Impact of obesity and epicardial fat on early left atrial dysfunction assessed by cardiac MRI strain analysis

Abstract

Background: Diastolic dysfunction is a major cause of morbidity in obese individuals. We aimed to assess the ability of magnetic resonance imaging (MRI) derived left atrial (LA) strain to detect early diastolic dysfunction in individuals with obesity and type 2 diabetes, and to explore the association between cardiac adipose tissue and LA function.Methods: Twenty patients with obesity and T2D (55 ± 8 years) and nineteen healthy controls (48 ± 13 years) were imaged using cine steady state free precession and 2-point Dixon cardiovascular magnetic resonance. LA function was quantified using a feature tracking technique with definition of phasic longitudinal strain and strain rates, as well as radial motion fraction and radial velocities.Results: Systolic left ventricular size and function were similar between the obesity and type 2 diabetes and control groups by MRI. All patients except four had normal diastolic assessment by echocardiography. In contrast, measures of LA function using magnetic resonance feature tracking were uniformly altered in the obesity and type 2 diabetes group only. Although there was no significant difference in intra-myocardial fat fraction, Dixon 3D epicardial fat volume(EFV) was significantly elevated in the obesity and type 2 diabetes versus control group (135 ± 31 vs. 90 ± 30 mL/m 2 , p < 0.001). There were significant correlations between LA functional indices and both BMI and EFV (p ≤ 0.007).Conclusions: LA MRI-strain may be a sensitive tool for the detection of early diastolic dysfunction in individuals with obesity and type 2 diabetes and correlated with BMI and epicardial fat supporting a possible association between adiposity and LA strain.

Critical role of the epicardium in mediating cardiac inflammation and fibrosis in patients with type 2 diabetes

“…11,12 Interestingly, changes in epicardial adipose tissue mass precede and predict the onset of diabetes, 13,14 and the degree of epicardial adiposity is closely associated with changes in diastolic filling dynamics. 15 This last finding is confirmed by Christensen et al in Diabetes, Obesity and Metabolism. 16 In addition, diabetes enhances the production of proinflammatory cytokines in epicardial adipocytes, which may adversely affect the adjoining myocardium, 17,18 and potentially, other organs.…”

“…Epicardial fat expands and becomes inflamed in both type 1 and type 2 diabetes; even in patients with concurrent obesity or renal disease, diabetes contributes independently to the volume of epicardial fat . Interestingly, changes in epicardial adipose tissue mass precede and predict the onset of diabetes, and the degree of epicardial adiposity is closely associated with changes in diastolic filling dynamics . This last finding is confirmed by Christensen et al in Diabetes, Obesity and Metabolism .…”

Validation of a rapid semi-automated method to assess left atrial longitudinal phasic strains on cine cardiovascular magnetic resonance imaging

“…The reported experience of using FT-CMR LA strain parameter assessment for clinical diagnosis is quite recent, and encompasses cohorts of patients undergoing atrial fibrillation catheter ablation [ 8 , 47 , 48 ], implantable cardioverter-defibrillator implant [ 47 , 49 ], community volunteers without cardiovascular disease at baseline [ 50 , 51 ], patients with acute myocarditis [ 45 ], obesity [ 52 ], and Ebstein’s anomaly [ 53 ]. These studies established the feasibility and validity of LA strain parameter measurement using CMR; and in [ 51 ] found negative correlation between LA strain and LA fibrosis.…”

Impact of overweight on left ventricular function in type 2 diabetes mellitus

“…Kishi et al [ 40 ] reported that high insulin resistance was associated with worse relative wall thickness and worse peak longitudinal strain and early diastolic strain rate from apical 4-chamber view, and e′, depending on obesity level from 3179 participants. Moreover, Evin et al [ 41 ] showed that left atrial strain as assessed by cardiac magnetic resonance imaging was a sensitive tool for the detection of early LV diastolic dysfunction in individuals with obesity and T2DM and correlated with BMI and epicardial fat. In this study, LV mass index and left atrial volume index in T2DM patients with overweight were significantly larger than those in T2DM patients without overweight (79 ± 21 g/m 2 vs. 71 ± 19 mg/m 2 , p < 0.05; 30 ± 9 mL/m 2 vs. 30 ± 9 mL/m 2 , p < 0.05, respectively).…”