Migraine has yet to be a found as a definite risk factor for venous thromboembolism (VTE) in older adults, according to a study recently published in Research and Practice in Thrombosis and Haemostasis.
At least 4 reports have suggested that migraine history may increase the risk for VTE, but how migraine can cause VTE is unclear. In this study, researchers followed 11,985 patients between the years 1995 and 2015 who had reported headache symptoms and were free of VTE. Patients were classified as having migraines with aura, migraines without aura, severe nonmigraine headaches, or no severe headaches. VTE incidents during this period were confirmed by medical record review. The mean age of patients at baseline was 60 years (standard deviation 6) and 11% were classified as having a migraine history (n=396 with aura and n=932 without aura). Over the follow-up period, 688 patients developed VTE.
Patients with a migraine history were found not to be at greater risk for VTE compared with those free of severe headache (hazard ratio [HR] 1.06; 95% CI, 0.82-1.36). Patients who had a history of migraine with aura had an HR of 1.25 (95% CI, 0.85-1.85) compared with those without severe headache. VTE was also not associated with a self-reported physician diagnosis of migraine (HR 1.22; 95% CI, 0.96-1.55).
This study had several limitations and drawbacks. The migraine history of patients may be misclassified because history was obtained by patient questionnaire without physician diagnosis and confirmation. Migraine prevalence peaks between 20 and 50 years of age, but the mean sample age was 60. Only hospitalized cases of VTE were captured. The follow-up period for VTE was long because the association of migraine with VTE is stronger at 0 to 1 years than within 1 to 19 years after diagnosis, and the study did not examine VTE incidence within 2 years following the questionnaire. Lastly, 3 of the 4 initial studies suggested that the association between migraine and aura may be at least 2-fold or 1.6 fold, but statistical power was limited to determine whether migraine doubled the risk for VTE.
The study researchers concluded that results from this study indicate that migraine history is not a critical risk factor for VTE in older adults. However, they note that due to the limitations of the study they cannot draw firm conclusions regarding whether migraine may be a small VTE risk factor.
Folsom AR, Lutsey PL, Misialek JR, Cushman M. A prospective study of migraine history and venous thromboembolism in older adults. Res Pract Thromb Haemost. 2019; 3(3):357-363.