The Auckland suburbs coronary study
Abstract (Summary)The Auckland Suburbs Coronary Study is designed to provide information concerning acute coronary events in Auckland. Within New Zealand, information Previously depended on either hospital data or death certificate data. The present study is community based and has provided more extensive information than has previously been available. A random sample of 125 primary care doctors was selected. The patients of these doctors were considered a random sample of the community and formed the study population. The size of this population was estimated using a postal survey, taking names from the electoral roll. A statistical theory is developed to allow a confidence interval to be placed about the maximum likelihood estimate. Hypothesis testing theory is applied to the problem of comparing disease frequencies at different locations or at different times at the same location. During overlapping one year periods, 293 cases of definite myocardial infarction, 178 cases of sudden cardiac death and 99 cases of possible myocardial infarction were collected. Information concerning demographic variables, past and prodromal medical histories, the acute event, the electrocardiograph, cardiac enzymes, mortality within 28 days and postmortem results, was collected As about 80% of sudden deaths are all over before any help is sought and in view of the geographic nature of Auckland city the utility of ‘cardiac arrest’ ambulances would not seem to be great. For sudden deaths surviving longer than five minutes after onset (about 50% of total) there was a significant tendency for there to be a lower social class predominance. This may imply inadequacies of acute health care--either availability or notification. Persons dying suddenly differed from persons experiencing definite myocardial infarction (but not dying suddenly) by experiencing less prodromal chest pain, taking digoxin and frusemide more frequently, consuming more alcohol and the acute event occurring in the cooler months proportionately more often. At postmortem, they had significantly more myocardial scarring and/or fibrosis. Persons experiencing definite myocardial infarction differed from persons experiencing possible myocardial infarction (who did not die suddenly) by being more likely a male, having less history of past acute coronary insufficiency, using less of beta-blocking drugs or frusemide/ethacrynic acid and describing prodromal lethargy less frequently. Clinical shock was more common in the acute phase and death more common in the succeeding 30 days. Persons dying suddenly differed from those suffering possible myocardial infarction (but not dying suddenly) by being older, more likely to be male and less likely to have had chest pain in the prodrome. The data could be interpreted as suggesting that a separate primary myocardial process is contributing towards sudden death. Alcohol may be a risk factor for sudden death. A hypothesis is, that in the presence of acute infarction, a history of chronic, moderate to high alcohol intake is associated with an increased likelihood of sudden death.
School Location:New Zealand
Source Type:Master's Thesis
Date of Publication:01/01/1979