Role of microvascular dysfunction in left ventricular dysfunction in type 2 diabetes mellitus

Area of Science:

• Cardiology
• Diabetology
• Medical Imaging

Background:

• Microvascular disease (mVD) is linked to poor cardiovascular outcomes in diabetes mellitus.
• The specific contribution of mVD to diabetic cardiomyopathy (DC) remains unexplored.
• This study investigated the association between left ventricular (LV) systolic and diastolic dysfunction and mVD in patients with type 2 diabetes mellitus (T2DM).

Purpose of the Study:

• To investigate the association between LV systolic and diastolic dysfunction and mVD in T2DM patients.
• To explore the role of mVD in the development of diabetic cardiomyopathy.
• To assess novel MRI biomarkers for mVD in asymptomatic T2DM patients.

Main Methods:

• Recruited 32 asymptomatic T2DM patients for comprehensive echocardiography and cardiac magnetic resonance imaging (CMR).
• Assessed global longitudinal strain (GLS) and diastolic function via echocardiogram.
• Measured coronary sinus flow (CSF) at rest and peak stress using adenosine stress perfusion CMR to calculate coronary flow reserve (CFR).

Main Results:

• Reduced resting CSF was observed in 47% of patients.
• Overall CFR was reduced (2.38 [IQR 2.20]) but not associated with diabetes duration or glycemic control.
• Abnormal CFR did not correlate with abnormal GLS but showed a modest negative correlation with e' (r=-0.49, p=0.004).

Conclusions:

• The pilot study found no correlation between subclinical systolic dysfunction and the novel MRI biomarker of mVD.
• A weak correlation was observed between mVD and myocardial relaxation (diastolic function).
• Larger studies are indicated to confirm these findings in T2DM patients.