Tools can help prevent coronary artery disease
By Joan Unger, RN, MS, ARNP and William T. Elliott, MD, FACP
As a result of a recently published report from the National Cholesterol Education Program (NCEP) in Bethesda, MD, nurses and physicians can incorporate tools into their practice for the primary prevention of coronary artery disease (CAD) in persons with multiple risk factors.
The report, titled Adult Treatment Panel III (ATP III), updates existing recommendations for the diagnosis and clinical management of high blood cholesterol. It includes new guidelines to help providers determine which patients require treatment and updates targets for cholesterol levels. (See New Features of ATP III, inserted in this issue.)
The report suggests aggressive treatment for those with risk factors, including drug therapy to lower low-density lipoprotein (LDL) cholesterol to 100 mg/dL. Another significant change is the elevation of diabetes to the risk equivalent of CAD when considering lipid-lowering therapy. The guidelines suggest that anyone with an LDL cholesterol greater than 130, high-density lipoprotein (HDL) less than 40, or a triglyceride level greater than 200 should be considered for drug therapy. (See Table 1, below.)
| Table 1-ATP III Classification of LDL (mg/dL) | |
| Classification | LDL level |
| Optimal | < 100 |
| Near or above optimal | 100-129 |
| Borderline high | 130-159 |
| High | 160-189 |
| Very High | ³ 190 |
| Source: U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Heart, Lung, and Blood Institute, Bethesda, MD. Adapted from NIH Publication No. 01-3670; May 2001. |
|
The expert panel recommends that a fasting lipid panel should be the standard screening exam obtained every five years in all adults age 20 years or older. The exam should include total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. If the test is nonfasting and the results show total cholesterol > 200 mg/dL or HDL is < 40 mg/dL, a follow-up lipoprotein profile (after a nine- to 12-hour fast) is necessary for appropriate management based on the LDL. In addition it is important, in persons with elevated LDL cholesterol or other hyperlipidemia, to rule out diabetes, hypothyroidism, obstructive liver disease, chronic renal failure, and drugs such as progestins, anabolic steroids, and corticosteroids, that increase LDL and decrease HDL.
The clinical approach to primary prevention calls for multifaceted lifestyle changes to reduce the risk for CAD. The ATP III designates these as therapeutic lifestyle changes (TLC). Nurses and other health care providers should encourage patients to:
• reduce intakes of saturated fats to < 7% of total calories;
• reduce cholesterol to < 200 mg per day;
• increase viscous (soluble) fiber to 10-25 g/day;
• control weight to lower cholesterol levels and reduce CAD risk;
• increase moderate physical activity.
ATP III’s TLC Diet generally contains the recommendations included in the Dietary Guidelines for Americans 2000. One exception is that total fat is allowed to range from 25%-35% of total calories, provided saturated fats and trans fats are kept low. A higher intake of unsaturated far helps reduce triglycerides and raise HDL in persons with a metabolic syndrome.
At the end of six weeks, the LDL response is measured. If the goal has not been reached, other therapeutic options for LDL lowering, such as viscous fiber (10-25 g/day) and plant stanols/sterols (2 g/day), may be added. Plant stanols/sterols is a natural plant substance found in cholesterol-lowering margarines such as Benacol and Take Control.
After maximum reduction of LDL with dietary therapy, the emphasis shifts to management of the metabolic syndrome and other lipid risk factors. A portion of the population whose risk for CAD is high will require LDL-lowering drugs in addition to TLC, but even when drugs are prescribed, it is important to maintain and reinforce attention to TLC.
The executive summary is available in the May 16 issue of The Journal of the American Medical Association (JAMA 2001; 285:2,486-2,497). More information also is available at www.nhlbi.nih.gov guidelines/cholesterol/index.htm.
Cholesterol-lowering therapy
Older patients may benefit more from cholesterol-lowering therapy than younger patients, according to an Australian study. More than 9,000 patients with a history of CAD were studied, of which 3,500 were age 65-75. Patients were randomized to pravastatin 40 mg/d or placebo and were followed for an average of six years. In patients 65-75 years of age, pravastatin therapy reduced:
• mortality by 21%;
• death from coronary heart disease by 24%;
• coronary heart disease death or nonfatal myocardial infarction by 22%;
• myocardial infarction by 26%;
• stroke by 12%.
