The same genetic variant that makes some people more prone to stress has been shown to increase the risk of having and dying from a heart attack.
Early identification of the gene and treatment of people at higher risk may reduce chances of having a fatal heart attack, researchers believe.
'This is one step towards the day when we will be able to identify people on the basis of this genotype who are at higher risk of developing heart disease', said Dr Redford Williams, director of the Behavioral Medicine Research Center at Duke University, USA, where the study was carried out. Researchers can now 'begin to develop and test early interventions for those heart patients who are at high risk of dying', he added.
A 'risk analysis' based on an assessment of your genes has become an increasingly useful tool in the fight against cancer. Knowledge of similar 'risk genes' in heart disease was lagging behind but this study marks 'a step in the direction of personalised medicine for cardiovascular disease', says Dr Williams.
The genetic variant that interested researchers was a single-letter change in the gene for a serotonin receptor. In a study last year, the same genetic variant was shown to double the amount of cortisol, a stress hormone.
Building on this work, the new research showed that having this stress-linked genetic variant increased the risk of a heart attack or death from heart disease by 38 percent, accounting for other factors like age, obesity and smoking. This genetic variant was found in ten percent of men and three percent of the 6,000 heart disease patients studied.
Exactly why the genetic change increases the risk of a heart attack is not yet fully understood. 'High cortisol levels are predictive of increased heart disease risk', says study author Dr Beverly Brummett, but the team also have another theory. Along with increased cortisol levels, the genetic change is associated with increased levels of an enzyme called MMP9. This enzyme's ability to break up hard plaques in blood vessels may make it easier for clots to form, leading to a heart attack.
Professor Jeremy Pearson from the British Heart Foundation said the study added further evidence to the link between stress and heart disease and highlighted that 'positive lifestyle changes you can make to help you cope with stress' may be an easy way to reduce your risk. Dr Peter Kaufmann from the US National, Heart, Lung, and Blood Institute cautioned that the findings required 'independent replication and evaluation in a more diverse population'.