title: Increased tissue plasminogen activator levels in patients with nonvalvular atrial fibrillation.
abstract: OBJECTIVE
  To determine whether plasma tissue plasminogen activator (tPA) levels (a) are higher in patients with novalvular atrial fibrillation (NVAF) than in control subjects in sinus rhythm; (b) differ between NVAF patients with and without a history of an embolic event (transient ischemic attack or embolic stroke); and (c) differ in control subjects with and without a history of thrombotic stroke.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Internal medicine outpatient group practice and anticoagulation clinic in 2 teaching hospitals.
  
  
  METHODS
  Seventy-four NVAF patients (24 with and 50 without a history of an embolic event), separated into 3 groups: no prior embolic event and no warfarin use (group 1), no prior embolic event and warfarin use (group 2), and prior embolic event and warfarin use (group 3). Forty control subjects in sinus rhythm (29 without and 11 with prior thrombotic stroke).
  
  
  METHODS
  Plasma tPA levels.
  
  
  RESULTS
  The age-adjusted mean tPA levels exceeded the upper limit of normal in all 3 NVAF groups but not in the control groups. The NVAF patients had significantly higher mean tPA levels than the control subjects (p = 0.015). The levels did not differ significantly between the NVAF patients with a history of an embolic event and those without such a history. The control subjects with a history of thrombotic stroke had significantly higher mean tPA levels than the other control subjects (p = 0.03).
  
  
  CONCLUSIONS
  NVAF patients, regardless of their history of embolic events, and control patients with a history of thrombotic stroke have higher tPA levels than subjects in sinus rhythm without a history of stroke. A prospective, longitudinal study involving NVAF patients is required to determine whether high baseline tPA levels are associated with, and perhaps causally related to, an increased risk of stroke.
authors.affiliation: Division of General Internal Medicine, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Que. susank@epid.jgh.mcgill.ca
authors.forename: S R
authors.initials: SR
authors.lastname: Kahn
authors.forename: S
authors.initials: S
authors.lastname: Solymoss
authors.forename: K M
authors.initials: KM
authors.lastname: Flegel
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000150:complications; D002546:Ischemic Attack, Transient / Q000150:complications; D008297:Male; D010959:Tissue Plasminogen Activator / Q000097:blood*; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D010959:Tissue Plasminogen Activator