Ischemic heart disease: an overview.

The studies on natural history of ischemic heart disease are reviewed and the major predictors of mortality identified. The severity of the coronary atherosclerosis and the status of ventricular function are found to be more important predictors of survival than the clinical presentation. The objectives of therapy in patients with ischemic heart disease are (1) to improve the quality of life by reducing symptoms, (2) to improve ventricular function, and (3) to increase survival time. The results of surgical therapy are examined in relation to these three objectives. Symptomatic improvement is present in 85 to 95 percent of patients after surgery, but convincing evidence for improved ventricular function is lacking and controlled studies of natural history have failed to show that surgery increases survival time. Analysis of the mechanism of symptomatic improvement after surgery suggests that increased blood flow to the ischemic area as well as infarction of ischemic myocardium and the nonspecific effects of surgery may account for the improvement. The prevention of coronary atherosclerosis is viewed as an attainable long-term solution to the problem of ischemic heart disease.