Researchers followed 18,725 Icelandic men and women over 26 years. People who had migraine with aura had a higher risk of dying from heart attack and stroke than those with normal migraine, as well as higher overall mortality.
A separate 13-year longitudinal study involving 27,860 American women found that those who had migraine with aura were at a higher risk of haemorrhagic stroke.
Both studies were published in the BMJ last week.
In an accompanying editorial, neuroepidemiologist Dr Klaus Berger of the University of Muenster said GPs need to consider carefully whether to tell patients diagnosed with migraine with aura about the associated risks.
'For many people, the information will cause unwarranted anxiety, although others may use the opportunity to modify their lifestyle and risk factors accordingly,' he said.