Consider Dual-Chamber Pacemaker for Sinus-Node Dysfunction or AV Block, Experts Say

Marlene Busko

August 02, 2012

August 1, 2012 (Calgary, Alberta) — A joint consensus statement issued by the Heart Rhythm Society (HRS) and the American College of Cardiology Foundation (ACCF) recommends that patients with sinus-node dysfunction or atrioventricular (AV) conduction block may benefit from dual-chamber rather than single-chamber pacemakers [1]. The statement was published online July 30, 2012 in Heart Rhythm and the Journal of the American College of Cardiology.

This guidance adds to the 2008 guidelines for device-based therapy of cardiac-rhythm abnormalities issued jointly by the ACCF, American Heart Association, and HRS, which didn't specify pacemaker device or mode, lead author Dr Anne Gillis (University of Calgary, AB) told heartwire .

"There has been some doubt about the potential benefit vs cost of dual-chamber technology," Gillis noted. However, over the past 15 years, a number of large clinical trials have compared patients randomized to dual-chamber vs single-chamber pacemakers. The HRS and the ACCF convened a writing group of 11 cardiac electrophysiologists and surgeons from the US, Canada, and Europe to review the literature and develop evidence-based recommendations.

The report applies to patients who already meet current guidelines for having a pacemaker implanted, where the decision to go ahead with this procedure has already been made, the authors stress.

They classified the recommendations according to the strength of the available evidence.

Suggested Devices for Three Patient Types

In patients with sinus-node dysfunction, the group recommends dual-chamber pacing or single-chamber atrial pacing over single-chamber ventricular pacing, to reduce the risk of atrial fibrillation (AF) and pacemaker syndrome, improve quality of life, and possibly reduce stroke risk.

In patients with AV block, they recommend dual-chamber pacemakers to reduce the risk of pacemaker syndrome and improve some aspects of quality of life. However, these devices are equivalent to single-chamber devices in terms of their impact on cardiovascular outcomes such as mortality, stroke, heart failure, and AF.

In patients with less common indications for a pacemaker--hypertensive carotid sinus syndrome, long-QT syndrome, and hypertrophic cardiomyopathy--large, randomized clinical trials have not been undertaken and likely never will be, the authors note.

"Estimates of the cost-effectiveness of dual-chamber pacemakers vary widely and should not be the dominant factor determining pacing device and mode selection," they conclude.

"The consensus statement brings together a review of the body of literature, which supports dual-chamber pacemakers in a clinical setting." Gillis summarized. "It reaffirms how clinicians currently practice and provides a detailed guidance document."

Clinical judgment also plays a role in deciding which device to implant, she added. "We recommend that clinical factors (such as associated comorbidity and other factors that may affect survival) may lead to a decision to implant a single-chamber pacemaker [as opposed to a dual-chamber pacemaker] in a particular patient."

This document applies specifically to pacemakers, but some recommendations could apply to implantable cardioverter defibrillators (ICDs) in patients with associated cardiac rhythm dysfunction, she noted, adding that the vast majority of patients who receive ICDs don't have underlying conduction disease.

Recommendations for cardiac resynchronization therapy, which was not part of this report, will be published next month.

Gillis reports receiving a research grant from Medtronic. Disclosures for the coauthors are listed in the paper.


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