The American Heart Association has updated and sharpened its guidelines for preventing heart disease in women.
The focus now is on a woman's lifetime risk for heart disease, not just her short-term risk, as was the case in the 2004 guidelines.
The 2007 Guidelines for Preventing Cardiovascular Disease in Women are published this week in a special issue of the journal Circulation devoted to women's health, and were outlined at an AHA press conference Tuesday.
Among other things, the guidelines refresh recommendations on aspirin use, hormone replacement therapy and vitamin and mineral supplementation.
"The new updated guidelines are extremely exciting, because they advance our science quite a bit and our ability to provide guidance to physicians and other health care providers on the best practices for prevention for women," said Dr Lori Mosca, chair of the American Heart Association's (AHA) expert panel that devised the guidelines. She is also director of preventive cardiology at New York-Presbyterian Hospital in New York City.
Accounts for 1 in 3 female deaths
Heart disease among women is practically epidemic, accounting for one in three female deaths.
"Cardiovascular disease is the leading cause of death among women," Mosca said. "The rate of awareness among women has increased from 30 to almost 60 percent, but we still need to work on the confusion around preventive strategies. We are very encouraged that the release of these new guidelines can help clear up some of this confusion and help our women engage in more conversations with physicians and health care providers as to what are the best strategies to reduce the burden of the number-one killer of women."
Here are the high points of the new guidelines, which incorporate the latest science from recent randomised, controlled trials:
- Where once women were classified as being at high, intermediate or low (optimal) risk for heart disease, they are now considered high, at-risk or optimal (the latter group representing probably no more than 10 percent of women). The new stratification incorporates, but does not rely solely on, the conventional Framingham Score that doctors use to assess cardiovascular risk. It also takes into account lifetime risk, not just short-term risk. "We wanted to align more with clinical trial evidence and acknowledge that cardiovascular disease is so ubiquitous in women," Mosca said.
- Expanded lifestyle interventions include a continued emphasis on quitting smoking and avoiding second-hand smoke. This time, the guidelines also recommend counselling, nicotine replacement or other forms of smoking cessation therapy.
- All women are still urged to exercise a minimum of 30 minutes per day, but women who need to lose weight or maintain weight loss are now advised to engage in 60 to 90 minutes of moderate-intensity activity on most, or preferably all, days of the week.
- A heart-healthy diet should still be rich in fruits, whole grains and fibre foods with a limited intake of alcohol and sodium.
- Saturated fat should now be reduced to less than 7 percent of calories (the previous guidelines stated 10 percent).
- Women should eat oily fish, a source of omega-3 fatty acids, at least twice a week. "This is not recommended for all women but can be considered a balance of benefit and risk for women at high risk," Mosca said.
- Women at very high risk for heart disease should try to lower their LDL ("bad") cholesterol to less than 70 mg/dL. Otherwise, high-risk women are still encouraged to lower their LDL to less than 100 mg/dL.
- Women aged 65 and over should consider taking low-dose aspirin on a routine basis, regardless of their risk. Aspirin has been shown to prevent both heart attacks and stroke in this age group.
- Women under 65 should not be taking aspirin routinely, as it has been shown only to have a benefit for stroke prevention.
- The upper dose of aspirin for high-risk women is now 325 mg per day, up from 162 mg.
- As stated in the previous guidelines, neither hormone replacement therapy, selective oestrogen receptor modulators or antioxidant supplements such as vitamins C and E should be used to prevent heart disease.
- Folic acid should also not be used to prevent cardiovascular disease, a major change from the last set of recommendations.
The current issue of Circulation also included heart information from several other studies:
- Age, rather than health care disparities, seems to explain why more women than men die in the hospital after a heart attack. "The differences in death rates are largely due to differences in age when the heart attack occurred and not due to differences in treatment," said Dr Alice Jacobs, professor of medicine at Boston University School of Medicine, who was also involved with the new guidelines.
- Differences in an oestrogen gene (ESR1) do not appear to affect the risk of heart attack and stroke in response to hormone replacement therapy, as was previously thought. The gene may, however, be associated with an elevated risk of breast cancer.
- Some 40 percent of postmenopausal women have "pre-hypertension," associated with a 58 percent higher risk of cardiovascular death, said researchers from the Women's Health Initiative. It's unclear if intervening in this group will reduce cardiovascular problems, Jacobs said.
- Supplementation with calcium/vitamin D had no effect on heart disease and stroke risk in postmenopausal women who were generally healthy.
- Oestrogen, when delivered by patch or gel, does not seem to increase the risk of blood clots in the vein (venous thromboembolism or VTE). Only oestrogen taken orally seems to increase this risk.