AHA Guidelines for CVD Prevention in Women Focus on Lifetime Risk Factors

February 27, 2007 — The American Heart Association's (AHA) updated prevention guidelines for women outline a bold prescription for prevention of CVD that urges women to start early, with adoption of a healthy lifestyle, and sets new target goals for risk-assessment.

The guidelines, appearing online in the February 19 Rapid Access issue of Circulation, were presented by lead author, Lori Mosca, MD, of the New York-Presbyterian Hospital in New York at an AHA media briefing.

The focus is on prevention, with the goal to widen the window of opportunity for women to fight their number 1 killer. "We want to prevent the risk factors," she stressed.

There are now 3 categories ("high risk," "at risk," and "optimal risk") instead of the 4 ("high," "intermediate," "lower," and "optimal") in the Framingham global risk model.

Dr. Mosca notes that limitations of Framingham are overcome by the new model, which better accounts for "lifetime risk, diversity and stroke risk."

Most clinical data for the new evidence-based guidelines categorized women with CVD as high risk and apparently healthy women as a spectrum of risk, "so we were able to allow the current scheme to align with the evidence."

"Physicians should look at this as an opportunity to reinforce prevention of CVD early on, so that women won't need interventions later in life," Dr. Mosca said in an interview with heartwire.

Class I Recommendations Are for All Women
As with most evidence-based guidelines, these too have 4 major classes: class I (intervention is useful and effective), class IIa (weight is in favor or efficacy), class IIb (less well established), and class III (intervention not useful, could be harmful).

The high-risk criteria are coronary heart disease (CHD), CVD, peripheral arterial disease, abdominal aortic aneurysm, end-stage or chronic renal disease, diabetes, and a global risk score of greater than 20%.

The at-risk criteria include one or more major CVD risk factors (smoking, poor diet, physical inactivity, obesity, family history of premature CVD, blood pressure [BP], hypertension, or dyslipidemia), subclinical disease, metabolic syndrome, and poor exercise capacity on treadmill testing.

The optimal-risk criteria are a global risk score of less than 10% and a healthy lifestyle with no risk factors.

All women aged 20 years and older need initial CVD risk evaluation (medical history, physical examination, fasting glucose, and lipids), Framingham risk assessment, and depression screening for women with CVD.

Women Need to Exercise at Least 30 Minutes Most Days of the Week
Class I lifestyle recommendations (smoking cessation, heart-healthy eating plan, and weight management) are indicated for all women older than 20 years.

"One of the major things we changed is the recommendation for all women to exercise, such as briskly walking a minimum of 30 minutes on most days of the week. To maintain weight goals, a woman needs to accumulate 60 to 90 minutes all day, every day of the week," Dr. Mosca says.

Diet should be rich in vegetables, whole grains, and oily fish (twice a week); saturated fat intake should be less than 10% of daily calories; and cholesterol intake should be less than 300 mg/day. (A high-risk woman would need to reduce saturated fat to 7% and cholesterol to < 200 mg/day.)

Class I recommendations for high-risk women are BP control, and in select women, low-density lipoprotein (LDL) cholesterol therapy. Class II recommendations — high-density lipoprotein (HDL) cholesterol, non-HDL cholesterol, triglyceride therapy, and aspirin (for older women) — should be considered.

Aspirin Useful in High-Risk Women Older Than 65 Years
Aspirin is recommended for high-risk women and those older than 65 years (class Ia recommendation) "if MI [myocardial infarction] risk prevention is likely to outweigh risk of gastrointestinal bleeding," Dr. Mosca says.

If a high-risk woman is intolerant to aspirin, clopidogrel should be substituted (class Ib recommendation).

The class I recommendations for women with a recent CVD event or procedure or congestive heart failure is rehabilitation; for other high-risk women, recommendations are BP control, LDL cholesterol therapy (goal, < 100 mg/dL), aspirin, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, angiotensin-receptor blockers (ARBs), glycemic control in diabetic patients, and in select women, aldosterone blockers.

Class II recommendations for very-high-risk women would be LDL therapy (goal of < 70 mg/dL), omega-3 fatty acids, and depression/referral treatment.

Not Recommended: Antioxidant Vitamin Supplements
Dr. Mosca stressed that 4 major recommendations were class III (not useful, may cause harm).

The therapies or supplements that are not recommended for primary or secondary prevention include:

hormone therapy or estrogen modulators;

antioxidant vitamin supplements (vitamin E, C, and beta-carotene);

folic acid; and

routine use of aspirin in healthy women younger than 65 years.
According to Sidney Smith, MD, of the University of North Carolina in Chapel Hill, the Framingham classification table has helped clinicians understand and risk estimates, but new women's guidelines are "an attempt to make things easier."

Dr. Smith told heartwire that the guidelines fill in missing information about the prevention and treatment of CVD in women. "Most of our evidence comes from trials of 75% male Caucasians, so this guideline is some of the best information we have."

Men still develop CVD 10 years earlier, so the guidelines should not take the spotlight completely off men, he notes.

Does a Sex Gap Exist in CVD Treatment; Is Hormone Therapy Good or Bad; and What Does Prehypertension Mean for Women?
These are some research topics covered at the AHA media briefing on women and CVD, which are also published in the February 20 issue of Circulation.

In a study by the Women's Health Initiative, investigators found prehypertension (systolic BP between 120 - 139 mm Hg and diastolic BP between 80 - 89 mm Hg) in 39% of women. Ten-year incidence of CVD was 3.32% for "norms," 7.11% for "prehypertensives," and 14.16 for "hypertensives." "Both lifestyle and pharmacologic interventions may reduce progression to hypertension," the authors conclude.

The Women's Health Initiative looked at calcium and vitamin D supplementation and says it "neither increased nor decreased coronary CVD risk" in healthy postmenopausal women in a 7-year study. Women should not "fear adverse consequences" if they still need them for bone health.

Researchers found that "route, type, and dose" of hormone therapy matters, in the Estrogen and Thromboembolism and Risk Study (ESTHER), a multicenter study conducted in 8 hospitals in France that included 271 cases and 610 controls. Compared with nonusers, oral estrogen users had an odds ratio of 4.2 (95% confidence interval [CI], 1.5 - 11.6) and 0.09 (95% CI, 0.4 - 2.3) for transdermal estrogen. Norpregnane derivatives were linked to a 4-fold increase in venous thromboembolism; but there was no risk for venous thromboembolism with micronized progesterone and pregnane derivatives in the study.

Another look at hormone therapy comes from a new study on the estrogen-receptor alpha polymorphism (CC genotype), a dangerous form of the gene. It did not raise myocardial infarction risk from response to hormone replacement therapy in the Danish study (2400 patients with myocardial infarction).

Whether or not a gender gap exists in the management of CVD was looked at by a French team. The "gender gap" issue was raised as early as 1991, when it was dubbed the "Yentl syndrome." A 7-year study of more than 74,000 patients hospitalized with myocardial infarction, 30% of whom were women, found 14.8% mortality in women, compared with 6.1% in men. Percutaneous coronary intervention was more common in men than women (7.4% vs 4.8% for percutaneous coronary intervention and 24.4% vs 14.2% for a stent). Women had a 1.95% increase in age-adjusted mortality — one third was attributed to gender disparities and two thirds of this was related to age and health problems.
Dr. Mosca commented to heartwire that the percutaneous coronary intervention study shows that gender bias may be explained by "age gap."

"Maybe its better that we are delaying the need for them, and of course, there is nothing we can do to change aging as a CVD risk factor," she adds.

Circulation. Published online February 19, 2007.

Source: http://www.medscape.com/viewarticle/552777?src=mp