The current series represents the total experience of one institution that has treated concurrently a large number of patients with medical or surgical therapy. As previously reported, surgery offers a greater chance for pain relief but no obvious protection from future myocardial infarction. Patients with single artery disease show no difference in survival or future myocardial infarction rate whether treated medically or surgically. Improvement in survival following surgery, determined by univariate analysis of clinical descriptors, in several subsets of patients in the present series has not been confirmed when multivariate analysis techniques are used. If surgical mortality can be further lowered there may well be subsets of patients with coronary artery disease who will outsurvive similar medically treated patients. The current and future natural history of coronary artery disease, whether treated medically or surgically, is not settled by this or any other series because both forms of therapy are rapidly changing and no current series meets valid statistical criticisms. We are in a state of evaluation concerning not only therapeutic approaches, but also the development of suitable statistical methods for determining the efficacy of various forms of therapy. Only by continual modification of therapeutic approaches and the statistical tools to measure their effectiveness can we approach confident conclusions.