Of the 202 T2DM patients, 156 were in T2DM(MI-) group (48[30.7%]) males, mean age 55.55±11.80 years) and 46 in T2DM(MI+) group (28[60.8%]) males, mean age 61.54±9.11 years). Table 1 presents their baseline characteristics, cardiovascular risk factors, metabolic parameters, and medications. The results showed that there were no statistically significant differences in the baseline characteristics among these groups, except that there were more males in the T2DM(MI+) group than that in T2DM(MI-) group. As for cardiovascular risk factors, more patients were previous or current smoker (50.5% vs. 28.3%) in T2DM(MI+) group than that in T2DM(MI-) group, but there was no difference in hyperlipidemia or family history of T2DM between the groups. HbA1c and GLU showed no statistically significant differences between the T2DM(MI+) and T2DM(MI-) groups.
In the T2DM(MI+) group, 20 patients received percutaneous coronary intervention, and one patient received coronary artery bypass grafting surgery. A total of 34 patients were identified with culprit vessels, among which 14 (30.43%) were the left anterior descending coronary artery (LAD), 6 (13.0%) were the left circumflex coronary artery (LCx) and 14 (30.43%) were the right coronary artery (RCA).
Comparison of the LV function and deformation among three groups
The CMR imaging results for LV function and deformation are summarized in Table 2. LVESVi was higher in the T2DM(MI-) group than in the control group. LVESVi, and LV mass were higher (all p < 0.005) in the T2DM(MI+) group compared with the T2DM(MI-) and normal control groups. Meanwhile, LVSVi (T2DM(MI+) vs. T2DM(MI-): 39.33(31.96–46.71) vs. 48.17(41.04–54.36); T2DM(MI+) vs. control: 39.33(31.96–46.71) vs. 47.52(42.13–53.67), p < 0.001) and LVGFI (T2DM(MI+) vs. T2DM(MI-): 27.37(18.12–40.02) vs. 48.99(44.38–54.33); T2DM(MI+) vs. control: 27.37(18.12–40.02) vs. 51.56(48.03–56.06)), p < 0.001) were lower in the T2DM(MI+) group compared with the T2DM(MI-) and control groups.
Regarding LV deformation, the global radial PS, global circumferential PS, and global longitudinal PS (all p < 0.001) were lower in the T2DM(MI+) group than in the T2DM(MI-) and control groups. The global circumferential PS (p < 0.017) and global longitudinal PS (p = 0.001) were lower in the T2DM(MI-) group than in the control group. There was no statistically significant difference in global radial PS between the T2DM(MI-) and control group. The global radial, circumferential and longitudinal PSSR and PDSR (all p < 0.001) were significantly lower in the T2DM(MI+) group than those in the T2DM(MI-) and control groups. except for longitudinal PDSR in the T2DM(MI+) group compared with the T2DM(MI-) group. For the T2DM(MI+) group, the circumferential and longitudinal PDSR were lower than those in the control group (p < 0.017).
LV infarct characteristics analysis
Association between LV deformation and LGE size in T2DM patients with MI
In this study, the range of infarct size of LV and total LV infarct extent were 17.96(11.07-25.26) and 17.12(9.58-27.53), respectively. As shown in Table 3, for T2DM(MI+) patients, there was a negative correlation between increased infarction size and decreased LVGFI (all p <0.001) and LV global PS in all three directions (all p <0.01). LV global radial and circumferential PSSR were inversely correlated with total LV infarct extent (r = − 0.353, p = 0.016; r = 0.533, p <0.001, respectively), enhanced mass of LV (r = − 0.302, p = 0.042; r = 0.525, p <0.001, respectively), and enhanced area of LV (r = − 0.297, p = 0.045; r = 0.528, p <0.001, respectively) in T2DM patients with chronic MI. However, LV global longitudinal PSSR and global PDSR in the three directions showed no significant relationship with infarction size (all p >0.05).
Multivariate linear regression analysis demonstrated that NYHA functional class and total LV infarct extent were independently associated with global radial PS (β = -0.400, p = 0.002; and β = -0.446, p = 0.001, respectively; model R2 = 0.37) and global circumferential PS (β = -0.339, p = 0.006; and β = -0.530, p = 0.001, respectively; model R2 = 0.41).
Association between LV deformation and LGE area in T2DM patients with MI
Regarding infarction-involve regions in the T2DM(MI+) group, 28 patients had LGE areas involving the interventricular septum, 20 involving the LV inferior wall, 13 involving the LV lateral wall, and 12 involving the LV anterior wall. There were no LGE areas detected in the T2DM(MI-) group.
For the LGE area in different regions of the LV wall, patients with anterior wall infarction had lower LV global radial PS (anterior vs. non-anterior: 11.91 ± 1.924 vs. 18.45 ± 1.671, p = 0.037), circumferential PS (anterior vs. non-anterior: -8.447 ± 0.7525 vs. -13.24 ± 0.8778, p = 0.034. figure.3) and longitudinal PS (anterior vs. non-anterior: -5.289 ± 0.4827 vs. -8.351 ± 0.6052 p = 0.006). Patients with interventricular septum infarction have lower LV global longitudinal PS (interventricular septum vs. non- interventricular septum: -6.515 ± 0.708 vs. -8.503 ± 0.6702, p = 0.043) (Figure.4). In addition, LV anterior wall infarction was independently associated with global longitudinal PS (β = − 0.398; p = 0.006, model R2 = 0.16; Table 4).
Inter‑ and Intraobserver variability
Table 5 summarizes the inter- and Intraobserver variability for LV deformation and LGE analysis. The ICCs for intra- and interobserver variability were 0.828–0.959 and 0.777–0.955, respectively, for LV deformation, and 0.827–0.895 and 0.882–0.893 respectively, for LGE parameters, which suggesting that both techniques are in agreement.