title: Medical therapy or coronary artery bypass graft surgery for chronic stable angina: an update using decision analysis.
abstract: OBJECTIVE
  Randomized trials comparing medical and surgical therapies for the treatment of chronic stable angina were completed in the early 1980s. Therapies developed since then have decreased mortality and myocardial infarction rates from coronary artery disease. Using decision analysis and incorporating current recommendations for treatment, we simulated a trial comparing coronary artery bypass graft surgery and medical therapy.
  
  
  METHODS
  A Markov decision analysis model was constructed to compare the 5-year and 10-year outcomes of a simulated trial of medical therapy versus bypass surgery for stable chronic angina. Baseline data were obtained from a meta-analysis of trials comparing the two treatments. Data on risk reduction from contemporary therapies were obtained from randomized trials and meta-analyses.
  
  
  RESULTS
  All subgroups experienced modest gains in survival with current therapies. At 5 years, the survival rate was 90% in the medical group (an absolute gain of 6%) and 94% in the surgical group (an absolute gain of 4%). Similar results were obtained for patients with triple-vessel disease. Among patients with a low ejection fraction, the 5-year survival rate was 85% for medical patients and 92% for surgical patients. Sensitivity analyses did not substantially affect the conclusions.
  
  
  CONCLUSIONS
  Advances in the treatment of chronic stable angina have improved the outcome both for patients treated initially with surgery and for those treated initially with medical therapy. The improvements were of similar magnitude in both groups, so the fundamental conclusions of the bypass trials are unchanged.
authors.affiliation: Division of General Internal Medicine, University of Washington Medical Center, Seattle, Washington 98105-6920, USA.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kwok
authors.forename: C
authors.initials: C
authors.lastname: Kim
authors.forename: P A
authors.initials: PA
authors.lastname: Heidenreich
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D002908:Chronic Disease; D001026:Coronary Artery Bypass; D003331:Coronary Vessels / Q000473:pathology; D003661:Decision Support Techniques; D005260:Female; D006333:Heart Failure / Q000517:prevention & control; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008390:Markov Chains; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D009203:Myocardial Infarction / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016019:Survival Analysis; D016896:Treatment Outcome