Evaluation of Age-Related Interstitial Myocardial Fibrosis With Cardiac Magnetic Resonance Contrast-Enhanced T1 Mapping

Abstract

Objectives 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). Background 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. Methods 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. Results 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. Conclusions 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.

T 1 mapping for assessment of myocardial injury and microvascular obstruction at one week post myocardial infarction

“…[27] Second, the T1 may have been abnormal in these patients prior to myocardial infarction, due to discrete microscopic fibrosis caused by comorbidities such as diabetes, hypertension or hypercholesterolemia. [30,31] In order to establish which hypothesis is correct, our findings would have to be validated through histology. Given that our proposed ROC-derived threshold is free from any assumptions regarding remote myocardium, we believe it is more appropriate than T2W imaging for delimiting myocardial oedema in vivo.…”

The Prognostic Role of T1 Mapping Sequences: Can T1 Mapping Parameters Have a Role in Risk Stratification?

“…In general, linear regression analyses demonstrated that a greater partition coefficient, native T1 values and ECV were associated with older age in men (multivariate regression coefficients=0.01; 5.9 ms; and 1.04% per 10 year change; all p<0.05). ECV was also significantly associated with age in women after multivariate adjustments [15]. In another MESA study, 25-minute post-gadolinium T1 time showed more statistically significant associations with cardiovascular disease risk scores (10/14 scores, 71%) compared to other cardiac magnetic resonance (CMR) imaging indices (e.g., native T1; 7/14 scores, 50%) and the partition coefficient (7/14, 50%) in men [17].…”

“…With MOLLI sequencing, which is the most popular T1 mapping sequence, normal myocardial native T1 ranges from 950 to 982 ms and thereby ECV is 25.0 to 26.9% in a 1.5 T magnetic field [5,6,14,15]. In a 3 T magnetic field, native T1 is somewhat prolonged to 1052 to 1159 ms [6,16].…”

“…Although reference values have been published in several studies, the current consensus statement recommends that each center should derive normal values for their specific center [11] Table 1 shows an overview of studies reporting normative ranges for T1-mapping indices. There are a few general population-based studies in which the relationships between T1 value and conventional cardiac risk factors such as gender, age, diabetes, hypertension or dyslipidemia are reported [15,17]. The recent Multi-Ethnic Study of Atherosclerosis (MESA) showed post-T1 was correlated with age and risk factors [15].…”

“…There are a few general population-based studies in which the relationships between T1 value and conventional cardiac risk factors such as gender, age, diabetes, hypertension or dyslipidemia are reported [15,17]. The recent Multi-Ethnic Study of Atherosclerosis (MESA) showed post-T1 was correlated with age and risk factors [15]. In that study, women had a significantly greater partition coefficient, ECV and native T1 than men, as well as lower post-contrast T1 values (all p<0.05).…”