Landmark heart research
If the number of clinical trials in an area of medicine indicates the scale of concern, then heart failure is at last getting the attention it deserves.
More than 1,200 separate plans are now recruiting around the world to examine anything from the best pacemaker, through gene therapy to the benefits of aggressive rhythm control.
The aim is to reduce the burden on healthcare from heart failure; a killer with a global death tally of 7.3 million, which the World Health Organization predicts will only rise as people live longer.
In the UK, where 58 clinical trials are currently recruiting, the British Heart Foundation says heart failure affects 750,000 at a conservative cost to the NHS of £625 million a year.
“The disturbing statistic is that heart failure accounts for more than 5 per cent of all deaths in the UK,” says Divaka Perera, reader in cardiology at King’s College London and consultant cardiologist at Guy’s and St Thomas’ Hospital, who is embarking on a landmark trial into heart failure treatment.
It will test the emerging school of thought that angioplasty and stenting can be safer and more viable than bypass surgery in many cases.
“People believe in the theory, and many units and cardiologists offer angioplasty to heart failure patients, but it is without an evidence base to support it,” says Dr Perera, who is recruiting 700 patients for the REVIVED study, which will take place in up to 25 medical centres in the UK.
Existing non-randomised data leads us to expect that we should be able to bring about a 25 per cent or better reduction in mortality
It will compare equal groups of 350, who will be given either angioplasty and medication or medication alone, to combat severe conditions where the left ventricle, the most powerful chamber of the heart, is working at less than half its normal capacity.
“This will be the first study aimed at eliminating a grey area. I don’t know what the answer will be, but we will have an answer,” he says.
“Existing non-randomised data leads us to expect that we should be able to bring about a 25 per cent or better reduction in mortality. That would be a huge impact so we have to have that confirmed or disproved.”
Heart failure, where the heart muscle does not work efficiently, is caused principally by coronary heart disease – problems with the blood flow to the heart – rather than defects within the heart muscle itself.
Angioplasty, using a catheter to introduce a balloon to relieve a narrowed or blocked artery and stents, the stainless steel mesh that act as permanent supports, are widely used for emergency heart attacks or angina.
Many cardiologists do deploy the techniques sporadically for heart failure but, Dr Perera maintains, the scientific community has been slow to provide the ultimate justification from clinical trials.
Mike Knapton, associate medical director at the British Heart Foundation, agrees that current evidence on the benefits of angioplasty is “unclear”.
A positive result for angioplasty and stents could lead to a dramatic re-shaping of heart failure treatment.
Dr Perera points to the last big clinical trial – STICH carried out in 2011 by Duke University in the United States – which provided no conclusive data that coronary by-pass surgery was the optimum approach to severe heart failure.
“It showed mortality at five years of nearly 50 per cent which was astonishing and the sort of figures we used to describe in cancers and survival,” he says. “Our devices are better, our tablets are better, but despite advances, there is a really high mortality with surgery and less than 40 per cent of heart failure patients manage to survive or stay out of hospital.
“We clearly haven’t cracked it. Whether the answer is going to angioplasty or not, I do not know, but we have to find the answer in a scientific and systematic way.”
The REVIVED study will be drawn from patients with problems in at least 50 per cent of their arteries leading to the heart, severely impaired left ventricle function, but with a heart muscle showing signs of recovery following treatment.
The study should finish enrolling patients in 2016 and report end-point analysis two years later.
“This is an important question to answer as the effects of heart failure can be devastating for the patient and their family,” Dr Knapton concludes.