title: Long-term survival of medically treated patients in the Coronary Artery Surgery Study (CASS) Registry.
abstract: BACKGROUND
  This study describes the impact of clinical, angiographic, and demographic characteristics on the long-term survival of Coronary Artery Surgery Study (CASS) patients while they were under medical treatment. Revascularization rates for the population are also provided.
  
  
  RESULTS
  All CASS patients who had not received heart surgery before enrollment (23,467 patients) were included in this survival analysis while they were under medical treatment or surveillance. Follow-up time ranged from 0 to 17 years (median, 12 years). Long-term vital status is known for 95.8% of these patients. Log-rank tests, Kaplan-Meier survival curves, and Cox proportional-hazards regression are used to describe and assess the impact of patient characteristics on survival. Characteristics that had a significant impact on survival, in order of observed explanatory power, are age, number of diseased vessels, congestive heart failure score, smoking history, ejection fraction, sex, presence of left main coronary artery disease, presence of diabetes, left ventricular wall motion score, presence of other illnesses, history of myocardial infarction, and presence of left main equivalent disease. Overall, 12-year survival for patients with zero-, one-, two- and three-vessel disease is 88%, 74%, 59%, and 40%, respectively. Twelve-year survival for patients with at least one diseased vessel and ejection fractions in the ranges of 50% to 100%, 35% to 49%, and 0% to 34% is 73%, 54%, and 21%, respectively. High myocardial jeopardy, high anginal class, and two or three proximal diseased vessels characterize the profile of patients most likely to have received surgical treatment during follow-up.
  
  
  CONCLUSIONS
  These results contribute to the understanding of the natural history of coronary artery disease and are also of historical interest. The poor survival of patients with three-vessel disease and low ejection fractions continues to emphasize the importance of considering revascularization for these patients.
authors.affiliation: Coordinating Center for Collaborative Studies in Coronary Artery Surgery, University of Washington, Seattle 98105.
authors.forename: M
authors.initials: M
authors.lastname: Emond
authors.forename: M B
authors.initials: MB
authors.lastname: Mock
authors.forename: K B
authors.initials: KB
authors.lastname: Davis
authors.forename: L D
authors.initials: LD
authors.lastname: Fisher
authors.forename: D R
authors.initials: DR
authors.lastname: Holmes
authors.forename: B R
authors.initials: BR
authors.lastname: Chaitman
authors.forename: G C
authors.initials: GC
authors.lastname: Kaiser
authors.forename: E
authors.initials: E
authors.lastname: Alderman
authors.forename: T
authors.initials: T
authors.lastname: Killip
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000401:mortality* / Q000628:therapy; D003331:Coronary Vessels / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012042:Registries; D016019:Survival Analysis