Wall Shear Stress Best Predicts Progressive Dilation of Ascending Aorta in BAV

aortic valve replacement
aortic valve replacement
Researchers analyzed the value of wall shear stress for predicting colocalized ascending aorta growth rate in patients with bicuspid aortic valve.

Progressive dilation of the ascending aorta in patients with bicuspid aortic valve (BAV) was found to be predicted by wall shear stress (WSS) as assessed via 4-dimensional (4D) flow cardiac magnetic resonance (CMR) imaging. The study findings were published in JACC: Cardiovascular Imaging.

Patients (N=47) with BAV with no valvular dysfunction who underwent 2 or more CMR assessments greater than or equal to 6 months apart and had no interventions or aortic events between scans were enrolled for the study between 2014 and 2017 at Vall d’Hebron Institut de Recerca in Spain. WSS was computed using a 4D flow CMR approach. Colocalized ascending aorta growth rate was assessed during 2 electrocardiogram-gated high-resolution contrast-enhanced computed tomography angiograms.

Patients had a mean age of 51±13 years; 38% were women; body surface area was 1.86±0.20 m2; systolic blood pressure was 134±17 mm Hg; diastolic blood pressure 77±10 mm Hg; 37 had BAV fusion of the right and left leaflets; and regurgitant fraction was 6.0%±4.9%.

At baseline, the mean ascending aortic diameter was 40.5±6.5 mm with a median growth rate of 0.19 (IQR, 0.00-0.34) mm/year over a median follow-up of 43 months.

Local growth rate was correlated with WSS magnitude (r, 0.291; P =.049) and its circumferential component (r, 0.358; P =.014). Both WSS magnitude and circumferential WSS were independently associated with local growth rate after adjusting for ascending aortic diameter and stroke volume (P =.046; P =.014) and ascending aortic z-score and stroke volume (P =.036; P =.012), respectively.

No correlations were observed between mid-ascending aortic growth rate and baseline diameter, z-score, age, body surface area, or stroke volume.

Circumferential WSS was the best predictor for local fast growth rate, especially in the inner-left regions of the proximal and mid ascending aorta.

This study may have been limited by power due to the low sample size, which resulted from the strict inclusion/exclusion criteria.

“In patients with BAV without significant valvular dysfunction, WSS and, particularly, its circumferential component independently predict progressive dilation of the [ascending aorta],” the study authors said.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.


Guala A, Dux-Santoy L, Teixido-Tura G, et al. Wall shear stress predicts aortic dilation in patients with bicuspid aortic valve. JACC Cardiovasc Imaging. Published online November 17, 2021. doi:10.1016/j.jcmg.2021.09.023