title: Atrial fibrillation in patients with cryptogenic stroke.
abstract: BACKGROUND
  Atrial fibrillation is a leading preventable cause of recurrent stroke for which early detection and treatment are critical. However, paroxysmal atrial fibrillation is often asymptomatic and likely to go undetected and untreated in the routine care of patients with ischemic stroke or transient ischemic attack (TIA).
  
  
  METHODS
  We randomly assigned 572 patients 55 years of age or older, without known atrial fibrillation, who had had a cryptogenic ischemic stroke or TIA within the previous 6 months (cause undetermined after standard tests, including 24-hour electrocardiography [ECG]), to undergo additional noninvasive ambulatory ECG monitoring with either a 30-day event-triggered recorder (intervention group) or a conventional 24-hour monitor (control group). The primary outcome was newly detected atrial fibrillation lasting 30 seconds or longer within 90 days after randomization. Secondary outcomes included episodes of atrial fibrillation lasting 2.5 minutes or longer and anticoagulation status at 90 days.
  
  
  RESULTS
  Atrial fibrillation lasting 30 seconds or longer was detected in 45 of 280 patients (16.1%) in the intervention group, as compared with 9 of 277 (3.2%) in the control group (absolute difference, 12.9 percentage points; 95% confidence interval [CI], 8.0 to 17.6; P<0.001; number needed to screen, 8). Atrial fibrillation lasting 2.5 minutes or longer was present in 28 of 284 patients (9.9%) in the intervention group, as compared with 7 of 277 (2.5%) in the control group (absolute difference, 7.4 percentage points; 95% CI, 3.4 to 11.3; P<0.001). By 90 days, oral anticoagulant therapy had been prescribed for more patients in the intervention group than in the control group (52 of 280 patients [18.6%] vs. 31 of 279 [11.1%]; absolute difference, 7.5 percentage points; 95% CI, 1.6 to 13.3; P=0.01).
  
  
  CONCLUSIONS
  Among patients with a recent cryptogenic stroke or TIA who were 55 years of age or older, paroxysmal atrial fibrillation was common. Noninvasive ambulatory ECG monitoring for a target of 30 days significantly improved the detection of atrial fibrillation by a factor of more than five and nearly doubled the rate of anticoagulant treatment, as compared with the standard practice of short-duration ECG monitoring. (Funded by the Canadian Stroke Network and others; EMBRACE ClinicalTrials.gov number, NCT00846924.).
authors: From the Division of Neurology (D.J.G.), Department of Medicine (D.J.G., P.D., A.L., M.S., J.A.B., L.K.C., D.S., M. Mehdiratta, K.B., M.K.K.), and Dalla Lana School of Public Health (K.E.T.), University of Toronto, the University of Toronto Stroke Program (D.J.G.), Division of Neurology, Department of Medicine, and Brain Sciences Program, Sunnybrook Health Sciences Centre and Sunnybrook Research Institute (D.J.G., R.A.), the Heart and Stroke Foundation Canadian Partnership for Stroke Recovery (D.J.G.), and the Applied Health Research Centre, Li Ka Shing Knowledge Institute of St. Michael's Hospital (V.P., K.E.T., J.H., H.V., A.L., M. Mamdani), Toronto, McMaster University, Hamilton, ON (M.S., D.J.S.), McGill University, Montreal (R.C.), University of Alberta, Edmonton (A.S., B.B.), Western University, London, ON (V.H., J.D.S.), Department of Clinical Neurosciences and Radiology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB (S.B.C.), University of British Columbia, Vancouver (P.T., S.Y.), Queen's University, Kingston, ON (A.J.), Thunder Bay Regional Health Sciences Centre, Thunder Bay, ON (D.H.), Université Laval, Quebec City (S.V.), and Vancouver Island Health Research Centre, Victoria, BC (A.P.) - all in Canada; and the National University of Ireland, Galway (M.O.).
authors: David J
authors: DJ
authors: Gladstone
authors: Melanie
authors: M
authors: Spring
authors: Paul
authors: P
authors: Dorian
authors: Val
authors: V
authors: Panzov
authors: Kevin E
authors: KE
authors: Thorpe
authors: Judith
authors: J
authors: Hall
authors: Haris
authors: H
authors: Vaid
authors: Martin
authors: M
authors: O'Donnell
authors: Andreas
authors: A
authors: Laupacis
authors: Robert
authors: R
authors: Côté
authors: Mukul
authors: M
authors: Sharma
authors: John A
authors: JA
authors: Blakely
authors: Ashfaq
authors: A
authors: Shuaib
authors: Vladimir
authors: V
authors: Hachinski
authors: Shelagh B
authors: SB
authors: Coutts
authors: Demetrios J
authors: DJ
authors: Sahlas
authors: Phil
authors: P
authors: Teal
authors: Samuel
authors: S
authors: Yip
authors: J David
authors: JD
authors: Spence
authors: Brian
authors: B
authors: Buck
authors: Steve
authors: S
authors: Verreault
authors: Leanne K
authors: LK
authors: Casaubon
authors: Andrew
authors: A
authors: Penn
authors: Daniel
authors: D
authors: Selchen
authors: Albert
authors: A
authors: Jin
authors: David
authors: D
authors: Howse
authors: Manu
authors: M
authors: Mehdiratta
authors: Karl
authors: K
authors: Boyle
authors: Richard
authors: R
authors: Aviv
authors: Moira K
authors: MK
authors: Kapral
authors: Muhammad
authors: M
authors: Mamdani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D012307:Risk Factors; D020521:Stroke / Q000188:drug therapy / Q000209:etiology*
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors