May 2007

Research provides hope for heart patients

New Austin Hospital research challenges the prevailing view that muscle-strengthening exercise is dangerous for patients with damaged hearts.

The study, performed in collaboration with the University of Melbourne and Victoria University and funded by the National Health and Medical Research Council, has found exercise for increasing general muscle strength, previously considered too dangerous for patients with weak hearts, is not only safe but, actually, beneficial.

The study involved patients with chronic heart failure randomly selected to undergo resistance training under the guidance of a personal trainer.

Their results were then compared with patients randomised to a control group.

Over the time of the study, the control group actually became weaker.

After training, those undertaking the muscle-strengthening exercise had stronger muscles, increased blood flow to the exercising muscles, better endurance and, also, improved aerobic fitness.

Austin Hospital Senior Cardiologist Associate Professor David Hare headed the research team.

He said the results challenged the notion that chronic heart failure patients should ‘take it easy.’

‘Before 1990, patients with heart muscle damage were told not to exercise at all as reducing physical activity was thought to be important to prevent the heart being put under undue stress.

‘As a result of good research studies, light aerobic exercise was deemed OK in the 1990s but muscle-strengthening exercise remained prohibited.

‘Now, however, we can see that muscle-strengthening exercise is not only safe but causes the heart to deliver more blood to exercising muscles, which become stronger and fitter.’

Associate Professor Hare said his research team’s most recent data, published in the USA and complementing more than 10 years of research in the area, had identified the mechanism by which this improvement occurred.

‘The energy producers in muscle cells, called mitochondria, are able to produce increased amounts of energy as a direct result of patients undergoing exercises designed to increase muscle strength,’ said Associate Professor Hare.

‘As a result, patients who were previously prohibited from many activities such as lifting and digging, and who were not allowed to perform anything more than ‘light duties’ at work, may be able to do so after speaking with their doctors.

‘This helps improve the quality of life for heart patients by improving mood and energy levels, while making them stronger.’

Chronic heart failure is an extremely common condition where the heart muscle is weak and cannot pump blood efficiently through the body.

In Australia, it is estimated there are more than 300,000 new cases presenting each year—enough to fill the MCG three times over.

Chronic heart failure is the most common cause of hospital admission in the western world.

It is estimated there are about 100,000 hospital admissions each year in Australia associated with heart failure.