Abstract 14921: Right Ventricular Extracellular Volume Fraction by Magnetic Resonance T1 Mapping in Pulmonary Hypertension and Heart Failure
Introduction: Current cardiac magnetic resonance (CMR) T1 mapping techniques such as Modified Look-Locker inversion recovery (MOLLI) imaging have limited resolution, but the Accelerated and Navigator-Gated Look-Locker Imaging for Cardiac T1 Estimation (ANGIE) is a novel CMR sequence with spatial resolution suitable for T1 mapping of the thin-walled RV.
Hypothesis: In pulmonary hypertension (PH) and heart failure (HF), RV extracellular volume (ECV) fraction (as a surrogate measure for RV fibrosis) is a unique parameter describing RV structure that tends to increase with increasing RV size and declining RV function.
Methods: Patients with either World Health Organization group 1 or group 4 pulmonary hypertension (PH) or heart failure with reduced ejection fraction (HFrEF) were recruited to undergo contrast-enhanced CMR. RV and LV ECV fractions were determined using pre-contrast and post-contrast T1 mapping using ANGIE (RV and LV) and MOLLI (LV).
Results: 22 patients (41% female, median age 61 years old, IQR 51-70 years old) were enrolled, including n=12 with PH and n=10 with HFrEF. ANGIE ECV imaging was of high quality (Figure). A multivariable linear model with RVEF and RVEDVI as independent variables and RVECV as the outcome variable showed independent associations for RVEF and RVEDVI with RVECV (R2=0.553) (Table), consistent with a complex relationship involving RV function, dilation, and fibrosis.
Conclusions: Pre- and post-contrast ANGIE imaging provides high-resolution ECV determination for the thin-walled RV. RV fibrosis increases with increasing RV size and decreasing overall RV function. Further studies of RVECV in PH and HFrEF are indicated.
Author Disclosures: K.C. Bilchick: None. B.B. Mehta: None. V. Workman: None. D. Auger: None. X. Chen: Employment; Significant; Siemens Healthcare. J. Kennedy: None. E. Gay: None. F.H. Epstein: Research Grant; Modest; Siemens Healthcare.
- © 2015 by American Heart Association, Inc.