Long AT/AF Episodes Associated with Adverse Clinical Events in ICD Patients

Summary

Many patients utilizing pacemakers (PMs) and implantable cardiac defibrillators (ICDs) who have only short atrial tachycardia/atrial fibrillation (AT/AF) are not at higher risk of adverse events than those without AT/AF over the study period of approximately 24 months. However, long AT/AF episodes are associated with adverse clinical events, including hospitalization for clinical AT/AF and all-cause death in patients with ICDs. This article discusses the outcomes from the Registry of Atrial Tachycardia and Atrial Fibrillation Episodes in the Cardiac Rhythm Management Device Population [RATE; NCT00837798].

  • Interventional Techniques & Devices
  • Arrhythmias
  • Cardiology Clinical Trials
  • Interventional Techniques & Devices
  • Arrhythmias
  • Cardiology Clinical Trials
  • Cardiology

Many patients utilizing pacemakers (PMs) and implantable cardiac defibrillators (ICDs) who have only short atrial tachycardia/atrial fibrillation (AT/AF) are not at higher risk of adverse events than those without AT/AF over the study period of approximately 24 months. However, long AT/AF episodes are associated with adverse clinical events, including hospitalization for clinical AT/AF and all-cause death in patients with ICDs. Michael Orlov, MD, PhD, Steward's St. Elizabeth's Medical Center/Tufts Medical School, Boston, Massachusetts, USA, presented the outcomes from the Registry of Atrial Tachycardia and Atrial Fibrillation Episodes in the Cardiac Rhythm Management Device Population [RATE; NCT00837798].

The RATE registry was a prospective, outcome-oriented registry designed to document the incidence of AT/AF, with associated clinical data, in a large group of patients with implanted cardiac rhythm management devices. The hypothesis was that short AT/AF episodes in the RATE population would be associated with prespecified adverse clinical events, including hospitalization for AT/AF, heart failure, stroke, and death. In addition, short AT/AF episodes would confer a high risk of subsequent longer AT/AF episodes.

Patients who received new PMs or ICDs with no documented AF in the prior 3 months were included in the study. They were followed-up every 6 months for up to 2 years. Adverse events included all hospitalizations, emergency room visits and short stays of <24 hours, and in-hospital deaths. These were adjudicated by two physicians blinded to electrogram data.

The study, which ran from 2007 to 2012, enrolled 5379 patients from 225 sites in the United States (3141 with PMs and 2238 with ICDs). The median follow-up was 23 months, with 2232 hospitalizations, 359 deaths, and 37,531 electrograms adjudicated.

  • In the RATE Registry AT/AF was documented in half of the device population within 2 years

  • Approximately 1 in 4 of these patients with implantable devices had short AT/AF only

  • Patients with ONLY short AT/AF episodes were not at higher risk of adverse events than those without AT/AF over the study period

  • Long AT/AF episodes were associated with adverse clinical events in the ICD group including

    » Composite endpoint of adverse events

    » Hospitalization for clinical AT/AF

    » All-cause death

  • Many patients with short AT/AF will not develop long AT/AF within a 24-month follow-up

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