Postmenopausal women in the study who reported at least one full-blown panic attack within six months of being interviewed were four times as likely as other older women to have a heart attack or related death over the next five years.
They were three times as likely to have either a heart attack, heart-related death, or stroke, and nearly twice as likely to die from any cause.
Earlier studies have implicated depression as a risk factor for heart disease, but the new research is the first to suggest a direct link between anxiety-related panic attacks and heart attack and stroke risk.
Harvard Medical School associate professor of psychiatry Jordan W. Smoller, MD, ScD, who led the study team, says more research is needed to confirm the finding.
"There is not a lot of previous evidence suggesting that panic attacks are in themselves dangerous (in terms of heart risk)," he tells WebMD. "Our study does not resolve the question. But it does suggest that older women with a recent history of panic attacks may warrant closer scrutiny for cardiovascular complications."
Panic Attacks and Heart Attacks
The study included 3,369 healthy postmenopausal women participating in the larger ongoing Women's Health Initiative (WHI) trial examining risk factors for heart disease and other health outcomes among older women.
When they entered the study between 1997 and 2000, the women, whose average age was 66, were asked if they had recently experienced a panic attack. They were then followed for an average of 5.3 years.
At enrollment, one out of 10 women reported having had a full-blown panic attack within six months.
After adjusting for the impact of other established cardiovascular risk factors, a recent panic attack was associated with a fourfold increased risk of heart attack or heart-related death and a twofold increase in death from any cause.
The findings are published in the October issue of the journal Archives of General Psychiatry. The research was funded by Glaxo Wellcome, now the pharmaceutical company GlaxoSmithKline.
"Our study adds panic attacks to the list of emotional states and psychiatric symptoms that have been linked to excess risk of cardiovascular disease and death," the researchers wrote.
Impact on Heart Hard to Measure
Smoller says it is not clear if the anxiety that leads to panic attacks directly increases cardiovascular risk or if panic attacks are actually a symptom of undiagnosed heart and vascular disease.
"Shortness of breath, chest pain, and raised heartbeat are all symptoms of panic attack," he says. "It is possible that some women who reported these symptoms might have unrecognized cardiac problems."
It is also not clear if the findings apply to younger women and men, or if aggressive treatment of panic attacks with antianxiety drugs lowers heart attack and stroke risk.
Cardiologist Gerald F. Fletcher, MD, tells WebMD that while there is growing evidence to suggest that depression, anxiety, and other psychological conditions have an adverse impact on the heart, the impact remains difficult to measure.
Fletcher is a professor of medicine at the Mayo Clinic Jacksonville and a spokesman for the American Heart Association.
"We have been able to show a direct link between heart disease and risk factors like hypertension, cholesterol, obesity, and smoking," he says. "These are easily measurable, but the impact of depression and anxiety on heart risk is not."