Cardiovascular disease (CVD) is a major healthcare issue for women in the United States. More than one in three women have some form of CVD, including hypertension, heart disease, stroke, peripheral artery disease (PAD), and diseases of the veins.1 CVD is the number one cause of death in all U.S. women. The majority of these deaths are attributed to coronary heart disease (CHD), and more than 60% of women who died suddenly of CHD had no previous symptoms.1
Historically, CVD has always been considered a man's disease. Most clinical research has been conducted on men, and as a result, little was known about risk factors, prevalence, and signs and symptoms in women. In 1999, the American Heart Association (AHA) published the first female-specific guidelines for preventing CVD.2 The first evidence-based guidelines were published in 2004, and then updated in 2007.3,4 As sex-specific research was conducted and published, CVD prevention guidelines for women became more refined. The most recent AHA guidelines were published in 2011, and a major change is the inclusion of preventive strategies that have demonstrated positive “effectiveness-based” outcomes in the clinical setting rather than limiting recommendations to “evidence-based” treatment benefits documented through clinical research.5
Although women today have an increased awareness of the prevalence and mortality of CVD, nearly half of U.S. women are still unaware that CVD is the leading cause of death—even surpassing cancer—in U.S. women.6 The prevalence, mortality, lack of warning signs in some women, and decreased awareness within this patient population make it imperative for nurse practitioners (NPs) to assume an active role in assessing these patients, evaluating risk factors, and advocating for prevention of CVD in all women.
Evaluation of risk factors
The first step in implementing the AHA guidelines is to evaluate a woman's risk factors for developing CVD. The NP should record a complete medical, family, lifestyle, and pregnancy history along with a complete physical exam, paying attention to a woman's history and/or current symptoms of CHD, cerebrovascular disease, PAD, abdominal aortic aneurysm, end-stage or chronic kidney disease, and diabetes mellitus. Manifestations of any of these diseases indicate the patient is in a “high-risk” category.
Because atrial fibrillation significantly increases the risk of stroke (there is an increased incidence of recurrent stroke in patients who are undertreated with anticoagulants), the new guidelines include treatment recommendations for atrial fibrillation to prevent stroke.5 The patient needs to be assessed regarding a history of atrial fibrillation, antithrombotic therapy, and if there is current ECG evidence of atrial fibrillation.
There is a lack of evidence that depression is directly associated with CVD outcomes. Nonetheless, screening for depression is recommended primarily because of the negative effect it may have on adherence to prescribed interventions.5 Pregnancy complications, such as history of preeclampsia, gestational diabetes, or pregnancy-induced hypertension, also increase the risk of CVD. Women with a history of preeclampsia have twice the risk of recurrent stroke, ischemic heart disease, and thrombotic events up to 15 years after pregnancy.7
When performing the physical exam, the NP should include BP, body mass index (BMI), and waist size. A fasting blood glucose lab result should also be reviewed as well as cholesterol levels.5 Once the history and physical exam are completed, the NP should consult the AHA's Classification of CVD Risk in Women to determine the patient's risk status (see Classification of CVD risk in women).
This system classifies women into “high-risk,” “at-risk,” or “ideal cardiovascular health” risk levels. Modifications in the 2011 classification system include changing the “optimal risk” category to “ideal cardiovascular health”; changing the cut point for high risk from a 10-year predicted score of 20% or greater for developing only CHD to a 10-year predicted risk of 10% or greater for developing all CVDs; and advocating for the use of the updated Framingham CVD risk profile, the Reynolds risk score, or other predictive models for determining a woman's 10-year predicted CVD risk.5 The updated Framingham is sex-specific and assigns points for a woman's risk related to her age, HDL, total cholesterol, untreated systolic BP, treated systolic BP, smoking status, or diabetes.8 The Reynolds Risk score also uses age, total cholesterol, HDL, systolic BP, and smoking status, to calculate a woman's risk, as well as the level of high-sensitivity C-reactive protein (hsCRP) and whe ther a parent had a myocardial infarction (MI) before the age of 60.9 The AHA does not recommend routine screening of hsCRP because lowering these levels have not been shown to improve clinical outcomes.5 Risk calculators for the updated Framingham and Reynolds Risk scores can be found at http://www.framinghamheartstudy.org/risk/index.html and http://www.reynoldsriskscore.org/, respectively.10,11
To meet the new “ideal cardiovascular health risk” status, patients must have no clinical manifestations of CVD, as well as all the following healthy parameters: an ideal total cholesterol level, fasting blood glucose, BMI, and certain healthy lifestyle behaviors such as abstinence from smoking, performing recommended physical activity, and eating a healthy (Dietary Approaches to Stop Hypertension [DASH]–like) diet. The “at-risk” category now includes women who have a history of preeclampsia, gestational diabetes, or pregnancy-induced hypertension during pregnancy or an autoimmune collagen-vascular disease such as lupus erythematosus or rheumatoid arthritis.5
The AHA published an algorithm summarizing evaluation of a wo men's CV risk and interventions (see Evaluation of CVD risk). This flow diagram assists NPs in determining the appropriate preventive intervention based on the woman's estimated risk status.