For every 1,000 older patients treated over six years, pravastatin prevented 45 deaths, including deaths from myocardial infarction and strokes.
The rate of decrease was similar for younger and older patients, but because older patients were at a higher absolute risk of death and major coronary events, the benefit was greater for those ages 65-75 (Ann Int Med 2001; 134:931-940).
Migraine treatment
The Food and Drug Administration has approved a new triptan for the treatment of migraine. Pharmacia’s almotriptan malate is approved for migraine in adults with or without aura. The drug, which will be sold under the trade name AXERT, is touted as being as effective as sumitriptan but with significantly fewer side effects, especially chest pain (company data). AXERT is not intended for prevention of migraine or for use in hemiplegic or basilar migraine. Safety and effectiveness of AXERT have not been established for cluster headache, which is present in an older, predominantly male population. The incidence of adverse effects (nausea, dry mouth, and paresthesia) was similar to that of placebo.
• Dosage.
AXERT comes in two doses: 12.5 mg and 6.25 mg. In clinical trials, AXERT 12.5 mg and 6.25 mg gave significant relief from migraine pain at two hours. Efficacy rates in comparison to placebo ranged from 57%-65% (12.5 mg) and 55%-56% (6.25 mg). If needed, the patient may take a second dose after two hours but should not exceed two doses within a 24-hour period.
• Nursing considerations.
AXERT should not be administered within 24 hours of treatment with ergotamine-containing or ergot-type medication such as dihydroergotamine, methysergide, or another 5-HT1 agonist. AXERT may cause coronary vasospasm. It also should not be given to patients with ischemic heart disease (angina pectoris, history of myocardial infarction, or documented silent ischemia) or who have symptoms or findings consistent with ischemic heart disease.
Because AXERT may increase blood pressure, it should not be given to patients with uncontrolled hypertension. Patients with renal or hepatic impairment should be started with 6.25 mg.
• Patient education.
AXERT is intended for acute treatment of migraine in adults and should not be used for prevention. It should not be taken in conjunction with other drugs prescribed for migraine. In studies, side effects occurred in only 1% of subjects, but encourage the patient to report unusual symptoms.
Allergy medicine and OTC status
A battle is shaping up in Washington over the status of three popular prescription allergy medications. Wellpoint Health, one of the nation’s largest HMOs, has petitioned the Food and Drug Administration (FDA) to switch loratidine (Claritin-Schering-Plough), fexofenadine (Allegra-Aventis), and cetirizine (Zyrtec-Pfizer) to over the counter (OTC) status.
At issue is the relative safety of these "nonsedating" antihistamines compared to currently available OTC antihistamines such as diphenhydramine and hydroxyzine. The manufacturers argue the drugs should be available only by prescription and covered by third-party payers. They say the drugs are too new to be considered for OTC status and that allergic rhinitis requires a doctor’s diagnosis.
An FDA panel has approved a prescription-to-OTC switch for the three drugs, but it is unclear whether the FDA has the ability to force the switch against the companies’ wishes.
Beta-blockers and CHF
Do beta-blockers benefit patients with advanced congestive heart failure? Subsequent articles in the May 31 New England Journal of Medicine give conflicting results. In the first study, more than 2,000 patients with severe heart failure were randomized to carvedilol therapy or placebo for a mean period of 10.4 months. Over the study period, there were 190 deaths in the placebo group and 130 deaths in the carvedilol group, and a 24% decrease in the combined risk of death or hospitalization with carvedilol (N Engl J Med 2001; 344:1,651-1,658).
In the second study, 2,700 patients with severe heart failure were randomized to treatment with the beta-blocker bucindolol or placebo. The study was stopped early because no significant overall survival benefit was shown with bucindolol. (N Engl J Med 2001; 344:1,659-1,667).
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