Despite continuing research on the pathogenesis of atherosclerosis and the etiology of coronary heart disease, this entity remains a major cause of death and disability among the elderly in the United States. The bulk of epidemiologic research in this field has been concerned with mortality statistics, prevalence and incidence data, and risk factors in young and middle-aged adults.Little information is available concerning possible factors enabling a person to live t o the seventh or eighth decade of life without suffering from coronary heart disease. This study was conducted over a nine-month period during 1965-1966 at the Veterans Administration Hospital, Portland, Oregon, in a n attempt t o determine some factors and living habits t h a t might be associated with the absence of coronary heart disease in patients 65 years of age and older.
MATERIAL AND METHODSThe U. S. Veterans Administration Hospital at Portland, Oregon is a 555-bed hospital consisting of a general medicine and surgical service, and is a major teaching unit of the University of Oregon Medical School. It has an average daily census of 522 predominantly male patients, of whom more than 50 per cent are 65 years of age or older. I t thus provides an ideal setting for clinical studies related to coronary heart disease in an elderly population.
Study patients-No heart diseasePatients were selected for study by initially screening those 65 years of age and older who had normal electrocardiograms. Approximately 8,000 electrocardiograms are taken yearly in this hospital and they are interpreted daily by the department head and the staff of the Cardiology Department. During the period June 30, 1965 to March 31, 1966, a total of 6,055 electrocardiograms were taken. Of these, 2,921 (48 per cent) were in patients 65 years of age and older, and 289 of them were interpreted as normal. The patients with normal electrocardiograms were then interviewed and examined to determine that they did not have coronary heart disease or other forms of heart disease. The diagnostic criteria used were those established by the New York Heart Association (1) for the diagnosis of cardiovascular disease.After full investigation, 133 patients (4 per cent of the sample of 2,921 patients 65 years of age and older) were found to be free from any type of heart disease. These 133 elderly persons (130 males and 3 females) with "normal hearts" became the study subjects. Their ages ranged from 65 to 85 years, with an average of 70 years.