Interactions of the major risk factors for coronary heart disease.

Since cardiovascular disease accounts for more than 50 percent of all deaths in the United States today, researchers in a number of major clinical studies have attempted to determine whether this epidemic of cardiovascular deaths can be controlled by reducing the primary risk factors for coronary heart disease and atherosclerosis. Treatment of one of these risk factors, hypertension, has clearly been proven beneficial in reducing the morbidity and mortality of cardiovascular disease. These positive effects are seen at the three levels of hypertension: mild, moderate, or severe. Another risk factor, cigarette smoking, is generally accepted to be the single most preventable cause of death from coronary heart disease in the United States. The mortality rate for coronary heart disease is two to three times greater in those who are heavy smokers, representing a substantial independent risk factor, and the risk is even higher when smokers are also hypertensive and hypercholesterolemic. A third risk factor, hypercholesterolemia, has come under renewed scrutiny, and several recent studies have shown that lowering cholesterol through the use of diet or drugs can reduce the progression of atherosclerotic plaque. Based on the results of various intervention trials over the years, it appears that methods of preventing cardiovascular disease in the general population, such as emphasizing the importance of diet and exercise, should be promoted. The American Heart Association recommendations, if adopted, could effect changes in attitudes of those in the medical community, at work sites, and even in schools. In addition to prophylactic measures, an intensive effort to identify and treat persons at high risk should be undertaken.