title: Clot architecture is altered in abdominal aortic aneurysms and correlates with aneurysm size.
abstract: OBJECTIVE
  Abdominal aortic aneurysm (AAA) is characterized by widening of the aorta. Once the aneurysm exceeds 5.5 cm, there is a 10% risk of death due to rupture. AAA is also associated with mortality due to other cardiovascular disease. Our aim was to investigate clot structure in AAA and its relationship to aneurysm size.
  
  
  RESULTS
  Plasma was obtained from 49 controls, 40 patients with small AAA, and 42 patients with large AAA. Clot formation was studied by turbidity, fibrin pore structure by permeation, and time to half lysis by turbidity with tissue plasminogen activator. Plasma clot pore size showed a stepwise reduction from controls to small to large AAA. Lag phase for plasma clot formation and time to half lysis were prolonged, with smaller AAA samples showing intermediate response. Clot structure was normal in clots made with fibrinogen purified from patients compared with controls, suggesting a role for other plasma factors. Endogenous thrombin potential and turbidity using tissue factor indicated that the effects were independent of changes in thrombin generation.
  
  
  CONCLUSIONS
  Patients with AAA form denser, smaller pored plasma clots that are more resistant to fibrinolysis, and these characteristics correlate with aneurysm size. Clot structure may play a role in AAA development and concomitant cardiovascular disease.
authors.affiliation: Division of Cardiovascular and Diabetes Research, Section on Mechanisms of Thrombosis, Leeds Institute for Genetics, Health and Therapeutics, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: D Julian A
authors.initials: DJ
authors.lastname: Scott
authors.forename: Priya
authors.initials: P
authors.lastname: Prasad
authors.forename: Helen
authors.initials: H
authors.lastname: Philippou
authors.forename: Sheikh Tawqeer
authors.initials: ST
authors.lastname: Rashid
authors.forename: Soroush
authors.initials: S
authors.lastname: Sohrabi
authors.forename: Daniel
authors.initials: D
authors.lastname: Whalley
authors.forename: Andy
authors.initials: A
authors.lastname: Kordowicz
authors.forename: Quen
authors.initials: Q
authors.lastname: Tang
authors.forename: Robert M
authors.initials: RM
authors.lastname: West
authors.forename: Anne
authors.initials: A
authors.lastname: Johnson
authors.forename: Janet
authors.initials: J
authors.lastname: Woods
authors.forename: Ramzi A
authors.initials: RA
authors.lastname: Ajjan
authors.forename: Robert A S
authors.initials: RA
authors.lastname: Ariëns
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D016022:Case-Control Studies; D005337:Fibrin / Q000378:metabolism; D005342:Fibrinolysis; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D013917:Thrombin / Q000378:metabolism; D013927:Thrombosis / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*
chemical_list: D005337:Fibrin; D013917:Thrombin