Bottling up emotions is thought to harm both mind and body, but a new study suggests that the opposite extreme may be no better.

In a study of thousands of heart attack patients, those who recalled having flown into a rage during the previous year were more than twice as likely to have had their heart attack within two hours of that episode, compared to other times during the year.

“There is transiently higher risk of having a heart attack following an outburst of anger,” said study author Elizabeth Mostofsky, postdoctoral fellow with the Cardiovascular Epidemiology Research Unit at Harvard Medical School in Boston.

The greater the fury - including throwing objects and threatening others - the higher the risk, Mostofsky’s team reports in The American Journal of Cardiology. The most intense outbursts were linked to a more than four-fold higher risk while milder bouts of anger were tied to less than twice the risk.

“The association is consistently stronger with increasing anger intensity; it’s not just that any anger is going to increase your risk,” Mostofsky told Reuters Health

The data came from a group of 3,886 patients who were part of a study between 1989 and 1996 to determine what brought on their heart attacks.

Within four days of having a myocardial infarction - the classic “heart attack” - participants were asked about a range of events in the preceding year, as well as about their diets, lifestyles, exercise habits and medication use.

A total of 1,484 participants reported having outbursts of anger in the previous year, 110 of whom had those episodes within two hours of the onset of their heart attacks.

Participants recalled their anger on a seven-point scale that ranged from irritation to a rage that caused people to lose control.

The researchers found that with each increment of anger intensity, the risk of heart attack in the next two hours rose. That risk was 1.7 times greater after feeling “moderately angry, so hassled it shows in your voice;” and 2.3 times greater after feeling “very tense, body tense, clenching fists or teeth” and 4.5 times greater after feeling “enraged! lost control, throwing objects, hurting yourself or others.”

The most frequent causes of anger outbursts that participants recalled were family issues, conflicts at work and commuting.

Although the research cannot prove that the angry outbursts led to the heart attacks, the results “make sense,” according to Dr. James O’Keefe Jr, a cardiologist at St. Luke’s Hospital in Kansas City who wasn’t involved in the research.

Anger is an emotion that releases the fight-or-flight-response chemicals epinephrine and norepinephrine, he said.

Those hormones raise our blood pressure, our pulse, constrict blood vessels, make blood platelets stickier (increasing the risk of blood clots), which O’Keefe says could be one way anger may be associated with increased heart risk.

“Contrary to the urban myth that it’s best to express anger and get it out there, expressing anger takes a toll on your system and there’s nothing really cathartic about it,” O’Keefe told Reuters Health.

“(Anger) serves no purpose other than to corrode the short and long-term health of your heart and blood vessels,” he said.

In the study, patients on blood pressure medications known as beta blockers had a reduced chance of having a heart attack following an angry outburst, Mostofsky’s team notes in their report.

The authors say that finding suggests doctors might consider using those drugs preventively in people at risk of heart attack and prone to anger.

In discussing other possibilities for protecting people at risk, the researchers also write that during the 1990s when the data were collected, not enough study participants were on the newer statin drugs to determine their potential effects on heart attack risk.

Similarly, the number of participants who were on antidepressants was too low to tell whether they would have made a difference.

Regular exercise, Mostofsky and her colleagues write, has been shown to lower overall heart attack risk. Though they found no differences in the link between angry outbursts and short-term heart attack risk among regular exercisers in the study, they conclude that maintaining an active lifestyle couldn’t hurt.

The study is part of a broader field of research looking at managing the effects of emotional states on cardiovascular systems, said Donald Edmondson, assistant professor of behavioral medicine at Columbia University Medical Center in New York, who studies heart attack survivors but was not involved in the new work.

“People prone to angry outbursts or more broadly, who are prone to anxiety, depression or other intense emotions should be aware that this is something that impacts their cardiovascular system,” Edmondson told Reuters Health.

SOURCE: The American Journal of Cardiology, online May 2, 2013