title: Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices.
abstract: OBJECTIVE
  Atrial tachyarrhythmias (ATs) detected by implanted devices are often atrial fibrillation or flutter (AF) associated with stroke. We hypothesized that introduction and termination of anticoagulation based upon AT monitoring would reduce both stroke and bleeding.
  
  
  RESULTS
  We randomized 2718 patients with dual-chamber and biventricular defibrillators to start and stop anticoagulation based on remote rhythm monitoring vs. usual office-based follow-up with anticoagulation determined by standard clinical criteria. The primary analysis compared the composite endpoint of stroke, systemic embolism, and major bleeding with the two strategies. The trial was stopped after 2 years median follow-up based on futility of finding a difference in primary endpoints between groups. A total of 945 patients (34.8%) developed AT, 264 meeting study anticoagulation criteria. Adjudicated atrial electrograms confirmed AF in 91%; median time to initiate anticoagulation was 3 vs. 54 days in the intervention and control groups, respectively (P < 0.001). Primary events (2.4 vs. 2.3 per 100 patient-years) did not differ between groups (HR 1.06; 95% CI 0.75-1.51; P = 0.732). Major bleeding occurred at 1.6 vs. 1.2 per 100 patient-years (HR 1.39; 95% CI 0.89-2.17; P = 0.145). In patients with AT, thromboembolism rates were 1.0 vs. 1.6 per 100 patient-years (relative risk -35.3%; 95% CI -70.8 to 35.3%; P = 0.251). Although AT burden was associated with thromboembolism, there was no temporal relationship between AT and stroke.
  
  
  CONCLUSIONS
  In patients with implanted defibrillators, the strategy of early initiation and interruption of anticoagulation based on remotely detected AT did not prevent thromboembolism and bleeding.
  
  
  BACKGROUND
  IMPACT ClinicalTrials.gov identifier: NCT00559988 ( http://clinicaltrials.gov/ct2/show/NCT00559988?term=NCT00559988&rank=1 ).
authors.affiliation: Lahey Hospital and Medical Center, Burlington, MA, USA.
authors.forename: David T
authors.initials: DT
authors.lastname: Martin
authors.affiliation: Veterans Administration and University of California Los Angeles School of Medicine, Los Angeles, CA, USA.
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: Bersohn
authors.affiliation: Case Western Reserve University School of Medicine, Cleveland, OH, USA.
authors.forename: Albert L
authors.initials: AL
authors.lastname: Waldo
authors.affiliation: Tennessee Heart, Cookeville, TN, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Wathen
authors.affiliation: Endovascular Heart Institute, San Antonio, TX, USA.
authors.forename: Wassim K
authors.initials: WK
authors.lastname: Choucair
authors.affiliation: University of Birmingham Centre for Cardiovascular Sciences, City Hospital, UK.
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
authors.affiliation: Sparrow Research Foundation, Lansing, MI, USA.
authors.forename: John
authors.initials: J
authors.lastname: Ip
authors.affiliation: Minneapolis, MN, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Holcomb
authors.affiliation: Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Akar
authors.affiliation: Icahn School of Medicine at Mount Sinai, New York, NY, USA jonathan.halperin@mssm.edu.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Halperin
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000628:therapy*; D058409:Cardiac Resynchronization Therapy Devices; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods; D016037:Single-Blind Method; D020521:Stroke / Q000517:prevention & control; D017216:Telemedicine / Q000379:methods; D013923:Thromboembolism / Q000517:prevention & control; D016896:Treatment Outcome; D059015:Wireless Technology
chemical_list: D000925:Anticoagulants
keywords: Arrhythmia monitoring; Atrial fibrillation; Oral anticoagulation; Randomized controlled clinical trial; Stroke prevention