Prognostic significance of diabetes as a predictor of survival after cardiac catheterization

PURPOSE: Diabetes is a recognized risk factor for the development of cardia c disease, but its importance as a prognostic factor among patients with kn own cardiovascular disease is less clear. We evaluated survival in patients with and without diabetes who underwent cardiac catheterization for presum ed coronary artery disease. SUBJECTS AND METHODS: We analyzed data from a prospective cohort study that captures detailed clinical information and longitudinal outcomes for all p atients who undergo cardiac catheterization in Alberta, Canada. We studied 11,468 patients, 1959 (17%) of whom had diabetes. Logistic regression was u sed to model predictors of 1-year mortality, and proportional hazards analy sis was used to model predictors of survival up to 3 years after cardiac ca theterization. RESULTS: One-year mortality was 7.6% for patients with diabetes versus 4.1% for those without diabetes (odds ratio = 1.9, 95% confidence interval [CI] : 1.6 to 2.3). After adjusting for other characteristics of the patients, i ncluding comorbid conditions, previous cardiac history, coronary anatomy, a nd renal function, the odds ratio for 1-year mortality was 1.1 (95% CI: 0.8 to 1.3). Similarly, the adjusted hazard ratio for longer term mortality wa s 1.2 (95% CI: 1.0 to 1.4, mean follow-up of 702 days). CONCLUSIONS: These results suggest that there is little or no independent a ssociation between diabetes and mortality for up to 3 years after cardiac c atheterization. Estimates of short- to intermediate-term prognosis for diab etic patients with coronary artery disease should be based on the presence of other prognostic factors associated with diabetes. Am J Med. 2000; 109:5 43-548. (C) 2000 by Excerpta Medica, Inc.