June 28, 2026Journal of the American College of Cardiology
Valve-Related Hemodynamics Mediate Human Bicuspid Aortopathy
Key result
Elevated aortic WSS in BAV patients is linked to greater medial elastin degradation and ECM dysregulation.
- P=0.01
- n=20
Why the study?
To determine the relationship between regional wall shear stress and aortic tissue remodeling to understand how regional wall shear stress influences extracellular matrix dysregulation in bicuspid aortic valve patients.
Does elevated wall shear stress correlate with extracellular matrix dysregulation in the ascending aorta of patients with bicuspid aortic valves?
Population
20 BAV patients undergoing ascending aortic resection
Comparison
Paired aortic wall samples from regions of elevated vs normal WSS
Design
Observational paired tissue-remodeling study using 4D flow CMR
Authors
Discussion
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Member takes
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“Abnormalities in systolic WSS were shown to be associated with colocalized medial elastin degradation, decreased elastic aortic wall fiber thickness, and progressive dilation, while scan-rescan studies showed good reproducibility, positioning this biomarker as top priority for its introduction in clinical care.”
“in the absence of 4-dimensional magnetic resonance imaging flow data, the assumption that concave versus convex segments of the ascending aorta are exposed to different hemodynamic flow patterns is speculative.”
“Despite vigorous research efforts, no biomarker or imaging tool has, however, till date been established to identify BAV patients at risk for thoracic aortic complications.”
Implication
May inform 4D flow CMR risk stratification in BAV; leaves open whether hemodynamics-targeted interventions alter outcomes.
Key Points
- This research aims to explore how wall shear stress affects tissue remodeling in patients with bicuspid aortic valves.
- BAV patients (n=20) undergoing ascending aortic resection underwent preoperative 4D flow CMR to measure wall shear stress.
- Aortic wall samples were collected from areas of high and normal wall shear stress for comparison of elastin and ECM factors.
- Histology and multiplex protein analyses were employed to assess elastin degeneration and ECM regulation.
- Regions with increased wall shear stress showed significantly lower total elastin (p=0.01) with thinner fibers (p=0.00007).
- Elevated wall shear stress areas had increased levels of transforming growth factor β-1 (p=0.04) and matrix metalloproteinases (MMP-1, MMP-2, MMP-3) indicating ECM dysregulation.
- The findings suggest a link between hemodynamics and aortic tissue degeneration, highlighting potential diagnostic uses of CMR.
Study Design
Type
Observational (n=20)
Structured PICO
Does elevated wall shear stress correlate with extracellular matrix dysregulation in the ascending aorta of patients with bicuspid aortic valves?
P
Population
20 patients with bicuspid aortic valves undergoing ascending aortic resection.
E
Exposure
Aortic wall samples from regions of elevated wall shear stress (WSS) identified by preoperative 4-dimensional (4D) flow cardiac magnetic resonance imaging (CMR)
C
Comparator
Paired aortic wall samples from regions of normal WSS within the same patients
O
Outcome
Medial elastin degeneration (by histology) and extracellular matrix (ECM) regulation (by protein expression)surrogate
Main Result
p-value: p=0.01
Elevated wall shear stress measured by 4D flow CMR correlates with extracellular matrix dysregulation and elastic fiber degeneration in the ascending aorta of BAV patients, suggesting hemodynamics contribute to aortopathy.
Cite This Study
Guzzardi et al. (2015) conducted an observational in Bicuspid aortic valves (BAV) aortopathy (n=20). Elevated regional wall shear stress (WSS) vs. Adjacent areas with normal WSS was evaluated on Medial elastin degradation (total elastin) (p=0.01). Elevated regional wall shear stress in the ascending aorta of BAV patients was associated with greater medial elastin degradation (p=0.01) and ECM dysregulation compared to adjacent normal WSS regions.