If you have one or more risk factors for heart disease, and your doctor was not sure at your last visit whether you needed drugs to lower cholesterol, chances are you should call back for a new assessment. And if you have diabetes and even moderate cholesterol levels, your doctor now might want to prescribe drugs to reduce those numbers, and your risk of heart disease.
These are two of the changes that may occur in the way doctors and their patients treat potential risks for heart disease as the result of new guidelines from the National Cholesterol Education Program, experts at Harvard Medical School say.
The program, which last released guidelines in 1993, is a partnership of the National Institutes of Health, the American Medical Association and numerous other government agencies and professional organizations.
Overall, the new guidelines urge more aggressive treatment — diet, exercise and often medicine — for patients with certain levels of cholesterol levels and other risk factors for heart disease.
The recommendations are based on a large volume of research in the last eight years that has shown the value of drugs, particularly those in a class called statins, to reduce cholesterol and lower the risk of heart attacks, even among people who are not known to have coronary heart disease, says Christopher Cannon, M.D., a cardiologist at Brigham and Women’s Hospital and assistant professor of medicine at Harvard Medical School.
If the recommendations are followed, the National Heart, Lung and Blood Institute estimates that the number of people taking cholesterol-lowering drugs will almost triple — from 13 million now to 36 million. And most of those people will have no known heart disease but will have factors known to increase their risk.
“The difference between the old guidelines and the new is that there’s more emphasis on primary prevention” before heart attacks or strokes occur, Dr. Cannon says. “It should lead to major reductions in heart disease, if the guidelines are followed.”
The biggest possible changes in treatment are likely to come for three groups, says Murray Mittleman, M.D., director of cardiovascular epidemiology at Beth Israel Deaconess Medical Center in Boston:
- People with many risk factors but no previous heart attack, stroke or other diagnosed coronary heart disease.
- People with less than 40 milligrams per deciliter (mg/dL) of high-density lipoproteins (HDL), also called “good cholesterol.”
One major difference is that the new guidelines recommend that all diabetics be treated the same as someone who has already had a heart attack in aggressively using diet, exercise and drugs, if necessary, to lower cholesterol. An estimated 15 million Americans have diabetes.
Dr. Mittleman, an assistant professor of medicine at Harvard who has done research about the risk factors for heart attack, says the American Diabetic Association has recommended such treatment for several years, but it may not be common practice among physicians who do not specialize in treating diabetes.
The new guidelines also recommend that people with many risk factors for a heart attack be treated as aggressively as those with known heart disease. They also raise the minimum level of HDL considered too low for heart health from 35 to 40 mg/dL.
“While that sounds like a small change, it actually represents a large group of the population,” Dr. Mittleman says. “That will actually put more people into the category of being considered to have an extra risk factor.” He says perhaps 5 percent of the population has levels under 35, but many more people have HDL of less than 40.
The guidelines also recommend more intensive treatment for patients with even moderate risk. “I would think if you have even one risk factor — high blood pressure or if you’re a smoker — or certainly if you have two risk factors, you should go in and talk to your doctor about what the best treatment for you is,” Dr. Cannon says.
Because the guidelines are based on research, many physicians already treat their patients based on similar criteria, but the guidelines draw together the findings of research into a format that makes it easier for physicians and patients to use, the Harvard doctors says.
Dr. Cannon, for instance, says he was especially pleased that the National Heart, Lung and Blood Institute Web site provides a risk calculator that physicians can download onto a Palm, or a similar handheld device, and use in their evaluations of patients.
The new guidelines divide patients into three categories and recommend various combinations of diet, exercise and drug therapy for each category to reduce so-called “bad cholesterol,” or low-density lipoprotein (LDL).
The categories are based on risk factors, each of which is assigned a certain number of points using an evaluation tool called the Framingham scale, based on a long-term Massachusetts study of heart disease. Various point ranges are equated to a percentage risk of having a heart attack in the next 10 years. The higher the risk, the lower the goal for LDL.
The highest risk level is for patients with established coronary heart disease, diabetes, carotid artery disease with symptoms, peripheral arterial disease, abdominal aortic aneurysm or multiple risk factors that add up to a 10-year heart attack risk of more than 20 percent on the Framingham scale.
Risk factors listed are cigarette smoking, high blood pressure, low HDL level, family history of premature heart disease (before age 55 in a father or brother, before 65 in a sister or mother) and age (45 or older for men, 55 or older for women).
Here are the recommendations for three levels of risk:
- Highest risk: This includes patients with diabetes, coronary heart disease or the equivalent, or a 10-year heart attack risk of more than 20 percent. The goal is to reduce low-density lipoprotein (LDL, or “bad cholesterol”) to less than 100 mg/dL. For levels above 100, patients should use diet, exercise and other lifestyle changes to reduce LDL. At 130 mg/dL or more, cholesterol-lowering drugs should be considered.
- Two or more risk factors: This includes patients with a 10-year heart attack risk of 20 percent or less. Lifestyle changes should be used to reduce LDL levels of 130 or more. Medicine should be considered if the 10-year risk is 10 to 20 percent, or if the risk is less than 10 percent but LDL is 160 or more.
- Zero or one risk factor: Lifestyle changes should be used to reduce LDL levels of 160 or more, and medicine may be suggested at 190 mg/dL or more.
This set of guidelines also refers for the first time to the importance of a group of risks, known collectively as metabolic syndrome, that research has shown increases the risk for heart disease. Metabolic syndrome is defined as any three of the following characteristics:
- Abdominal obesity: A waist measurement of at least 40 inches in men or 35 inches in women
- Elevated triglycerides: Defined for the first time in this study as 150 mg/dL or more (200 or more in previous guidelines)
- Low HDL: Defined as less than 40 in men and less than 50 in women
- High blood pressure: At least 130 systolic or at least 85 diastolic (130/85)
- High fasting blood sugar: At least 110 mg/dL
Like most of the other risk factors, metabolic syndrome is best treated with dietary changes and exercise, the Harvard doctors say. Although the guidelines are considered likely to increase use of cholesterol-lowering medicines, they always list such lifestyle changes as the first treatment to use for any heart-disease risk factors.
“I think it’s a reaffirmation from this panel that lifestyle changes are the single best thing a patient can do for themselves,” Dr. Cannon says, “so please go out and exercise and reduce your fat intake.”