By Frances Griss
Since the beginning of the 1960s, deaths from heart disease in the UK have halved so that today only 26% of people have a cause of death attributable to the condition, compared with more than half of deaths half a century ago.
Huge as that achievement is, it still means that a quarter of the population are dying from a disease that has been proved to be often preventable and highly treatable.
Given the prevalence of cardiovascular disease, it is no surprise that a great deal of money and effort is directed towards research in the area, both on lifestyle and environmental factors and into pharmaceutical and surgical interventions.
One of the most controversial treatments is the prescription of statins to apparently healthy people as well as those with known disease, but the benefits have been shown to outweigh the costs.
Since 1994, the University of Oxford Clinical Trial Service Unit Heart Protection Study has been following 20,000 patients. At the beginning of this decade, it showed the effectiveness of larger doses (80mg over 20mg) of simvastatin for reducing major vascular events in 12,000 heart attack survivors.
In 2012, Cholesterol Treatment Trialists showed that there were benefits to taking the drugs even in apparently healthy patients with a low risk of heart disease.
Figures from the British Heart Foundation suggest that the use of statins already saves 10,000 lives each year in England alone. The debate continues as to whether they should be prescribed more widely.
Despite the fact that coronary artery disease is the most common cause of death in the United Kingdom among people over the age of 65 years and almost half of all heart attacks occur in those over the age of 70 years, older people are often excluded from trials of treatments.
Doctors at the Newcastle Biomedical Research Centre are taking advantage of their partnership with Volcano Corporation, a specialist in coronary intravascular imaging, to look at the effectiveness of one particular treatment in older people, stents, for NHS National Institute for Health Research.
The centre says that older patients, particularly those that are frail who present with acute coronary syndrome (heart attack or unstable angina), have much poorer outcomes compared to their younger counterparts.
Despite this, the team says, there is very little research data available on older patients with acute coronary syndrome; more than half of all trials between 1996 and 2000 did not enrol patients over the age of 75 years, and over a third actively excluded them. ICON1 has been designed to investigate patients over the age of 75 years who are at a higher risk following an acute coronary syndrome, by performing a comprehensive evaluation of their cardiovascular disease burden.
The results will be used to develop a risk score that will inform physicians of the patient’s future risk of developing adverse effects and provide a better understanding of how to manage older patients with coronary artery disease. It will also help to plan future studies evaluating treatment strategies that might be beneficial in improving outcomes in high risk older patients.
Other institutions undertaking research for the NIHR are focusing on different areas and a team at the Liverpool Heart and Chest Hospital (LHCH) led by Dr Rod Stables recently published results which could led to both increased survival rates and economies for a cash-strapped NHS.
The study had the title Unfractionated heparin versus bivalirudin in primary percutaneous coronary intervention (HEAT-PPCI) and, with more than 1800 participants, was record-breaking in size.
Dr Stables, Consultant Cardiologist at LHCH, said: “As far as we are aware, our study is one of the first trials to recruit 100% of eligible patients presenting with the medical condition being examined, which means that it more closely resembles real life practice than many previous trials.”
Over a 22-month period, 1,829 patients undergoing emergency angiography (an x-ray examination of the heart’s arteries after a suspected heart attack) at LHCH were recruited to the trial.
More than four fifths of the participants went on to receive PPCI; approximately half of the participants received heparin, and half received bivalirudin.
Researchers then recorded how many patients in both groups experienced a major adverse cardiac event, such as death, stroke or another heart attack, within 28 days after surgery.
The results suggest that heparin should be used rather than bivalirudin during PPCI and after it has been completed. Where heparin was used, there was a lower rate of major adverse cardiac events, although there was no significant difference between the groups in terms of the rate of bleeding complications, which are an acknowledged risk of drugs that prevent clotting.
Within 28 days of surgery, 46 patients (5.1%) in the bivalirudin group died, compared to 39 (4.3%) of patients in the heparin group; 24 patients (2.7%) in the bivalirudin group had another heart attack in the same period, compared to seven patients (0.8%) in the heparin group.
The results are interesting in light of the fact that bivalirudin is roughly 400 times more expensive than heparin and, at the time of the study, bivalirudin was in widespread use in high-income countries around the world.
Dr Stables said: “This finding might provide an opportunity, rare in modern health care, to provide improved outcomes at much reduced cost.
“In our centre performing about 1,000 PPCI procedures a year, the cost saving would be about £500,000 a year. Translated to the global stage, the potential savings could amount to several billion pounds.”
The results led to the European Society of Cardiology modifying its guidelines to bring them in line with the study, and a shift in clinical practice globally.
In a different approach, medics working in clinics in the Royal Liverpool University Hospital, Warrington Hospital and the Countess of Chester Hospital are looking at how a patient’s genes influence their response to the blood thinning drug warfarin, which is taken by about one per cent of the population to treat ventricular fibrilation.
An international trial in Liverpool, Newcastle and Sweden included genotype testing of patients into an algorithm to calculate dosages. This proved highly accurate and is now being put into practice at the clinics in north west England. They are using equipment which can give a genotype result in 45 minutes with only a saliva sample. If the trial is successful, the method could be rolled out across the country.
The work is led by Professor Sir Munir Pirmohamed of the University of Liverpool’s Wolfson Centre for Personalised Medicine and Theme Leader of Delivering Personalised Health and Care for CLAHRC NWC.
He said: “This is innovation and it is disruptive; it is a way of personalising care which can be replicated in many areas of medicine, creating a major paradigm shift in how we diagnose and treat people.
“This is how we get patients onto the right drugs at the right doses – using ‘precision dosing’ so that they are effective. This improves the treatment of patients and improves the efficiency of existing and new drugs.”
Cardiovascular disease, although it is still a major problem and blights the life of millions, is an area where research is making inroads into better understanding and providing effective interventions.
With science producing refinements and new discoveries on so many different fronts as varied as using stem cells to regenerate dead heart muscle genetic testing for rarer conditions the future is exciting and the prospects for patients very positive.
