A flash of anger may send the body down a path ending in a heart attack or stroke, a systematic review showed.
Although relatively few studies have explored the link between short bouts of anger and cardiovascular events in the hours immediately following the outburst, the evidence is consistent in showing a direct relationship, according to Murray Mittleman, DrPH, of the Harvard School of Public Health, and colleagues.
But it's not clear how substantial the risk is, the researchers reported online in theEuropean Heart Journal.
"The relative risks estimated in this meta-analysis indicate that there is a higher risk of cardiovascular events after outbursts of anger among individuals at risk of a cardiovascular event, but because each episode may be infrequent and the effect period is transient, the net absolute impact on disease burden is extremely low," they wrote. "However, with increasing frequency of anger episodes, these transient effects may accumulate, leading to a larger clinical impact."
Several smaller studies have examined the link between anger and cardiovascular health, but Mittleman and colleagues set out to explore the consistency of the association. A review of the literature turned up nine independent case-crossover studies conducted in the U.S., Sweden, England, Israel, and the Netherlands.
Outcomes included myocardial infarction, acute coronary syndromes, stroke, and ventricular arrhythmia in the 2 hours following angry outbursts.
In pooled results of four of the studies, the risk of MI or acute coronary syndrome was 4.74-fold higher in the hours after an outburst (95% CI 2.50-8.99). In pooled results of two studies, the risk of ischemic stroke was not significantly elevated (incidence rate ratio 3.62, 95% CI 0.82-16.08).
One study evaluated intracranial hemorrhage and showed that the risk was higher in the hour after a bout of anger (IRR 6.30, 95% CI 1.59-24.90).
Two studies had ventricular arrhythmia in patients with implantable cardioverter-defibrillators as an outcome, although the results could not be combined because of differences in the measurement of anger, study design, and hazard periods. One showed that risk was significantly higher in the 15 minutes after an outburst (IRR 1.83, 95% CI 1.05-3.19) and the other showed that the risk was higher in the hour after the angry episode (IRR 3.20, 95% CI 1.80-5.69).
Mittleman and colleagues noted that magnitude of increased risks was higher for individuals who had a greater cardiovascular risk initially.
For MI/acute coronary syndrome, for example, "the absolute impact of one episode of anger per month is only one excess cardiovascular event per 10,000 individuals per year at low (5%) 10-year cardiovascular risk and four excess cardiovascular events per 10,000 individuals per year at high (20%) 10-year cardiovascular risk," they wrote.
In an accompanying editorial, Suzanne Arnold, MD, of Saint Luke's Mid America Heart Institute in Kansas City, Mo., and colleagues discussed some of the potential mechanisms tying anger to cardiovascular events.
"Mediated through increases in circulating catecholamines, increased myocardial oxygen demand, coronary vasospasm, and increased platelet aggregability, anger can cause transient ischemia, disruption of vulnerable plaques, and increased thrombotic potential," they wrote. "These changes can then result in myocardial or cerebral ischemia or malignant arrhythmias."
They pointed out that the review was limited by the small number of available studies and the significant heterogeneity between them, but said that the findings highlight the consistency of results linking acute anger and increased cardiovascular risk.
"However, how to move forward in reducing the burden of these risk factors in patients and, hopefully, its impact on cardiovascular health is still in question," they wrote. "Given the lessons we have learned from trying to treat depression after MI, treating anger in isolation is unlikely to be impactful. Instead, a broader and more comprehensive approach to treating acute and chronic mental stress, and its associated psychological stressors, is likely to be needed to heal a hostile heart."
Mittleman and colleagues noted in their paper that studies of medications -- including beta-blockers and selective serotonin reuptake inhibitors -- have not shown substantial benefits, and said that psychological interventions might help.
In an email to MedPage Today, Redford Williams, MD, of Duke University, said that beta-blockers could ease some of the negative consequences of angry outbursts but that their use would be limited by side effects. He agreed the psychological interventions might be worthwhile.
"Behavioral interventions that train folks to reduce angry outbursts and/or the accompanying physiological arousal could be an effective means of reducing the health damage associated with angry outbursts," he said, backing that up with three prior studies.
The first showed that a group-based psychosocial intervention designed to reduce stress cut mortality among women with coronary heart disease.
The second demonstrated that cognitive behavioral therapy with a focus on stress management lowered the risk of recurrent cardiovascular events in men and women with established coronary heart disease.
And the final paper cited by Williams showed that a psychosocial skills training workshopreduced anger levels and the size of the increases in blood pressure and heart rate that accompanied the recall of situations that made men who had undergone CABG angry.