title: Can we predict new AF occurrence in single-chamber ICD patients? Insights from an observational investigation.
abstract: BACKGROUND
  Atrial tachyarrhythmias (AT/AF) have been associated with an increased risk of mortality, morbidity and ischemic stroke. Up to now, single chamber ICD diagnostics was not able to detect AT/AF, therefore the incidence of new onset AT/AF in patients with single chamber ICD is not known.
  
  
  OBJECTIVE
  To evaluate incidence and predictors of AT/AF occurrence in patients with dual-chamber ICD with no pacing indications and no history of AT/AF that strictly mimic single chamber ICD recipient.
  
  
  RESULTS
  Consecutive dual-chamber ICD patients were prospectively followed by 47 Italian cardiologic centers in an observational research. Clinical and device data were reviewed by expert cardiologists to assess AT/AF occurrence. Multivariate regression analysis evaluated the risk of new-onset AT/AF and its association with patients' baseline characteristics and with CHADS2score. 428 (13.4% female, 64years old) patients were followed for a median observation period of 31months. AT/AF episodes occurred in 160 (37.4%) patients when considering at least 5min duration, in 95 (22.2%) for AT/AF ≥6h, in 47 (11.0%) for AT/AF ≥1day, in 29 (6.8%) for AT/AF ≥7days. Patients with CHADS2≥2, who comprised 36% of the whole population, showed higher incidence of AT/AF ≥6h compared with patients with CHADS2<2 (Hazard Ratio=1.69, 95% Confidence Interval=1.13-2.53, p=0.011).
  
  
  CONCLUSIONS
  Our observations in a population of dual-chamber ICD patients with no pacing indications and no history of AT/AF, who strictly mimic single-chamber ICD recipients, highlight that AT/AF episodes occurred in the 37.5% of the population and CHADS2score is predictive of new-onset AT/AF.
authors.affiliation: Policlinico S. Orsola - Malpighi, Bologna, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.affiliation: Policlinico S. Orsola - Malpighi, Bologna, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Ziacchi
authors.affiliation: San Filippo Neri Hospital, Roma, Italy.
authors.forename: Renato Pietro
authors.initials: RP
authors.lastname: Ricci
authors.affiliation: Azienda Ospedaliero-Universitaria Santa Maria della Misericordia, Udine, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Facchin
authors.affiliation: Ospedale Borgo Trento, Verona, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Morani
authors.affiliation: Ospedale Maggiore di Crema, Crema, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Landolina
authors.affiliation: Ospedale Niguarda Ca' Grande, Milano, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Lunati
authors.affiliation: Gruppo Villa Maria, Cotignola, Italy.
authors.forename: Saverio
authors.initials: S
authors.lastname: Iacopino
authors.affiliation: Ospedali Riuniti di Ancona, Ancona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Capucci
authors.affiliation: Fatebenefratelli Hospital Roma, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bianchi
authors.affiliation: Villa Sant'Anna, Catanzaro, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Infusino
authors.affiliation: Ospedale S. Anna, Como, Italy.
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Botto
authors.affiliation: University of Florence, Italy; IRCCS Multimedica, Milano, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
authors.affiliation: Policlinico di Modena, Modena, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000628:therapy*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D013997:Time Factors
keywords: Atrial fibrillation; Atrial fibrillation diagnosis, single chamber defibrillator; CHADS(2) score