Women age 45 years or older who have migraine headaches with neurological aura symptoms such as temporary visual disturbances are at higher risk for myocardial infarction, stroke, angina and death due to ischemic cardiovascular disease, according to an article in the July 19 issue of the Journal of the American Medical Association. In contrast, migraine without aura, the most common form of migraine, and a negative history for migraine headaches have the same, baseline risk for a major cardiovascular event.

In the United States, the one-year prevalence of migraine is approximately 18 percent in women and 6 percent in men; an estimated 28 million Americans have severe and disabling migraines, according to background information in the article. Migraine with aura has been previously linked with increased risk of ischemic stroke. Because some studies have suggested that migraine, particularly migraine with aura, is associated with an unfavorable cardiovascular risk profile, an association with other cardiovascular disease was plausible but had not been firmly established.

Tobias Kurth, MD, ScD, of Brigham and Women's Hospital and the Harvard School of Public Health, Boston, and colleagues evaluated the association of migraine with or without aura and subsequent risk of overall and specific cardiovascular disease.

The study included 27,840 women, age 45 years or older, who were participating in the Women's Health Study, were free of cardiovascular disease and angina at baseline (1992-1995), and who had information on self-reported migraine and aura status and lipid measurements.

At baseline, 5,125 women (18.4 percent) had a history of migraine. Of the 3,610 women with migraine in the prior year, 1,434 (39.7 percent) had aura symptoms. During an average of 10 years of follow-up, 580 major cardiovascular events occurred.

The researchers found that a history of migraine was associated with increased risk of major cardiovascular disease event. This increased risk differed according to aura status. Compared with no migraine history, women who reported active migraine with aura had a significantly increased risk of subsequent major cardiovascular events, ischemic stroke, myocardial infarction, coronary revascularization, angina, and death due to ischemic cardiovascular disease.

The increased risks, which remained after adjustment for a large number of cardiovascular risk factors, ranged from a 1.7-fold increase for coronary revascularization to a 2.3-fold increase for ischemic cardiovascular disease death. In contrast, women who reported active migraine without aura did not have significantly increased risk for any ischemic vascular event.

"Since migraine without aura is far more common than migraine with aura, our data demonstrate no increased risk of cardiovascular disease for the majority of migraine patients. Future research should focus on a better understanding of the relationship between migraine, aura status, and cardiovascular events," the authors concluded.

In an accompanying editorial, Richard B. Lipton, MD, and Marcelo E. Bigal, MD, PhD, of the Albert Einstein College of Medicine, and the Montefiore Headache Center, Bronx, New York, commented on the study:

"Why is there an association between migraine with aura and risk factors for cardiovascular disease? One suggestion is that genetic polymorphisms may predispose to both cardiovascular risk factors and migraine with aura. A polymorphism in the methyltetrahydrofolate reductase gene (C677T) is associated with a moderately increased homocysteine level, which, in turn, is associated with risk of cardiovascular disease. The same polymorphism is overexpressed in migraine with aura but not migraine without aura."

"For patients with migraine with aura, clinicians should have heightened vigilance for modifiable cardiovascular risk factors, such as hypertension, hyperlipidemia, and smoking. Ultimately, it will be important to determine whether migraine with aura is itself a modifiable risk factor for cardiovascular disease. Future studies should investigate the possibility that preventive medications for migraine or antiplatelet therapy might reduce the risk of cardiovascular disease in patients with migraine with aura."