The AHA guidelines for preventing CVD in women are divided into three major groups of interventions: lifestyle interventions, major risk factor interventions, and preventive drug interventions. After an updated review of the literature, each recommended intervention was classified based on the strength of the recommendation (Class I, IIa, IIb, or III) and the level of evidence (A, B, or C).5 (See Classifications and levels of evidence.)
Class III interventions, however, are not useful or effective for preventing CVD in women and in fact, may be harmful. These include the use of selective estrogen-receptor modulators and hormone therapy for menopause, antioxidant supplements including vitamins E and C and beta carotene, and folic acid with or without vitamin B6 and B12 supplementation for primary or secondary prevention of CVD. The routine use of aspirin for preventing MI is also not recommended in healthy women less than age 65.5
Some Class I lifestyle interventions include recommendations related to cigarette smoking, physical activity, cardiac rehabilitation, dietary intake, and weight maintenance/reduction, and should be recommended for all women.5 It is important for the NP to educate patients about these risk factors and interventions at each visit.
Cigarette smoking is a well-known risk factor for CVD; however, 21.1 million women (18.1% of all women) in the United States continue to smoke.12 Referral to a formal nonsmoking or a behavioral program and treatment with nicotine replacement and other pharmacologic agents, if needed, are important recommendations, as well as reinforcements not to smoke and to avoid second-hand smoke (Class I, Level B).5
The AHA recommends moderate and vigorous exercise (or a combination of the two), for at least 10 minutes at a time and preferably spread throughout the week. The prescribed exercise periods include 150 minutes/week of moderate intensity and 75 minutes/week of vigorous intensity. In addition, muscle strengthening exercises of all major muscle groups are recommended at least two times a week (Class I, Level B).5
Women at high risk who have had a recent cardiovascular event, acute coronary syndrome (ACS), coronary revascularization procedure, new-onset or chronic angina, cerebrovascular event, or PAD should be referred to a comprehensive rehabilitation program (Class I, Level A). Women who currently experience or previously experienced left ventricular (LV) failure with a left ventricular ejection fraction (LVEF) of 35% or less may also benefit from a rehabilitation program (Class I, level B).5
A diet rich in vegetables and fruits is strongly encouraged. Patients should also include whole grain, high-fiber foods, and eat fish (especially oily fish) twice a week. Intake of saturated fat, cholesterol, alcohol, sodium, and sugar should be limited, and trans fatty acids should be avoided (Class I, Level B).5
Obesity is a major risk factor for CVD. The obesity epidemic is likely a contributing factor to the increase in CHD deaths in women who are 35 to 54 years old.5 Obesity has been associated with the rise in type 2 diabetes mellitus and hypertension as well. Unfortunately, the trend for obesity is increasing in U.S. women older than age 20. White, Black, and Mexican American women are significantly overweight or obese with 59.3%, 70.8%, and 75.1%, respectively, having a BMI of 25.0 or higher.12 Weight reduction or maintenance of a normal weight by balancing caloric intake and physical activity is crucial. Optimal weight parameters include a BMI less than 25 and a waist circumference less than 35 inches. The AHA recommends at least 60 to 90 minutes of moderate-intensity activity most days of the week for women who need to maintain weight loss or lose weight. Women should also be encouraged to attend a formal program (Class I, Level B).5
Consumption of omega-3 fatty acids is a Class IIb intervention and may be considered for women with high cholesterol and/or high triglyceride levels. Consumption of 1,800 mg/day in the form of fish or fish capsules should be encouraged for primary and secondary prevention of CVD.5
Major risk factor interventions
Major risk factors addressed in the AHA guidelines include hypertension, lipid and lipoprotein levels, and diabetes mellitus. Both preventive lifestyle and pharmacotherapy approaches for these risk factors are recommended.
