Atrial pacing or ventricular backup-only pacing in implantable cardioverter-defibrillator patients.

Publication/Presentation Date

11-1-2010

Abstract

BACKGROUND: The need for pacing support in typical ICD patients is unknown.

OBJECTIVE: This study sought to determine whether atrial pacing with ventricular backup pacing is equivalent to ventricular backup pacing only in implantable cardioverter-defibrillator (ICD) patients.

METHODS: We randomized 1,030 patients from 84 sites with indications for ICDs, with sinus rhythm, and without symptomatic bradycardia to atrial pacing with ventricular backup at 60 beats/min (518) or ventricular backup pacing at 40 beats/min (512). The primary end points were time to death, heart failure hospitalization (HFH), and heart failure-related urgent care (HFUC).

RESULTS: Follow-up was 2.4 ± 0.8 years when the trial was stopped for futility. There were 355 end point events (103 deaths, 252 HFH/HFUC) in 194 patients favoring ventricular backup pacing (event-free rate 77.7% vs. 80.3% for atrial pacing at 30 months; hazard ratio 1.14, upper confidence bound 1.59, prespecified noninferiority threshold 1.21), therefore equivalence between pacing arms was not demonstrated. Overall HFH/HFUC rates were slightly higher during atrial pacing (event-free rate 85.4% vs. 86.4% for ventricular backup pacing). Exploratory analyses revealed that the difference in HFH/HFUC rates was largely seen in patients with a PR interval ≥230 ms. There were no differences between groups for atrial fibrillation, ventricular tachycardia/ventricular fibrillation, quality of life, or echocardiographic measurements. Fewer patients in the atrial pacing group were reported to develop an indication for bradycardia pacing (3.7% vs. 7.3%, P = .0053).

CONCLUSION: Equivalence between atrial pacing and ventricular backup pacing only could not be demonstrated.

CLINICAL TRIALS IDENTIFIER: NCT00281099.

Volume

7

Issue

11

First Page

1552

Last Page

1560

ISSN

1556-3871

Disciplines

Medicine and Health Sciences

PubMedID

20685401

Department(s)

Department of Medicine, Cardiology Division

Document Type

Article

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