Abstract 20204: Cost-Effectiveness of Computed Tomography of the Coronary Arteries for Patients with Indeterminate or Positive Stress Tests in the Observation Unit
Objectives: One strategy for excluding coronary artery disease (CAD) among patients presenting with low risk chest pain is observation unit (OU) admission with serial cardiac enzymes and stress testing for cardiac risk stratification. In our OU patient population, only 8% of indeterminate stress tests and 36% of positive stress tests yielded confirmed CAD on catheterization. The aim of this study is to estimate the cost-effectiveness of computed tomography of the coronary arteries (CTCA) in the OU for the evaluation of low-risk chest pain patients with indeterminate or positive stress test results.
Methods: We used a multivariate Monte-Carlo model to compare health outcomes and costs between three cardiac risk stratification strategies in a population of patients at low cardiac risk admitted to the OU who subsequently had indeterminate or positive stress tests. The patient population and test characteristics were based on the published literature and a retrospective cohort review of 1194 low risk patients admitted to our OU. Three strategies were compared: (1) CTCA: patients with positive or indeterminate stress tests subsequently underwent CTCA, and only received catheterization if CTCA results were positive (2) standard-of-care: all patients with positive or indeterminate stress tests were admitted for catheterization, and (3) do-nothing: all patients were discharged home after stress testing regardless of outcome. Outcomes measured were cost of care and life expectancy.
Results: Both CTCA and standard-of-care strategies were cost effective when compared to the do-nothing strategy. The incremental cost effectiveness ratio (ICER) for standard-of-care vs. CTCA of was $352,651 per year of life gained. This translates to cost savings were $1967 per patient, with a decrease in life expectancy of only 2 days when instituting a CTCA strategy over standard-of-care. Sensitivity analysis demonstrated that the CTCA strategy was significantly less costly than standard-of-care with no significant decrease in life expectancy.
Conclusion: The addition of CTCA following positive or indeterminate stress test to an OU cardiac risk-stratification pathway for low risk chest pain patients achieved significant cost savings with minimal change in life expectancy.
- © 2010 by American Heart Association, Inc.