A drug used to treat asthma may be a new way to tackle heart failure. It works by boosting the heart’s action, helping it pump faster.
About 900,000 Britons — most of them older people — suffer from heart failure, with the condition more common in men. Put simply, it means the heart is having difficulty pumping blood around the body.
It can be caused by a range of conditions, including high blood pressure or a heart attack, which damage the heart muscle in some way.
Common symptoms include breathlessness, extreme tiredness and fluid retention (the latter happens as fluid backs up in the tissues, particularly in the legs, ankles, feet and lungs).
Heart failure is a chronic condition that can’t be cured, but can be controlled with lifestyle changes and medication.
Drugs for heart failure work in a variety of ways, including dilating the blood vessels to help blood flow or slowing the heart beat to reduce the heart’s workload.
In a new trial, doctors at the U.S. National Institutes of Health are looking at the asthma drug Fenoterol as a possible treatment. The drug stimulates the body’s ‘fight or flight’ response.
When under threat, the brain signals to the body to release stress hormones — these increase heart rate, blood flow and breathing, providing a burst of energy.
Fenoterol is known to stimulate the same response in the lungs. During an asthma attack, when the lungs are irritated, bands of muscle around the airways tighten, narrowing the airways and resulting in breathlessness.
The drug helps by stimulating the stress hormone receptors on the lung cells to widen or dilate the airways, making breathing easier. The same stress hormone receptors are found on the heart.
‘Research indicates that Fenoterol causes the heart to pump more blood to the rest of the body by increasing a person’s heart rate,’ say the U.S. team.
A bonus is the drug doesn’t lead to a rise in blood pressure, despite making the heart work faster.
And because Fenoterol has been used in patients for many years, if it is effective for heart failure, it could be available quite soon. Some small studies have already shown the drug may help heart failure patients.
A study reported in the German medical journal, Klin Wochenschr, based on seven patients with severe heart failure, found the drug was effective.
‘Results indicate that Fenoterol produces a significant improvement in pump function,’ said the researchers.
About 250 healthy volunteers will take part in the new trial and be monitored for the effects of the drug on heart rate, blood pressure, and heart function.
Professor Martin Cowie, a consultant cardiologist at Royal Brompton Hospital and Professor of Cardiology at Imperial College, says: ‘This is interesting. If you stimulate these receptors, the heart looks perky and more active.
‘More trials are needed as we would have to be convinced this sudden kick to the heart would not have a damaging effect in heart failure patients.
If it was safe and effective, the fact this drug can be inhaled and that its effects are long-lasting is a big plus for patients.’
Meanwhile, a device that sets up a low-frequency electromagnetic field is being used to treat the painful heart condition angina.
Researchers involved in a new clinical trial believe the therapy can improve symptoms by helping restore heart tissue.
Previous animal studies have shown the treatment reduces heart muscle damage following a heart attack. Angina is a condition triggered by a restriction in the supply of blood to the heart.
A common cause is furred up arteries; risk factors include older age, smoking, obesity, a family history of coronary heart disease, high blood pressure and cholesterol levels.
Symptoms, in some patients, develop over time, last for only a few minutes and can be eased with medication, such as glyceryl trinitrate, which widens blood vessels to increase blood supply.
Others may not respond to medication and be offered interventional procedures or surgery such as a coronary artery bypass. In the new clinical trial, 40 patients with angina will be exposed to a weak electromagnetic field (the technology is similar to that used in barcode readers).
Patients will undergo two exercise tests on a treadmill, one after being exposed to 30 minutes of electromagnetic field and another after being exposed to sham therapy.
After the two tests, researchers will measure changes in the heart’s activity, workload and reported anginal pain.
The doctors, from the Sheba Medical Centre, in Israel, say several studies have shown electromagnetic fields have a protective effect on heart tissue.
Earlier research on animals by the same group showed it led to reduced heart damage after a heart attack compared to animals not given the treatment.
It is thought the treatment increases the number of stem cells in bone marrow, leading to a rise in immune cells, which are crucial for repairing damage in the body.
However, the researchers say more work is needed.