Migraine Plus High Blood Pressure May Raise Stroke Risk: Expert

Milan, Italy - Although some issues still need to be clarified, accumulating evidence suggests that migraine should one day be considered a risk factor for cardiovascular disease or, more specifically, stroke, says one expert.

During a lecture on migraine and hypertension at the European Society of Hypertension (ESH) European Meeting on Hypertension 2011 here today, Dr Enrico Agabiti-Rosei (University of Brescia, Italy) discussed findings from a study published earlier this year, which showed that those who had hypertension and suffered from migraine had a higher probability of a history of cerebrovascular events than hypertensive-only patients.

"The prevalence of hypertension and migraine comorbidity is clinically rare, but doctors should pay attention when they see this, because it might help identify patients at risk of an event. Migraine might be considered as a factor to be included in the score for risk of stroke," he observed.

To heartwire, he commented: "When a young person has hypertension it's important, particularly if it's a woman, to look for the possible presence of migraine. Once comorbidity is found, it's very important to make an appropriate screening of cardiovascular risk factors, because what a doctor can do is try to reduce as much as possible these risk factors that are correctable by treatment—this includes not only hypertension but also high cholesterol, diabetes, and so on."

Issues that remain to be resolved, he said, include whether migraine itself is a modifiable risk factor for stroke and whether the treatment of migraine can reduce the risk of stroke. "We need more studies in order to assess the true importance of this relationship. We need prospective studies to confirm this interesting result."

Those with migraine and high BP develop hypertension at early age

In his talk, Agabiti-Rosei outlined previous studies in the field, mainly epidemiologic and observational, that have indicated a correlation between migraine and CVD events, mainly stroke. "Migraine seems to be associated with vascular damage, perhaps endothelial dysfunction," he noted.

The prevalence of hypertension and migraine comorbidity is clinically rare, but doctors should pay attention when they see this, because it might help identify patients at risk of an event.

And although migraine with aura as opposed to migraine alone has shown the greatest association with CVD in prior work, he told heartwire that the diagnosis of migraine in much of this research was not necessarily that scientific, having often been based on the results of questionnaires.

To examine the characteristics of those with both hypertension and migraine, he and his colleagues performed a large, multicenter, cross-sectional survey in Italy—the Hypertension and Migraine Comorbidity: Prevalence and Risk of Cerebrovascular Events (MIRACLES) study—in which they compared prior events in patients with both conditions with those who had hypertension alone.

The study included 2973 patients with hypertension, migraine, or both, of whom 517 (17%) suffered from hypertension-migraine comorbidity, 1271 (43%) from hypertension only, and 1185 (40%) from migraine only.

In those with both conditions, the onset of comorbidity occurred at about 45 years of age, with migraine starting significantly later than in the migraine-only group, and hypertension significantly earlier than in the hypertension-only group. Blood pressure was more difficult to control in those with both conditions, and such individuals frequently had a positive family history for both migraine and hypertension.

Those with comorbidity up to five times more likely to have had stroke

The comorbidity group had a higher prevalence (4.4%) of history of cerebrovascular events, compared with those with hypertension only (3.1%) or migraine alone (0.7%), with an odds ratio of a predicted history of stroke/transient ischemic attack (TIA) of 1.76 (95% CI 1.01-3.07) compared with the hypertension group. And in the age range of 40 to 49 years, prevalence of history of stroke/TIA was fivefold greater (4.8% in those with comorbidity vs 0.9% in the hypertension group).

Agabiti-Rosei said that although they carefully diagnosed migraine with aura in MIRACLES, the majority of patients just had migraine, so no separate analysis on migraine with aura was performed.

In conclusion, he said: "The prevalence of hypertension-migraine comorbidity is clinically relevant and might help identify patients at future risk for cardiovascular events."

"Doctors should look for this association, and of course migraine onset is at a relatively young age in comparison with hypertension onset, but as you know, our purpose is to try to convince doctors to measure BP quite early, starting at a young age, even in adolescents and children," he commented to heartwire.