Flow dynamics and systemic arterial stiffness distinguish bicuspid aortic valve aortopathy from heritable thoracic aortic disease
Diego Segura-Rodríguez, Miguel Morales-García, Eduardo Moreno-Escobar, Pilar Martín de la Fuente, Francisco Burillo Gómez, José Antonio Miras Gómez, Elvira Pérez Cuenca, Inés Uribe, Rocío García-OrtaAbstract
Aims
Bicuspid aortic valve-associated aortopathy (BAVA) and heritable thoracic aortic disease (HTAD) share clinical manifestations but may represent distinct pathophysiological entities. We aimed to compare morphological and haemodynamic profiles between both groups using cardiovascular magnetic resonance imaging (CMR) and non-invasive systemic haemodynamic assessment.
Methods and results
A total of 185 patients (111 BAVA, 74 HTAD) were prospectively enrolled. CMR 4D-flow assessed aortic distensibility (ADCMR), pulse wave velocity (PWVCMR), global wall shear stress (WSSCMR) and energy loss (ELCMR). Oscillometry assessed systemic PWVM, augmentation index (AIxM) and systemic vascular resistance (SVRM). Composite adverse aortic events (AAE) comprised acute aortic syndrome, cardiovascular death or guideline diameter-based indication for surgery over 42.1±17.6 months. BAVA showed greater tubular ascending aorta and sinotubular junction dilation, ascending aorta WSSCMR (0.42±0.18 vs 0.28±0.12 Pa, p=0.020), ELCMR (19.8±8.4 vs. 12.3±6.1 mW, p<0.001) and ADCMR (6.1 ± 3.5 vs. 4.8 ± 2.9 ×10−3 mmHg−1, p=0.023), yet lower systemic stiffness than HTAD (PWVM 6.2±1.7 vs 7.8±2.1 m/s; AIxM 12.1±7.6 vs 18.4±9.2%; both p<0.001). AAE rates were similar. In exploratory aetiology-specific analyses, ascending aorta WSSCMR was associated with events in BAVA (HR 8.92, 95% CI 2.85-27.95) and systemic PWVM in HTAD (HR 2.16, 95% CI 1.30-3.57).
Conclusion
BAVA and HTAD show distinct morphological and haemodynamic phenotypes: BAVA with focal dilation, elevated WSSCMR/ELCMR and preserved systemic function; HTAD with reduced local distensibility and greater systemic stiffness. These aetiology-specific predictors are exploratory and require external validation.