Abstract 14919: Myocardial T 1 Mapping for Prediction of Left Ventricular Reverse Remodeling in Patients With Recent-onset Dilated Cardiomyopathy: a Comparison With Histological Tissue Characterization

Abstract

Background: Accurate prediction of left ventricular reverse remodeling (LVRR) in dilated cardiomyopathy (DCM) remains challenging. The purpose of this study is to assess the potential of cardiovascular magnetic resonance (CMR) T 1 mapping to predict LVRR by histological confirmation. Methods: Twenty-one DCM patients (12 male, mean age 49 ± 13 years) underwent cine, late gadolinium enhancement (LGE) CMR, and triple-slice T 1 mapping using a modified Look-Locker inversion recovery sequence at 3T before receiving optimal medical therapy. LVRR was defined as an absolute increase in LV ejection fraction (LVEF) from ≥10% to a final value of >35%, accompanied by a decrease in LV end-diastolic volume (LVEDV) ≧10% at midterm (mean time 18 months) CMR follow-up. Extra-cellular volume (ECV) was quantified from pre and post-contrast T 1 values of the blood and myocardium with hematocrit correction. Biopsy samples were used for quantification of collagen volume fraction (CVF). Results: LVRR was observed in 11 patients (52%). The mean native T 1 , ECV, and histological CVF were 1395 ± 49 ms, 0.33 ± 0.03, 0.13 ± 0.04, respectively. Native T 1 yielded comparable ability to ECV measurements for detecting histological CVF (r=0.49, 0.52, both p <0.05). While 14 patients (67%) showed focal scar on LGE, there was no significant difference in histological CVF between patients with and without focal scarring (p=0.6). Native T 1, but not ECV and CVF, correlated well with absolute LVEF increase and relative percent decrease of LVEDV and LV end-systolic volume (r=-0.55, 0.55, 0.56, all p <0.05). Native T 1 <1400 ms provided 90% sensitivity and 82% specificity, with the C-statistic of 0.86 (95% CI 0.64-0.97), for predicting LVRR. On the other hand, the C-statistic of ECV, LGE and histological CVF were 0.72 (95% CI 0.48-0.89), 0.53 (95% CI 0.31-0.75) and 0.66 (95% CI 0.43-0.85), respectively. Conclusions: Myocardial native T 1 have the potential to predict LVRR beyond LGE and histological assessment.