Introduction
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Diabetic cardiomyopathy contributes to increased cardiovascular mortality in diabetes mellitus (DM) patients and is characterized by a progressive alteration of left ventricular (LV) function. At a preclinical stage, a decrease in systolic myocardial strain has been suggested in echocardiographic studies.

MRI techniques remain the gold standard for quantification of myocardial deformation but only a single study suggested systolic abnormalities in type 2 DM patients with evidence of diastolic dysfunction.

MR-tagging is the most common technique for strain calculation using CMR but is intrinsically limited in measuring transmural variations. Cine-Displacement ENcoding Imaging with Stimulated Echoes(DENSE) has been recently proposed as an alternative that benefits from an increased spatial resolution.

Purpose
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To evaluate whether cine-DENSE and MR-tagging confirm the existence of a sub-clinical myocardial dysfunction in a population of type 2 DM patients with no sign or history of heart disease and normal conventional echo and MRI parameters.

Methods
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37 patients with type 2 DM (50.6±5.6 years, 8 females, HbA1c 7.6±1.2%) and 21 age-matched controls (49.7±8.0 years, 11 females) underwent a CMR study on a 1.5T scanner. Subjects were excluded if standard echocardiography showed significant abnormality. After a standard CMR study for conventional LV function assessment, two-dimensional cine-DENSE pulse sequence with short-echo train echo-planar imaging readout and cine-tagging with complementary spatial modulation of magnetization(CSPAMM) were acquired in short axis views at the same basal, mid and apical levels. LV volumes and ejection fraction were measured on cine-MRI images. Regional circumferential maximal systolic strain(ε~c~) was calculated from cine-DENSE and MR-tagging acquisitions on 16 LV segments. Average maximal systolic strain in each slice and a whole heart mean value(ε~c~mean) for each patient were calculated. Post-processing of cine-DENSE acquisitions included adaptive phase-unwrapping and spatial filtering. CSPAMM images were processed using *InTag* post-processing toolbox (Creatis, Lyon, France) implemented in OsiriX software (Geneva, Switzerland) with motion estimation based on the *Sine Wave Modeling* approach.

Results
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Standard cine-MRI LV function parameters were normal and comparable between groups (table [1](#T1){ref-type="table"}). Whereas LV ejection fraction was similar in the 2 groups, cine-DENSE showed a significant decrease in ε~c~ at basal, mid and apical LV level and in ε~c~mean in the DM group as compared to controls. MR-tagging confirmed a decrease in ε~c~ at the 3 LV levels and in ε~c~mean in DM patients as compared with controls.

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Left ventricular function in type 2 diabetes mellitus patients and controls.

                          DM patients      Controls         P
  ----------------------- ---------------- ---------------- ---------
  LVEDV (mL)              120 ± 26         129 ± 28         0.26
  LVESV (mL)              41 ± 12          41 ± 12          0.90
  LVEF (%)                66 ± 6           68 ± 6           0.30
                                                            
  ε~c~ base MR-tagging    -0.173 ± 0.040   -0.200 ± 0.028   0.004
  ε~c~ mid MR-tagging     -0.177 ± 0.045   -0.220 ± 0.035   \<0.001
  ε~c~ apex MR-tagging    -0.189 ± 0.056   -0.232 ± 0.025   \<0.001
  ε~c~ mean MR-tagging    -0.179 ± 0.045   -0.216 ± 0.025   \<0.001
                                                            
  ε~c~ base cine-DENSE    -0.134 ± 0.019   -0.155 ± 0.019   \<0.001
  ε~c~ mid cine-DENSE     -0.150 ± 0.021   -0.174 ± 0.020   \<0.001
  ε~c~ apex cine- DENSE   -0.153 ± 0.022   -0.193 ± 0.018   \<0.001
  ε~c~ mean cine-DENSE    -0.144 ± 0.016   -0.171 ± 0.016   \<0.001

LVEDV= left ventricular end-diastolic volume; LVESV= left ventricular end-systolic volume; LVEF= left ventricular ejection fraction; ε~c~ =Régional circumferential maximal systolic strain.

Conclusions
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Cine-DENSE and MR-tagging confirm subclinical myocardial dysfunction in asymptomatic patients with Type II DM.
