Endotrophin and matrix metalloproteinase-2 levels in bicuspid aortic valve and hypertension associated aortopathy and their relationship with strain parameters of the ascending aorta.

Objective: Bicuspid aortic valve (BAV) is the most common congenital heart defect. Ascending aorta dilatation is related to BAV- and hypertension (HTN)-associated aortopathy. The aim of this study was to investigate aortic elasticity, as well as aortic deformation of the ascending aorta, using strain imaging, and to evaluate the possible relationship of biomarkers, such as endotrophin and matrix metalloproteinase-2 (MMP-2), with ascending aorta dilatation in patients with BAV- or HTN-associated aortopathy.

Patients And Methods: This prospective study included patients with ascending aorta dilatation with BAV (n = 33), or normal tricuspid aortic valve with HTN (n = 33), and 20 control subjects. The mean age of the total patients was 42.76 ± 10.4 years (67% male, 33% female). We calculated aortic elasticity parameters using the relevant formula by M-mode echocardiography and determined layer-specific longitudinal and transverse strains of the proximal aorta by speckle-tracking echocardiography. Blood samples of the participants were drawn for the analysis of endotrophin and MMP-2.

Results: Aortic strain and aortic distensibility were significantly decreased, whereas the aortic stiffness index was significantly increased in patient groups with BAV or HTN compared to the control group (p < 0.001). Moreover, longitudinal strain of both the anterior and posterior aortic walls of the proximal aorta were significantly impaired in BAV and HTN patients (p < 0.001). Serum endotrophin levels were significantly reduced in the patient cohort compared to the controls (p = 0.001). Endotrophin was noted to be significantly positively correlated with aortic strain and aortic distensibility (r = 0.37, p = 0.001; r = 0.45, p < 0.001, respectively), whereas inversely associated with aortic stiffness index (r = -0.402, p < 0.001). Furthermore, endotrophin was the single independent predictor of ascending aorta dilatation (OR = 0.986, p < 0.001). A cut-off value of endotrophin ≤ 82.38 ng/mL predicted ascending aorta dilatation with a sensitivity of 80.3% and specificity of 78.5% (p < 0.0001).

Conclusions: The present study showed that aortic deformation parameters and elasticity are impaired in BAV and HTN patients, and strain imaging allows for a good analysis of ascending aorta deformation. Endotrophin could be a predictive biomarker of ascending aorta dilatation in BAV and HTN aortopathy.