People with strong chest and back less likely to have a heart attack, analysis suggests

Researchers suspect people with greater muscle density in torso area, who are also less likely to die prematurely, are those who exercise more

People with strong chest and back muscles are less likely to have a heart attack or die prematurely, analysis using artificial intelligence suggests.

Researchers led by the University of Edinburgh used AI to examine hospital scans of 1,722 patients, aged mostly in their 50s, who had chest pain.

Those with greater muscle density in their chests and backs were less likely to have a heart attack or die in the decade after the scan, the study found.

Researchers suspect people with this type of “good-quality skeletal” muscle are those who exercise more and have greater strength in their torsos. The findings, published in the journal Radiology, suggest this could help reduce the risk of having a heart attack or dying early.

Prof Michelle Williams, the senior author of the study, found the study’s findings so compelling that she has started going to the gym twice a week and aims to walk for an hour a day.

“It is fascinating that people’s skeletal muscle could be linked to their risk of having a heart attack. The muscles which show up in the scans we used – coronary computed tomography angiogram scans – are principally the back muscles, part of the pectoral muscles – or ‘pecs’ – and the intercostal muscles between the ribs.

“So I am now personally interested in exercises like cycling, planks and pilates, which I enjoy and may have an effect on these muscles. However, we need far more research to better understand how exercise may affect muscle density, and how this may relate to heart health.”

Researchers used AI to examine people’s muscle, organs, bones and fat in their upper bodies. This included looking at skeletal muscle attenuation – the brightness or darkness of the muscle in a scan.

Denser muscle appears lighter in a scan image because more X-ray beams bounce off it. A brighter image indicates that someone has better quality, more dense muscle, which may contain a lower proportion of fat.

For every 10-point increase in scan brightness, suggesting better quality muscle with less fat in it, a person was calculated to be 31% less likely to have a heart attack. They were also 39% less likely to die in the 10 years after the scan, researchers said.

The size of people’s muscles was not linked to their risk of a heart attack or early death, suggesting it is the composition of the muscle that matters, the researchers said.

In future, routine heart scans could be used to identify people with less good-quality muscle who may be at greater risk of heart attacks. These people could then be helped to exercise more, be monitored more closely, or be prioritised for drugs that reduce the risk of a heart attack.

Prof Bryan Williams, the chief scientific and medical officer at the British Heart Foundation, which part-funded the study, said: “It is likely that people in this study with more dense muscle mass were more physically active and as a result may have better heart health. That is yet more evidence supporting the power of exercise.”