The optimal BP is less than 120/80 mm Hg. Lifestyle approaches for maintaining an optimum BP include controlling weight; increasing physical activity; limiting alcohol intake; and increasing intake of fruits, vegetables, and low-fat dairy products (Class I, Level B). Women with a BP of 140/90 mm Hg or above should be treated with a drug regimen that includes thiazide diuretics (for most patients). Earlier intervention with pharmacotherapy is recommended in women with comorbid conditions such as chronic kidney disease and diabetes (treat when BP is 130/80 mm Hg or above). The initial treatment of hypertension in high-risk women who have ACS or MI should include beta-blockers and/or angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs) in combination with other drugs like thiazide diuretics, as needed, to reach the target BP (Class I, Level A).5
The optimum level of lipids and lipoproteins include: low-density lipoprotein cholesterol (LDL-C) less than 100 mg/dL, high-density lipoprotein cholesterol (HDL-C) over 50 mg/dL, and triglycerides less than 150 mg/dL. Fewer adult men (41.8%) than adult women (46.3%) have total blood cholesterol levels 200 mg/dL or higher; however, women are less likely to be treated with HMG-CoA reductase inhibitors (statins), aspirin, and beta-blockers than their male counterparts, even though women are reported to tolerate drug therapy for coronary artery disease as well as men.1,13 Understanding this dichotomy, the NP needs to ensure that female patients are not being undertreated.
Class I interventions for “high-risk” women include LDL-C-lowering drugs and lifestyle changes in women with CHD (Class I, Level A) and in women with atherosclerotic CVD or diabetes or 10-year absolute risk above 20% (Class I, Level B) with the goal of attaining a LDL-C level of less than 100 mg/dL.5
Class I interventions for LDL-C-lowering drugs and lifestyle therapy for “at-risk” women depend upon the level of LDL-C, presence of other risk factors, and the 10-year absolute risk level. For example, women with multiple risk factors and a 10-year absolute risk between 10% and 20% should receive treatment when their LDL-C is 130 mg/dL or greater, whereas women with multiple risk factors, but a 10-year absolute risk less than 10%, should be treated for a LDL-C level of 160 mg/dL or greater. However, all women who have LDL-C levels of 190 mg/dL or greater should be treated regardless of whether they have other cardiovascular risk factors (Class I, Level B).5
Class II interventions may be useful in select women. For example, the use of a combination of LDL-lowering drugs may be needed for very high-risk women, such as those who have recent ACS, poorly controlled multiple cardiovascular risk factors, or CHD. A lower target LDL-C of less than 70 mg/dL is reasonable in these women (Class IIa, Level B). Niacin or fibrate therapy may be recommended for high-risk women who have a low HDL-C (less than 50 mg/dL) or elevated non-HDL-C (above 130 mg/dL), and who have attained their LDL-C goal (Class IIb, Level B). Statins may be considered for women who are older than 60, have an estimated CHD risk greater than 10%, have no evidence of an acute inflammatory process, and who have a hsCRP greater than 2 mg/dL after lifestyle modifications (Class IIb, Level B).5
Diabetes is a major risk factor for CVD. Lifestyle and pharmacotherapeutic interventions for women with diabetes are recommended with a goal of keeping the A1c under 7% without significant hypoglycemia (Class IIb, Level B).5
Preventive drug interventions
The AHA guidelines for preventive drug interventions include recommendations for the use of aspirin, warfarin (Coumadin, Jantoven), dabigatran (Pradaxa), beta-blockers, ACE inhibitors/ARBs, and aldosterone blockade.
