The Cardiovascular Health Study

BACKGROUND:

In 1984, there were an estimated 28 million Americans ages 65 and over of whom 11 million were ages 75 and over. Projected growth in both the numbers and proportion of the elderly population in the United States showed marked increases, attributed primarily to declines in death rates from cardiovascular and non-cardiovascular diseases.

Although there has been a decline in the cardiovascular diseases over the past twenty years, they are still a major source of morbidity and mortality for middle-aged and older populations. An estimated 2.8 million persons in the United States ages 65 years and over have coronary heart disease based on the 1982 National Health Interview Survey of the National Center for Health Statistics (NCHS). About 1.4 million are men and 1.4 million are women. Prevalence of coronary heart disease is 11 percent in this age group: 13 percent in men, 9 percent in women, 12 percent in whites, and 13 percent in Blacks.

The characteristics of increased blood pressure and serum cholesterol, cigarette smoking, overweight, and diabetes have been documented as risk factors for cardiovascular disease among men and women in their middle years. A few studies have found that some of these characteristics operate as risk factors in older populations whereas the role of cigarette smoking and cholesterol is uncertain. The influence of hemostatic factors remains to be determined. The traditional risk factors are present in a substantial proportion of the elderly population. From the 1983 National Health Interview Survey, it is estimated that 21 percent of persons 65-74 years of age are current cigarette smokers. From the 1976-80 National Health and Nutrition Examination Survey of NCHS, it is estimated that 29 percent of persons 65-74 years of age are overweight, and 28 percent have a serum cholesterol level of 260 mg/100 ml or greater. From the SHEP pilot study, an estimated 68 percent of persons 65-74 years of age and 75 percent of persons ages 75 and over have hypertension, that is, systolic blood pressure of 160 mmHg or greater or a diastolic pressure of 90 or greater (based on average of three measurements) or are on anti-hypertensive medication. Isolated systolic hypertension is quite common in the elderly population.

The Framingham Heart Study observed an average annual incidence of new coronary heart disease events of 20.4 per 1,000 men ages 65-74 years and 14.5 per 1,100 women in that age group, based on 20 years of follow-up. The Study has shown a marked increase in incidence with age and significant physical disability from cardiovascular diseases in the elderly.