Migraine Frequency Tied to Stroke, Heart Attack Risk

ByABC News
June 24, 2009, 6:02 PM

June 25 -- WEDNESDAY, June 24 (HealthDay News) -- The research team that found an increased risk of stroke in women who had a certain kind of migraine now reports a relationship between migraine frequency and heart attacks.

"Our earlier study showed an increased risk of ischemic strokes in women with a higher frequency of migraine headaches with aura," said Dr. Tobias Kurth, lead author of a report in the June 24 issue of Neurology. "Our new data confirms this. What we add is data in regard to coronary disease."

But the finding is "complex," varying with migraine frequency, said Kurth, an assistant professor of neurology at Harvard Medical School and a senior scientist at INSERM, the French national institute for medical research. "We see a U-shaped association -- an increased risk of myocardial infarction [heart attack] in the low-frequency migraine group and an increased risk for stroke in the high-frequency migraine group, those who have headaches at least weekly," he explained.

In both studies the association with stroke or heart attack is seen only in women who have migraines accompanied by an aura, a visual disturbance such as seeing flashing lights before the headache starts.

Women who had migraine with aura at least once a week were four times more likely to have a stroke as women who do not have migraine, the study found. Women who had migraine with aura less than once a month were more than twice as likely to have a heart attack and nearly twice as likely to have had coronary procedures such as bypass surgery. Migraines with aura once a month were not associated with increased risk of stroke or heart attack.

The findings come from an analysis of the Women's Health Study, which includes nearly 28,000 U.S. women health professionals who had no heart or brain blood-vessel problems at the start and were followed for 12 years. Of the 3,568 women with migraine at the start of the study, 75 percent had migraine less than once a month, 20 percent had migraine once a month and 5 percent had migraine at least once a week.