People with heart failure are being left at risk of dying because of a 90-day “wait-and-see” policy on fitting implantable defibrillators, researchers have warned.
The study, published in the journal Circulation, has recommended that such devices, properly known as implantable cardioverter defibrillators (ICDs), should instead be given to heart failure patients at highest risk of heart rhythm problems at an earlier stage in their treatment.
The team behind the multi-centre clinical trial, led by Professor Divaka Perera at King’s College London (KCL) and funded by the charity the British Heart Foundation, say their results potentially provide new evidence that could influence heart failure guidelines in the UK, Europe and internationally.
There are estimated to be 2.3 million people living with coronary heart disease in the UK, and it is a leading cause of heart failure. It develops when the blood vessels supplying the heart become narrowed by a build-up of fatty substances in their walls, stopping blood carrying oxygen and vital nutrients from getting to the heart muscle.
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This can lead to damage to the left chamber of the heart – responsible for pumping blood around the rest of the body – and a higher risk of atrial fibrillation (dangerously abnormal heart rhythms) and sudden death.
For people who have severe heart failure due to coronary heart disease, as well as prescribing medication, doctors may insert stents to open any blocked arteries in the first instance.
They then normally wait for at least 90 days to see if the pumping action of the heart has improved based on these treatments.
It is only after this wait that patients are re-evaluated to see if they are still at high risk of a life-threatening heart rhythm disturbance and would benefit from having an implantable cardioverter defibrillator device (ICD). These defibrillators shock and kickstart the heart if it goes into a life-threatening rhythm or cardiac arrest.
The KCL study recruited 700 patients from 40 hospitals across the UK who had coronary heart disease and severely weakened function of the left ventricle of their heart.
All patients received ‘optimal medical therapy’, which included heart failure medication and, in many cases, pacemakers designed to improve heart function and ICDs.
Half were randomly assigned to also have stents fitted to open up their narrowed arteries that supply the heart with blood. Patients were followed-up closely for at least two, and up to eight, years.
The research team found that stents did not reliably improve the heart’s ability to pump, nor did they reduce the risk of life-threatening heart rhythm disturbances, or the number of cardiac arrests and deaths.
As a result, the team has recommended that patients who are at risk should not have to wait until after stent insertion before they are fitted with a potentially lifesaving ICD.
However, while stents were shown not to improve heart function in patients with severe heart failure, the researchers have still stressed that they are an effective treatment for heart attack patients or people with angina.
Dr Holly Morgan, BHF clinical research fellow at the KCL BHF Centre of Research Excellence, who was involved in the research said: “Our findings have revealed that many patients with high risk of heart failure could benefit from receiving an ICD straight away, rather than facing a 90-day wait.
“By showing that coronary stents had limited benefit for this group of heart patients, we have exposed a clear window of missed opportunity to reduce chances of dying from an abnormal heart rhythm. We hope our findings will influence existing guidance, so patients can be spared unnecessary waits to receive a potentially lifesaving defibrillator.”
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