MedWire News: Patients who suffer migraine with aura may have an increased risk for hemorrhagic stroke and all-cause mortality, in addition to the already established high risk for ischemic stroke, show two large cohort studies.

The link between migraine with aura and hemorrhagic stroke emerges from a re-analysis of the Women's Health Study. A previous analysis, with 9 years of follow-up, found no association, but the present analysis, with 13.6 years of follow-up found an adjusted 2.31-fold risk increase for hemorrhagic stroke among women who had migraine with aura, relative to those with no migraine.

The relationship persisted after adjusting for multiple confounders, Tobias Kurth (Harvard Medical School, Boston, Massachusetts, USA) and team report in the British Medical Journal.

Having a history of any migraine, reported by 18% of the 27,860 women, did not increase their hemorrhagic stroke risk. Seventy per cent of these women had active migraine (symptoms within the previous year) and 40% reported having aura.

Women had a 2.78-fold increased risk for intracerebral hemorrhage and a 3.56-fold increased risk for fatal hemorrhagic stroke if they had migraine with aura. But their risks for subarachnoid hemorrhagic and nonfatal hemorrhagic stroke were unaffected.

Overall, migraine with aura accounted for four additional hemorrhagic strokes per 10,000 women per year.

The second study, based on 18,725 men and women living in and around Reykjavik, Iceland, found that people who reported having migraine with aura were 27% more likely to die of cardiovascular disease and 21% more likely to die of any cause, relative to those without migraine.

Larus Gudmundsson (University of Iceland, Reykjavik) and colleagues report a 28% increase in mortality from coronary heart disease and a 40% increase in fatal stroke among people who had migraine with aura.

But they also had a significant 19% increase in the risk for death from non-vascular causes.

Editorialists Klaus Berger (University of Münster, Germany) and Stefan Evers (University Hospital Münster) urged doctors to be cautious about communicating these findings to their patients.

"For many people the information will cause an unwarranted amount of anxiety, although others may use the opportunity to modify their lifestyle and risk factors accordingly."

They added: "Future research will have to assess whether prophylactic drug treatment of migraine not only reduces the number and severity of migraine attacks but also reduces subsequent cardiovascular and cerebrovascular events.

"However, because this will require long follow-up, in the meantime clinicians must carefully weigh the decision whether or not to discuss the risks related to this condition."

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

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