Under the pump

Hopes are high for a new drug to slow heart failure and tackle other life-threatening conditions as well.

- Nicky Pellegrino

Around 175,000 New Zealanders live with heart failure. It is another of those conditions that become more likely as we age and, although there is no cure, it can be managed with a range of medications.

Heart failure doesn't mean the heart has actually failed or stopped, but that pumping enough blood around the body has become harder. This may be because the heart muscle has stretched and weakened, or it may have thickened and stiffened, or been irreversibly damaged by a heart attack. Either way, sufferers experience fluid build-up leading to a range of symptoms such as shortness of breath, extreme fatigue and swelling in the legs and feet. More than half of people diagnosed with heart failure will survive for five years and about 35% survive for 10 years.

Now, researchers at the University of Auckland are trialling a drug they believe has the potential to not only improve the heart's ability to pump, but also reverse the progression of heart failure.

"This is a completely new class of drug with a different mechanism," says Julian Paton, director of the university's Manaaki Manawa Centre for Heart Research. "What it does, that the others do not, is reduce autonomic nervous system activation to the heart."

Known as AF-130, the drug was first developed as a medication for unexplained chronic cough, a common and hard-to-treat ailment. It is a P2x3 receptor blocker and it seems to have multiple other uses. P2x3 receptors are channels that let sodium and calcium ions into the cells, which create electrical excitability and are key to communication with the brain. The chemical that stimulates these receptors is called ATP (adenosine triphosphate) and it is essential for many cellular processes.

"ATP is doing a lot in the body," says Paton. "But what caught our attention is that in disease, it does too much."