title: Stroke event rates in anticoagulated patients with paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  To test the hypothesis that stroke and systemic embolic events (SEE) in the stroke prevention using an oral thrombin inhibitor in atrial fibrillation (SPORTIF) III and V trials are different between paroxysmal and persistent atrial fibrillation (AF).
  
  
  METHODS
  Data analysis from two cohorts of patients enrolled in the prospective SPORTIF III and V clinical trials (n = 7329); 836 subjects (11.4%) with paroxysmal AF [mean age 70.1 years (SD = 9.5)] were compared with 6493 subjects with persistent AF for this ancillary study.
  
  
  RESULTS
  The annual event rates for stroke/SEE are 1.73% for persistent AF and 0.93% for paroxysmal AF. In a multivariate analysis, after adjusting for stroke risk factors, gender and aspirin usage, the differences remained statistically significant with a higher hazard ratio (HR) for stroke/SEE in persistent AF [vs. paroxysmal AF, HR 1.87, 95% confidence interval (CI) 1.04-3.36; P = 0.037]. In 'high risk' patients (with >or=2 stroke risk factors) annual event rates for stroke/SEE were 2.08% for persistent AF and 1.27% for paroxysmal AF (adjusted HR = 1.68, 95% CI 0.91-3.1, P = 0.098). Elderly patients had annual event rates for stroke/SEE of 2.38% for persistent AF and 1.13% for paroxysmal AF (adjusted HR = 2.27, 95% CI 0.92-5.59, P = 0.075). Vitamin K antagonist (VKA)-naive paroxysmal AF patients had a 1.89%/year stroke/SEE rate, compared with 0.61% for previous VKA takers (HR = 0.33, 95% CI 0.11-1.01, P = 0.052).
  
  
  CONCLUSIONS
  In this large clinical trial cohort of anticoagulated AF patients, those with paroxysmal AF had stroke rates which were lower than for patients with persistent AF, although both groups had broadly similar stroke risk factors. Subjects with paroxysmal AF at 'high risk' had stroke/SEE rates that were not significantly different to persistent AF subjects.
authors.affiliation: University Department of Medicine, City Hospital, Birmingham, B18 7QH, United Kingdom. g.y.h.lip@bham.ac.uk
authors.forename: G Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: L
authors.initials: L
authors.lastname: Frison
authors.forename: M
authors.initials: M
authors.lastname: Grind
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology*; D001384:Azetidines / Q000627:therapeutic use; D001596:Benzylamines / Q000627:therapeutic use; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D001384:Azetidines; D001596:Benzylamines; C426686:ximelagatran; D014859:Warfarin