Coronary Heart Disease Risk Factors Part 1

Heart disease is the leading cause of death among adults in the United States. Specifically, coronary heart disease (CHD) is the single largest killer of American males and females. Seven million Americans suffer from CHD, and about a half million people die each year from heart attacks caused by CHD. One out of two men, and one out of three women will develop heart disease sometime in their life. CHD is also the leading cause of death among African Americans, affecting this population disproportionately when compared to whites. In 1996 CHD death rates were 120.2 per 100,000 for white males, 125.4 for black males, 58.9 for white females, and 80.0 for black females. For those aged 35–74, the age-adjusted death rate from CHD for black women is nearly 72% higher than that of white women.

Both epidemiologic and clinical trials have documented the prevalence of lipid disorders, and have proven that elevated levels of low-density lipoprotein (LDL) cholesterol and decreased levels of high-density lipoprotein (HDL) are associated with an increased risk of CHD. (Pharmacists should be aware that certain diseases and medications are also capable of affecting cholesterol levels. Therefore, patient medication profiles and medical histories should be reviewed thoroughly to rule out these possible secondary causes of dyslipidemia.) In addition to elevated cholesterol, other risk factors for CHD have been identified:

• Age: Male 45 years or older; female 55 years or older, or experiencing premature menopause without estrogen replacement therapy
• Family history: History of premature CHD (definite myocardial infarction or sudden death before age 55 in father or other male first-degree relative, or before age 65 in mother or other female first-degree relative)
• Current cigarette smoking
• Hypertension (blood pressure 140/90 mmHg or greater) or taking antihypertensive medicine
• Diabetes mellitus

Management of Elevated Cholesterol
The National Cholesterol Education Program (NCEP) of the National Heart, Lung and Blood Institute (NHLBI) has established guidelines for the prevention and treatment of lipid disorders. According to the NCEP guidelines, all patients at least 20 years of age should have an initial cholesterol measurement. It is recommended that the initial laboratory test measure both total and HDL cholesterol. The American Diabetes Association (ADA) recommends that diabetic patients receive a complete lipid profile (i.e., LDL, HDL and triglycerides) annually. Further evaluation of the patient is based on the results of these initial tests. The goals of lipid-lowering interventions vary depending on whether the focus is primary or secondary prevention of CHD. In primary prevention the goal is to prevent the onset of CHD; secondary prevention focuses on avoiding further CHD events. Treatment should be modeled after NCEP recommendations. These guidelines include nonpharmacologic, lifestyle modifications (e.g., diet, exercise, smoking cessation), and pharmacologic measures. Table 1 outlines the LDL treatment goals based on the number of CHD risk factors present.

Lifestyle Modification: Dietary therapy is the first line of treatment for elevated cholesterol levels. NCEP recognizes dietary modification as the cornerstone in the management of dyslipidemia. The general goal of dietary therapy is to reduce elevated serum cholesterol while maintaining a nutritionally appropriate eating pattern. A reduction in saturated fat and cholesterol in the diet, as well as regular physical activity, are two important lifestyle changes that pharmacists must emphasize to patients. Dietary therapy is a two-step process. Step I begins the process of reducing intake of saturated fat and cholesterol. The diet should involve an intake of 10% of total calories from saturated fat, 30% or less of calories from total fat, and 300 mg or less of cholesterol per day (Table 2). If the goals of therapy are not achieved with Step I, patients should be advanced to the Step II diet. Step II requires further reduction in saturated fat and cholesterol. For this step, a registered dietitian should assist with management.

Both physical activity and weight reduction are considered essential components in the nonpharmacologic management of elevated serum cholesterol. A program of physical activity for at least 20 minutes three times weekly provides significant cardiovascular benefit. The benefits of physical activity include an increase in HDL and a decrease in weight, especially for obese and overweight patients. It may also lead to a reduction in triglyceride levels. Patients should be advised to consult their physician prior to initiating an exercise program.
Smoking cessation should also be encouraged. Pharmacists should have information available, and be able to direct patients to local smoking cessation programs. They should be knowledgeable about the various smoking cessation aids available (e.g., nicotine gum and patches).

Pharmocologic Measures: The goal of drug therapy is to reduce the LDL cholesterol to below 160 mg/dL or to below 130 mg/dL if two other risk factors are present. Drug therapy is considered for the adult patient who has an LDL cholesterol level of 190 mg/dL or greater without two other risk factors; or 160 mg/dL or greater with two other risk factors. Table 3 outlines the NCEP guidelines for treatment, and Table 4 summarizes patient counseling information specific to each lipid-lowering agent available.