Abstract 1041: Migraine Headache and the Risk of Ischemic Stroke: A Systematic Review and Meta-analysis of Observational Studies
Context: Observational studies have suggested an association between migraine headache and the risk of ischemic stroke.
Objective: To quantitatively summarize the strength of association between migraine and the risk of ischemic stroke across observational studies of migraineurs.
Data Sources: Comprehensive search of computerized databases through February 2009, including MEDLINE and EMBASE, for published and unpublished studies of human subjects in the English language, and manual searches of bibliographies of key retrieved articles.
Study Selection: Selection criteria were applied independently by pairs of reviewers and included case-control and cohort study design, reported or extractable quantitative estimate of ischemic stroke risk, and exclusion of studies in which migraine did not precede stroke. Of 35 studies eligible for full-text review, 21 (60%) met the selection criteria for the meta-analysis.
Data Extraction: Data extraction and assessment of study quality were conducted independently by pairs of reviewers using standardized forms.
Results: A total of 610,505 participants (13 case-control and 8 cohort studies) were included in the meta-analysis. The pooled adjusted odds ratio (OR) of ischemic stroke using a random effects model was 2.30 (95% confidence interval, 1.91–2.76). A similar magnitude of association was seen for studies that reported relative risks (pooled adjusted relative risk, 2.41; 95% confidence interval, 1.81–3.20). The association was stronger in subgroup analyses of migraine with aura (OR, 2.51; 95%confidence interval, 1.52– 4.14) and in women (OR, 2.89; 95% confidence interval 2.42–3.45), but was attenuated for migraine without aura (OR, 1.29; 95% confidence interval 0.81–2.06). Results were robust to sensitivity analyses excluding lower quality studies.
Conclusions: Migraine is associated with an increased risk of ischemic stroke, particularly in persons with migraine with aura and in women. These findings may have implications for the management of migraineurs, especially those with other modifiable stroke risk factors.