NICE promotes use of dual-chamber pacemakers for treating bradycardia

Feb 23 2005

In new medical guidance for England and Wales published today, the National Institute for Clinical Excellence (NICE) promotes the expanded use of dual-chamber pacemakers for treating slow heart rhythms, called bradycardia, which affect an estimated 100,000 people in the UK.

NICE advises in its latest guidance that up to 90 per cent of all pacemakers implanted to treat sick sinus syndrome and atrioventricular block - the two primary causes of bradycardia - should be dual-chamber devices, which deliver electrical impulses to both the right atrium and the right ventricle. The atria are the top two chambers of the heart; the ventricles, the bottom two. Currently 60 per cent of the approximately 26,000 pacemakers implanted annually in the UK are dual-chamber devices; the remaining 40 per cent are single-chamber devices, which usually stimulate only the right ventricle.

"NICE rightly recognises that dual-chamber pacemakers improve clinical outcomes cost-effectively for the treatment of bradycardia associated with sick sinus syndrome and atrioventricular block", said consultant cardiologist Prof Richard Sutton of the Royal Brompton Hospital, London. "This new guidance is based on an exhaustive review of the medical literature on the subject and should encourage specialists in heart rhythm disorders to implant a greater proportion of dual-chamber devices for patients suffering from this type of arrhythmia".

According to the guidance, titled "Dual-chamber pacemakers for symptomatic bradycardia due to sick sinus syndrome and/or atrioventricular block", NICE estimates that the cost to the NHS of implementing these recommendations will range from GBP8 million to GBP10 million per year (section 6.3) - an investment in the nation's heart health that the assessment committee deemed cost-effective (section 4.2.11).

"Dual-chamber pacemakers are well worth the extra cost," Prof Sutton pointed out. "The incremental cost-effectiveness ratio developed by NICE at GBP8,500 per quality-adjusted life year falls well within the generally accepted threshold of GBP30,000".

In addition to cost-effectiveness, the new guidance emphasizes the clinical benefits of dual-chamber pacing. For example, meta-analyses of various published studies considered by the committee showed a statistically significant reduction in atrial fibrillation (section 4.1.4), improvement in exercise capacity (section 4.1.7) and improvement in quality of life (section 4.1.8) with dual-chamber pacing compared with single-chamber pacing.

"NICE influences treatment decisions not just in the UK, but internationally as well," explained Medtronic health economist Dr Jenifer Ehreth, "so we are especially pleased with this guidance on dual-chamber pacing. Because of these recommendations, people with bradycardia - starting with those in the UK - now stand a better chance of getting a dual-chamber pacemaker when that is the most appropriate choice for them".

Results of one of the randomised clinical trials considered by NICE for the new guidance appeared in the 18 Jan. issue of the journal Circulation. The authors of the study, the Mode Selection in Sinus Node Dysfunction Trial (MOST), write: "For patients with sick sinus syndrome requiring pacing, dual-chamber pacing increases quality-adjusted life expectancy at a cost that is generally considered acceptable".

They continue: "Compared with [single-chamber] pacemakers, dual-chamber pacemakers in the MOST trial significantly reduced the rates of atrial fibrillation and hospitalization for heart failure and were associated with somewhat lower rates of stroke. This reduction in nonfatal events with dual-chamber pacemakers resulted in better quality of life observed during the trial on a number of measures and projected to an even greater extent beyond the trial because of the life expectancy of affected patients".

Bradycardia is an abnormally slow heart beat that, according to the NICE guidance, can cause "faints, falls, dizziness and confusion, palpitations, fatigue on exertion, difficulty with breathing, and chest pain" (section 2.2). It is typically treated with pacemakers, which "control or replace the heart's intrinsic electrical activity" (section 2.7) and improve its ability to pump blood to the body.

"In summary, the Committee concluded that, for most people who have [bradycardia from] sick sinus syndrome with atrioventricular block, and for those with atrioventricular block without continuous atrial fibrillation, dual-chamber pacing is preferred to single-chamber pacing" (section 4.3.9).

NICE guidance is available online at www.nice.org.uk.