心肌炎症和纤维化共存，那么所测量的 ECV 将反映这些不同病理的总和，但不会仅反映弥漫性纤维化的程度。
