Brain Scans Give Clues to Stress- Heart Attack Link
Increased activity in the amygdala -- the fear
center of the brain -- appears to create an immune
system reaction that increases inflammation in the
arteries, researchers plan to report at the upcoming
American College of Cardiology meeting in Chicago.
Such arterial inflammation is a precursor to heart
disease, heart attack and stroke, said senior
researcher Dr. Ahmed Tawakol, a cardiologist at
Massachusetts General Hospital in Boston.
Tawakol and his colleagues followed nearly 300 people
and found their amygdala activity -- as seen on
brain scans -- indicated whether they would suffer a
major cardiac event in the near future.
"By the end of the study, roughly 5 percent with low
activity had events, compared to roughly 40 percent
of the individuals with high amygdala activity,"
Tawakol said.
Doctors need to be aware of the heart-health
consequences of current events such as the Syrian
crisis and this week's terror attacks in Brussels, said
Dr. Richard Becker, director of cardiovascular health
and disease at the University of Cincinnati College of
Medicine. He is also director of the university's Heart,
Lung & Vascular Institute.
"After there's an earthquake or a tsunami, the
incidence of heart attacks over the next six to eight
weeks increases substantially," said Becker, an
American Heart Association spokesman, citing prior
research. "The same thing happens with human
disasters, with terrorism, particularly if it's on a large
scale."
Evidence of the strong link between stress and heart
disease has been mounting. The heart-health risk
posed by stress is now believed to be on par with
factors like smoking, cholesterol, high blood pressure and
diabetes, Tawakol said.
But little is known about how stress from anger,
hostility, hopelessness or uncertainty might directly
affect the heart, Tawakol said.
Animal studies have suggested that stress can cause
bone marrow to release inflammatory cells, which
then increase inflammation in the arteries, he said.
To see whether that happens in humans, researchers
examined PET/CT scans for 293 patients, average age
55, who originally received the test between 2005
and 2008 for cancer screening but were found to be
cancer-free.
The scans allowed researchers to measure activity in
regions of the brain, the bone marrow and arteries.
Patients were excluded if they had evidence of
cancer, established heart disease or were younger
than 30 years old.
During the five-year study, 22 patients experienced a
heart attack or stroke.
Researchers found that increased amygdala activity
meant greater activity in the bone marrow and
increased inflammation in arteries.
Further, amygdala activity was linked to an increased
risk of heart attack or stroke. Patients experienced a
14-fold greater risk of heart attack or stroke for
every unit increase in measured brain stress activity,
researchers said.
The amygdala also affected the timing of a heart
attack or stroke. "Individuals with an event within a
year after imaging had the highest amygdala activity
values," Tawakol said. People with the lowest amygdala
activity went the longest before suffering a heart
attack or stroke, the study found.
Becker praised the study.
"They [the study authors] were able to connect the
dots from the brain to inflammation in the blood
vessels to cardiovascular events," Becker said. "This is a
very important contribution to helping us understand
what stressors really mean to human health."
These findings show the importance of stress relief in
a person's life, be it through meditation, exercise,
friendships or humor, Becker and Tawakol said.
"For primary care physicians and cardiologists, we need
to be more cognizant of how to gauge a patient's
stress," Becker said. "We're very good at picking up
when blood pressure is high and whether someone has
diabetes, but we need increasing rigor in detecting a
person's stress."
But the study also hints at new strategies to head
off stress-related heart attacks, the researchers said.
For example, animal studies have shown that some
beta blockers can reduce the amount of inflammatory
cells produced by the bone marrow in response to
stress, Tawakol said. However, knowing whether those
results would be replicated in humans is a long way
off.
Data and conclusions presented at meetings are usually
considered preliminary until published in a peer-
reviewed medical journal.
SOURCES: Ahmed Tawakol, M.D., co-director, Cardiac
MR PET CT Program, Massachusetts General Hospital,
Boston; Richard Becker, M.D., director, cardiovascular
health and disease, University of Cincinnati College of
Medicine, and director and physician-in-chief, UC
Heart, Lung & Vascular Institute; abstract, April 4,
2016, presentation, American College of Cardiology
meeting, Chicago
center of the brain -- appears to create an immune
system reaction that increases inflammation in the
arteries, researchers plan to report at the upcoming
American College of Cardiology meeting in Chicago.
