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November 18, 2004
News this month
New cholesterol guidelines for high-risk patients
A recent update to the National Cholesterol Education Program’s (NCEP) clinical practice guidelines advises more aggressive cholesterol management for patients who already have cardiovascular disease or who are at high or moderately high risk for a heart attack. These new guidelines have been endorsed by the National Heart, Lung and Blood Institute, the American Heart Association and the American College of Cardiology.
Lower is better when it comes to LDL (“bad”) cholesterol for individuals in high-risk categories.
The NCEP issued a set of cholesterol guidelines, known as the Adult Treatment Panel (ATP) III report, in 2001. Since that time, five major clinical trials of statin therapy (cholesterol-lowering medication) have provided evidence that lower is better when it comes to LDL (“bad”) cholesterol for individuals in high-risk categories. The studies have established the effectiveness of the statin drugs, and in addition to lower targets, the new guidelines recommend initiating cholesterol-lowering drug therapy at lower LDL levels than previously recommended.
Therapeutic lifestyle changes (TLC) (healthful nutrition, physical activity and weight control) for cholesterol management continue to be important, the report emphasizes; however, the primary message is for physicians to take a more aggressive approach in drug treatment of patients with cardiovascular disease and those who are at very high, high and moderately high risk.
The new guidelines recommend initiating cholesterol-lowering drug therapy at lower LDL levels than previously recommended.
Risk categories redefined
Very high risk. The NCEP update creates a subset of the high-risk group, which it dubs the “very high risk” group. These are individuals with established cardiovascular disease and one of the following:
- Multiple major risk factors for cardiovascular disease*
- Metabolic syndrome, which includes the following: abdominal obesity, triglycerides over 200 mg/dL, HDL (“good”) below 40 mg/dL, insulin resistance and glucose intolerance
- Severe and poorly controlled risk factors, especially smoking or diabetes
- Acute coronary syndrome, which is an umbrella term used to cover any group of clinical symptoms compatible with a heart attack
High risk. This group includes those with a history of heart disease or one of the following:
- Diabetes
- Evidence of diseased blood vessels to the brain or extremities
- Two or more risk factors for heart disease, including smoking and high blood pressure, that create a greater than 20 percent chance of having a heart attack in the next 10 years
Moderately high risk. These individuals have:
- Two or more risk factors for heart disease that create a 10-20 percent chance of having a heart attack in the next 10 years
Moderate risk. This group has:
- Two or more risk factors for heart disease that create less than a 10 percent chance of having a heart attack in the next 10 years
Low risk. These people have:
- One or no risk factors for heart disease
*A discussion of risk factors and a formula for determining your risk are included in Dr. Freed’s discussion.
ATP III update targets and recommendations
The ATP update recommends either more aggressive LDL targets, earlier drug therapy or both for all but the moderate and lower-risk populations. Recent clinical trials do not suggest any absolute benefits to modifying the treatment plan for people at lower-risk levels.
| Risk category |
LDL goal |
Initiate TLC |
Drug therapy |
| High risk* |
<100** Optional goal
< 70 |
≥ 100 |
≥ 100
< 100; consider drug option |
| Moderately* high risk |
< 130 Optional goal
< 100 |
≥ 130 |
≥ 130 100-129; consider drug option |
| Moderate risk |
< 130 |
≥ 130 |
≥ 160 |
| Lower risk |
< 160 |
≥ 160 |
≥ 190 160-189; consider drug option |
*Drug therapy should be sufficient to achieve at least a 30 to 40 percent reduction in LDL levels.
**All numbers are in mg/dL
For seniors
Like ATP III, the update emphasizes cholesterol lowering in older people. One of the five trials (Prospective Study of Pravastatin in the Elderly at Risk) that forms the basis for the ATP update specifically looked at statin therapy for men and women, 70 - 82 years old, who had a history of vascular disease or were at risk of developing it. Results indicated a definite benefit for this population in reducing nonfatal and fatal coronary events.
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Aggressive LDL treatment becomes practice standard
Over the past several years, five large clinical trials involving statin drugs have demonstrated a direct relationship between lower LDL cholesterol levels and reduced risk of major coronary events such as heart attacks. As a result, the Coordinating Committee of the National Cholesterol Education Program (NCEP) issued an update to their most recent practice guidelines.
“Five large clinical trials… have demonstrated a direct relationship between lower LDL cholesterol levels and reduced risk of major coronary events such as heart attacks.”
The major modifications to the NCEP’s Adult Treatment Panel III (ATPIII) entail beginning drug therapy earlier and setting LDL cholesterol goals lower for patients in the higher risk groups.
