Cost-efficacy modeling of functional testing with perfusion imaging to detect asymptomatic restenosis following percutaneous transluminal coronary angioplasty

The objective of this study was to perform a theoretical cost-efficacy anal ysis on the use of routine functional testing with perfusion imaging to ide ntify patients with asymptomatic restenosis following percutaneous translum inal coronary angioplasty (PTCA) procedures. Approximately 50% of patients with restenosis following PTCA are asymptomatic, Routine functional testing is commonly performed at 3 to 6 months to identify these patients. The cos t-efficacy associated with this strategy is unknown. Theoretical models wer e constructed based on assumed costs for functional testing (U.S. $1,300) a nd coronary angiography (U.S. $3,000). Restenosis rates were assumed to be 40%, and half of patients with restenosis were assumed to be asymptomatic. To provide a range of costs to identify a patient with asymptomatic resteno sis, three scenarios were constructed based on the diagnostic test characte ristics of functional testing. Sensitivity analyses were performed using a range of costs for functional testing, restenosis rates, and proportion of patients with restenosis who are asymptomatic. Depending on the diagnostic accuracy of functional testing, it costs $8,200 to $22,400 to identify an a symptomatic patient with restenosis following PTCA. The cost to identify a patient with asymptomatic restenosis varies inversely with the rates of res tenosis. When restenosis rates are < 20%, the cost to identify a patient wi th asymptomatic restenosis exceeds $10,000. Similarly, the cost to identify a patient with asymptomatic restenosis increases when the proportion of pa tients with asymptomatic restenosis decreases, The cost, associated with th e use of routine functional testing for the identification of asymptomatic patients with restenosis appears exorbitant. However, a formal study is war ranted to determine the cost-efficacy of such a strategy. Cathet. Cardiovas c. Intervent 48.352-356, 1999. (C) 1999 Wiley-Liss, Inc.