Propranolol Linked to Stroke Protection in Women With Migraine

Women taking propranolol for migraine prevention may reap reduced risk of ischemic stroke as an added benefit, according to data presented as an abstract this week at the International Stroke Conference in Los Angeles, CA.

Although men were included in the retrospective study, they did not show the same benefit from propranolol as women. In two different databases, women on propranolol saw a 52% and a 39% lower risk of ischemic stroke over a mean follow-up of 10 years compared with women not on propranolol. The interaction was strongest for those who had migraine without aura.

The authors, led by Mulubrhan Mogos, PhD, MSc (Vanderbilt University School of Nursing, Nashville, TN), say their findings are not surprising since there is strong evidence that antihypertensives substantially reduce stroke risk. They also note that the reductions in stroke were seen at multiple time points over the follow-up period.

Seemant Chaturvedi, MD (University of Maryland School of Medicine, Baltimore), who commented on the study for TCTMD, added that these are thought-provoking data.

“Propranolol has been used for migraine prevention for decades. The thought that it could reduce the stroke rate would be an added bonus,” he said. “Since propranolol can reduce blood pressure, one wonders if part of the benefit could be due to blood pressure-lowering. It could also reduce the risk of abnormal heart rhythms, which could be connected with stroke.”

Tracy E. Madsen, MD, PhD (University of Vermont, Burlington), chair of the American Heart Association’s Clinical Cardiology/Stroke Women’s Health Science Committee, said in a recorded video summary that the 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.”

Two Databases, Same Outcome

Using their institution’s patient database and the National Institutes of Health (NIH)’s All of Us database, Mogos and colleagues identified adults with migraine who developed stroke and those who did not. In all, there were 378 cases and 15,209 controls in the institutional database as well as 267 cases and 6,579 controls in the NIH database.

The cumulative incidence of stroke was numerically lower among women taking propranolol in both databases at 1, 2, 5, and 10 years. The mean age of those who had a stroke was 50 years.

After adjusting for age, sex, race, comorbid conditions, and hormonal factors, including birth control and pregnancy, the rate of stroke was 0.86% at 10 years in women on propranolol in the institutional database versus 2.03% for women not on propranolol (P = 0.011) and 0.92% at 10 years in women on propranolol in the NIH database versus 3.3% for women not on propranolol (P = 0.048).

The authors note that the number of stroke events was relatively low over the study period, potentially limiting the power to detect significant associations.

To TCTMD, Chaturvedi said another limitation of the analysis is that migraine is far more common in women than men, so it’s possible that there were not enough men in the analyses to reliably answer the question.

“A randomized trial comparing propranolol versus other migraine prevention medications would be of interest,” he noted. “In addition, analyzing existing migraine registries would be another avenue to pursue.”