Ventricular-arterial coupling in patients with bicuspid aortic valve – a transthoracic echocardiography study

Introduction: Bicuspid aortic valve (BAV) is a condition involving not only the aortic valve, but the entire aortic root and is associated with increased aortic stiffness. Data regarding the ventricular stiffness or the combined arterial and ventricular stiffness in this setting are scarce. Purpose: To assess the ventriculararterial coupling (VAC) and its correlations with parameters of left ventricular (LV) function in patients with BAV. Methods: We enrolled 30 subjects with BAV (38 ± 11 years, 13 men) and 21 age and gender matched healthy controls (41 ± 15 years, 10 men). Exclusion criteria were more than mild aortic stenosis, LV ejection fraction (EF) < 50%, LV wall motion abnormalities or documented coronary artery disease. VAC was assessed as the ratio between arterial elastance (Ea) and end-systolic LV elastance (Ees). Ea was calculated from stroke volume (SV) and end-systolic pressure (Ea = (Systolic BP x 0.9)/SV) and Ees was calculated using an estimated normalized ventricular elastance at arterial end diastole: Ees = [Diastolic BP-(ENd(est) x Systolic BP x 0.9)]/( ENd(est) x SV). S-wave velocity at septal site by TDI and LV global longitudinal strain (GLS) by speckle tracking echocardiography were measured. Results: All BAV patients had aortic regurgitation (16% mild, 26% moderate and 57% severe). LVEF was similar in both groups (60.4 ± 3.3% in BAV group vs 60.2 ± 3.3% in control group, p = 0.85). Also, S velocity was similar in BAV patients (8.1 ± 1.1 cm/s) and in healthy subjects (7.9 ± 1.3 cm/s, p = 0.18). Instead, GLS was significantly reduced in BAV patients (-18.5 ± 1.9 vs -19.7 ± 1.2%, p = 0.007). BAV patients had lower Ea (1.05 ± 0.42 vs 1.67 ± 0.31 mm Hg/ml, p < 0.001) and Ees (0.90 ± 0.50 vs 2.33 ± 0.55 mm Hg/ml, p < 0.001) and also significantly impaired VAC (1.98 ± 2.16 vs 0.72 ± 0.12, p = 0.003) than healthy subjects. In BAV group, VAC correlated with Ees (r = -0.71, p < 0.001) and GLS (r = 0.54, p = 0.002) and did not correlate with Ea, ascending aorta dimensions or the aortic regurgitation degree. Conclusions: BAV is associated with subtle ventricular and arterial function abnormalities and an impaired VAC. The clinical implications of these findings remain to be established.

ISSN – online: 2734 – 6382
ISSN-L 1220-658X
ISSN – print: 1220-658X
The Romanian Journal of Cardiology is indexed by:
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CODE: 379
CME Credits: 10 (Romanian College of Physicians)