Dilation-dependent activation of platelets and prothrombin in human thoracic ascending aortic aneurysm.
OBJECTIVE
The purpose of this study was to investigate whether thoracic ascending aortic aneurysm (TAAA) induces platelet activation as mural thrombus participates in aortic dilatation in abdominal aortic aneurysm and TAAA are associated with rheological factors favoring coagulation activation.


RESULTS
We studied the relation between coagulation activation and aortic diameter in Marfan patients (MFS) with various aortic diameters (n=52). We then studied patients presenting large aneurysms associated with bicuspid aortic valve (BAV) and degenerative form. Lastly, we used immunochemistry and biochemistry to investigate prothrombin/thrombin retention within the aortic wall. Microparticles, sGPV, tissue factor, and TAT complexes were increased in plasma from MFS with large aneurysms (>or=45 mm) compared to MFS with limited aortic dilatation (<45 mm). Similar elevations were observed in all patients with large aortic aneurysms, regardless of the etiology, the site of maximal aortic dilation, associated valvulopathy, risk factors, or treatments. P-selectin and platelet-bound fibrinogen were also increased, demonstrating platelet activation in large aneurysms. Significant increase in sCD146 plasma concentration suggested alteration of endothelium.


CONCLUSIONS
Platelet activation occurs in patients with large aneurysms of the ascending aorta, is dependent on aortic dilation, and is associated with thrombin generation, part of which appears to be retained in mucoid degeneration areas.
Touat
Ziad
Z
INSERM, U698, University Paris 7, Paris, France.
Lepage
Laurent
L
Ollivier
Véronique
V
Nataf
Patrick
P
Hvass
Ulrich
U
Labreuche
Julien
J
Jandrot-Perrus
Martine
M
Michel
Jean-Baptiste
JB
Jondeau
Guillaume
G
D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000473:pathology*; D017545:Aortic Aneurysm, Thoracic / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000378:metabolism; D051929:CD146 Antigen / Q000378:metabolism; D023201:CD40 Ligand / Q000378:metabolism; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D008297:Male; D008382:Marfan Syndrome / Q000150:complications / Q000378:metabolism / Q000503:physiopathology; D008875:Middle Aged; D019007:P-Selectin / Q000378:metabolism; D015539:Platelet Activation / Q000502:physiology*; D011516:Prothrombin / Q000378:metabolism*; D013917:Thrombin / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D014664:Vasodilation / Q000502:physiology*
D051929:CD146 Antigen; D019007:P-Selectin; D019010:Vascular Cell Adhesion Molecule-1; D023201:CD40 Ligand; D011516:Prothrombin; D005340:Fibrinogen; D002097:C-Reactive Protein; D013917:Thrombin