Importance of coronary heart disease risk factors in the management of hypertension: An overview

Abstract

In the United States, the number of deaths due to coronary heart disease has declined progressively since the early 19’70s in part as a result of the treatment of hypertension. Nevertheless, the overall mortality rate from coronary heart disease in this country remains high; moreover, in a number of cases its first clinical sign is sudden death. Because of this, investigators have spent years conducting a wide range of epidemiologic and clinical studies in an attempt to identifv the factors responsible for coronary atherosclero&. Results of these st,udies demonstrate that cigarette smoking, elevated levels of total cholesterol in the plasma, and hypertension are major risk factors for coronary heart disease. In the last few years, the relationship among these three major risk factors for coronary heart disease has received considerable attention. Although each risk factor can contribute to the development of atherosclerosis, the interaction among risk factors complicates the clinician’s efforts to select the most appropriate treatment and prevention regimens. In the Framingham Heart Study, for example, investigators found that there is a powerful interaction between two of the major risk factors: hypertension and elevated serum cholesterol levels. The benefits of effective management of one factor, such as high blood pressure, may be offset or negated by adverse effects on lipid levels Ill. As such, physicians should monitor both blood pressure and cholesterol levels to ensure that good control of the former does not have an unfavorable effect on the latter. Similarly, results of the Lipid Research Clinics Coronary Primary Prevention Trial have clearly demonstrated the benefits of lowering cholesterol levels [a]. In fact, this study, which was carried out in approximately 3,800 patients, provided strong evidence that a 1 percent reduction in cholesterol levels reduces the risk of death due to myocardial infarction by 2 percent. Finally, within the last year, the report of an expert panel of the National Cholesterol Education Program provided new guidelines for the treatment of high blood cholesterol levels in adults 20 years of age and over. The panel classified total cholesterol levels as follows: 200 mgidl or less is desirable; between 200 and 239 mgidl indicates borderline-high bloocl cholesterol levels; and 240 mgidl or more signifies high blood cholesterol levels 131. Based on the results of these and other findings,