New guidelines outline stroke risks unique to women

A new set of guidelines on the prevention of stroke in women calls for the development of a female-specific stroke risk score and recommends risk-reduction strategies related to preeclampsia, oral contraceptives, hormone therapy and other factors.

The guidelines, developed by a writing group from the American Heart Association and the American Stroke Association, focus on risk factors that are unique to women or more common in women than men.

Sex-specific risk profile needed

There is an increasing need for more research on risk-profile development to tailor stroke prevention strategies for women, according to the document.

“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. Prospective research is needed for these women-specific risk factors, including pregnancy-related risk factors and hormonal exposure, as well as changes in hormonal status across the lifespan,” Cheryl Bushnell, MD, MHS, FAHA, writing group chair, and the guideline authors wrote.

Several recommendations concern preeclampsia and pregnancy outcomes. Pregnant women with chronic primary or secondary hypertension or previous pregnancy-related hypertension are recommended to take low-dose aspirin from the 12th week of gestation until delivery and calcium supplementation ≥1 g/day should be considered for the prevention of preeclampsia in women with dietary intake of calcium <600 mg/day.

Severe hypertension in pregnancy, defined as systolic BP ≥160 mm Hg or diastolic BP ≥110 mm Hg, should be treated with antihypertensive medications known to be safe and effective in pregnant women, including methyldopa, labetalol and nifedipine, according to the document. Treatment should also be considered for pregnant women with systolic BP of 150 mm Hg to 159 mm Hg or diastolic BP of 100 mm Hg to 109 mm Hg, as evidence suggests this group has elevated risk for stroke. Pregnant women should not be given atenolol, angiotensin receptor blockers and direct renin inhibitors, the authors wrote.

Physicians should be aware that women with preeclampsia have a twofold increased risk for stroke and fourfold increased risk for high BP later in life, according to the document.

The guideline recommends measurement of a woman’s BP before prescription of oral contraceptives because women with high BP who take oral contraceptives are also at higher risk for stroke. The authors noted that oral contraceptives may be harmful in women with other risk factors for stroke, such as smoking and prior thromboembolic events, and that aggressive therapy of stroke risk factors may be reasonable in those taking oral contraceptives.

The guideline does not recommend hormone therapies for stroke prevention. Specifically, the authors caution against use of conjugated equine estrogen for primary or secondary stroke prevention in postmenopausal women and selective estrogen receptor modulators, including raloxifene (Evista, Lilly), tamoxifen and tibolone, for primary stroke prevention.

Smoking cessation should be encouraged in women who have migraines with aura because there is an elevated risk for stroke in women who smoke and have migraines with aura. Treatments to reduce the frequency of migraines may help prevent stroke, but more evidence is needed, Bushnell and colleagues wrote.

Lifestyle recommendations

The writing group made the following lifestyle recommendations for primary stroke prevention in women with CV risk factors:

Regular physical activity; and
Alcohol consumption of less than one drink per day for nonpregnant women,
Smoking cessation, and
A diet such as Dietary Approaches to Stop Hypertension (DASH) that is rich in fruits, vegetables, grains, nuts and olive oil, but low in saturated fat.

Because of the high rate of stroke in women aged at least 75 years who have atrial fibrillation, active screening for AF should be conducted in that population, according to the document.

The writing group supported the use of novel oral anticoagulants for prevention of stroke and systemic thromboembolism in women with paroxysmal or permanent AF and other risk factors, but did not recommend any oral anticoagulation in women aged 65 years and younger with AF but no other risk factors.

The guideline recommends aspirin for women undergoing carotid endarectomy, even in the presence of diabetes. However, if a high-risk woman is intolerant of aspirin therapy, clopidogrel should be substituted. The guidelines also outline when to perform prophylactic carotid endarectomy in women and when to perform it in women with recent ischemic stroke or transient ischemic attack.

The guidelines have been endorsed by the American Association of Neurological Surgeons and the Congress of Neurological Surgeons, and have been affirmed by the American Academy of Neurology as an educational tool for neurologists.

For more information:

Bushnell C. Stroke. 2014;doi:10.1161/01.str.0000442009.06663.48.

Disclosure: See the full statement for a list of the authors’ relevant financial disclosures.