Assessment of myocardial partition coefficient of gadolinium (λ) in dilated cardiomyopathy and its impact on segmental and global systolic function

Abstract

Materials and Methods: Seventeen patients with DCM and 11 controls were prospectively included. All patients and controls underwent a 1.5T MRI using: 1) cine to quantify LV volumes and function; 2) tagging to quantify circumferential strain in mid-LV; 3) T1 mapping before and 9 minutes after contrast injection to quantify R1, DR1, and λ; and 4) inversion recovery 3D Flash was used to assess late gadolinium enhancement (LGE) 10 minutes after Gd DOTA injection (0.2 mmol/kg). We used Student's t-test to compare means, Pearson's test for correlation assessment, and a mixed linear model to integrate the dependency between myocardial segments. Purpose:: 1) To assess the myocardial partition coefficient(λ) of gadolinium quantified using T1 mapping in dilated cardiomyopathy (DCM); and 2) to assess the impact of increased l on left ventricular (LV) circumferential strain and ejection fraction in DCM. Results: No difference in median l was measured between patients with (0.52 [interquartile range=0.48-0.56]) and without enhancement on LGE (0.51 [0.47-0.54]; P=0.07). Circumferential strain value measured in each segment was correlated with the λ measured in the corresponding segment (r=0.55; P<0.0001). Multivariate analysis revealed a significant link between the λ in each segment and circumferential strain (0.00260±001; P=0.009) and also with ejection fraction (-0.001±0.0008; P=0.04). Conclusion: In DCM, λ correlates independently with circumferential strain and ejection fraction, suggesting that there is a link between λ and systolic function.