Relationship between left ventricular diastolic function and arterial stiffness in patients with bicuspid aortic valve.

摘要

Bicuspid aortic valve (BAV), one of the most common congenital cardiac abnormalities, is the result of abnormal aortic leaflet formation during valvulogenesis. Recent studies have reported BAV to be associated with abnormal aortic stiffness, which has a negative impact on left ventricular (LV) diastolic function. The study aim was to investigate the relationship between LV diastolic function, as measured with two-dimensional speckle tracking echocardiography (2D-STE), and arterial stiffness. A total of 38 patients with isolated BAV, and 18 age- and gender-matched healthy controls were enrolled prospectively. Patients with aortic valve velocity > 1.7 m/s, more than mild aortic regurgitation (AR) and ascending aorta diameter > 3.6 cm (indexed diameter > 2.1 cm/m2) were excluded. BAV was classified as either anterior-posterior (AP) orientation or right-left (RL) orientation. The LV diastolic function (E/A and E/Em ratio), left atrial (LA) volume index (LAVI), LA systolic strain and strain rate (SR) was assessed using echocardiography. Strain measurements were reported as longitudinal LA strain during ventricular systole (LA-Res), strain during late diastole (LA-Pump), and also as SR during ventricular contraction (LA-SR(s)), during passive ventricular filling (LA-SR(E)), and during active atrial contraction (LA-SR(A)) from four-chamber views. Arterial stiffness was evaluated by measuring the aortic pulse wave velocity (PWV), wave reflection was assessed by measuring the central systolic blood pressure (cSBP), central pulse pressure (cPP) and augmentation index (AIx) with applanation tonometry. The aortic diameter at the proximal ascending aorta was larger in patients with BAV than in controls. Compared to controls, the E/Em ratio and LAVI were significantly higher in BAV patients. Although PWV was higher in BAV patients than in controls, no differences were found between the groups in terms of cSBP, cPP and AIx. The BAV group was observed to have significant lower LA-Res and LA-Pump strain values compared to controls. Significant correlations were identified between the PWV and echocardiographic parameters of LV diastolic function determinants, such as LA-Res and LA-Pump. However, there were no significant differences between BAV subgroups in terms of LV diastolic parameters and PWV. Patients with isolated BAV have early features of subclinical LV diastolic dysfunction, as measured with 2D-STE. In addition, aortic stiffness assessed by PWV was impaired. The LV diastolic parameters were related to aortic stiffness.