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Durham, N.C. -- It is not necessary to perform cardiac stress tests for first-time users of the class of migraine drugs known as triptans, even though concerns have been raised about the drugs' possible relationship with cardiac disease, according to Duke University Medical Center researchers who have analyzed data on the drugs' effects.

Clinicians prescribe triptans such as Imitrex® and Zomig® to patients with severe migraines who do not respond to first-line treatment with non-steroidal anti-inflammatory drugs (NSAIDS). Migraines are caused by abnormal nerve activation and inflammation. Triptans interfere with these processes and can relieve the pain and other symptoms associated with migraine. However, studies have shown that these drugs can constrict blood vessels in the heart, which could be hazardous to people with heart disease by further reducing blood to the heart muscle.

Individuals who exhibit signs of cardiac disease should not use triptans, said the Duke scientists. However, patients without known cardiac disease and who otherwise would not be considered for an evaluation for cardiac disease do not need exercise testing simply to screen them prior to starting triptans. The research is featured in the July 2004 issue of the journal Headache.

"Migraines are under-diagnosed and under-treated. Over-stressing cardiac risk or adding an unnecessary test may be a roadblock for some patients," said David Matchar, M.D., director, Center for Clinical Health Policy Research at Duke University Medical Center and senior author on the paper. "The risk of cardiac disease in a person with no signs of disease is sufficiently low that any reduction in the likelihood of a heart attack is far outweighed by the substantial likelihood of continued suffering from debilitating migraines."

Another consideration is that most migraines occur in individuals at low risk for cardiac events. "Migraines are most commonly found in younger women, who are considered a low-risk group for heart disease. Twenty to 30 percent of migraine sufferers are women between ages 25 and 30," said Matchar. "After menopause, when a woman's risk of heart disease increases, the rates of migraine drop by two-thirds."

A factor that raises concern for patients and physicians is that some patients who take triptans may experience a tightening of the chest shortly after ingesting the drug, said Matchar. The side effect may mimic heart pain, but it occurs 20 to 30 minutes after taking the drug and dissipates after an hour. The tightening in the chest is not an indication of a cardiac event and is not related to exertion.

To study the clinical benefits of stress testing among healthy patients prescribed triptans, the Duke researchers developed a "virtual clinical trial" that would assess risk and benefit without endangering real patients. This virtual trial used population data from previous migraine studies to create a simulated patient pool, and the virtual patients were assigned to three treatment groups for risk analysis, in which

• All patients were given triptans regardless of individual risk.
• All patients received stress tests first, and the medication given to all who test negative.
• The medication was not given to anyone.

The analysis included other variables such as known risks of the drug, accuracy of stress test, epidemiology of heart disease and the recurrence pattern of chronic migraine.

For each of the treatment strategies, the number of heart attacks and cardiovascular deaths were similar, found the researchers. However, in the arm of the virtual clinical trial that treated everyone with triptans, there were 70 percent fewer migraines than the group that gave triptans to no one.

"For every heart attack prevented in our model, an average of 16 people with migraines spent the remainder of their lives without the benefit of migraine relief," said Lori Orlando, M.D., physician researcher at the Duke's Center for Clinical Health Policy Research and the Durham VA Medical Center. "That's a large part of the population living with unnecessary pain for little or no benefit."

"The bottom line is that people have to make a tradeoff between the disability of a migraine and the risk of an adverse event. No matter what we think of the reasonableness of the tradeoff, some people will not accept even the smallest risk of a heart attack. It's that simple," said Matchar.

Migraines affect 10 percent of the U.S. population, and symptoms include severe headache, nausea, vomiting and sensitivity to light, noise and smell.

"Migraines can be severely disabling," said Orlando. "Patients suffer a significant loss of quality of life and some have to stop working. Nearly 60 percent of these patients find relief with these drugs. It's a risk over benefit question. There's a one in a million chance that using triptans could lead to heart disease in healthy people."

The researchers acknowledge that the study is limited because there are little data on the true cardiac risk of triptans; therefore, researchers had to recreate risk using general statistics on heart disease and also on trial and adverse event reporting.

"Even factoring in this limitation, our study shows little clinical utility to stress testing the vast majority of patients who are beginning treatment with triptans," concluded Matchar.