Epidemiological Study of Sudden and Unexpected Deaths due to Arteriosclerotic Heart Disease

A study of sudden unexpected nontraumatic deaths was begun on June 1, 1964. A sample of all nontraumatic deaths in Baltimore residents between the ages of 20 and 64 from June 15, 1964, to June 14, 1965, was obtained. The deaths were then studied by reviewing all available medical information in order to determine: (1) whether the death was possibly sudden or not and (2) the accuracy of the diagnosis reported on the death certificate. The next of kin or other relative or friend of each deceased person who died suddenly was then interviewed. For comparison, information was obtained on (1) a probability sample of the Baltimore population, and (2) deaths due to arteriosclerotic heart disease (ASHD deaths) that were found to be "not-sudden." There were 1,857 deaths in the original sample, of which 589 were sudden according to the definition of sudden death. After adjustment for sampling, it was estimated that 1,178 (32%) of the total 3,648 deaths in Baltimore were sudden. Arteriosclerotic heart disease (ASHD) accounted for 58% and the cardiovascular group together for 69% of the sudden deaths. Sixty per cent of all ASHD deaths were sudden. Of the 1,030 ASHD deaths in Baltimore City between the ages of 40 and 64, 20.6% occurred outside of a hospital and 46.2% represented deaths on arrival at a hospital. Only 18.9% of all ASHD deaths occurred after the first 24 hours of hospitalization. By use of data provided in several crosssectional and prospective studies, it was estimated that 22% of new coronary events were sudden deaths and that the case-fatality rate was 31%. In approximately half of the ASHD sudden deaths the deceased had a history of heart disease prior to death and in 24% the deceased had seen a physician within the week prior to death. Unfortunately we were not able to determine the reasons for these visits. In considering the implications of these findings with regard to the prevention of ASHD deaths, it would appear that prevention of only a comparatively small percentage (8.2%) of ASHD deaths is completely dependent on primary prevention. For the remaining ASHD deaths a combination of both primary and secondary prevention may be effective. Because of the rapidity of death and the high frequency of these deaths either occurring outside of a hospital or being called deaths on arrival, hospital treatment may well have little effect on reducing the ASHD mortality, while, on the other hand, the combination of better and earlier diagnosis and intensive treatment in a hospital could conceivably re- duce the mortality.