The effect of bariatric surgery type on cardiac reverse remodelling

Abstract

Abstract Introduction Bariatric surgery has been shown to improve adverse cardiac remodelling associated with obesity. Three operations are commonly performed: Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Sleeve Gastrectomy (LSG) and Laparoscopic Adjustable Gastric Band (LAGB). Whilst all three of these procedures result in weight loss, it is currently unclear as to which procedure is most effective at reversing cardiac remodelling. Purpose We assessed differences in cardiac remodelling following each type of surgery using cardiac magnetic resonance (CMR) imaging. Methods 58 patients underwent bariatric surgery (26 RYGB, 22 LSG and 10 LAGB) with CMR before and after surgery, including 46 with short-term (median 251, 219 and 273 days) and 43 with long-term (median 1026, 983 and 1027 days) follow-up. CMR was used to assess cardiac volumes, LV mass (LVM) and LV mass:volume ratio (LVMVR – a marker of concentric remodelling). Adipose tissue depots were also assessed during the scan, including visceral adipose tissue (VAT) at L5 level and epicardial adipose tissue (EAT) (manual contouring in end-ventricular systole on short axis slices from the mitral valve to the apex). Results Changes in percentage body weight were similar between surgery groups in the short term, but appeared to diverge in the longer term (LSG vs LAGB, p=0.039; RYGB vs LAGB, p=0.341) (Figure 1A). Percentage change in VAT and EAT however where significantly greater following RYGB and LSG compared to LAGB at both short- and long-term time points (Figure 1B). Changes in left ventricular end diastolic volume (LVEDV) were similar between groups in both the short term and long term (Figure 2A). We observed a significant difference in LVM change following RYGB or LSG versus LAGB (Figure 2B). This change in LVM at the long-term time point correlated with change in VAT normalised to body weight (r=0.3399, p=0.0368, Figure 2C). Finally, there was a significant decrease in LVMVR at the long-term time point following both RYGB (p=0.006) and LSG (p=0.021), whereas no such change was observed following LAGB (p=0.912). Conclusions Our results suggest that RYGB and LSG are significantly better at decreasing body adipose depots than LAGB. This greater reduction in visceral adipose tissue may account for the greater cardiac reverse remodelling seen with RYGB and LSG compared to LAGB.Figure 1Figure 2