Class I interventions for a high-risk woman with CHD include aspirin 75 to 325 mg/day, unless contraindicated (Class I, Level A), or clopidogrel (Plavix) therapy if the patient is unable to tolerate aspirin (Class I, Level B). Aspirin doses of 75 to 325 mg/day may also be reasonable for preventive treatment in women with diabetes (Class IIa, Level B).5 Aspirin 81 mg/day or 100 mg every other day may be useful for other at-risk or healthy women who are 65 years or older and whose BP is controlled (Class IIa, Level B). However, the NP must consider the risk and benefits associated with this therapy. The benefit of preventing ischemic stroke and MI should outweigh the risks for gastrointestinal bleeding and hemorrhagic stroke. Aspirin therapy (81 mg/day or 100 mg every other day) may also be reasonable for stroke prevention in women who are 65 years or older (Class IIb, Level B).5
Atrial fibrillation is a significant risk factor for ischemic stroke.1 The AHA recommendations for antithrombotic therapy in women with atrial fibrillation vary depending on the woman's level of risk for stroke and contraindications to antithrombotics. Stroke risk is estimated by calculating the CHADS2 score, an assessment tool used specifically to evaluate risk of stroke in those who have atrial fibrillation. Numbers are assigned for Congestive heart failure, Hypertension, Age 75 or older, Diabetes, and prior Stroke or transient ischemic attack. A score of 1 is assigned for each factor present except history of prior stroke which is assigned a value of 2.14 In women with chronic or paroxysmal atrial fibrillation and a low stroke risk (less than 1%/year or CHADS2 score of less than 2), aspirin 75 to 325 mg is recommended. Aspirin therapy is also recommended for women in whom warfarin therapy is contraindicated (Class I, Level A).5
Warfarin treatment to maintain the individualized normalized ratio at 2.0 to 3.0 is recommended for women who have chronic or paroxysmal atrial fibrillation and a stroke risk greater than 1%/year (Level I, Class A).5 Warfarin should not be given to women who have a high risk of bleeding.
Dabigatran is a useful substitution for warfarin in women who have nonvalvular paroxysmal to permanent atrial fibrillation and risk factors are present for stroke and systemic thromboembolism. However, the NP should note if the patient has a prosthetic heart valve or hemodynamically significant valve disease, severe kidney failure with a creatinine clearance less than 15 mL/minute, or advanced liver disease with impaired baseline clotting functions because dabigatran is not recommended in these women.5
Short-term or long-term treatments with beta-blockers are recommended for women with certain conditions unless contraindicated. All women who experience MI or ACS and have normal LV function should be treated with beta-blockers for up to 12 months (Class I, Level A) or 3 years (Class I, Level B). Women with LV failure should be treated with beta-blockers indefinitely (Class I, Level A). Women who have other coronary or vascular disease and normal LV function may also be treated with long-term beta-blockers (Class IIb, Level C).5
Women who have had an MI, develop heart failure, or have a LVEF of 40% or less, or have diabetes should be treated with ACE inhibitors unless contraindicated (Class I, Level A).5 If the patient does not tolerate ACE inhibitors, alternative therapy with ARBs should be used (Class I, Level B). If the woman experiences symptomatic heart failure and the LVEF is 40% or less post-MI and therapeutic doses of beta-blockers and ACE inhibitors have been ordered, an aldosterone blockade agent such as spironolactone is indicated. Aldosterone blockade therapy is not recommended if the woman has significant hypotension, kidney dysfunction, or hyperkalemia (Class I, Level B).5
Educating women about their identified risk factors and treatment plan is crucial in promoting CVD prevention. Women who are knowledgeable about their risk factors are more likely to follow recommended lifestyle behaviors and therapeutic regimen for prevention.15 The NP may begin this process by assessing the woman's current knowledge level. Utilization of a knowledge tool such as the CHD Knowledge Tool or a similar tool may assist with this process.16 The NP should also identify and explore the patient's perceived barriers to implementing prescribed lifestyle behaviors and pharmacotherapy. Family obligations/caregiving responsibilities and confusion about media presentation of risk factors have been identified as the top two perceived barriers in women.6 Discussion of identified barriers along with potential solutions is vital for promoting adherence to the prescribed regimen.
The NP is in a prime position to assess, treat, and educate women about CVD risks. The updated AHA effectiveness-based guidelines provide a framework for assessing and treating CVD risks with the ultimate goal of preventing CVD and the associated morbidity and mortality. The NP must be familiar with these guidelines and diligently screen and treat women across the lifespan. Older women are at higher risk for CVD than younger women are; however, intervention at an early age can make a positive impact on disease prevention. The NP must continually review the AHA guidelines, provide positive reinforcement for patient progress, and discuss needed adjustments to lifestyle modifications as well as pharmacotherapy with patients at every visit.