Abstract
ObjectiveTo detect diffuse myocardial fibrosis in different severity levels of left ventricular diastolic dysfunction (DD) in spontaneous type 2 diabetes mellitus (T2DM) rhesus monkeys.MethodsEighteen spontaneous T2DM and nine healthy monkeys were studied. Echocardiography was performed for diastolic function classification. Cardiac magnetic resonance (CMR) imaging was performed to obtain extracellular volume fraction (ECV) maps and T1ρ maps at two different spin-locking frequencies. ECV values, T1ρ values, and myocardial fibrosis index (mFI) values which are based on the dispersion of T1ρ, were calculated. Global peak diastolic longitudinal strain rates (GSrL) were also obtained.ResultsEchocardiography results showed mild DD in nine T2DM monkeys and moderate DD in the other nine. The global ECV values were significantly different among healthy animals as compared with animals with mild DD or moderate DD, and the ECV values of animals with moderate DD were significantly higher as compared with those of mild DD. The mFI values increased progressively from healthy animals to those with mild DD and then to those with moderate DD. Diastolic function indicators (e.g., early diastolic mitral annulus velocity, GSrL) correlated well with ECV and mFI.ConclusionsMonkeys with T2DM exhibit increased ECV, T1ρ, and mFI values, which may be indicative of the expansion of extracellular volume and the deposition of excessive collagen. T1ρ mapping may have the potential to be used for diffuse myocardial fibrosis assessment.Key Points• Monkeys with T2DM exhibit increased ECV, T1ρ, and mFI values, which may be indicative of the expansion of extracellular volume and the deposition of excessive collagen.• The relationship between diastolic dysfunction and diffuse myocardial fibrosis may be demonstrated by imaging markers.• Non-contrast T1ρ mapping may have the potential to be used for diffuse myocardial assessment.
Highlights
Monkeys with type 2 diabetes mellitus (T2DM) exhibit increased extracellular volume fraction (ECV), T1ρ, and myocardial fibrosis index (mFI) values, which may be indicative of the expansion of extracellular volume and the deposition of excessive collagen
Diabetes leads to abnormalities in cardiac relaxation that predominantly results in heart failure with preserved ejection fraction (HFpEF) [1]
Monkeys with T2DM exhibited increased ECV, T1ρ, and mFI values, which may be indicative of the expansion of extracellular volume and the deposition of excessive collagen
Summary
There were nine T2DM monkeys with mild DD in group 2 and nine T2DM monkeys with moderate DD in group 3. Despite the non-significant findings related to the basic cardiac function of the three groups, the global myocardial ECV (%) was significantly different among the three groups (24.61 (22.96–25.88) vs 26.34 (25.39– 26.97) vs 29.02 (27.46–34.48); p < 0.000), and the ECV values of group 3 were significantly higher as compared with those of group 2 (p = 0.027). There was no significant difference in ECV values between group 1 and group 2 (p = 0.307) T1ρ relaxation time was significantly higher in groups 2 and 3 as compared with group 1; there was no significant difference between group 2 and group 3. There was a moderate positive correlation between ECV and mFI (r = 0.603) (Fig. 3). E’ was correlated with mFI (r = − 0.465), T1ρ (r = − 0.549), and ECV (r = − 0.715) (Table 4; Fig. 4).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
