The economic consequences of available diagnostic and prognostic strategies for the evaluation of stable angina patients: An observational assessmentof the value of precatheterization ischemia

OBJECTIVES The study aim was to determine observational differences in cost s of care by the coronary disease diagnostic test modality. BACKGROUND A number of diagnostic strategies are available with few data to compare the cost implications of the initial test choice. METHODS We prospectively enrolled 11,372 consecutive stable angina patients who were referred for stress myocardial perfusion tomography or cardiac ca theterization. Stress imaging patients were matched by their pretest clinic al risk of coronary disease to a series of patients referred to cardiac cat heterization. Composite 3-year costs of care were compared for two patients management strategies: 1) direct cardiac catheterization (aggressive) and 2) initial stress myocardial perfusion tomography and selective catheteriza tion of high risk patients (conservative). Analysis of variance techniques were used to compare costs, adjusting for treatment propensity and pretest risk RESULTS Observational comparisons of aggressive as compared with conservati ve testing strategies reveal that costs of care were higher for direct card iac catheterization in all clinical risk subsets (range: $2,878 to $4,579), as compared with stress myocardial perfusion imaging plus selective cathet erization (range: $2,387 to $3,010, p < 0.0001). Coronary revascularization rates were higher for low, intermediate and high risk direct catheterizati on patients as compared with the initial stress perfusion imaging cohort (1 3% to 50%, p < 0.0001); cardiac death or myocardial infarction rates were s imilar (p > 0.20). CONCLUSIONS Observational assessments reveal that stable chest pain patient s who undergo a more aggressive diagnostic strategy have higher diagnostic costs and greater rates of intervention and follow-up costs. Cost differenc es may reflect a diminished necessity for resource consumption for patients ,with normal test results. (C) 1999 by the American College of Cardiology.