Background: Migraine with aura is associated with an increased risk of ischemic vascular conditions, but the reasons for this are poorly understood. Kurth and colleagues used data from the Women's Health Study to evaluate the association between migraine and cardiovascular risk.

The Study: The prospective cohort study involved more than 39,000 female health professionals who were 45 years or older. Participants did not have cardiovascular disease, cancer, or any other major illness on entry into the study. Extensive information on cardiovascular and lifestyle factors was collected at baseline and at least annually thereafter. The data included self-reported migraine status and Framingham risk score. All participants were monitored for major ischemic vascular events. The outcomes in women with migraine were compared with those in women who did not report migraine. Within the migraine group, women who reported migraine with aura were compared with women who had other migraine types.

Results: After exclusions, the study included more than 27,500 women. A history of migraine was reported by 5,074 women (18.4 percent). Thirteen percent of women reported active migraine, 39.6 percent of whom had migraine with aura. Women with active migraine were younger, less likely to use alcohol or exercise regularly, and more likely to use hormone therapy after menopause than those without migraine. Women with a history of migraine were more likely to smoke, have elevated cholesterol levels, and have current or previous hypertension. Family history of myocardial infarction (MI) was equally distributed among the migraine groups. The mean concentration of high-density lipoprotein cholesterol was higher in women without migraine.

Over nearly 12 years of follow-up, 697 women had a first major ischemic cardiovascular event, including 306 strokes, 301 MIs, and 148 cardiovascular deaths. During follow-up, 647 women underwent coronary revascularization and 412 developed angina.

Overall, the risk of a major cardiovascular event increased with increasing Framingham risk score. Women with non-aura migraine were not at increased risk of MI or ischemic stroke compared with women without migraine. Active migraine with aura was associated with about a twofold increase in risk of major cardiovascular disease, ischemic stroke, and MI. When stratified by Framingham risk score, a U-shaped pattern was found with high, but different, risks for women with migraine with aura in the lowest and highest Framingham score groups. Compared with women without migraine, women who had migraine with aura had age adjusted hazard ratios for ischemic stroke and MI of 3.88 and 1.29, respectively, in the lowest Framingham risk score group and of 1.00 and 3.34, respectively, in the highest risk score group.

Conclusion: The authors conclude that in women who have migraine with aura, the increased risk of ischemic stroke is apparent only in the lowest Framingham risk score group. Conversely, the risk of MI is increased only in the highest Framingham risk score group. The authors propose that migraine be regarded as a manifestation of altered systemic vasculature, and they recommend that cardiovascular risk factors be carefully identified and managed in women with migraine with aura.

editor's note: The main message from the study and related editorial¹ is that cardiovascular risk factors should be managed vigorously in women who have migraine with aura to reduce cardiovascular events. Fewer suggestions are offered to impact the increased risk of ischemic stroke in women who have migraine with aura and low Framingham risk scores. Experts suggest a mechanism for ischemic stroke that is based on changes in cerebral blood flow during migraine with aura, and they express hope T that aggressive migraine preventive therapy could reduce stroke and MI rates. Experts further suggest that the disappearance of migraine with aura as a person ages may be related to developing atherosclerosis.—a.d.w.