Impact of left ventricular dilatation on biventricular function and deformation in diabetes mellitus with reduced ejection fraction: a CMR feature tracking study.

BACKGROUND: Left ventricular (LV) dilatation has been found to be associated with poor prognosis in patients with reduced left ventricular ejection fraction (LVEF). However, the relationship between LV dilatation and biventricular myocardial dysfunction in patients with diabetes mellitus (DM) and reduced LVEF unclear. METHODS: From September 2017 to March 2025, 265 clinically diagnosed patients with DM who underwent cardiac magnetic resonance (CMR) scanning in our hospital were included. According to LVEF and LV dilatation status, these patients were divided into three groups: 122 DM with preserved LVEF (DMpEF) group, 51 DM with reduced LVEF and no LV dilatation (DMrEF-NLVD) group, and 92 DM with dilated cardiomyopathy (DMrEF-DCM) group. Biventricular strain parameters, including left/right ventricular global radial strain (LV-/RVGRS), left/right ventricular global circumferential strain (LV-/RVGCS), and left/right ventricular global longitudinal strain (LV-/RVGLS) were evaluated and compared among the three groups. Additionally, multiple linear regression analysis was performed to assess the independent effect of LV dilatation on biventricular strains in DM patients with reduced LVEF. RESULTS: Significant differences were observed in both left and right ventricular strain parameters among the three groups. For left ventricular function, LV global strains progressively declined from the DMpEF group to the DMrEF-NLVD group and further to the DMrEF-DCM group (all p < 0.001). For right ventricular function, RV global strains were significantly more impaired in the DMrEF-DCM group and the DMrEF-NLVD group compared with the DMpEF group (all p < 0.05). The DMrEF-DCM group had decreased RVGCS (- 6.18 ± 3.52 vs. - 8.89 ± 4.15, p < 0.001) compared with the DMrEF-NLVD group. In DM patients with reduced LVEF, multivariable linear regression analysis revealed that LV dilatation was independently associated with reduced LVGCS (β = 0.176, p = 0.009). CONCLUSIONS: In DM patients with reduced LVEF, LV dilatation was associated with biventricular dysfunction and deformation injury. LV dilatation was found to be independently associated with impaired LVGCS, the further decrease of LVGCS in DM patients with reduced LVEF.