Over the last few years, there has been a great deal of discussion regarding Migraine disease and increased risk of stroke. There had not been, however, sufficient study of Migraine and cardiovascular disease (CVD) to either acknowledge or dismiss any connection between Migraine and CVD. Now, thanks to the Women's Health Study, which was conducted by the National Institutes of Health and followed various aspects of the participants' health for 10 years, there is new information surfacing.
 

Study design, setting, and participants

Tobias Kurth, M.D., Sc.D., of Brigham and Women's Hospital and the Harvard School of Public Health, Boston, and his colleagues evaluated the association of Migraine with or without aura and subsequent risk of overall and specific CVD. The study included 27,840 women, 45 years of age or older, who were participating in the Women's Health Study, were free of CVD and angina when they entered the study in 1992-1995, and who had information on self-reported Migraine with aura and lipid test results. Their study report was based on follow-up data through March of 2004.
 

Study results

• Of the 3,610 with active Migraine (Migraine attacks in the prior year), 1,434 (39.7%) reported aura symptoms.
• During a mean of 10 years of follow-up, 580 major CVD events occurred.
• When compared with women with no Migraine history, the women who reported active Migraine with aura were...
  • 2.15 times as likely to experience major CVD events;
  • 1.91 times as likely to experience ischemic stroke;
  • 2.08 times as likely to experience myocardial infarction;
  • 1.74 times as likely to experience coronary revascularization;
  • 1.71 times as likely to experience angina; and
  • 2.33 times as likely to die of ischemic CVD.
• After adjusting for age, there were 18 additional major CVD events attributable to Migraine with aura per 10,000 women per year.
• Women who reported active Migraine without aura did not have increased risk of any vascular events or angina.

Study conclusions

Kurth and his colleagues concluded,

"In this large, prospective cohort of women, active Migraine with aura was associated with increased risk of major CVD, myocardial infarction, ischemic stroke, and death due to ischemic CVD, as well as with coronary revascularization and angina. Active Migraine without aura was not associated with increased risk of any CVD event."

Analysis of and comments on the study

Dr. Richard Lipton and Dr. Marcelo Bigal reviewed the study by Kurth et al and evaluated possible reasons for the connection between Migraine with aura and CVD...

• They ruled out coincidence because the design of the study protects against bias and Kurth et al measured and adjusted for many CVD risk factors.
• Lipton and Bigal also ruled out the theory that the stress of Migraine attacks could "unmask coronary artery disease acutely or could contribute to the development of vasculopathy over the course of multiple headache attacks." If that were the case, one would expect the correlation in Migraine without aura as well as Migraine with aura, which was not the outcome of the study.
• The hypothesis of an environmental exposure was also ruled out because of the absence of correlation in Migraine without aura.
• Lipton and Bigal suggest that there may be a genetic link that predisposes people to both cardiovascular risk factors and Migraine with aura. A polymorphism (A variation that is too common to be due merely to new mutation) in gene C677T is associated with both increased risk of CVD and Migraine with aura, but not Migraine with out aura.

Lipton and Bigal commented,

"From a clinical perspective, most Migraine patients have Migraine without aura and, therefore, are not at increased risk of CVD. They can be reassured... For patients with Migraine with aura, clinicians should have heightened vigilance for modifiable cardiovascular risk factors, such as hypertension, hyperlipidemia, and smoking... Future studies should investigate the possibility that preventive medications for Migraine or antiplatelet therapy might reduce the risk of CVD in patients with Migraine with aura."

Summary

With their study, Kurth et al provide compelling evidence of increased risk of cardiovascular disease in women over 45 with Migraine with aura. The evidence also shows no increased risk with Migraine without aura. Even though there is increased risk with Migraine with aura, it's no reason for panic. The increased risk translates to 18 additional major CVD events attributable to Migraine with aura per 10,000 women per year. This study provides incentive for patients and physicians to be more vigilant about modifiable cardiovascular risk factors and for studies to determine if there are medications that can be used to prevent Migraine attacks and reduce CVD risk. If you have Migraine with aura, this is a topic to discuss with your doctor.

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Resources:

Kurth, Tobias, MD, ScD; Gaziano, J. Michael, MD, MPH; Cook, Nancy R., ScD; Logroscino, Giancarlo, MD, PhD;Diener, Hans-Christoph, MD, PhD; Buring, Julie E., ScD. (2006) "Migraine and Risk of Cardiovascular Disease in Women." JAMA: The Journal of the American Medical Association. 2006;296:283-291.

Lipton, Richard B., MD; Bigal, Marcelo E., MD, PhD. "Migraine and Cardiovascular Disease." JAMA: The Journal of the American Medical Association. July 19, 2006—Vol 296, No. 3.

Women's Health Initiative. Women's Health Study. National Institutes of Health. Bethesda.

© Teri Robert, July 18, 2006