Such arterial inflammation is a precursor to heart
disease, heart attack and stroke, said senior
researcher Dr. Ahmed Tawakol, a cardiologist at
Massachusetts General Hospital in Boston.
Tawakol and his colleagues followed nearly 300 people
and found their amygdala activity -- as seen on
brain scans -- indicated whether they would suffer a
major cardiac event in the near future.
"By the end of the study, roughly 5 percent with low
activity had events, compared to roughly 40 percent
of the individuals with high amygdala activity,"
Tawakol said.
Doctors need to be aware of the heart-health
consequences of current events such as the Syrian
crisis and this week's terror attacks in Brussels, said
Dr. Richard Becker, director of cardiovascular health
and disease at the University of Cincinnati College of
Medicine. He is also director of the university's Heart,
Lung & Vascular Institute.
"After there's an earthquake or a tsunami, the
incidence of heart attacks over the next six to eight
weeks increases substantially," said Becker, an
American Heart Association spokesman, citing prior
research. "The same thing happens with human
disasters, with terrorism, particularly if it's on a large
scale."
Evidence of the strong link between stress and heart
disease has been mounting. The heart-health risk
posed by stress is now believed to be on par with
factors like smoking, cholesterol, high blood pressure and
diabetes, Tawakol said.
But little is known about how stress from anger,
hostility, hopelessness or uncertainty might directly
affect the heart, Tawakol said.
Animal studies have suggested that stress can cause
bone marrow to release inflammatory cells, which
then increase inflammation in the arteries, he said.
To see whether that happens in humans, researchers
examined PET/CT scans for 293 patients, average age
55, who originally received the test between 2005
and 2008 for cancer screening but were found to be
cancer-free.
The scans allowed researchers to measure activity in
regions of the brain, the bone marrow and arteries.
Patients were excluded if they had evidence of
cancer, established heart disease or were younger
than 30 years old.
During the five-year study, 22 patients experienced a
heart attack or stroke.
Researchers found that increased amygdala activity
meant greater activity in the bone marrow and
increased inflammation in arteries.
Further, amygdala activity was linked to an increased
risk of heart attack or stroke. Patients experienced a
14-fold greater risk of heart attack or stroke for
every unit increase in measured brain stress activity,
researchers said.
The amygdala also affected the timing of a heart
attack or stroke. "Individuals with an event within a
year after imaging had the highest amygdala activity
values," Tawakol said. People with the lowest amygdala
activity went the longest before suffering a heart
attack or stroke, the study found.
Becker praised the study.
"They [the study authors] were able to connect the
dots from the brain to inflammation in the blood
vessels to cardiovascular events," Becker said. "This is a
very important contribution to helping us understand
what stressors really mean to human health."
These findings show the importance of stress relief in
a person's life, be it through meditation, exercise,
friendships or humor, Becker and Tawakol said.
"For primary care physicians and cardiologists, we need
to be more cognizant of how to gauge a patient's
stress," Becker said. "We're very good at picking up
when blood pressure is high and whether someone has
diabetes, but we need increasing rigor in detecting a
person's stress."
But the study also hints at new strategies to head
off stress-related heart attacks, the researchers said.
For example, animal studies have shown that some
beta blockers can reduce the amount of inflammatory
cells produced by the bone marrow in response to
stress, Tawakol said. However, knowing whether those
results would be replicated in humans is a long way
off.
Data and conclusions presented at meetings are usually
considered preliminary until published in a peer-
reviewed medical journal.
SOURCES: Ahmed Tawakol, M.D., co-director, Cardiac
MR PET CT Program, Massachusetts General Hospital,
Boston; Richard Becker, M.D., director, cardiovascular
health and disease, University of Cincinnati College of
Medicine, and director and physician-in-chief, UC
Heart, Lung & Vascular Institute; abstract, April 4,
2016, presentation, American College of Cardiology
meeting, Chicago
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