Stress seems to be a strong driver of cardiovascular events, including heart attack, stroke, and even death.
For the first time, brain imaging has confirmed a link that has long been suspected: Activation of one of the brain’s prime emotional centers, the amygdala, directly correlates with the risk of cardiovascular events.
“This study illustrates a clear relationship between the activity of the amygdala and heart disease,” Dr. Ahmed A. Tawakol said at a press teleconference leading up to the annual meeting of the American College of Cardiology.
“Stress is known to be associated with an increase in the risk of cardiovascular events, and the risk is on par with that exerted by smoking, hypertension, and diabetes, but we don’t address it,” said Dr. Tawakol, codirector of the Cardiac MRI PET CT Program at Massachusetts General Hospital, Boston.
The findings also highlight a possible pathway for this relationship, suggesting that stress-related noradrenalin stimulates extramedullary hematopoiesis, a key driver of inflammation. This can contribute to atherosclerotic inflammation, which increases the likelihood of a heart attack or stroke, said Dr. Tawakol.
His study comprised 293 subjects who had undergone a PET or CT scan for cancer evaluation, but were determined to be cancer free. All scans contained brain and bone imaging data. Dr. Tawakol assessed amygdala and bone marrow activation, and evaluated inflammatory response in arteries.
These findings were then correlated with any cardiovascular events occurring in the next 5 years; the median follow-up was 3.8 years. Events were significantly more common among those with high levels of amygdala activation, occurring in 35% of this group, but in just 5% of those with low activation.
After adjusting for risk factors in the Framingham model, Dr. Tawakol found that high amygdala activation conferred a 14-fold increase in the risk of a cardiovascular event. These were likely to be precipitous as well, he said: The higher the level of activation, the more likely the event was to happen within the first year of follow-up.
He had no financial disclosures.