By Olga Rukovets
Although men and women do share many of the same high-risk predictors for stroke — such as smoking, family history, and physical inactivity — some risk factors are either exclusive to women or affect women disproportionately. With this in mind, the American Heart Association/American Stroke Association convened a panel of experts in neurology, obstetrics, cardiology, epidemiology, and internal medicine to review and assess the literature on stroke risk in adults through May 15, 2013. They published the first gender-specific guidelines for stroke prevention in women — which were endorsed by the AAN, the American Association of Neurological Surgeons, and the Congress of Neurological Surgeons — in the Feb. 6 online edition of Stroke.
“This endeavor is important because women differ from men in a multitude of ways, including genetic differences in immunity, coagulation, hormonal factors, reproductive factors including pregnancy and childbirth, and social factors, all of which can influence risk for stroke and impact stroke outcomes,” the guideline authors wrote.
Overall, our extensive review of the evidence pointed to more gaps in knowledge than definitive recommendations, the lead author Cheryl Bushnell, MD, an associate professor of neurology, and director of the Wake Forest Baptist Stroke Center in Winston-Salem, NC, told Neurology Today. The primary message from the guidelines “is that many of the unique risk factors for women are present at younger ages (due to oral contraceptive use, pregnancy complications), so recognition of stroke risk and prevention strategies could start early to keep women from having a preventable stroke,” she said.
The most important recommendation from our review, Dr. Bushnell said, “is that women with a history of hypertension or preeclampsia during pregnancy are at risk for stroke and hypertension later in life.” Before this guideline, some providers and few women knew about this risk, she explained, and “the evidence for this relationship is pretty solid, as multiple meta-analyses have come to the same conclusion.” For this reason, the guidelines recommend documenting hypertension in women during pregnancy, preeclampsia/eclampsia, or gestational diabetes as risk factors for stroke in the medical record, “and beginning strategies to decrease their future risk of stroke at early ages, even as early as during their childbearing years.”
“We suggest considering treating blood pressure in the moderate range (150-159 mmHg systolic) for pregnant women, although there has to be careful consideration of maternal and fetal risk and benefit in this group” because of medication side effects. Predicting which women may go on to develop severe hypertension during pregnancy (>160/110 mmHg), she added, might also help identify which women should be treated.
The guidelines also make a strong recommendation for treating women at high risk of preeclampsia with low-dose aspirin or calcium supplements. “The implication is that if you can prevent preeclampsia, perhaps you have reduced the future risk of stroke by at least one notch,” said Dr. Bushnell.
The guidelines may be useful for neurologists who are counseling female patients with migraine with aura on how to reduce their overall stroke risk by focusing on some of the factors unique to or more common in women. Many migraine medications may also lower blood pressure, she said, thus, reducing stroke risk and “killing two birds with one stone.”
The authors recommended the development of a female-specific risk score to reflect stroke risk across the lifespan. This would help clinicians “determine a woman’s long term-risk in the future, and be used as a guide to developing early prevention strategies and determine how early they should start,” said Dr. Bushnell. Potentially, these differences in risk score may point to gender-specific dosing or pharmacological approaches, “but there is a huge gap in research in this area,” she said, adding that recognizing these risk factors is the first step.
Dr. Bushnell noted that further research is also needed to determine if these gender-specific risk factors are independently related to future stroke risk when traditional risk factors, such as cholesterol and hypertension, are included in the score. Studies are needed, she said, to determine which women with hypertension during pregnancy or preeclampsia will be at highest risk for stroke later in life, as well as among “diverse populations, since African Americans, in particular, are at risk for hypertension during pregnancy.”
Stay tuned for the full discussion of the guidelines and their implications in the March 20 issue of Neurology Today. Read up on emerging research in stroke here: http://bit.ly/ZpC0CF.