title: Clot Formation in the Presence of Acetylsalicylic Acid Leads to Increased Lysis Rates Regardless of the Chosen Thrombolysis Strategy.
abstract: BACKGROUND
  Patients with acute ischemic strokes frequently take an acetylsalicylic acid (ASA) premedication. We determined the impact of ASA on different thrombolysis strategies in vitro.
  
  
  METHODS
  For two clot types made from platelet-rich plasma (one with and one without ASA) lysis rates were measured by weight loss after 1 h for five different groups: in control group A clots were solely placed in plasma; in groups B and C clots were treated with rt-PA (60 kU/ml), and in groups D and E clots were treated with desmoteplase (DSPA; 2 µg/ml). Ultrasound (2 MHz, 0.179 W/cm2) was included in groups C and E. The fibrin mesh structures of the clots were investigated by electron microscopy.
  
  
  RESULTS
  For both clot types lysis rates increased significantly for all treatment strategies compared to their control group (each p < 0.001). The addition of ASA significantly increased the lysis rate in all 5 groups (each p < 0.001) and led to a ceiling effect concerning the treatment. A semiquantitative analysis of transmission electron micrographs revealed a decreased fibrin density for clots with ASA. For both clot types DSPA and ultrasound led to a significant dissolution of the fibrin mesh (both p = 0.029).
  
  
  CONCLUSIONS
  In vitro ASA pretreatment leads to significantly increased lysis rates due to a weaker fibrin mesh in platelet-rich plasma clots.
authors.affiliation: Department of Neurology, Justus Liebig University Giessen, Giessen, Germany.
authors.forename: Florian C
authors.initials: FC
authors.lastname: Roessler
authors.forename: Sabrina
authors.initials: S
authors.lastname: Schumacher
authors.forename: Andreas
authors.initials: A
authors.lastname: Sprenger
authors.forename: Ulrich
authors.initials: U
authors.lastname: Gärtner
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Khaled
authors.forename: Jürgen
authors.initials: J
authors.lastname: Eggers
mesh_terms: D001241:Aspirin / Q000494:pharmacology*; D005337:Fibrin / Q000378:metabolism* / Q000648:ultrastructure; D005342:Fibrinolysis / Q000187:drug effects*; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D010960:Plasminogen Activators / Q000494:pharmacology*; D015912:Thrombolytic Therapy / Q000379:methods*; D014464:Ultrasonic Therapy
chemical_list: D005343:Fibrinolytic Agents; C069588:salivary plasminogen activator alpha 1, Desmodus rotundus; D005337:Fibrin; D010960:Plasminogen Activators; D001241:Aspirin