title: Temporal relationship between subclinical atrial fibrillation and embolic events.
abstract: BACKGROUND
  Among patients with implantable pacemakers and defibrillators, subclinical atrial fibrillation (SCAF) is associated with an increased risk of stroke; however, there is limited understanding of their temporal relationship.
  
  
  RESULTS
  The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT) enrolled 2580 pacemaker and defibrillator patients aged ≥65 years with a history of hypertension but without a history of atrial fibrillation. Pacemakers and implantable cardioverter-defibrillators precisely logged the time and duration of all episodes of SCAF and recorded electrograms that were adjudicated by experts. We examined the temporal relationship between SCAF >6 minutes in duration and stroke or systemic embolism. Of 51 patients who experienced stroke or systemic embolism during follow-up, 26 (51%) had SCAF. In 18 patients (35%), SCAF was detected before stroke or systemic embolism. However, only 4 patients (8%) had SCAF detected within 30 days before stroke or systemic embolism, and only 1 of these 4 patients was experiencing SCAF at the time of the stroke. In the 14 patients with SCAF detected >30 days before stroke or systemic embolism, the most recent episode occurred at a median interval of 339 days (25th to 75th percentile, 211-619) earlier. Eight patients (16%) had SCAF detected only after their stroke, despite continuous monitoring for a median duration of 228 days (25th to 75th percentile, 202-719) before their event.
  
  
  CONCLUSIONS
  Although SCAF is associated with an increased risk of stroke and embolism, very few patients had SCAF in the month before their event.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov. Unique identifier: NCT00256152.
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Michela
authors.initials: M
authors.lastname: Brambatti
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Connolly
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Michael R
authors.initials: MR
authors.lastname: Gold
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Morillo
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Alessandro
authors.initials: A
authors.lastname: Capucci
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Carmine
authors.initials: C
authors.lastname: Muto
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Chu P
authors.initials: CP
authors.lastname: Lau
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Isabelle C
authors.initials: IC
authors.lastname: Van Gelder
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Hohnloser
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Mark
authors.initials: M
authors.lastname: Carlson
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Eric
authors.initials: E
authors.lastname: Fain
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Juliet
authors.initials: J
authors.lastname: Nakamya
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Georges H
authors.initials: GH
authors.lastname: Mairesse
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Marta
authors.initials: M
authors.lastname: Halytska
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Wei Q
authors.initials: WQ
authors.lastname: Deng
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
authors.forename: Carsten W
authors.initials: CW
authors.lastname: Israel
authors.affiliation: From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.). Jeff.Healey@phri.ca.
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Healey
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D004617:Embolism / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000639:trends; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D013997:Time Factors
keywords: arrhythmia; pacemaker; stroke