Carl J. Pepine, MD, MACC

The association between migraine headache and CV events had been inconsistent, but this study adds important new information on the long-term risk for CV events among patients with a first-time diagnosis of migraine headache from a contemporary Danish registry. The strengths include its size (> 50,000 patients with migraine) and its contemporary (1995-2013) data. Migraine was associated with significantly increased risks for MI, stroke, venous thromboembolism and atrial fibrillation/flutter, and risks were greater among women vs men.

These data add to our recent analysis (Rambarat CA, et al. Am J Med. 2017;doi:10.1016/j.amjmed.2016.12.028) showing migraine may be an important risk factor for most CVDs among women under evaluation for suspected ischemic heart disease in the WISE cohort. More than 24% reported a history of migraine headache and these participants had an 83% excess risk for a CV event, among CV death, nonfatal MI, HF or stroke (HR = 1.83; 95% CI, 1.22-2.75) at 6.5 years’ follow-up vs. women without migraine history.

This result was driven mainly by a more than twofold increase in stroke risk (HR = 2.33; CI 1.16-4.68), but risks for all CV events were numerically greater among participants with migraines.

Marysia S. Tweet, MD, FACC

This is a large, matched cohort study assessing the association of migraine diagnosis and subsequent CVD among the Danish general population. Over 51,000 patients with migraine were matched on age, sex, and calendar year to over 510,000 controls. Although absolute risk was low, the researchers found higher risk for MI, ischemic stroke, hemorrhagic stroke, venous thromboembolism and AF/ atrial flutter among those with migraines, who were predominantly young women.

The findings are consistent with other studies, which have found that migraines are associated with increased risk for CVD. This study specifically assesses for several specific CVD-related outcomes. They also found that although the associations were stronger in women than men and in those with aura than those without aura, all of those subgroups had increased associated risk. An important note is that the migraine cohort did have a slightly increased CV risk factor burden at index time, as shown in a table.

These findings further demonstrate the importance for considering migraine history in the assessment of CV risk and discussion of preventative measures. It is also hypothesis-generating regarding mechanisms of disease, particularly among young women, which can prompt much-needed further dedicated studies.

Due to limitations in the study design and coding diagnoses, certain factors such as reproductive history, oral contraceptive use, diagnosis of fibromuscular dysplasia (if known) and the presence of patent foramen ovale (if known) were not assessed. Given that the large proportion of patients were young women, these factors would be helpful for further understanding the relevance and significance of the associations found. Also, among those who had MI, identifying the mechanism of MI (eg, plaque rupture vs. paradoxical embolus vs. spontaneous coronary artery dissection vs. other) would again be helpful to attempt to better unify hypotheses regarding mechanisms of disease. Specifically, myocardial infarction due to spontaneous coronary artery dissection and a condition called fibromuscular dysplasia both predominantly affect young women, and recent studies of persons with these conditions have demonstrated notable prevalence of migraine history.