Systolic Flow Displacement Correlates With Future Ascending Aortic Growth in Patients With Bicuspid Aortic Valves Undergoing Magnetic Resonance Surveillance

Abstract

Systolic flow displacement calculated from conventional 2D PC-MRI in the ascending aorta correlates with future aortic growth in patients undergoing routine surveillance imaging for BAV. With a cutoff valve of 0.2, flow displacement may be used to identify a subset of patients likely to have elevated growth rates and may better risk-stratify patients with BAV for aortic disease progression than vessel diameter alone.

Transcatheter aortic valve replacement alters ascending aortic blood flow and wall shear stress patterns: A 4D flow MRI comparison with age-matched, elderly controls

“…TAVR resulted in eccentric and displaced flow in the mid-and distal-ascending aorta, whereas blood flow displacement and eccentricity in the SAVR predominantly occurs in the distal-ascending aorta. In a study comprising patients with BAV disease, the degree of flow displacement correlated with the aortic growth rate in these patients, proposing flow displacement as a potential risk factor for aortic dilatation [9]. Recently, Trauzeddel et al have shown that both TAVR and stented SAVR result in altered blood flow across the newly implanted valve when compared with much younger, healthy controls.…”

“…A recent histological study has shown that abnormal WSS results in increased deregulation of the aortic extracellular matrix and degeneration of elastic fibres, which may result in progressive aortic dilatation [8]. Furthermore, in a study among bicuspid aortic valve disease patients, flow eccentricity has been correlated to progressive ascending aortic dilatation [9,10]. Previous studies have reported alterations in aortic WSS distribution and flow eccentricity after both TAVR and SAVR [11].…”

“…2D peak systolic planes were placed at the sinotubular junction, in the mid-ascending aorta and in the distal-ascending aorta and flow displacement was calculated [9]. Blood flow displacement was defined as the distance between the centre of the lumen and the 'center of velocity' of the flow, normalised to the lumen diameter [9].…”

“…2D peak systolic planes were placed at the sinotubular junction, in the mid-ascending aorta and in the distal-ascending aorta and flow displacement was calculated [9]. Blood flow displacement was defined as the distance between the centre of the lumen and the 'center of velocity' of the flow, normalised to the lumen diameter [9]. Blood flow eccentricity was graded semi-quantitatively by two blinded observers as previously described; central flow (high velocity flow in the majority of the vessel), mildly eccentric (high velocity flow in one-to two-thirds of the vessel lumen) and severely eccentric (one-third or less of the vessel) blood flow ( Fig.…”

Evolving treatment options for valve and aortic disease with bicuspid aortic valve

“…Furthermore, when comparing SAVR and TAVR techniques, the degree of helical and vertical flow in the ascending aorta is less with TAVR, despite both prostheses being constructed around a stented frame. The underlying cause of these differences remains unclear, but considering that eccentric flow has been proposed as a driver of ascending aortic growth, these findings suggest that TAVR may reduce rates of progressive BAV aortopathy via reduced flow abnormality (19). If future studies demonstrate long-term valve durability and function to be equal between SAVR and TAVR, the technique that minimizes abnormal blood flow in the ascending aorta may be best suited for a younger BAV population that is subject to high rates of ascending aortic disease.…”