Blacks in the coronary artery surgery study

Abstract

This thesis examines the experience of blacks in the Coronary Artery Surgery Study (CASS) with respect to (1) risk factors, symptoms, and coronary artery disease, (2) clinical decision making for coronary artery bypass graft surgery, and (3) therapeutic outcome as indicated by mortality, morbidity, and quality of life. Data from the CASS registry are used to examine these topics which are reviewed in the introductory chapter. In this thesis, race is defined as a social category which is related to the epidemiology and treatment of coronary disease as well as to outcome. The findings of this study are as follows. First, blacks in CASS had high levels of modifiable risk factors, yet low levels of angiographic coronary artery disease despite the presence of chest pain. Second, blacks and in particular black laborers were underserved with respect to coronary bypass surgery; the black-white difference in surgery rates persisted even when statistical controls for the predictors of surgery were instituted. Third, blacks had higher mortality, morbidity, and poorer quality of life than did their white counterparts. However, differences in survival for black and white surgical patients were not statistically significant.Alternative explanations for these findings are evaluated, although the absence of relevant data makes this a speculative venture. The findings of this study raise several important questions. First who were these blacks in CASS, and how were they selected for angiography? Second, to what groups of blacks beyond those in CASS are these findings applicable? Third, what is the nature of coronary artery disease in blacks, and fourth, what is the place of hypertension? Fifth, could blacks, who were surgical candidates yet did not have bypass surgery, have lived longer and better lives if they had had the operation? Finally, the many questions left unanswered by this study point to the need for the collection of socioeconomic data in future clinical trials and data registries. Also, multidimensional concepts of socioeconomic status and the input of social scientists are required.