That’s due in part, because there are limited clinical research data including outcomes for women. Despite these limits, primary care providers and obstetricians and gynecologists, as the primary care providers for women, should routinely follow evidence-based guidelines to prevent coronary artery disease, Judith A. Hsia, MD, professor of medicine and director of the Lipid Research Center, The George Washington University Medical Center, Washington, DC.

New in the guidelines established by the American Heart Association (AHA) for lipid management are three recommendations, said Dr. Hsia. They are as follows: (1) Initiate statin treatment for high-risk women regardless of their low-density lipoprotein cholesterol (LDL-C) levels; (2) Maintain an optimal level high-density lipoprotein cholesterol (HDL-C) higher than 50 mg/dL; and (3) Initiate niacin or fibrate therapy for low HDL-C or elevated non-HDL-C levels in high-risk women.

Major cardiac risk factors include: blood pressure more than 120/80 mm Hg, LDL-C levels higher than 100 mg/dL, HDL-C levels lower than 50 mg/dL, triglyceride levels higher than 150 mg/dL, non-HDL-C levels (total cholesterol minus HDL-C) higher than 130 mg/dL, and glycated hemoglobin levels higher than 7% for women with diabetes.

In outlining the evidenced-based guidelines for women, the AHA developed three classification levels based on the strength of evidence from studies including the Women's Health Initiative, National Health and Nutrition Examination Survey (NHANES), Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), Comparison of Amlodipine vs Enalapril to Limit Occurrences of Thrombosis (CAMELOT), and Framingham Heart Study. Class 1 recommendations call for interventions that are deemed useful and effective. These include: smoking cessation, physical activity of 30 minutes or more each day, cardiac rehabilitation for women with a recent myocardial infarction, weight maintenance or reduction (body mass index, 18.5-24.9 kg/m2 and waist circumference < 35 in), and a heart-healthy diet.

A heart-healthy diet is described as limited saturated fat intake to less than 10% of total daily calories, limited cholesterol to less than 300 mg/dL, and limited intake of trans-fatty acids combined with a diet that includes fruits, vegetables, grains, low-fat or nonfat dairy products, fish, legumes, and sources of protein low in saturated fat.

The AHA guidelines also call for stricter diet therapy of reduced saturated fat intake to less than 7% of calories, cholesterol to less than 200 mg/dL, and low trans-fatty acid intake for women at high risk for cardiac disease.

Dr. Hsia outlined three risk categories of coronary artery disease in women. High-risk women are those with a 20% risk of developing cardiac disease in 10 years. Intermediate-risk women have a risk of 10% to 20% of developing cardiac disease in 10 years. Low-risk women have a lower than 10% risk of developing the disease within 10 years.

The use of niacin or fibrate therapy for low HDL-C and/or elevated non-HDL-C levels is a class I recommendation for women deemed at high risk for coronary artery disease, Dr. Hsia told attendees at the meeting. Other class I recommendations for high-risk women are initiating statin therapy (unless contraindicated) and lifestyle therapy for women with an LDL-C level of 100 mg/dL or more.

Statin, lifestyle, and niacin therapy are also recommended for women with intermediate risk in these circumstances. Statin therapy and lifestyle therapy when LDL-C levels are 130 mg/dL or higher, niacin therapy when HDL-C levels are low or non-HDL-C levels are elevated after the LDL-C goal is met. In this patient population, statin therapy is considered class I with sufficient evidence from multiple randomized trials. Niacin therapy is rated as class I, level B, because the evidence is limited to one randomized trial only or other nonrandomized trials.

The evidence of benefit from these therapies is further limited in women with low risk. Guidelines suggest consideration of LDL-C lowering therapy when LDL-C level is 190 mg/dL or higher, and the woman has multiple risk factors for coronary artery disease. This is considered a class IIa recommendation, meaning that the weight of evidence or opinion is in favor of usefulness and efficacy. Niacin or fibrate therapy in this group of women might be considered when HDL-C level is low or non-HDL-C level is elevated after the LDL-C goal is reached. This is considered a class IIa, level B recommendation, meaning that the usefulness and efficacy are less well-established by evidence or opinion and that the limited evidence comes from a single randomized trial or other nonrandomized trials.

Dr. Hsia emphasized that the AHA guidelines also include class III interventions. These are considered noneffective and may be harmful. They include hormone therapy, antioxidant supplements, and aspirin in lower-risk women. Vitamin E is not recommended for coronary prevention, Dr. Hsia added, and may increase mortality. "Women should not take vitamin E. It is a distraction from other therapies," said Dr. Hsia.

"The bottom line is that physicians can identify women at risk for cardiac disease, and we do have the therapy to reduce this risk, but we are not uniformly applying this knowledge," Dr. Hsia said at the conference. "Physician awareness and the importance of these guidelines should be stressed," Dr. Hsai noted. "If the control rate for cardiac disease in women is low then something must be done. There is plenty of room for improvement. A team effort is needed," Dr. Hsai concluded.

Source: Diabetes In Control.com: AACE 14th Annual Meeting and Clinical Congress: General Session. Presented May 19, 2005.

News Article Index