Dual-chamber implantable cardioverter defibrillators reduce clinical adverse events related to atrial fibrillation when compared with single-chamber defibrillators: a subanalysis of the DATAS trial

Europace. 2009 May;11(5):587-93. doi: 10.1093/europace/eup072.


Aims: The aim of the present analysis of the DATAS study was to compare the impact of dual- vs. single-chamber defibrillators on atrial fibrillation (AF) occurrence and AF-related clinical events in patients with Class I indication for implantable cardioverter defibrillators (ICDs) and no indication for dual-chamber pacing.

Methods and results: Three hundred and thirty-four patients were randomized, through a centralized assignment, to single-chamber ICDs, dual-chamber ICDs programmed as single-chamber ICDs, and dual ICDs with full diagnostics and AF prevention and therapy capabilities. The latter two groups in the first 8 months of the study, when the study design was that of a randomized parallel trial, were compared in the present analysis. The primary endpoint was composed by the following AF-related clinical events: permanent AF, AF-related hospitalizations, cardiac-embolic events, and inappropriate ICD shocks due to AF misclassification. Two hundred and twenty-three patients were available for this analysis, of whom 111 in the single-chamber-simulated group and 112 in the dual-chamber true group. Atrial fibrillation-related composite endpoint raw incidence was 9 of 111 (8.1%) in the single-chamber group vs. 1 of 112 (0.9%) in the dual-chamber group (P = 0.0098 by Fisher's exact test). Single-chamber ICDs were associated with a significantly higher risk to develop the AF-related composite endpoint by Cox regression analysis (hazard ratio 8.25, 95% CI 1.03-65.96, P = 0.047) and by the Kaplan-Meier survival analysis (log-rank test, P = 0.047).

Conclusion: Dual-chamber ICDs compared with single-chamber ICDs reduced the incidence of an endpoint composed by permanent AF, AF-related hospitalizations, and ICD shocks deemed inappropriate due to AF misclassification.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Atrial Fibrillation / complications*
  • Atrial Fibrillation / therapy*
  • Cross-Over Studies
  • Defibrillators, Implantable* / adverse effects
  • Embolism / epidemiology
  • Endpoint Determination
  • Equipment Design
  • Hospitalization
  • Humans
  • Kaplan-Meier Estimate
  • Regression Analysis
  • Risk Factors