Lack of exercise may be a big reason some heart attacks kill instantly

A recently published analysis of data from 10 European studies has found a potential reason that some heart attacks kill instantly: lack of exercise. The lifestyle factor may play a big role in whether someone survives a heart attack, according to the study published in the European Journal of Preventative Cardiology.

Past research has extensively evaluated the link between lifestyle factors, including physical activity, and one's odds of developing heart disease — the leading global cause of death. This new study narrows things down, evaluating whether physical activity or lack thereof influences one's chance of instantly dying from a heart attack.

The analysis involved data on around 28,000 people who were healthy when the data was first collected, and who later had a heart attack at some point during the follow-up period. Activity data on the participants was split into four categories ranging from sedentary to high; as well, the study adjusted for other potential influencing factors like BMI, smoking status, and diabetes.

The study looked at individuals who died within 28 days of experiencing a heart attack — out of 4,976 people, 3,101 of them died instantly from the heart attack. The researchers found an association between instant death risk and lack of physical activity, one that presents 'in a dose-response-like manner.'

Compared to people who led sedentary lifestyles, the participants who got moderate and high levels of physical activity faced a respective decrease in instant death risk of 33- and 45-percent. The findings indicate that getting regular exercise may help protect against fatal heart attacks.