UK-wide trial shows simple pacemakers are as good as complex ones for elderly patients
13 July 2005
A £1.6 million 8 year trial funded by the Medical Research Council and involving 46 hospitals around the UK shows that complex pacemakers provide no advantage over simple pacemakers for elderly patients with heart-block. The results are published in this week’s edition of The New England Journal of Medicine. The United Kingdom Pacing and Cardiovascular Events (UKPACE) trial was led by the University of Leicester and the University Hospitals of Leicester NHS Trust. Researchers say the study will help clinicians to choose the appropriate treatment options for heart-block in elderly patients as well as stimulate new approaches in the way cardiac pacing is delivered.
Heart-block is a condition where the heart rate slows because of a disruption to the conduction of the electrical signals that control the heartbeat. The UKPACE trial aimed to determine whether dual-chamber pacemakers were of more benefit in elderly patients with this condition.
It had previously been thought, based on reports from non-randomised studies, that the more sophisticated dual-chamber devices resulted in better outcomes. These studies, which were not focused on elderly patients, showed a lower incidence of complications such as atrial fibrillation (an irregular heart rhythm), stroke and heart failure with dual-chamber pacing. However, the dual-chamber device is more expensive, more difficult to implant and more prone to complications around the time of the procedure. This, combined with uncertainty regarding the clinical benefits, led to apparent under-use in elderly patients.
The UKPACE trial involved 2,021 patients, aged 70 years or over, who were due to receive their first pacemaker for heart-block. The patients were randomly assigned to receive either a simple single-chamber pacemaker or a more sophisticated dual-chamber system with two leads.
The patients were followed up for at least 3 years and the incidence of death, atrial fibrillation, strokes or blood clots, and heart failure was found to be no different in the two groups.
The study’s principal investigators were Dr William Toff, Senior Lecturer in Cardiology, University of Leicester, Dr Douglas Skehan, Consultant Cardiologist, University Hospitals of Leicester NHS Trust, and Professor A. John Camm, Division of Cardiac and Vascular Sciences, St George’s University of London.
Dr William Toff said, "Cardiac pacing is a dramatically effective and often life-saving treatment for patients with heart-block. This study shows that in elderly patients with this condition, a single-chamber system is an acceptable alternative to the more costly and sophisticated dual-chamber system."
Dr Douglas Skehan added, "This study was prompted by our concern that elderly patients were being disadvantaged by the infrequent use of dual-chamber pacing with advancing age. It may be that any benefit from dual-chamber pacing is diminished because the ventricular lead is not in an ideal position. We believe that the rethink stimulated by our trial and others will help to drive new approaches in the way we deliver pacing, particularly for elderly patients."
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Notes to editors:
Heart-block is a condition in which conduction of the spontaneous electrical activity of the heart, which starts in the upper chambers (the atria), fails to reach the main pumping chambers (the ventricles), resulting in a failure of the coordinated contraction of the muscular pumping chambers. This may result in symptoms, such as dizziness, breathlessness, light-headedness and loss of consciousness, and in some cases, death.
Single-chamber pacemakers sense the intrinsic heart rhythm and deliver electrical stimulation when it fails, using a single lead (electrode), the tip of which is located in the right ventricle (the lower pumping chamber) of the heart. Dual-chamber pacemakers have an additional lead, the tip of which is located in the right atrium (the upper pumping chamber) and are able to restore the synchronised and sequential contraction of the upper and lower chambers.
The Medical Research Council (MRC) is a national organisation funded by the UK tax-payer. Its business is medical research aimed at improving human health; everyone stands to benefit from the outputs. The research it supports and the scientists it trains meet the needs of the health services, the pharmaceutical and other health-related industries and the academic world. MRC has funded work which has led to some of the most significant discoveries and achievements in medicine in the UK. About half of the MRC’s expenditure of £450 million is invested in its 40 Institutes, Units and Centres. The remaining half goes in the form of grant support and training awards to individuals and teams in universities and medical schools.
The Glenfield, Leicester General and Leicester Royal Infirmary hospitals merged together in April 2000 to become University Hospitals of Leicester (UHL) NHS Trust. The Trust serves a population of one million and employs nearly 12,000 staff. UHL is nationally recognised for high quality specialist care in cardiac, cancer and renal services and receives patient referrals from all over the country. Web site at: www.uhl-tr.nhs.uk
