Heart attacks may not be genetic: study

Lifestyle factors such as poor diet, smoking and lack of exercise are more likely to trigger heart attacks than family history, a new study has warned.

Heart attacks are not as connected to family history and genetics as may have been previously believed, according to researchers at the Intermountain Medical Centre Heart Institute in Salt Lake City, US.

These new findings may help those with a family history of coronary disease and those diagnosed with narrow coronaries realise that heart attacks aren't inevitable and that their lifestyle choices and environment, not just their genetics, may make the difference in whether or not they have a heart attack, researchers said.

In the study, Benjamin D Horne, director of cardiovascular and genetic epidemiology at the Intermountain Medical Centre Heart Institute, and his team studied patients with different severities of coronary disease who had or had not suffered a heart attack.
The research team found that while severe coronary artery disease can be inherited regardless of whether someone has a heart attack, the presence of heart attacks in people with less severe coronary disease was not clustered in families.

The medical importance of this finding is two-fold: first, it can help guide physicians and researchers to look for triggers or risk factors for heart attacks that result from behaviours or environmental factors rather than genetic ones.

Second, it can help researchers better design genetic studies focused on heart attacks so they can best utilise the resources they have to find the limited set of genetic mutations that are actually involved in predisposing people to heart attack.

"Because coronary disease and heart attacks are so closely related, researchers in the past have assumed they're the same thing," Horne said."They thought that if someone had coronary disease, they would eventually have a heart attack. This finding may help people realise that, through their choices, they have greater control over whether they ultimately have a heart attack," said Horne.

The idea for Horne to study the connection between heart attacks and family history began in 2008 when researchers found that genetic factors related to chromosome 9 were strongly connected to coronary artery disease but those same mutations had no connection to heart attacks.

This supported the biological understanding that a heart attack is different than coronary disease where heart attack results when the atherosclerosis causing coronary disease is unstable. Some atherosclerosis is stable and will not result in a heart attack, researchers said.