title: Chronic performance of a leadless cardiac pacemaker: 1-year follow-up of the LEADLESS trial.
abstract: BACKGROUND
  A leadless cardiac pacemaker (LCP) system was recently introduced to overcome lead-related complications of conventional pacing systems. To date, long-term results of an LCP system are unknown.
  
  
  OBJECTIVE
  The aim of this study was to assess the complication incidence, electrical performance, and rate response characteristics within the first year of follow-up of patients implanted with an LCP.
  
  
  METHODS
  We retrospectively assessed intermediate-term follow-up data for 31 of 33 patients from the LEADLESS trial cohort who had an indication for single-chamber pacing and received an LCP between December 2012 and April 2013.
  
  
  RESULTS
  The mean age of the cohort was 76 ± 8 years, and 65% were male. Between 3 and 12 months of follow-up, there were no pacemaker-related adverse events reported. The pacing performance results at 6- and 12-month follow-up were, respectively, as follows: mean pacing threshold (at a 0.4-ms pulse width), 0.40 ± 0.26 V and 0.43 ± 0.30 V; R-wave amplitude 10.6 ± 2.6 mV and 10.3 ± 2.2 mV; and impedance 625 ± 205 Ω and 627 ± 209 Ω. At the 12-month follow-up in 61% of the patients (n = 19 of 31), the rate response sensor was activated, and an adequate rate response was observed in all patients.
  
  
  CONCLUSIONS
  The LCP demonstrates very stable performance and reassuring safety results during intermediate-term follow-up. These results support the use of the LCP as a promising alternative to conventional pacemaker systems. Continued evaluation is warranted to further characterize this system. (Evaluation of a New Cardiac Pacemaker; NCT01700244).
authors.affiliation: AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. Electronic address: r.e.knops@amc.uva.nl.
authors.forename: Reinoud E
authors.initials: RE
authors.lastname: Knops
authors.affiliation: AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Fleur V Y
authors.initials: FV
authors.lastname: Tjong
authors.affiliation: Cardiology Department, Homolka Hospital, Prague, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Neuzil
authors.affiliation: Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Sperzel
authors.affiliation: Helmsley Electrophysiology Center, Mount Sinai School of Medicine, New York, New York.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Miller
authors.affiliation: Cardiology Department, Homolka Hospital, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Petru
authors.affiliation: Cardiology Department, Homolka Hospital, Prague, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Simon
authors.affiliation: Cardiology Department, Homolka Hospital, Prague, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Sediva
authors.affiliation: AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Joris R
authors.initials: JR
authors.lastname: de Groot
authors.affiliation: Helmsley Electrophysiology Center, Mount Sinai School of Medicine, New York, New York.
authors.forename: Srinivas R
authors.initials: SR
authors.lastname: Dukkipati
authors.affiliation: Helmsley Electrophysiology Center, Mount Sinai School of Medicine, New York, New York.
authors.forename: Jacob S
authors.initials: JS
authors.lastname: Koruth
authors.affiliation: AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Arthur A M
authors.initials: AA
authors.lastname: Wilde
authors.affiliation: Department of Cardiology, Institute of Clinical and Experimental Medicine-IKEM, Prague, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Kautzner
authors.affiliation: Helmsley Electrophysiology Center, Mount Sinai School of Medicine, New York, New York.
authors.forename: Vivek Y
authors.initials: VY
authors.lastname: Reddy
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000628:therapy*; D002304:Cardiac Pacing, Artificial; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012189:Retrospective Studies
keywords: arrhythmia; leadless pacing; pacing; rhythm disorders