The sad passing of Kimberley Kitching and Shane Warne (both 52) from suspected cardiac conditions has put a spotlight on the causes of heart disease.

In recent days, attention has turned to the issue of psychological stress in the context of allegations of workplace bullying as a potential contributor to Ms Kitching’s physical health before her death. Ms Kitching’s ALP colleagues have strongly denied bullying claims.

But we are learning more and more about how mental stress can endanger our hearts.

Heart disease is more common in those who experience extreme stress

Psychological factors are under-recognised risk factors for heart attack when compared to more established ones like high cholesterol or blood pressure. Yet centuries of evidence show the intricate link between the heart and mind.

Historical accounts dating back to the 17th century show heart conditions were more prevalent in people exposed to extreme stress and trauma, like those serving in the military compared to the civil population.

Much of this excess burden was thought to be due to rheumatic fever or heavy labour. But studies of contemporary, community-based veterans show stress plays a key role. Veterans with post traumatic stress disorder (PTSD) have a greater risk of developing heart conditions like heart failure when compared to those without PTSD.

Further evidence comes from people experiencing acute distress following natural disasters or the loss of a loved one. The latter can lead to Takotsubo syndrome (an acute heart failure syndrome) also known as “broken heart syndrome” which is especially common in women.

What our research shows

Our recent paper, presenting research led by Deakin University’s Food and Mood Centre’s Meghan Hockey, found it is not just exposure to extreme stress that can increase one’s risk of having a heart event.

The study followed 195,531 American adults over 5.9 years. We found people reporting mild, moderate and severe levels of psychological stress died prematurely from cardiovascular disease (usually stroke or heart attack).

What was striking was that the association worked in a dose-response manner – the risk of someone dying from a heart condition increased with the severity of psychological stress (22% for mild stress, 44% for moderate and 79% for severe levels, respectively). This association remained even after we considered other factors like age, gender, ethnicity, education, income, body mass index, physical activity, smoking and alcohol intake.

Job stress increases your chance of having a heart attack

Workplace conditions – how much control you have at work, long working hours, shift work, discrimination, bullying and sedentary activity – can shape your cardiovascular and emotional responses over the course of a working day. This, in turn, affects your risk of heart disease.

Chronic exposure to these forms of stress can influence your “fight or flight response” causing a release of cortisol and an inflammatory response that can accelerate the thickening or hardening of the arteries that lead to heart attacks, called the “atherosclerotic process”.

While there is evidence some of the association between stress and heart disease may be explained by behavioural factors like poor diet, smoking or drinking that might be used as stress coping mechanisms, research shows an independent relationship exists between both acute and chronic psychosocial stressors and cardiac disease.

What can employers do?

Often, the assumption is that the responsibility for preventing heart disease rests solely with an individual. But given the sources of stress and trauma may be beyond an individual’s control, it is important we consider the environment in which we work, age and play when we think about our heart health.

Scientists have calculated 5% of new cardiovascular events (first hospitalisation from heart attack or stroke) could potentially be prevented if workplace bullying was eliminated. Given there are approximately 161 cases of heart attack or unstable angina in Australia each day, this is not insignificant.

In 2015, the American Heart Association launched a Worksite Health Achievement Index by which employers can benchmark their practices related to heart disease prevention.

Such a tool goes beyond assessing individual employees’ health based on conventional risk factors to consider policy, programs and environmental factors that can improve the heart health of their employees. The benefit to employers is likely to be happier, healthier, more productive employees. Of course, rigorous research is needed to confirm this.

What can you do if you are struggling?

Seeking professional support via your GP, psychologist, publicly available services like beyond blue or employee assistance programs to help manage stress is critical.

Promisingly, there is evidence people who receive comprehensive mental health care over one year (antidepressants, therapy) halve their risk of having a cardiac event over the next eight years compared to those who do not.

We are currently developing clinical guidelines on behalf of the World Federation of Societies of Biological Psychiatry that aim to provide clinicians with evidence-based recommendations for treating patients with depression that include considerations around employment, environmental, social and lifestyle targets (due for publication mid 2022).

This type of approach is likely to have both mental health and cardiovascular benefits which in turn benefit individuals, families, businesses and society.

If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.

This article was first published on The Conversation on March 21st 2022.

Prof Adrienne O’Neil is co-director of the Food & Mood Centre. She is a Principal Research Fellow & Heart Foundation Future Leader Fellow.