Aggravation of functional mitral regurgitation on left ventricle stiffness in type 2 diabetes mellitus patients evaluated by CMR tissue tracking

Abstract

Background: Functional mitral regurgitation (FMR) is one of the most common heart valve diseases in diabetes and may increase left ventricular (LV) preload and aggravate myocardial stiffness. This study aimed to investigate the aggravation of FMR on the deterioration of LV strain in type 2 diabetes mellitus (T2DM) patients and explore the independent indicators of LV peak strain (PS).

Materials and methods: In total, 157 T2DM patients (59 patients with and 98 without FMR) and 52 age- and sex-matched healthy control volunteers were included and underwent cardiac magnetic resonance examination. T2DM with FMR patients were divided into T2DM patients with mild (n = 21), moderate (n = 19) and severe (n = 19) regurgitation. LV function and global strain parameters were compared among groups. Multivariate analysis was used to identify the independent indicators of LV PS.

Results: The T2DM with FMR had lower LV strain parameters in radial, circumferential and longitudinal direction than both the normal and the T2DM without FMR (all P < 0.05). The mild had mainly decreased peak diastolic strain rate (PDSR) compared to the normal. The moderate had decreased peak systolic strain rate (PSSR) compared to the normal and PDSR compared to the mild and the normal. The severe FMR group had decreased PDSR and PSSR compared to the mild and the normal (all P < 0.05). Multiple linear regression showed that the regurgitation degree was independent associated with radial (β = - 0.272), circumferential (β = - 0.412) and longitudinal (β = - 0.347) PS; the months with diabetes was independently associated with radial (β = - 0.299) and longitudinal (β = - 0.347) PS in T2DM with FMR.

Conclusion: FMR may aggravate the deterioration of LV stiffness in T2DM patients, resulting in decline of LV strain and function. The regurgitation degree and months with diabetes were independently correlated with LV global PS in T2DM with FMR.

Keywords: Functional mitral regurgitation; Left ventricle; Magnetic resonance imaging; Strain; Type 2 diabetes mellitus.

Fig. 1

Cardiac cine images and three-dimensional pseudo-colour images of LV longitudinal strain in T2DM patients with mild, moderate and severe regurgitation. A1-3, T2DM patient with severe mitral regurgitation, female, 44 years old, left ventricular short axis (A1), four-chamber (A2), two-chamber (A3) cine sequence images showed large black regurgitation signal from left ventricle into left atrium (red arrow) reached the posterior wall of left atrium, RF = 65.31%; B1–3, T2DM with moderate mitral regurgitation, female, 58 years old, left ventricular short axis (B1), four-chamber (B2), two-chamber (B3) cine sequence images showed moderate mitral regurgitation (red arrow), RF = 41.90%; C1–3, T2DM patient with mild mitral regurgitation, male, 61 years old, left ventricular short axis (C1), four-chamber (C2), two-chamber (C3) cine sequence images showed a small regurgitation signal (red arrow), RF = 10.11%. A4, B4 and C4 were three-dimensional pseudo color maps of left ventricular longitudinal strain. T2DM, type 2 diabetes mellitus; RF, regurgitation fraction; PS, peak strain

Fig. 2

Correlation between the regurgitation degree of/months with diabetes and LV global PS. The absolute value of PS was used in the circumferential and longitudinal direction analysis to avoid the influence of directional sign. T2DM, type 2 diabetes mellitus; r, correlation coefficient