Longitudinal Evaluation of Aortic Hemodynamics in Marfan Syndrome: New Insights from a 4D Flow Cardiovascular Magnetic Resonance Multi-Year Follow-Up Study.
BACKGROUND
The aim of this 4D flow cardiovascular magnetic resonance (CMR) follow-up study was to investigate longitudinal changes in aortic hemodynamics in adolescent patients with Marfan syndrome (MFS).


METHODS
4D flow CMR for the assessment of in-vivo 3D blood flow with full coverage of the thoracic aorta was performed twice (baseline scan t1/follow-up scan t2) in 19 adolescent MFS patients (age at t1: 12.7 ± 3.6 years, t2: 16.2 ± 4.3 years) with a mean follow-up duration of 3.5 ± 1.2 years. Ten healthy volunteers (24 ± 3.8 years) served as a control group. Data analysis included aortic blood flow visualization by color-coded 3D pathlines, and grading of flow patterns (helices/vortices) on a 3-point scale (none, moderate, severe; blinded reading, 2 observers). Regional aortic peak systolic velocities and systolic 3D wall shear stress (WSS) along the entire aortic wall were quantified. Z-Scores of the aortic root and proximal descending aorta (DAo) were assessed.


RESULTS
Regional systolic WSS was stable over the follow-up duration, except for a significant decrease in the proximal inner DAo segment (p = 0.02) between t1 and t2. MFS patients revealed significant lower mean systolic WSS in the proximal inner DAo compared with volunteers (0.78 ± 0.15 N/m2) at baseline t1 (0.60 ± 0.18 N/m2; p = 0.01) and follow-up t2 (0.55 ± 0.16 N/m2; p = 0.001). There were significant relationships (p < 0.01) between the segmental WSS in the proximal inner DAo, DAo Z-scores (r = -0.64) and helix/vortex pattern grading (r = -0.55) at both t1 and t2. The interobserver agreement for secondary flow patterns assessment was excellent (Cohen's k = 0.71).


CONCLUSIONS
MFS patients have lower segmental WSS in the inner proximal DAo segment which correlates with increased localized aberrant vortex/helix flow patterns and an enlarged diameter at one of the most critical sites for aortic dissection. General aortic hemodynamics are stable but these subtle localized DAo changes are already present at young age and tend to be more pronounced in the course of time.
Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA. Geiger_J4@ukw.de.|Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany. Geiger_J4@ukw.de.
Julia
http://orcid.org/0000-0003-3621-9955
J
Geiger
Department of Congenital Heart Disease and Pediatric Cardiology, University Heart Center Freiburg, Freiburg, Germany.
Daniel
D
Hirtler
Department of Congenital Heart Disease and Pediatric Cardiology, University Heart Center Freiburg, Freiburg, Germany.|Department of Anesthesiology, University Hospital Mainz, Mainz, Germany.
Kristina
K
Gottfried
Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Ozair
O
Rahman
Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Emilie
E
Bollache
Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Alex J
AJ
Barker
Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.|Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA.
Michael
M
Markl
Department of Congenital Heart Disease and Pediatric Cardiology, University Heart Center Freiburg, Freiburg, Germany.
Brigitte
B
Stiller
D000293:Adolescent; D000367:Age Factors; D001011:Aorta / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D001783:Blood Flow Velocity; D055424:Cardiac-Gated Imaging Techniques; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008382:Marfan Syndrome / Q000150:complications* / Q000175:diagnosis; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012039:Regional Blood Flow; D055425:Respiratory-Gated Imaging Techniques; D013997:Time Factors; D055815:Young Adult
4D flow cardiovascular magnetic resonance; Aorta; Follow-up; Hemodynamics; Marfan syndrome; Wall shear stress