Researchers here provide epidemiological evidence to suggest that exercise, an active lifestyle, reduces the impact of heart attacks, making them less severe. We can hypothesize that this may be due to an increased generation of redundant blood vessels, perhaps, via upregulation of the processes of angiogenesis over the long term. Heart attacks are usually caused by blockage of an important blood vessel by fragments of a ruptured atherosclerotic plaque. If there are alternative paths for blood to flow into the affected tissue, then the immediate harms done are reduced.
Heart disease is the leading cause of death globally and prevention is a major public health priority. The beneficial impact of physical activity in stopping heart disease and sudden death on a population level is well documented. This study focused on the effect of an active versus sedentary lifestyle on the immediate course of a heart attack - an area with little information.
The researchers used data from 10 European observational cohorts including healthy participants with a baseline assessment of physical activity who had a heart attack during follow-up - a total of 28,140 individuals. Participants were categorised according to their weekly level of leisure-time physical activity as sedentary, low, moderate, or high. The association between activity level and the risk of death due to a heart attack (instantly and within 28 days) was analysed in each cohort separately and then the results were pooled.
A total of 4,976 (17.7%) participants died within 28 days of their heart attack - of these, 3,101 (62.3%) died instantly. Overall, a higher level of physical activity was associated with a lower risk of instant and 28-day fatal heart attack, seemingly in a dose-response-like manner. Patients who had engaged in moderate and high levels of leisure-time physical activity had a 33% and 45% lower risk of instant death compared to sedentary individuals. At 28 days these numbers were 36% and 28%, respectively. The relationship with low activity did not reach statistical significance.