Abstract 313: Rates of All-cause Mortality, Myocardial Infarction and Coronary Revascularization Stratified by Appropriate Use Criteria in Coronary Artery Disease Patients Managed with Optimal Medical Therapy

Abstract

Appropriate use criteria (AUC) have been developed for guiding clinical decision-making for coronary revascularization (revasc). We studied a prospective cohort of 693 pts initiated in 1992 and managed with optimal medical therapy (OMT). AUC scores could be calculated using noninvasive test results and coronary angiographic data in 230 pts, which constitute the study group. When non-invasive findings were discordant, patients were put in the higher risk stratum. Revasc status and myocardial infarction (MI) events were ascertained as of June 2005. Mortality status was ascertained as of December 31, 2008. Based on AUC scores, pts were classified as Appropriate (A), Inappropriate (I), or Uncertain (U) for revasc. Decisions to pursue invasive evaluation and revasc were based solely on stability of symptoms, LV function, and exercise duration. Survival analysis and stepwise Cox modeling was used to assess AUC class as a predictor of outcomes. Results: The majority of pts, 53% (121 of 230), were AUC Class A, with almost all the remainder in Class U, 34% (79 of 230). The mean age of the study group was 66.0 years. The annual incidence of all-cause mortality over a mean follow up period of 12.1 years was 3.6%. A total of 99 deaths occurred. There were no significant differences in the mortality curves of the 3 AUC classes. The annual incidence of non-fatal MI over a mean follow up of 6.45 years was 2.2%. AUC class A was not a predictor of non-fatal MI. The annual incidence of revasc over a mean follow up period of 5.38 years was 6.5%. Multivariate stepwise Cox models showed AUC class A was a significant predictor of revasc, along with diabetes mellitus. Beta-blocker therapy at entry was protective. Kaplan-Meier curves confirmed the findings for revasc and nonfatal MI. Conclusions: In an OMT cohort initiated in 1992, 53% of pts in whom AUC scores were calculable were deemed appropriate for revasc but were managed with OMT alone. Low annual incidence of mortality and rates of eventual revascularization were observed. Retrospective stratification showed no adverse mortality experience with OMT by AUC class. AUC Class A pts had a significantly higher rate of revasc during OMT, reflecting the goals of the AUC system, yet the annualized rates of death and MI in this class were comparable to the rates in the medical arms of recent RCT’s of OMT. These findings suggest that contemporary AUC classification may permit revasc in OMT pts without distinguishing that subset with a future mortality risk on OMT alone. AUC Classification of pts for revasc may require further refinement to enhance the selection of mortality benefit over OMT.