Stress worsens heart disease symptoms and increases the risk of dying from a stroke or heart attack, according to a new JAMA study.
The condition causes blockages in blood flow to the heart called myocardial ischemia.
These blockages more than double the risk of death in people with coronary heart disease (CHD) – even if their condition is ‘stable’ and controlled by medication, the study found.
All of the participants in the study had been diagnosed with heart disease and were considered stable having received treatment.
Study co-author, Dr Viola Vaccarino, professor of cardiovascular research at Emory University in Atlanta, said: “Psychological stress is a powerful risk factor for adverse outcomes in people with heart disease.
“Exposure to acute stress can cause a reduction of blood flow to the heart muscle in some people, and this can increase their risk of cardiac events or death.”
Researchers studied the effects of stress on 918 adults with CHD aged 18 – 79.
Around 300 of the participants had been hospitalised with a heart attack within eight months of the study commencing.
The researchers triggered mental stress by asking the participants to perform a public speaking task.
The participants were given two minutes to prepare a speech and three minutes to deliver it in front of an audience of four or more people.
Their mental stress levels were based on blood pressure and heart rate readings recorded throughout the duration of the task.
The researchers also measured ‘conventional’ stress on the heart caused by physical exercise.
Among the participants, 16 per cent developed mental stress-induced myocardial ischemia, 31 per cent had conventional stress-induced myocardial ischemia and 10 per cent suffered both.
A total of 8 per cent of the participants who had mental stress-induced myocardial ischemia died of a cardiovascular-related event within five years.
Meanwhile, 4 per cent of those who did not develop mental stress-induced myocardial ischemia died from a heart-related condition within the five-year window.
Around 12 per cent participants with mental stress-induced myocardial ischemia died from any cause within five years, compared to just under 8 per cent of those who were not affected by the condition.
Vaccarino said: “This was not because these individuals were sicker, or prone to reduction in blood flow with other forms of heart challenge, like a physical stress using treadmill.
“Actually, those who developed ischemia with mental stress only were at higher risk of recurrent events and death than those who developed ischemia with a conventional stress test only.”
CHD is responsible for around 64,000 deaths each year in the UK.
By age 60, 7.4 per cent of CHD adults will have an ischemic stroke, a 2019 study found.
