Assessment of Subclinical Left Ventricular Dysfunction in Type 2 Diabetes Mellitus Using Echocardiographic Strain Imaging

Abstract

Background
Type 2 diabetes mellitus (T2DM) is associated with a high burden of cardiovascular complications, including diabetic cardiomyopathy, which may develop before the onset of clinically apparent cardiac dysfunction. Conventional echocardiographic parameters such as left ventricular ejection fraction (LVEF) may fail to identify early myocardial abnormalities. Echocardiographic strain imaging, particularly global longitudinal strain (GLS), provides a sensitive method for detecting subclinical left ventricular (LV) dysfunction.

Aim
The present study was conducted to assess subclinical LV dysfunction in patients with T2DM using echocardiographic strain imaging and to evaluate its association with clinical and metabolic parameters.

Methods
This prospective observational study included 80 patients with type 2 diabetes mellitus who underwent clinical evaluation, biochemical assessment, conventional echocardiography, and two-dimensional speckle-tracking echocardiography (2D-STE). LV systolic function was assessed using LVEF, while myocardial deformation was evaluated using GLS. Associations between strain parameters and clinical variables, including duration of diabetes, glycaemic control, and cardiovascular risk factors, were analyzed.

Results
The mean age of study participants was 56.8 ± 9.4 years, with males comprising 62.5% of cases. The mean duration of diabetes was 8.2 ± 4.6 years. Although all patients had preserved LVEF (61.4 ± 4.8%), impaired GLS suggestive of subclinical LV dysfunction was observed in 40% of patients. Patients with impaired GLS had significantly longer duration of diabetes (10.8 ± 4.9 vs 6.5 ± 3.8 years, p<0.001) and higher HbA1c levels (8.5 ± 1.2 vs 7.3 ± 1.0%, p<0.001). GLS showed significant negative correlation with duration of diabetes and HbA1c levels.

Conclusion
Echocardiographic strain imaging enables detection of early myocardial dysfunction in patients with T2DM despite preserved LVEF. Global longitudinal strain may serve as a useful marker for early identification of diabetic cardiomyopathy and cardiovascular risk stratification.