Cardiac magnetic resonance T1 mapping for evaluating myocardial fibrosis in patients with type 2 diabetes mellitus: correlation with left ventricular longitudinal diastolic dysfunction.

OBJECTIVES: We aimed to evaluate myocardial fibrosis using cardiac magnetic resonance (CMR) T1 mapping in type 2 diabetes mellitus (T2DM) patients and investigate the association between left ventricular (LV) subclinical myocardial dysfunction and myocardial fibrosis. METHODS: The study included 37 short-term (≤ 5 years) and 44 longer-term (> 5 years) T2DM patients and 41 healthy controls. The LV global strain parameters and T1 mapping parameters were compared between the abovementioned three groups. The association of T1 mapping parameters with diabetes duration, in addition to other risk factors, was determined using multivariate linear regression analysis. The correlation between LV strain parameters and T1 mapping parameters was evaluated using Pearson's correlation. RESULTS: The peak diastolic strain rates (PDSRs) were significantly lower in longer-term T2DM patients compared to those in healthy subjects and short-term T2DM patients (p < 0.05). The longitudinal peak systolic strain rate and peak strain were significantly lower in the longer-term T2DM compared with the short-term T2DM group (p < 0.05). The extracellular volumes (ECVs) were higher in both subgroups of T2DM patients compared with control subjects (all p < 0.05). Multivariate linear regression analysis showed that diabetes duration was independently associated with ECV (ß = 0.413, p < 0.001) by taking covariates into account. Pearson's analysis showed that ECV was associated with longitudinal PDSR (r = - 0.441, p < 0.001). CONCLUSION: T1 mapping could detect abnormal myocardial fibrosis early in patients with T2DM, which can cause a decline in the LV diastolic function. KEY POINTS: • CMR T1 mapping could detect abnormal myocardial fibrosis early in patients with T2DM. • The diabetes duration was independently associated with ECV. • Myocardial fibrosis can cause a decline in the LV diastolic function in T2DM patients.

Evaluation of the effects of glycated hemoglobin on cardiac function in patients with short-duration type 2 diabetes mellitus: A cardiovascular magnetic resonance study.

AIMS: To investigate the association between glycated hemoglobin (HbA1c) and myocardial dysfunction and to determine whether its association is independent of myocardial perfusion. METHODS: Sixty-four patients with type 2 diabetes mellitus (T2DM) were recruited. They were divided into groups according to their HbA1c level: the controlled T2DM group (HbA1c < 7%) and uncontrolled T2DM groups (HbA1c ≥ 7%). Meanwhile, 30 age-matched healthy volunteers were included. All patients with T2DM and healthy controls underwent cardiovascular magnetic resonance imaging to evaluate the myocardial mechanics and perfusion parameters. RESULTS: The circumferential and longitudinal peak strain (PS) (p = 0.009 and 0.002 respectively) and global radial, circumferential, and longitudinal peak strain diastolic strain rates (PDSRs) (p = 0.002, 0.001, and 0.001 respectively) were lower in the uncontrolled T2DM group than in the controls without diabetes. In multivariable linear regression analysis, HbA1c was independently related to all directions of the PS and PDSR. The myocardial perfusion parameters were not independently associated with the PS or PDSR. CONCLUSIONS: Cardiac function is impaired in Chinese T2DM patients with poor glucose control (HbA1c ≥ 7%), with preserved left ventricular (LV) ejection fraction, and disease duration <10 years. Poor blood glucose control is an independent predictor of LV myocardial dysfunction for patients with short-term T2DM.

Evaluation of myocardial fibrosis in diabetes with cardiac magnetic resonance T1-mapping: Correlation with the high-level hemoglobin A1c.

AIM: The aim of the study was to assess the extracellular volume fraction (ECV) in type 2 diabetes mellitus (T2DM) patients with different level of hemoglobin A1c (HbA1c) by cardiac magnetic resonance (CMR), and the ability of HbA1c to predict myocardial fibrosis. METHODS: In total, 80 T2DM patients and 20 age- and sex-matched controls were prospective enrolled and underwent CMR to obtain ECV value and LV function parameters. We divided all patients into a group of HbA1c < 7.0% and a group of HbA1c ≥ 7.0%. RESULTS: In the higher HbA1c group the ECV value (all p < 0.001) was higher than both lower HbA1c group (36.23% vs. 32.19%, p < 0.001) and controls (36.23% vs. 29.73%, p < 0.001). HbA1c was positively associated (ß = 0.36, p = 0.004) with ECV, and it was also an independent predictor of myocardial fibrosis (OR = 2.00, P = 0.014). The ROC analysis showed that 7.1% was the optimal cutoff value of HbA1c that predicted the risk of myocardial fibrosis with high diagnostic accuracy (area under the curve = 0.78). CONCLUSION: T1 mapping provided myocardial fibrosis information in T2DM patients. HbA1c is positively correlated with myocardial fibrosis and can be an independently predictor of myocardial fibrosis, which may be helpful for the clinical decision-making of blood glucose control.