Effect of epicardial obesity on myocardial remodeling after mitral valve surgery

Aim

To assess the relationship between epicardial obesity (EO) and the nature of perioperative myocardial remodeling in patients undergoing surgical correction of mitral valve (MV) disease.

Material and methods

The study included 148 patients with acquired non-infectious MV disease who were hospitalized for surgical correction under cardiopulmonary bypass. Preoperative computed tomography (CT) of the heart was performed to assess epicardial adipose tissue (EAT) volume. Transthoracic echocardiography (Echo) with evaluation of left ventricular (LV) longitudinal myocardial strain (GLS), as well as RV systolic function (2D/3D Echo), was conducted before surgery and on postoperative day 7, day 30, and 1 year after surgery. Groups were divided based on EO presence: EO group (n=62) and no-EO group (n=86). Adipokines in blood serum were evaluated. Epicardial adipose tissue samples were taken intraoperatively, followed by an assessment of the expression of adipokine genes.

Results

Echo before MV correction showed that patients with EO had larger left and right atrial (LA/RA) volumes (149.0 [113.3; 209.8] vs 114.0 [97.5; 144.0] ml (p=0.03) and 96.0 [75.8; 113.3] vs 65.0 [50.0; 86.0] ml (p=0.01), respectively), and more pronounced RV systolic dysfunction (EAT volume >115.1 cm³ was associated with a 4.6-fold increase in the odds of detecting TAPSE <1.7 cm pre-MV correction [95% CI 1.254; 16.748], p=0.02). An increase of blood leptin level by 1 ng/ml is associated with a decrease in GLS LV by B - coefficient= 0.0894 (p = 0.0269) and a decrease in the RV ejection fraction by B-coefficient= -0.1488 (p = 0.0447). The expression of ADIPOQ and LEP gene had no correlation with the parameters of myocardial remodeling in patients with MV disease.

In the early postoperative period, EO patients had larger atrial sizes, greater RV end-systolic volume, and worse RV/pulmonary artery coupling. One year post-MV correction, EO patients exhibited larger indexed atrial volumes and basal RV size. In the no-EO group, dynamic improvements by one year included a 10.7% increase in GLS LV (p=0.02), 33.6% reduction in indexed LA volume (p=0.004), 28% reduction in LV mass index (p=0.003), 10.3% reduction in LV end-diastolic dimension (p=0.01), 15% increase in LV stroke volume (p=0.009), 17.6% increase in TAPSE (p=0.02), and 6.5% increase in RV ejection fraction (p=0.04), which were not observed in the EO group.

Conclusion

The presence of epicardial obesity (verified by cardiac CT) in cardiac surgery patients with acquired non-infectious mitral valve disease is associated with less favorable remodeling of the left and right heart chambers pre-correction and less favorable reverse myocardial remodeling within one year post-surgery. A comprehensive approach identifying various obesity manifestations at the preoperative stage will allow to modify factors negatively impacting disease progression in cardiac surgery patients with MV disease.Figure 1