Assessment of Myocardial Microvascular Dysfunction in Patients with Different Stages of Diabetes Mellitus: an Adenosine Stress Perfusion Cardiac Magnetic Resonance Study

Purpose To examine myocardial perfusion and T1 mapping indicesin individuals with type 2 diabetes mellitus (T2DM) at various stages of glycemic control and whether uncontrolled glycemic levels would worsen myocardial microvascular function. Method Cardiac magnetic resonance examinations were performed on 114 T2DM patients without obstructive coronary artery disease and 55 matched controls. Participants were further divided into four subgroups: Q1 (control); Q2 (prediabetes); Q3 (controlled T2DM) and Q4 (uncontrolled T2DM). The correlation between HbA1c levels and myocardial perfusion parameters was evaluated. Results MPRI was decreased in the Q4 group than in the Q3 group, with borderline significance (P = 0.065). Compared with the Q1 group, stress T1 reactivity (ΔT1) was significantly reduced in the Q3 and Q4 group (P = 0.004 and < 0.001, respectively), but elevated in the Q2 group (P = 0.018). Extracellular volume (ECV) was considerably higher in the Q2 group and gradually rose in the Q3 and Q4 groups as compared to the Q1 group (P = 0.011, 0.001, and 0.007, respectively). HbA1c correlated negatively with MPRI and stress ΔT1, but positively with ECV (β = -1.993, P < 0.001; β = -0.180, P < 0.001; and β = 0.127, P < 0.001, respectively). Conclusions Stress ΔT1 reduced in T2DM patients but rose in prediabetes patients. Diabetes-induced elevated ECV begins early in the prediabetic stage and persists throughout the disorder. Myocardial perfusion and T1 mapping at stress can be used to detect early signs of microvascular dysfunction and subclinical risk factors in T2DM patients.