Duke Cardiovascular Magnetic Resonance Center Duke University Medical Center, Durham, North Carolina, USA; Division of Cardiology, Duke University Medical Center, Durham, North Carolina, USA.
Duke Cardiovascular Magnetic Resonance Center Duke University Medical Center, Durham, North Carolina, USA; Division of Cardiology, Department of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Bangkok, Thailand.
JACC Cardiovasc Imaging. 2021 Jul;14(7):1338-1350. doi: 10.1016/j.jcmg.2020.11.006. Epub 2021 Jan 13.
The purpose of this study was to assess whether the presence and extent of fibrosis changes over time in patients with nonischemic, dilated cardiomyopathy (DCM) receiving optimal medical therapy and the implications of any such changes on left ventricular ejection fraction (LVEF) and clinical outcomes.
Myocardial fibrosis on cardiovascular magnetic resonance (CMR) imaging has emerged as important risk marker in patients with DCM.
In total, 85 patients (age 56 ± 15 years, 45% women) with DCM underwent serial CMR (median interval 1.5 years) for assessment of LVEF and fibrosis. The primary outcome was all-cause mortality; the secondary outcome was a composite of heart failure hospitalization, aborted sudden cardiac death, left ventricular (LV) assist device implantation, or heart transplant.
On CMR-1, fibrosis (median 0.0 [interquartile range: 0% to 2.6%]) of LV mass was noted in 34 (40%) patients. On CMR-2, regression of fibrosis was not seen in any patient. Fibrosis findings were stable in 70 (82%) patients. Fibrosis progression (increase >1.8% of LV mass or new fibrosis) was seen in 15 patients (18%); 46% of these patients had no fibrosis on CMR-1. Although fibrosis progression was on aggregate associated with adverse LV remodeling and decreasing LVEF (40 ± 7% to 34 ± 10%; p < 0.01), in 60% of these cases the change in LVEF was minimal (<5%). Fibrosis progression was associated with increased hazards for all-cause mortality (hazard ratio: 3.4 [95% confidence interval: 1.5 to 7.9]; p < 0.01) and heart failure-related complications (hazard ratio: 3.5 [95% confidence interval: 1.5 to 8.1]; p < 0.01) after adjustment for clinical covariates including LVEF.
Once myocardial replacement fibrosis in DCM is present on CMR, it does not regress in size or resolve over time. Progressive fibrosis is often associated with minimal change in LVEF and identifies a high-risk cohort.
本研究旨在评估非缺血性扩张型心肌病（DCM）患者在接受最佳药物治疗时，纤维化的存在和程度是否会随时间发生变化，以及任何此类变化对左心室射血分数（LVEF）和临床结局的影响。
心血管磁共振（CMR）成像上的心肌纤维化已成为 DCM 患者的重要风险标志物。
共有 85 例 DCM 患者（年龄 56±15 岁，45%为女性）接受了系列 CMR（中位间隔 1.5 年）评估 LVEF 和纤维化。主要结局为全因死亡率；次要结局为心力衰竭住院、心脏性猝死未遂、左心室（LV）辅助装置植入或心脏移植的复合终点。
在 CMR-1 上，34 例（40%）患者的 LV 质量存在纤维化（中位数 0.0[四分位距：0%至 2.6%]）。在 CMR-2 上，没有患者出现纤维化消退。70 例（82%）患者的纤维化发现稳定。15 例（18%）患者出现纤维化进展（LV 质量增加>1.8%或出现新纤维化）；其中 46%的患者在 CMR-1 上无纤维化。尽管纤维化进展总体上与不良的 LV 重构和 LVEF 降低相关（40±7%至 34±10%；p<0.01），但在这些情况下，LVEF 的变化很小（<5%）。纤维化进展与全因死亡率（危险比：3.4[95%置信区间：1.5 至 7.9]；p<0.01）和心力衰竭相关并发症（危险比：3.5[95%置信区间：1.5 至 8.1]；p<0.01）显著相关，调整 LVEF 等临床协变量后。
一旦 DCM 的心肌替代纤维化在 CMR 上存在，其大小就不会随时间缩小或消退。进行性纤维化通常与 LVEF 的微小变化相关，并确定了一个高危人群。
