Abstract 19019: Costs and Diagnostic Yield of Exercise Treadmill Testing vs. Exercise SPECT in Symptomatic Patients at Intermediate Risk of CAD
Objective: To analyze direct costs and early revascularization rates among intermediate risk symptomatic patients undergoing exercise treadmill testing (ETT) vs. exercise myocardial perfusion SPECT.
Methods: Intermediate risk patients (Morise score 9-15) clinically referred for ETT or exercise SPECT between January 2006-December 2010 were retrospectively analyzed. Patients were excluded for prior CAD evaluation within 5 years, uninterpretable baseline ECG, cardiac surgery, cardiomyopathy, or valvular disease. One-year direct costs were based on Medicare reimbursement rates and included all non-invasive and invasive diagnostic testing for CAD. Patients were followed for early (< 90d) revascularization, a surrogate of identified obstructive CAD.
Results: The study cohort included 1,930 patients, in whom ETT was performed in 1,029 (53%) and exercise SPECT in 901 (47%). The exercise SPECT group was older (60± 10 yrs) than the ETT group (57±9 yrs), p = 0.01. 88% of the ETT group and 94% of the exercise SPECT group did not undergo any downstream testing (p < 0.001). Accordingly, 1-year total costs were driven by the baseline test and were lower for ETT (mean $177±331) compared to SPECT (mean $722±403), p <0.001. Exercise SPECT was associated with higher downstream costs versus ETT in low-intermediate risk patients (Morise score <12), p < 0.001, but lower downstream costs in intermediate-high risk patients (Morise score ≥ 12), p < 0.03 (Figure 1a). Finally, exercise SPECT resulted in more early revascularizations than ETT, suggesting that the higher initial cost is accompanied by a higher diagnostic yield (Figure 1b).
Conclusion: ETT is associated with lower 1-year costs, but also lower diagnostic yield, than exercise SPECT in intermediate risk symptomatic patients. The downstream cost-benefit of exercise SPECT is limited to intermediate-high risk patients, in whom ETT results in increased test layering.
Author Disclosures: N.R. Shah: None. M.K. Cheezum: None. M.S. Bittencourt: None. V. Veeranna: None. V.R. Taqueti: None. T. Kato: None. J. Hainer: None. C. Foster: None. M. Gaber: None. S. Dorbala: Research Grant; Significant; Astellas Pharma. Ownership Interest; Significant; General Electric. R. Blankstein: None. M.F. Di Carli: None.
- © 2014 by American Heart Association, Inc.