Brain Imaging Shows Connection Between Stress, CV Risk

The idea that stress can lead to cardiovascular events like heart attacks or strokes isn’t new. But the mechanism behind this connection has remained something of a mystery–until now.

Researchers from Massachusetts General Hospital (MGH) in Boston studied brain scans for 293 patients and found that higher levels of activity in the amygdala–the area known to be the brain’s “stress center”–were associated with arterial inflammation, a predictor of heart attacks and strokes.

The results will be presented at the upcoming 65^th Scientific Session of the American College of Cardiology, which meets April 2-4, 2016, in Chicago.

Ahmed Tawakol, MD, an associate professor at Harvard Medical School and co-director of the Cardiac MR PET/CT Program at MGH, said in a briefing that while cardiologists tend to pay attention to cardiovascular (CV) risk factors such as smoking, high cholesterol levels, or diabetes, levels of stress get less attention. Yet understanding how chronic stress affects patients–and addressing it–is important in preventing cardiovascular events, he said.

“Over the past several years, it’s become clear that stress is not only a result of adversity but may itself also be an important cause of disease,” Tawakol explained.

In animal models, it is known that stress leads to inflammation in the bone marrow and release of harmful cells, called monocytes, that cause arterial inflammation. The result can be atherosclerotic disease, which occurs when plaque accumulates in the arteries and restricts blood flow, causing CV events.

To conduct the study, the first group of researchers started with health records from patients who had received PET/CT scans to screen for cancer but did not have the disease. This group evaluated the brain images and scored them for levels of activity in the amygdala. A separate team of cardiologists that did not have access to brain imaging data then evaluated the patient records for cardiovascular events in the follow-up period, which averaged 3.8 years.

Activity levels in the amygdala were associated with a corresponding level of arterial inflammation. In fact, after correcting for demographic and other known risk factors, each unit of elevated activity in the brain’s stress sector was associated with a 14-fold greater risk of a CV event.

“Our study illuminates, for the first time, a relationship between activation of neural tissues–those associated with fear and stress–and subsequent heart disease events,” Tawakol said.

The question is: what can be done about stress? Tawakol said future studies should address potential interventions–and they need not involve pharmaceuticals. Things like meditation and mindfulness, which are getting increased attention, could prove “fruitful,” he said.

“These behavioral interventions could be effective and very cheap,” Tawakol said.

Reference

Ishai A, Takx R, Nahrendorf M, Pitman R, Lisa SM, Tawakol A. Greater activity of the brain’s emotional stress center associates with arterial inflammation and predicts subsequent CVD events. To be presented at the 65^th Scientific Session of the American College of Cardiology, Chicago; April 4, 2016. Abstract 16-A-12805.