Migraine with aura was a large risk factor for cardiovascular events among women who participated in the Women’s Health Study.
Although the physiologic connection isn’t yet clear, the finding is, according to Dr. Tobias Kurth, who is the primary investigator in the study that examined the association. He will present the full results of the study in March at the annual meeting of American Academy of Neurology in San Diego.
"Migraine with aura was the second-largest factor contributing to the risk of heart attack and stroke," said Dr. Kurth of the French National Institute of Health and Medical Research in Bordeaux. "It was ahead of diabetes, smoking, body mass index, and a family history of heart disease."
Dr. Tobias Kurth
Dr. Kurth, also of Brigham and Women’s Hospital in Boston, used the Women’s Health Study to examine how migraine with aura fits in with other well-known risk factors for cardiovascular disease in women. The 15-year study was originally designed to examine the impact of low-dose aspirin and vitamin E for the primary prevention of cardiovascular disease and cancer. It enrolled nearly 40,000 women who were aged 45 years or older when they were entered in 1993, he said in an interview.
The cohort for Dr. Kurth’s study comprised 27,860 women who provided baseline blood samples and were without major cardiovascular disease at baseline. Overall, 1,435 had migraine with aura.
During the entire study, there were 1,030 cases of heart attack, stroke, or cardiovascular death. A systolic blood pressure of 180 mm Hg or higher was the strongest risk factor, with an incidence of 9.8 per 1,000 women per year. That was an expected association, Dr. Kurth said.
What he did not expect was to see was an incidence of 7.9 per 1,000 women per year in women who had migraine with aura. This exceeded the rates of cardiovascular disease in all other risk groups, including diabetes (7.1), family history of prior myocardial infarction (5.4), current smoking (5.4), and having a body mass index of 35 kg/m2 or more (5.3).
The study doesn’t address any underlying physiologic connections. There are some theories, however.
"These involve vascular dysfunction," Dr. Kurth said. "People with migraines may have a different vascular reactivity, which might lead to some kind of a shared mechanism between migraine and cardiovascular disease. Inflammation, which is seen in both migraine and cardiovascular disease, might play a role. And genetic factors could be contributing as well."
Recognition of these patients is important, he said. "Patients who have migraine with aura could also potentially develop cardiovascular disease. This should be carefully assessed, because, unlike some of the other risk factors, migraine is not really modifiable."
Patients who have migraine with aura might especially benefit from lifestyle modification to further reduce their risk of heart disease. "People with migraine with aura can reduce their risk in the same ways others can, such as [by] not smoking, keeping blood pressure low and weight down, and exercising."
The National Institutes of Health funded the study. Dr. Kurth had no financial disclosures.