How to determine your risk group
To understand if the NCEP update affects how your cholesterol is being managed, it’s important to understand which risk group category describes your cardiac health profile. One of the factors used in determining the risk groups (very high, high, moderately high, moderate and low), described in the update, is your chance of having a heart attack within a 10-year period.
- Those in the very high and high group have greater than a 20 percent chance;
- Those in the moderately high category have between a 10 and 20 percent chance; and
- Those in the moderate group have less than a 10 percent chance.
These calculations are based on data from the Framingham Heart Study. You can calculate your own 10-year risk by going online to the National Cholesterol Education Program
In addition to these risk percentages, the update uses the presence of coronary heart disease (CHD), which they define as a history of heart attack, unstable angina, coronary artery procedures such as angioplasty or bypass surgery or significant myocardial ischemia, which is narrowing of the coronary arteries. CHD equivalents are defined as evidence of diseased blood vessels to the brain or extremities. Diabetes is also considered equivalent to CHD as a risk factor. If you fall into any of these categories, the update places you in the very high or high-risk categories.
Traditional cardiac risk factors are also used to determine risk category. The NCEP group considers the following as major risk factors in this report:
- Smoking
- High blood pressure
- Low HDL cholesterol
- Family history of heart disease
- Age (men over 45 and women over 55)
Major modifications of the update
Several specific treatment recommendations are made in the report that differ from the 2001 ATP III guidelines.
- The update offers a therapeutic option of lowering LDL cholesterol to below 70 mg/dL for the highest-risk patients.
- For patients at high risk, the new guidelines also advise beginning statin therapy at 100 mg/dL or higher.
- If a high-risk patient also has high triglycerides (> 200 mg/dL) or low HDL cholesterol (< 40 mg/dL for men; < 50 mg/dL for women), the update suggests physicians should consider adding fibrate or nicotinic acid along with statin therapy.
- For patients in the moderately high-risk category, the new guidelines offer a therapeutic option of lowering LDL to below 100 mg/dL
- For moderately high-risk patients whose LDL is between 100 and 129 mg/dL, statin drugs should be considered.
- Diet, exercise and weight reduction should be tried by everyone and especially anyone at high or moderately high risk who has a potentially lifestyle-related risk factor such as obesity, sedentary lifestyle, elevated triglycerides, low HDL or metabolic syndrome.
- Statin therapy for high and moderately high-risk patients should be intense enough to result in a 30 to 40 percent reduction in LDL levels.
Treating the elderly
The PROSPER study showed that seniors benefited considerably from statin therapy, and the new guidelines underscore the importance of treating older people. I treat my elderly patients up to about age 90 when the initiation of statin therapy can begin to upset the delicate balance of these often medically fragile patients. If these patients are stable on statin drugs, I do continue drug therapy. I do prescribe statin drugs for even very elderly patients who have had an acute heart attack since we believe that statin therapy has some effect on stabilizing the vascular system after an acute event.
Strong single risk factor
There is some controversy about treating patients who may be at low risk but whose LDL is in the 160 to 189 mg/dL range (goal< 160). I would prescribe statins for those whose one risk factor was a strong one. For example, if I had a patient who was a heavy smoker, I would probably treat him or her, but I might not prescribe statins to a patient whose only risk factor was being a male over age 45. I would encourage them to make modifications in their lifestyle instead.
Treating sooner
I believe this update underscores the importance of starting statins and other cholesterol-lowering medications relatively soon after a lipid problem is identified. Lifestyle changes are still crucial to include in a treatment plan, but medications are much more effective and quicker at reducing LDL cholesterol levels.
Cautions
There was a time when we thought there might be some health risk if we reduced LDL cholesterol to a very low point, but there is no clinical data suggesting this is true, so we are no longer concerned about this, particularly with the very strong evidence that low levels are so effective in reducing the risks of a heart attack for our patients. There are relatively few patients, however, who are not able to tolerate high doses of statin drugs due to severe muscle pain or liver damage found by blood tests. It is important to report these side affects to your physician. And patients with serious liver disease should consult with their physicians before taking any statin medications.
Some trials are continuing, and it’s possible that this ATP update may not be the last word on cholesterol management. Many physicians would not be surprised to see these very low levels of LDL become the goal for an even larger group of patients.
If this report indicates you may be a candidate for more aggressive cholesterol-lowering therapy, please discuss your options with your physician.
Dr. Freed is a cardiologist and an associate with The Cardiology Group with offices in New Haven and Branford. She is an attending physician at Yale-New Haven Hospital and Yale-New Haven Heart Center.
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