Relation of epicardial fat thickness to subclinical right ventricular dysfunction assessed by strain and strain rate imaging in subjects with metabolic syndrome: a two-dimensional speckle tracking echocardiography study

Background: Right ventricular (RV) function is known to be impaired in the presence of metabolic syndrome (MetS). Epicardial adipose tissue is a metabolically active organ that generates various bioactive molecules, which might affect cardiac function and morphology. Thus, we hypothesized that RV dysfunction in patients with MetS may be related to increased epicardial fat thickness (EFT) in these patients. In patients with MetS, we aimed to assess the relation of EFT with RV function using two-dimensional speckle tracking echocardiography (2DSTE)-derived strain and strain rate imaging.

Methods: The study involved 76 subjects with MetS and 61 subjects without MetS. Biventricular structure and function together with EFT were evaluated by conventional echocardiography. RV free and septal walls strain (RVFW-S & RVSW-S), systolic and early diastolic strain rates (RVSRs & RVSRe) were evaluated by 2DSTE.

Results: Epicardial fat thickness was significantly higher in subjects with MetS (6.45 ± 1.48 mm vs. 5.49 ± 1.05 mm, P < 0.001). RVFW-S (-22.95 ± 4.97% vs. -24.96 ± 3.63%; P = 0.007), RVSRs (1.53 ± 0.33/sec vs. -1.70 ± 0.33/sec; P = 0.002), and RVSRe (1.40 ± 0.44/sec vs. 1.75 ± 0.49/sec; P < 0.001) were all lower in subjects with MetS, while RVSW-S did not differ. Multiple regression analysis showed that EFT was independently associated with RVFW-S (β = -0.547, P < 0.001), RVSRs (β = -0.332, P = 0.001), and RVSRe (β = -0.187, P = 0.019) in subjects with MetS.

Conclusions: Metabolic syndrome is associated with subclinical RV systolic and diastolic dysfunction. In subjects with MetS, increased EFT is independently related to RV systolic and diastolic dysfunction.