New guidelines for preventing stroke in women were published online ahead of print February 6 in Stroke.

“If you are a woman, you share many of the same risk factors for stroke with men, but your risk is also influenced by hormones, reproductive health, pregnancy, childbirth, and other sex-related factors,” said Cheryl Bushnell, MD, lead author of the guidelines. Dr. Bushnell is an Associate Professor of Neurology and Director of the Stroke Center at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina.

Pre-Eclampsia Increases Stroke Risk
The guidelines describe stroke risks that are unique to women, and the authors provide evidence-based recommendations on how to reduce these risks. They suggest, for example, that women with a history of high blood pressure before pregnancy be considered for low-dose aspirin or calcium supplement therapy to lower the risk of pre-eclampsia.

Because women with pre-eclampsia have twice the risk of stroke and a fourfold risk of high blood pressure later in life, the guidelines recommend that pre-eclampsia be recognized as a risk factor well after pregnancy. Physicians should evaluate women with pre-eclampsia within one year of giving birth, and, based on their individual and family risk factors, possibly treat them for cardiovascular risk factors. Other risk factors such as smoking, high cholesterol, and obesity in these women should be treated early, according to the authors.

Blood Pressure, Birth Control, and Stroke
Clinicians may consider prescribing blood pressure medication for pregnant women with moderately high blood pressure (ie, 150 to 159 mmHg/100 to 109 mmHg), but should treat expectant mothers with severe high blood pressure (160/110 mmHg or above), according to the guidelines. Methyldopa, labetalol, and nifedipine are recommended for treating severe hypertension, but atenolol, angiotensin receptor blockers, and direct renin inhibitors are contraindicated because of teratogenicity.

Physicians should screen women for high blood pressure before the women take birth control pills because the two factors increase stroke risk. But evidence does not support routine screening for prothrombotic mutations before a woman initiates oral contraception, according to the guidelines.

On the other hand, evidence suggests that oral contraceptives may be harmful in women who have risk factors, including smoking and prior thromboembolic events. In addition, the guidelines recommend that women with migraine with aura stop smoking to avoid higher stroke risks. Treatments that reduce the frequency of migraine may also reduce the risk of stroke, but the evidence for this effect is not strong.

Obesity and Metabolic Syndrome
Data indicate that a healthy lifestyle that includes whole foods, exercise, and abstaining from tobacco lowers stroke incidence in women and men. Subgroup analyses, however, suggest that men derive more benefit from a healthy lifestyle than women do. Research focusing on women alone has been inconclusive about whether lifestyle interventions reduce stroke in women.

Nonetheless, the guidelines recommend that women maintain a lifestyle of exercise, healthy eating, and abstinence from tobacco use. Moderate alcohol intake (ie, one drink per day or fewer) is acceptable for women who are not pregnant.

Hormone Therapy and Stroke
The authors reviewed seven studies, including the Women’s Health Initiative, to analyze the link between stroke and hormone therapy. Hormone therapy should not be used for primary or secondary stroke prevention in postmenopausal women, according to the guidelines. Selective estrogen receptor modulators (eg, raloxifene, tamoxifen, and tibolone) should not be used for primary prevention of stroke.

Atrial Fibrillation
Similar numbers of women and men have atrial fibrillation, but the condition becomes more common with age, and women have a longer life expectancy than men do. The guidelines recommend that primary care physicians actively screen women for atrial fibrillation once they reach age 75. The screening method should be pulse followed by an electrocardiogram.

No evidence supports oral anticoagulation for women age 65 or younger who have atrial fibrillation but no other risk factors, said the authors. Evidence does support antiplatelet therapy, however.

A Need to Identify Women at Risk
High blood pressure, migraine with aura, atrial fibrillation, diabetes, depression, and emotional stress are stroke risk factors that tend to be stronger or more common in women than in men. More research is necessary for the development of a female-specific score to identify women at risk for stroke, said Dr. Bushnell.

The guidelines’ intended audience is primary care providers, including obstetricians and gynecologists. The authors obtained evidence for their recommendations by examining dozens of studies that included hundreds of thousands of women. Although much information on stroke among women is available, more research should be conducted, said the authors.

“There is a need for recognition of women’s unique, sex-specific stroke risk factors, and a risk score that includes these factors would thereby identify women at risk,” said Dr. Bushnell. “Similarly, it is important to improve stroke awareness and provide more rigorous education to women at younger ages, including childbearing ages.”

—Erik Greb and Michele G. Sullivan

New Guidelines Focus on Reducing Strokes Among Women