(Health.com) -- Losing a loved one can bring overwhelming feelings of grief, depression, and anger. For some people, the shock and stress of bereavement may even bring on a heart attack.
A new study of nearly 2,000 heart-attack survivors found that attacks were far more likely to happen soon after the death of a family member or close friend than at other times. And the risk of having a heart attack appears to decline as grief subsides.
Roughly 14% of the study participants -- who were interviewed by researchers within days of their attack -- had lost someone close to them in the previous six months. After analyzing the relative timing of each heart attack and bereavement, the researchers estimated that the risk of having an attack is 21 times higher in the 24 hours following a death than it is one to six months later.
Risk declines steadily with each day after a loved one's passing, but it remains eight times higher one week after the death and four times higher one month afterward, according to the study, which was published today in the American Heart Association journal Circulation.
The link between grief and bereavement was strongest among people who had preexisting risk factors for heart disease and heart attacks, such as high blood pressure or unhealthy cholesterol levels.
"This suggests that if you add grief to traditional risk factors for coronary artery disease, whether it be smoking, hypertension, or family history, the grief may potentially put you over the edge," says Eugene Storozynsky, M.D., a cardiologist at the University of Rochester Medical Center, in Rochester, New York, who was not involved in the study.
The depression, anxiety, and other strong emotions associated with grief may be partly responsible for the spike in heart-attack risk, says lead author Elizabeth Mostofsky, Sc.D., a post-doctoral research fellow at Beth Israel Deaconess Medical Center and the Harvard School of Public Health, both in Boston.
Grief-related stress can increase blood pressure and heart rate, raise levels of the stress hormone cortisol, constrict blood vessels, and disrupt cholesterol-filled plaques that line arteries. Any one of these changes raises the risk of heart attack, Mostofsky says.
Grief also makes blood "stickier" and therefore more likely to clot, Mostofsky says. Acute stress tends to increase levels of the hormones known as catecholamines, she explains, which causes platelets to stick together. If a plaque bursts, the resulting clot is more likely to cut off blood to the heart.
People mourning the loss of a loved one might further increase their heart-attack risk by sleeping poorly, eating less, and skipping their medications -- although medication did not appear to be a culprit in this particular group of people, the study notes.
"There hasn't been any systematic research, but it's plausible that providing social support and making sure people are compliant with medications may reduce the risk," Mostofsky says.
Mostofsky and her colleagues based their findings on one-on-one interviews with 1,985 still-hospitalized heart-attack patients. Their analysis assessed heart-attack risk by, in effect, comparing the number of days between each study participant's bereavement and heart attack with the number of days in the recent past in which he or she coped with a similar loss without experiencing a heart attack.
The number of overall heart attacks that can be attributed to grief is quite small, the authors say. According to their estimates, stress during the one-week period following a death could be expected to cause one additional heart attack for every 1,394 people with few or no preexisting risk factors and one additional heart attack per 320 individuals already at high risk.
Several questions remain unanswered, however. For instance, the researchers weren't able to determine whether heart-attack risk was affected by the relationship the survivors had with the deceased. Of the 193 participants who provided details, 40 reported losing a parent, child, spouse, or sibling, and 153 lost a friend or more distant relative.
Also, due to a lack of data from angiograms (a type of X-ray), the authors can't rule out the possibility that some of the participants had Takotsubo cardiomyopathy, also known as "broken heart syndrome." This condition -- so called because it's associated with intense stress (including grief) -- involves a ballooning out of the bottom of the heart but no actual obstruction in the blood vessels.
Copyright Health Magazine 2011