Changes in epicardial and visceral adipose tissue depots following bariatric surgery and their effect on cardiac geometry

Figure 1. CMR images. (A) – contouring of epicardial adipose tissue in the short axis view. (B) – 17 segment view overlayed on short axis images. Highlighting the septal segments (in orange) and the lateral segments (in green). (C) – Short axis view with measurements of the maximal anterior-posterior (AP) diameter parallel to the septum and maximal septal-lateral (SL) diameter orthogonal to the AP diameter, with left ventricular eccentricity index being calculated by diving AP/SL diameters.

Figure 2. Anthropomorphic changes following bariatric surgery. (A) – change in weight, (B) – percentage change in visceral adipose tissue, (C) – percentage change in epicardial adipose tissue, (D) – change in systolic blood pressure, (E) – change in HOMA-IR as a marker of insulin resistance, (F) – change in heart rate. HOMA-IR, homeostatic model assessment of insulin resistance. * < 0.05, ** < 0.01, ***<0.001, ****<0.0001, ns, Non significant.

Figure 3. Changes in cardiac geometry following bariatric surgery. (A) – percentage change in left ventricular mass, (B) – percentage change in left ventricular mass:volume ratio, (C) – percentage change in left ventricular end diastolic volume, (D) – percentage change in left atrial volume, (E) – percentage change in left ventricular stroke volume, (F) – percentage change in cardiac output. * < 0.05, ** < 0.01, ***<0.001, ****<0.0001, ns, Non significant.

Figure 4. The effect of epicardial adipose tissue on cardiac geometry following bariatric surgery. (A) – correlation between baseline lateral/septal wall thickness ratio and baseline epicardial adipose tissue, (B) – correlation between baseline lateral/septal wall thickness ratio and baseline visceral adipose tissue, (C) – change in left ventricular eccentricity index, (D) - correlation between left ventricular eccentricity index and baseline epicardial adipose tissue, (E) - correlation between change in left ventricular eccentricity index and change in epicardial adipose tissue, (F) – correlation between left ventricular eccentricity index and baseline visceral adipose tissue. *<0.05, *** < 0.001, **** < 0.0001 ns, Non significant.

Figure 5. (central figure) – following bariatric surgery the left ventricle undergoes a biphasic remodelling response. Initially there is a reversal of eccentric remodelling as total body tissue to perfuse falls, with reductions in left ventricular mass, end diastolic volume and epicardial adipose tissue. In the longer term there is a reversal of concentric remodelling as insulin resistance (HOMA-IR) decreases, with a further fall in left ventricular mass but an increase in end diastolic volume. LVEDV, left ventricular end diastolic volume; EAT, epicardial adipose tissue; LVM, left ventricular mass; HOMA-IR, homeostatic model assessment of insulin resistance. Created with BioRender.com.