Both men and women share many of the same high-risk predictors for stroke, such as smoking, family history, and physical inactivity. However, some risk factors are either exclusive to women or affect women disproportionately. The American Heart Association (AHA) and American Stroke Association (ASA) recently convened a panel of experts in neurology, obstetrics, cardiology, epidemiology, and internal medicine to review and assess the literature on stroke risk in adults. This resulted in the publishing of the first gender-specific AHA/ASA guidelines for stroke prevention in women.
“The development of these guidelines is important because women differ from men in many ways with regard to stroke,” explains Cheryl B. Bushnell, MD, who chaired the AHA/ASA writing group that developed the document. Several characteristics can influence stroke risk and impact outcomes, including genetic differences in immunity, coagulation, hormonal factors, reproductive factors (eg, pregnancy and childbirth), and social factors. “Many of the unique risk factors for women present at younger ages due to things like oral contraceptive use and pregnancy complications,” Dr. Bushnell explains. “Recognition of stroke risk and identification of prevention strategies could start early in at-risk women.”
Highlighting Key Recommendations
Based on available evidence, the AHA/ASA guidelines categorized risk factors by those that were sex-specific, more prevalent in women, or similar between women and men (Table 1). Dr. Bushnell says it is critical to recognize that women with a history of hypertension or preeclampsia during pregnancy are at risk for stroke and hypertension later in life. “Before this guideline emerged, few providers and women knew about this risk,” she says. “The evidence for this relationship is strong, and multiple meta-analyses have come to the same conclusion.”
The AHA/ASA guidelines, which were published in Stroke, recommend documenting hypertension in women during pregnancy, preeclampsia or eclampsia, or gestational diabetes as risk factors for stroke in medical records. At this time, strategies should be used to decrease future stroke risk at early ages, even as early as the childbearing years. The recommendations for preventing stroke in women with symptomatic or asymptomatic carotid disease remain the same as those that have been previously published for men (Table 2).
Dr. Bushnell adds that treating blood pressure in the moderate range—150 to 159 mm Hg systolic—should be considered for pregnant women but notes to carefully consider maternal and fetal risks and benefits by reviewing potential medication side effects. “Predicting which women may go on to develop severe hypertension during pregnancy might help identify those who should receive treatments,” she says. “We should also proactively review blood pressure across the lifespan because stroke risks persist after pregnancy.” Another strong recommendation is to treat women at high risk of preeclampsia with low-dose aspirin or calcium supplements. If preeclampsia can be prevented, there is a chance to reduce the future risk of stroke.
Tailoring Long-Term Risk Assessment
The AHA/ASA guideline recommends developing a female-specific stroke risk score to reflect risk across a lifespan. Such a tool could help clinicians determine long-term risk for women, guide early prevention strategies, and establish when these interventions should begin. A women-specific risk score may point to gender-specific dosing or pharmacologic approaches. “Unfortunately, there’s a large gap in research in this area,” says Dr. Bushnell. “That said, recognizing the risk factors that should be incorporated into stroke risk scores is an important first step.” A better understanding is also needed on recovery from stroke and the long-term functional impairment in women.
More research is warranted to determine if specific risk factors are independently related to future stroke risk when traditional risk factors, such as cholesterol and hypertension, are included in stroke risk assessments. “We need studies that determine which women with hypertension during pregnancy or preeclampsia will be at highest risk for stroke later in life,” Dr. Bushnell says. Studies are also needed to determine which subgroups of women, such as African Americans, are at risk for hypertension during pregnancy because this can increase stroke risk.
A Welcome Addition
The AHA/ASA guidelines emphasize that there are different stroke risk factor patterns in women and that pregnancy, preeclampsia, migraines, atrial fibrillation, diabetes, and hypertension are among the important differences that should be known when evaluating risk profiles. “These guidelines have been warmly received,” says Dr. Bushnell. “They may encourage important educational conversations with patients to help identify any heightened risks of hypertension or risk factors for stroke. This is an especially important guideline for public awareness and for clinicians who may not be up to date with the literature about gender-specific stroke risk factors.”