Patients with coronary artery disease undergoing angioplasty do not benefit from having their circulation artificially supported with a balloon pump as a preventative measure during angioplasty, according to the first randomised trial studying the practice and published today in the Journal of the American Medical Association (JAMA).
The trial was carried out across 17 tertiary referral cardiac centres in the UK and was designed and led by Dr Divaka Perera and Dr Simon Redwood, interventional cardiologists at Guy's and St Thomas' Foundation Trust in London1. The study was funded by unrestricted educational grants and the principal investigators were supported by the atherosclerosis theme of the National Institute for Health Research (NIHR) comprehensive Biomedical Research Centre at Guy's and St Thomas' and King's College London.
Angioplasty is a common procedure performed under local anaesthetic to open up the narrowed sections of a patient's arteries. A small balloon is inflated within the narrowed artery to open the blockage, and a metal scaffold (stent) is inserted to keep the artery open. Patients with poor heart function and extensively narrowed heart arteries are at higher risk of complications following angioplasty and there has been much interest in the balloon pump as a means of reducing such adverse events. When a balloon pump is used, it is placed inside the patient's aorta (the main artery supplying blood to the body) to provide circulatory support to their failing hearts. Over the last 20 years, cardiologists across the world have adopted use of the balloon pump as a preventative measure during high risk angioplasty, but this common practice has been based on anecdotal accounts and small observational studies, which are limited by selection bias.
The Balloon pump assisted Coronary Intervention Study (BCIS-1) involved 301 patients with severe left ventricular dysfunction and extensive coronary artery disease. They were randomly assigned to either have the balloon pump inserted before angioplasty or to have angioplasty without planned balloon pump support.
There was no difference in the proportion of patients who suffered major cardiovascular complications (comprising death, acute myocardial infarction, cerebrovascular events or further revascularisation, at hospital discharge capped at 28 days) in the group who received a balloon pump beforehand (15.2%), compared to those who did not (16%). However, approximately one in eight of the latter group required an emergency balloon pump insertion during the procedure, emphasising the importance of having a balloon pump on standby when undertaking such cases2.
Dr Simon Redwood, Reader in Interventional Cardiology at King's College London and Honorary Consultant Cardiologist at Guy's and St Thomas' said: "For many years we have strongly advocated the use of the balloon pump to support patients' circulatory system during high risk coronary angioplasty and wanted to build up definitive evidence to support its use. We believed this multi-centre study would establish once and for all the clinical and safety benefits of using the pump as a preventative measure.
"However, rather than demonstrating the benefits, we found that inserting a balloon pump into the aorta as a preventative measure has little or no impact on the incidence of major complications and death in high risk cardiac patients, although there is still an important role for using a pump in an emergency.
"Angioplasty is now the most common interventional treatment for treating coronary artery disease. The study findings raise important questions about current clinical practice and whether it is necessary to use a balloon pump routinely during the procedure. The findings may reflect the fact that angioplasty has become a less risky procedure over time as cardiologists have increased their skills."
Dr Martyn Thomas, lead of the cardiovascular clinical academic group at King's Health Partners Academic Health Science Centre, which includes Guy's and St Thomas', King's College London and the NIHR Biomedical Research Centre said: "It is vitally important that high quality research underpins clinical practice, and studies such as this are key to informing cardiac practice nationally and internationally."
The cardiac units at Guy's and St Thomas' and King's College Hospital NHS Foundation Trusts, the two acute Trusts within King's Health Partners, jointly perform approximately 3000 interventional cardiology procedures a year, and form one of the biggest cardiac centres in the UK.
Note to editors:
1. Perera D, Stables R, Booth J, Thomas M, Redwood S. The balloon pump-assisted coronary intervention study (BCIS-1): rationale and design. Am Heart J. 2009; 158(6): 910-916
2. Perera D, Stables R, Thomas M, Booth J, Pitt M, Blackman D, De Belder A, Redwood S. Elective Intra-aortic balloon counterpulsation during high-risk percutaneous coronary intervention: a randomized controlled trial. JAMA 2010; 304(8) in press
17 hospitals recruited patients into this study. Over half of the patients were recruited into the study at: St Thomas' Hospital, Birmingham Heartlands Hospital, Brighton and Sussex University Hospital, Leeds Teaching Hospitals and Liverpool Heart and Chest Hospital
1. Contact: Andrea Ttofa, Guy's and St Thomas' NHS Foundation Trust tel: +44 (0)20 7188 5577 or email: andrea.ttofa@gstt.nhs.uk. Out of hours, please call our pager bureau on +44 (0)844 822 2888, ask for pager number 847704 and give the pager operator your message.
2. Guy's and St Thomas' provides around 900,000 patient contacts in acute and specialist hospital services every year. As one of the biggest NHS Trusts in the UK, it employs almost 11,000 staff. The Trust works in partnership with the Schools of Medicine, Dentistry, Nursing and Biomedical Sciences of King's College London and other Higher Education Institutes to deliver high quality education and research. Website: www.guysandstthomas.nhs.uk.
3. King's College London is one of the top 25 universities in the world (Times Higher Education 2009) and the fourth oldest in England. A research-led university based in the heart of London, King's has more than 21,000 students from nearly 140 countries, and more than 5,700 employees. King's is in the second phase of a £1 billion redevelopment programme which is transforming its estate.
4. Guy's and St Thomas' is part of King's Health Partners Academic Health Sciences Centre (AHSC), a pioneering collaboration between King's College London, and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts.
King's Health Partners is one of only five AHSCs in the UK and brings together an unrivalled range and depth of clinical and research expertise, spanning both physical and mental health. Our combined strengths will drive improvements in care for patients, allowing them to benefit from breakthroughs in medical science and receive leading edge treatment at the earliest possible opportunity.
For more information, visit www.kingshealthpartners.org
5. The comprehensive Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, is one of five National Institute for Health Research (NIHR) comprehensive Biomedical Research Centres in England. With its strong focus on 'translational research' across seven research themes and a number of cross-cutting disciplines, it aims to take advances in basic medical research out of the laboratory and into the clinical setting to benefit patients at the earliest opportunity. Access to the uniquely diverse patient population of London and the south east enables it to drive forward research into a wide range of diseases and medical conditions. Website: www.biomedicalresearchcentre.org
6. The National Institute for Health Research (NIHR) provides the framework through which the research staff and research infrastructure of the NHS in England is positioned, maintained and managed as a national research facility. The NIHR provides the NHS with the support and infrastructure it needs to conduct first-class research funded by the Government and its partners alongside high-quality patient care, education and training. Its aim is to support outstanding individuals (both leaders and collaborators), working in world-class facilities (both NHS and university), conducting leading-edge research focused on the needs of patients. www.nihr.ac.uk
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JAMA