Co-senior author Zahi A. Fayad, PhD, vice-chair for Research in the Department of Radiology and the director of TMII at ISMMS in NY, says, "This pioneering study provides more evidence of a heart-brain connection, by elucidating a link between resting metabolic activity in the amygdala, a marker of stress, and subsequent cardiovascular events independently of established cardiovascular risk factors". "Our results provide a unique insight into how stress may lead to cardiovascular disease", Ahmed Tawakol, MD, author of the study, said in a press release.
With more study, the results could lead to new treatments for stress-related cardiovascular issues.
But what exactly is the link between stress and the heart?
In the study, the researchers looked at two groups of patients, the first of which included almost 300 adults ages 30 and up.
"A better understanding of this link can help us develop methods of prevention" of heart disease, Borenstein said. These people were then tracked for an average of 3.7 years to see if they developed cardiovascular disease. The researchers observed that those who had higher amygdala activity had a higher chance of developing heart problems compared to those who had low amygdala activity.
High levels of activity in the amygdala at the start of the study were associated with an increased risk of experiencing a cardiac event.More news: Marine Le Pen makes unannounced visit to Trump Tower in NY
In addition, heightened activity in the amygdala was associated with greater amounts of inflammation in the blood vessels and higher levels of activity in the parts of the bone marrow where new blood cells are made, according to the study.
While amygdalar reactivity is known to be increased in patients with atherosclerosis, "neither human nor animal studies have yet shown whether amygdalar activation precedes and predisposes to the subsequent development of cardiovascular events", the researchers wrote.
Dr. Tawakol's paper describes two studies that aimed to combat the same problem in a similar way.
In a small sub-study, 13 patients who had a history of post-traumatic stress disorder (PTSD), also had their stress levels assessed by a psychologist, underwent a PET scan and had their levels of C-reactive protein - a protein that indicates levels of inflammation in the body - measured. Based on previous studies that showed that depression and anxiety trigger the amygdala, the researchers observed that this area in the brain is responsible for stress.
Publishing their work in The Lancet medical journal, the researchers said the stress signalled in the amygdala is also linked to increased bone marrow activity and to inflammation in the arteries, which can cause heart attack and stroke. Twenty-two of them did, going on to have heart attacks, angina, heart failure, stroke and narrowing of the arteries. In people with more active amygdalas, these bad heart events also seemed to happen sooner.
Stress can be as unsafe as smoking and high blood pressure, the USA researchers said.Heart experts said, heart-risk patients should be helped to manage stress.