Epicardial fat, left ventricular strain, and T1-relaxation times in obese individuals with a normal ejection fraction

Abstract

Background Cardiac magnetic resonance (CMR) may detect early signs of cardiomyopathy. Purpose The purpose of this CMR study was to evaluate epicardial fat volume (EFV), T1-relaxation times (T1), and left ventricular (LV) strain in non-obese (<30 kg/m2) and obese (>30 kg/m2) individuals with no other cardiovascular risk factor and with a normal LV ejection fraction (LVEF) to detect early changes of obesity cardiomyopathy. Material and Methods Seventy-five individuals (38 men) without additional cardiovascular risk factors were examined at 1.5 T. EFV was assessed by a 3D-Dixon sequence. A 3(3)3(3)5 MOLLI scheme was used to assess T1 (ms). Myocardial strain (%) was evaluated by longitudinal (LS) and circumferential strain (CS) analysis. Results Obese individuals (n = 34; age = 55.6 ± 13.8 years; BMI = 33.4 ± 2.9 kg/m2) had higher EFVs (70.2 ± 27.9 vs. 56.1 ± 25.2 mL/m2; P < 0.05) and T1 values (991.0 ± 38.6 vs. 974.6 ± 32.0; P = 0.061) as well as worse LS and CS values (LS = −21.0 ± 4.8 vs. −23.2 ± 3.7; CS = −23.8 ± 5.7 vs. −27.7 ± 4.2; P < 0.05, for all) compared to non-obese individuals (n = 41; age = 57.2 ± 15.5 years; BMI = 25.1 ± 2.3 kg/m2). Individuals with severe obesity (BMI > 35 kg/m2) had a significantly higher T1 compared to non-obese (1010.5 ± 39.9 vs. 974.6 ± 32.0 ms; P < 0.05). There were no significant differences regarding age or gender. Conclusion Obesity is associated with an increased EFV and a disturbed LV contractility despite a normal LVEF. Myocardial fibrosis as well as metabolic and inflammatory mechanisms of increased epicardial fat may play role. Multi-parametric CMR may be a valuable tool for the detection of such early signs of an obesity cardiomyopathy.

Cardiac remodeling and subclinical left ventricular dysfunction in adults with uncomplicated obesity: a cardiovascular magnetic resonance study

“…The present study did not find any significant differences in LVEF between adults with uncomplicated obesity and HCs, which is consistent with results of previous reports (4,5,23). However, impaired LV contractility was detected during strain analysis, with global radial, circumferential, and longitudinal PS being lower in the obesity group than the HC group.…”

“…These results indicate that PS has higher sensitivity than LVEF as marker for subclinical myocardial contractile dysfunction. Similar results were reported by Homsi et al (23), who reported that their obesity group had lower mean LV longitudinal and circumferential strain on CMR than their non-obesity group. However, previous echocardiographic studies revealed decreased longitudinal strain, increased or decreased radial strain, and reduced or no marked changes in circumferential strain among children with obesity (24,25).…”

“…Previous studies have also shown that myocardial dysfunction is caused by an increased LV load and hypertrophy (7,17,18,27,28). Diffuse myocardial fibrosis observed on T 1 -weighted mapping was also found to have adverse effects on ventricular function (23,29). In the present study, none of the participants in the obesity group had LGE in the myocardial LV.…”

DeepStrain Evidence of Asymptomatic Left Ventricular Diastolic and Systolic Dysfunction in Young Adults With Cardiac Risk Factors

“…Multiple studies in older adults have reported reduced systolic strain with preserved ejection fraction in obesity, hypertension, and T2DM ( 10 , 14 , 15 , 24 , 26 ). For example, cardiac MRI studies measuring global circumferential end-systolic strain have reported a clear reduction in obesity ( 14 ), and progressive decline from controls to hypertension to hypertension with T2DM ( 15 ). Evidence of reduced systolic strain in younger asymptomatic populations is less clear.…”

Cardiac Alterations on 3T MRI in Young Adults With Sedentary Lifestyle-Related Risk Factors

“…In mature patients with T2D, ECV was mainly higher without clear changes in native T 1 values (21). In both younger and older adult obese populations, no differences were reported in native T 1 values and ECV (22,23). T 2 mapping values have only been reported in mature hypertensive and T2D subjects, both show higher values than in healthy controls (24,25).…”