The relationship between serum apelin levels and aortic dilatation in bicuspid aortic valve patients

OBJECTIVE: The bicuspid aortic valve (BAV) is the most common congenital heart disease. The process of aortic dilatation is not completely clear in patients with the BAV. Apelin is a peptide found at high levels in vascular endothelial cells which has a role in vascular regulation and cardiovascular function. The aim of this study was to determine the relationship between serum apelin levels and ascending aortic dilatation in adult patients with BAV. DESIGN: This cross-sectional study included 62 patients with isolated BAV and to an age, gender, and body mass index-matched control group of 58 healthy volunteers with tricuspid aortic valve. Transesophageal echocardiography was performed on all patients to determine the type of BAV. Aortic diameters of the aortic root, sinus valsalva, sinotubular junction, and ascending aorta were evaluated with echocardiography. Patients with BAV were divided into two subgroups according to the aortic diameters, as the nondilated BAV group and the dilated BAV group. Serum apelin level was analyzed with ELISA method. RESULTS: The serum apelin levels of the BAV patients were significantly lower than those of the control group (833.5, 25th-75th percentile (713.5-1745) pg/dL vs 1669 (936-2543) pg/dL; P = 0.006). In the subgroup analysis, serum apelin level was significantly different between the nondilated BAV group and the dilated BAV group [977 (790-2433) pg/dL vs 737 (693-870) pg/dL, P < 0.05] and between the dilated BAV group and the control group [737 (693-870) pg/dL vs 1669 (936-2543) pg/dL, P < 0.001]. In multivariate logistic regression analysis apelin [7.27 (95% CI: 1.73-30.42), P = 0.007] and age [1.05 (95% CI: 0.99-1.20), P = 0.049] were determined as independent predictors for ascending aortic dilatation. CONCLUSION: Low serum apelin level was associated with dilatation of ascending aortic in BAV patients. However, apelin was not relevant to BAV without aortic dilatation.