title: Impact of Dabigatran versus Phenprocoumon on ADP Induced Platelet Aggregation in Patients with Atrial Fibrillation with or without Concomitant Clopidogrel Therapy (the Dabi-ADP-1 and Dabi-ADP-2 Trials).
abstract: BACKGROUND
  A relevant number of patients receive triple therapy with clopidogrel, aspirin, and oral anticoagulation. Clopidogrel's efficacy on ADP induced platelet function may be influenced by concomitant antithrombotic therapies. Data regarding the effect of dabigatran on platelet function is limited to in vitro studies and healthy individuals.
  
  
  METHODS
  The "Dabi-ADP-1" and "Dabi-ADP-2" trials randomized patients with atrial fibrillation to either dabigatran or phenprocoumon for a 2-week period. In Dabi-ADP-1 (n = 70) patients with clopidogrel therapy were excluded and in Dabi-ADP-2 (n = 46) patients had to be treated concomitantly with clopidogrel. The primary endpoint was ADP-induced platelet aggregation between dabigatran and phenprocoumon at 14 days. Secondary endpoints were ADPtest HS-, TRAP-, and COL-induced platelet aggregation.
  
  
  RESULTS
  There was no significant difference regarding the primary endpoint between both groups in either trial (Dabi-ADP-1: Dabigatran: 846 [650-983] AU × min versus phenprocoumon: 839 [666-1039] AU × min, P = 0.90 and Dabi-ADP-2: 326 [268-462] versus 350 [214-535], P = 0.70) or regarding the secondary endpoints, ADPtest HS-, TRAP-, and COL-induced platelet aggregation.
  
  
  CONCLUSIONS
  Dabigatran as compared to phenprocoumon has no impact on ADP-induced platelet aggregation in atrial fibrillation patients neither with nor without concomitant clopidogrel therapy.
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München, 80636 Munich, Germany.
authors.forename: Amadea M
authors.initials: AM
authors.lastname: Martischnig
authors.affiliation: Ludwig-Maximilians-Universität München, 80337 Munich, Germany ; German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, 80802 Munich, Germany.
authors.forename: Julinda
authors.initials: J
authors.lastname: Mehilli
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München, 80636 Munich, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Pollak
authors.affiliation: Ludwig-Maximilians-Universität München, 80337 Munich, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Petzold
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München, 80636 Munich, Germany.
authors.forename: Anette K
authors.initials: AK
authors.lastname: Fiedler
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München, 80636 Munich, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Mayer
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München, 80636 Munich, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schulz-Schüpke
authors.affiliation: Ludwig-Maximilians-Universität München, 80337 Munich, Germany ; German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, 80802 Munich, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Sibbing
authors.affiliation: Ludwig-Maximilians-Universität München, 80337 Munich, Germany ; German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, 80802 Munich, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Massberg
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München, 80636 Munich, Germany ; German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, 80802 Munich, Germany.
authors.forename: Adnan
authors.initials: A
authors.lastname: Kastrati
authors.affiliation: Ludwig-Maximilians-Universität München, 80337 Munich, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Sarafoff
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000097:blood / Q000188:drug therapy; D000077144:Clopidogrel; D000069604:Dabigatran / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010644:Phenprocoumon / Q000008:administration & dosage*; D010974:Platelet Aggregation / Q000187:drug effects*; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D000244:Adenosine Diphosphate; D000077144:Clopidogrel; D000069604:Dabigatran; D013988:Ticlopidine; D010644:Phenprocoumon