Abstract 12144: Quantifying Myocardial Fibrosis in Hypertensive Left Ventricular Hypertrophy Using T1 Mapping
Background: Diffuse myocardial fibrosis contributes to increased cardiovascular risk in hypertensive heart disease (HHD) and left ventricular hypertrophy (LVH). We hypothesize that T1 mapping by cardiac magnetic resonance could detect diffuse fibrosis in subjects with HHD, LVH, and normal LV ejection fraction as compared to age-matched controls.
Methods: T1 mapping was performed in 20 subjects (54±11 years) and 14 age-matched healthy volunteers (51±10 years) on a Siemens 1.5T Avanto using a previously described 3-5 MOLLI technique. Patients with coronary disease, valvular disease, and other causes of LVH were excluded. T1 was determined pre- and 10, 15 and 20 minutes post-injection of 0.15 mmol/kg Gd-DTPA. T1 maps were created using MATLAB. Partition coefficient (λ) was determined from the slope of the plot of 1/T1 of myocardium vs. 1/T1 of blood. Volume of distribution of Gd (Vd) was calculated as λ*(1-Hematocrit). LV mass and function was assessed by SSFP cine imaging. Groups were compared using 2-tailed t-tests.
Results: HTN LVH subjects had significantly higher blood pressure, creatinine, LV mass and pre-contrast T1 values than controls (Table). LVH subjects had greater fibrosis than controls as measured by λ(0.48 ± 0.03 vs. 0.43 ± 0.02, p ≤0.001)(Figure)and Vd(0.29 ± 0.03 vs. 0.26 ± 0.01, p = 0.01)(Table).
Conclusions: Pre-contrast T1 times, λ and Vd were increased in HHD with LVH, suggesting diffuse fibrosis in these patients. The 3-5 MOLLI T1 mapping technique holds promise for the assessment and monitoring of therapies in HHD and diastolic heart failure patients.
- © 2013 by American Heart Association, Inc.