Research Highlights:
- Propranolol, a beta blocker medication used for treating high blood pressure and preventing migraines, may lower ischemic stroke risk in women who experience migraines frequently.
- In the large analysis of more than 3 million medical records, the protective effect of propranolol was stronger for ischemic stroke compared to other stroke types and in women with migraine without aura. However, it did not have the same effect on men.
- Note: The study featured in this news release is a research abstract. Abstracts presented at the American Heart Association's scientific meetings are not peer-reviewed, and the findings are considered preliminary until published as full manuscripts in a peer-reviewed scientific journal.
Embargoed until 4 a.m. CT/5 a.m. ET, Thursday, Jan. 30, 2025
DALLAS, Jan. 30, 2025 – A medication often used to treat high blood pressure and prevent migraines was associated with a reduction in ischemic stroke risk among women using the drug for migraine prevention, according to a preliminary study to be presented at the American Stroke Association's International Stroke Conference 2025 . The meeting is in Los Angeles, Feb. 5-7, 2025, and is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.
Propranolol, a beta blocker medication used for treating high blood pressure and preventing migraines, had a stronger protective effect for ischemic stroke risk in women with migraine, particularly those without aura. However, the medication did not have the same protective effect on men.
Migraine headaches are common in the general population, but they occur three times more often in women than in men. This debilitating condition is associated with an increased risk of stroke. While the beta blocker propranolol can be used to prevent migraines, its effectiveness in reducing overall stroke risk is still uncertain.
"Migraine is an often-ignored risk factor for cardiovascular issues. Until recently, preventive treatments for people who have migraines were not available," said lead study author Mulubrhan Mogos, Ph.D., M.Sc., FAHA, an assistant professor at Vanderbilt University School of Nursing in Nashville, Tennessee. "Many women suffer from migraines, and it's important to note that propranolol may be beneficial for these women, particularly those who experience migraine without aura. This is an important discovery for those dealing with migraines."
Mogos also noted that migraine disproportionately affects women from historically under-resourced communities, and this disparity may impact the ability to achieve education goals or maintain stable employment, creating a vicious cycle. While new treatments have proven effective, they may not be accessible to women in these groups due to high costs.
For the study, researchers reviewed more than 3 million electronic health records from two large databases. In separate analyses, researchers identified people with migraine who developed stroke and those with migraine who did not develop stroke (control group). They then assessed whether the individuals were treated with propranolol for migraine and whether that treatment had impacted stroke risk.
"We initially looked at overall stroke and then ischemic stroke specifically. We refined our analysis further by controlling for possible confounders and found the association is significant and stronger for ischemic stroke," Mogos said.
After adjusting for potential variables, such as demographics (age, sex, race), other conditions (high blood pressure, diabetes, etc.) and hormonal factors (use of birth control, pregnancy - considered separately for each woman) that might affect results the analysis found:
- Propranolol was significantly associated with a reduced risk of ischemic stroke in women with migraine, particularly in those without aura. The risk of developing a stroke was 52% lower for women taking the medication in one database analysis and 39% lower in the other. No stroke risk reduction was seen in men in either analysis group.
- The protective effect of propranolol was stronger for ischemic stroke and in women with migraine without aura. Migraine aura can include disturbances, such as flashing lights, blind spots, zigzag patterns or seeing colored spots. Other symptoms include tingling or numbness in the face or hands, difficulty speaking, dizziness or confusion.
- Secondary analyses showed lower overall stroke rates in women taking propranolol at multiple time points in both databases.
"Our findings indicate that women and health care professionals should discuss the advantages of preventive migraine interventions. For under-resourced individuals who bear a greater burden from this condition and may lack access to new treatments, we must ensure these treatments are available to them. This approach can help reduce health disparities," Mogos said.
"Migraine without aura may often be overlooked as a risk factor for stroke, especially in women, in whom previous literature has demonstrated that migraine is a stronger, more important risk factor compared with men. The study's findings are not surprising since we have strong evidence that medications similar to propranolol used to treat blood pressure reduce stroke risk substantially. The findings are potentially quite helpful, though, for women living with frequent migraine, as they suggest we have a good medication option that helps to prevent both migraines and strokes. This study is a great example of the important information that can be gained by studying women and men separately – we can take advantage of known sex differences in stroke risk factors and move towards more personalized care," said Tracy E. Madsen, M.D., Ph.D., chair of the American Heart Association Clinical Cardiology (CLCD)/Stroke Women's Health Science Committee and associate professor of emergency medicine at The Robert Larner, M.D. College of Medicine at The University of Vermont. Madsen was not involved in the study.
The main limitation is that this was a review of past data using electronic health records, which may introduce biases, such as misclassification errors from reliance on ICD codes (codes used to classify and report health conditions and diseases). These findings highlight the need for studies that look forward in time to confirm these results.
Study details, background or design:
- Using existing data, the study evaluated the effect of migraine treatments in lowering the risk of stroke. The study used two de-identified electronic health record databases: the Synthetic Derivative (SD) maintained by Vanderbilt University Medical Center (VUMC) and the All of Us Research Program managed by the National Institutes of Health (NIH).
- The study was conducted at Vanderbilt University School of Nursing and the Department of Biomedical Informatics at Vanderbilt University Medical Center in Nashville.
- The SD database from Vanderbilt University Medical Center comprises de-identified longitudinal research data of over 3 million people spanning more than 15 years. As of May 2024, the All of Us Research Program has electronic health record data for over 230,000 diverse participants across the United States.
- The SD database is more region-specific with a relatively similar population, while the All of US database includes a broader, more diverse population representative of various regions of the United States. This could account for some of the differences found.
- Researchers included men and women with a primary diagnosis of stroke after onset of first migraine. People in the control group had no stroke diagnosis after the first onset of migraine.
- The analysis looked at the association between propranolol use and stroke risk at four points in time over ten years.
Co-authors, disclosures and funding sources are listed in the manuscript.
Statements and conclusions of studies that are presented at the American Heart Association's scientific meetings are solely those of the study authors and do not necessarily reflect the Association's policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association's scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
