Structural and Functional Correlates of Myocardial T1 Mapping in 321 Patients With Hypertrophic Cardiomyopathy

Objective: The aim of this study was to evaluate the structural and functional correlates of T1 mapping in 321 patients with hypertrophic cardiomyopathy (HCM). Methods: Three hundred twenty-one patients with HCM who underwent cardiac magnetic resonance from 2003 to 2013 were retrospectively identified from our institution's HCM registry. Left ventricular volume, function, late gadolinium enhancement (LGE), and Look-Locker T1 time were quantified. T1 time was normalized to blood pool to calculate T1 ratio. Correlations between LGE%, T1 ratio, and structural and functional features were performed using Pearson correlation coefficient. Results: Late gadolinium enhancement showed stronger correlation with left ventricular mass index (r = 0.41, P < 0.001) compared with T1 ratio (r = -0.17, P = 0.004). Both LGE% and T1 ratio correlated with ejection fraction (r = -0.18 and P = 0.002 vs r = 0.21 and P < 0.001, respectively). E/e' showed correlation with LGE% but not with T1 ratio. Conclusions: Late gadolinium enhancement was more strongly correlated with the phenotypic expression of HCM compared with T1 ratio.