Increased left ventricular extracellular volume and enhanced twist function in type 1 diabetic individuals

Area of Science:

• Cardiology
• Radiology
• Diabetology

Background:

• Type 1 diabetes (T1D) can lead to cardiac complications like fibrosis and impaired myocardial function due to hyperglycemia.
• T1D patients often develop diabetic cardiomyopathy, characterized by structural and functional heart abnormalities.
• Magnetic resonance imaging (MRI) T1 mapping can quantify myocardial extracellular volume fraction (ECV) to assess fibrosis.

Purpose of the Study:

• To investigate the extent of extracellular volume (ECV) alterations and associated changes in left ventricular (LV) function and morphology in individuals with T1D.
• To determine if MRI-derived myocardial T1 and ECV values differ between T1D patients and healthy controls.
• To explore the correlation between ECV, native T1 values, and LV mechanics in T1D.

Main Methods:

• Fourteen individuals with long-term T1D and 14 matched controls underwent cardiac MRI.
• Measurements included myocardial T1 values, ECV, LV function (ejection fraction, strain), and morphology.
• Analysis focused on differences between groups and correlations between cardiac measures.

Main Results:

• Individuals with T1D exhibited significantly increased myocardial ECV and native T1 values compared to controls.
• Despite normal LV structure, ejection fraction, and global strain, T1D patients showed augmented LV torsion and circumferential-longitudinal shear strain (Ecl).
• Both ECV and native T1 values correlated significantly with measures of LV torsion and Ecl.

Conclusions:

• Individuals with T1D have increased interstitial fibrosis and altered myocardial T1 values, even with normal LV structure and global function.
• These MRI-derived measures, reflecting interstitial fibrosis and myocardial changes, correlate with augmented LV twist function.
• Increased ECV and native T1 values may serve as early biomarkers for detecting diabetic cardiomyopathy in T1D patients.