Abstract 10747: Age is Related to Interstitial Myocardial Fibrosis in Asymptomatic Adults: Magnetic Resonance T₁ Mapping in the Multi-ethnic Study of Atherosclerosis (MESA)

Abstract

Introduction: Animal and human studies have demonstrated increased collagen deposition in senescent hearts. Cardiac magnetic resonance (CMR) indices of tissue composition using T₁ mapping are sensitive to the presence of myocardial fibrosis. The purpose of this study was to determine the relationship of CMR measures of tissue composition to age in MESA.

Methods: 585 women and 534 men (age 52-93) of the MESA cohort were evaluated using 1.5T CMR scanners. All participants did not have findings of delayed enhancement. Single slice T₁mapping was performed at the mid-ventricular level before and at 12 and 25 minutes delay after administration of gadolinium (Magnevist; 0.15mmol/kg) using a Modified Look Locker Inversion Recovery sequence. Partition coefficient was determined by the slope of linear relationship of (1/T_1myo vs. 1/T_1blood) at various time points. Extracellular volume fraction (ECV) was derived accounting for the hematocrit. Multivariable regression analysis was performed, adjusting for traditional risk factors and left-ventricular structure.

Results: Women had significantly higher partition coefficient, pre-contrast T₁, and ECV, but lower post-contrast T₁ than men (Table 1). Linear regression analyses (Table 2) demonstrate that greater partition coefficient, pre-contrast T₁, and ECV were associated with older age. Greater post-contrast T₁ and T₁ change (ΔT₁/Δt) were also associated with older age. These relationships were stronger in men than in women.

Conclusion: CMR parameters that are associated with fibrosis were related to older age in the MESA study. These fibrosis indices suggest greater age-related change in men than women.