Department of Radiology, Johns Hopkins University, Baltimore, Maryland; Radiology and Imaging Sciences, National Institutes of Health, Bethesda, Maryland.
Department of Radiology, Johns Hopkins University, Baltimore, Maryland; Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, College of Medicine, Chang Gung University, Taipei, Taiwan; Cardiology Division, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland.
J Am Coll Cardiol. 2013 Oct 1;62(14):1280-1287. doi: 10.1016/j.jacc.2013.05.078. Epub 2013 Jul 17.
This study sought to determine the relationship of cardiovascular magnetic resonance (CMR) measures of tissue composition to age in the Multi-Ethnic Study of Atherosclerosis (MESA).
Animal and human studies have demonstrated increased collagen deposition in senescent hearts. New CMR indices of tissue composition by using T1 mapping are sensitive to the presence of myocardial fibrosis.
A total of 1,231 study participants (51% women; age range 54 to 93 years) of the MESA cohort were evaluated with T1 mapping by using 1.5-T CMR scanners. None of the participants had focal scar on delayed enhancement CMR. Single-slice T1 mapping was performed at the midventricular level before and at 12- and 25-min delay after administration of gadolinium contrast by using a modified Look-Locker inversion recovery sequence. The partition coefficient was determined by the slope of the linear relationship of (1/T1myo vs. 1/T1blood). The extracellular volume fraction (ECV) was derived accounting for the hematocrit level. Multivariable regression analyses were performed, adjusting for traditional risk factors and left ventricular structure.
Women had significantly greater partition coefficient, ECV, and precontrast T1 than men, as well as lower post-contrast T1 values (all p < 0.05). In general, linear regression analyses demonstrated that greater partition coefficient, pre-contrast T1 values, and ECV were associated with older age in men (multivariate regression coefficients = 0.01; 5.9 ms; and 1.04% per 10 years' change; all p < 0.05). ECV was also significantly associated with age in women after multivariable adjustments.
CMR parameters that have been associated with myocardial fibrosis were related to older age in the MESA study. Women had higher ECV than men but less ECV change over time.
本研究旨在探讨多民族动脉粥样硬化研究（MESA）中心血管磁共振（CMR）组织成分测量值与年龄的关系。
动物和人体研究表明，衰老心脏中的胶原蛋白沉积增加。利用 T1 映射新的组织成分 CMR 指数对心肌纤维化的存在敏感。
共有 1231 名 MESA 队列的研究参与者（51%为女性；年龄范围为 54 至 93 岁）接受了 1.5-T CMR 扫描仪的 T1 映射检查。无参与者在延迟增强 CMR 上有局灶性瘢痕。在钆对比剂给药后 12 分钟和 25 分钟，使用改良的 Look-Locker 反转恢复序列在中心室水平进行单次切片 T1 映射。通过（1/T1myo 与 1/T1blood 的线性关系斜率）确定分区系数。考虑到血细胞比容水平，推导细胞外体积分数（ECV）。进行多变量回归分析，调整传统危险因素和左心室结构。
女性的分区系数、ECV 和预对比 T1 值明显大于男性，而对比后 T1 值较低（均 p < 0.05）。一般来说，线性回归分析表明，男性的分区系数、预对比 T1 值和 ECV 与年龄呈正相关（多元回归系数=0.01；5.9 ms；每 10 年变化 1.04%；均 p < 0.05）。ECV 在多变量调整后也与女性的年龄显著相关。
与心肌纤维化相关的 CMR 参数与 MESA 研究中的年龄有关。女性的 ECV 高于男性，但随时间的 ECV 变化较小。
