Diabetes-duration-related myocardial microstructural remodeling and diastolic dysfunction in type 2 diabetes with preserved ejection fraction: a cardiac diffusion tensor imaging study

To evaluate the ability of second-order motion-compensated cardiac diffusion tensor imaging (cDTI) to characterize diabetes-duration-related myocardial microstructural abnormalities and their associations with myocardial mechanics in patients with type 2 diabetes mellitus (T2DM) and preserved left ventricular ejection fraction (LVEF). In this prospective single-centre study, 70 patients with T2DM and preserved LVEF (30 with ≤5 years and 40 with >5 years of diabetes duration) and 45 age-matched controls underwent cDTI. Short-duration T2DM already showed higher mean diffusivity (MD), higher absolute secondary eigenvector angle (|E2A|), and lower helix angle transmurality (HAT), whereas fractional anisotropy (FA) was reduced only with longer duration (all p < 0.05). In covariate-adjusted analyses, longer diabetes duration was independently associated with lower FA and HAT and higher MD and |E2A| (all p ≤ 0.001). FA and HAT correlated positively and MD and |E2A| inversely with peak longitudinal diastolic strain rate (PDSR-L; all Holm-adjusted p < 0.004). In adjusted logistic regression, |E2A| was independently associated with diastolic dysfunction (OR 2.549, 95% CI 1.538–4.224; p < 0.001) and discriminated diastolic dysfunction (AUC 0.904). Second-order motion-compensated cDTI identifies diabetes-duration-related myocardial microstructural remodelling that is associated with early diastolic mechanical impairment in patients with T2DM and preserved LVEF.