Radiology: Volume 254: Number 3—March 2010

Cost-effectiveness of Coronary CT Angiography versus Myocardial Perfusion SPECT for Evaluation of Patients with Chest Pain and No Known Coronary Artery Disease

James K. Min, MD Amanda Gilmore, PhD Matthew J. Budoff, MD Daniel S. Berman, MD Ken O'Day, PhD

Purpose: To evaluate the cost-effectiveness of diagnostic strategies for individuals with chest, pain without known coronary artery disease (CAD) in the Assessment by Coronary Computed Tomographic Angiography of Indi­viduals Undergoing Invasive Coronary Angiography-eligible population.

Materials and Methods: A decision analysis was performed in which the following were com­pared: coronary computed tomographic (CT) angiography followed by invasive coronary angiography for positive or equivocal findings (coronary CT angiography only), coronary CT angiography followed by invasive coronary angiography for positive findings and myocardial perfusion single photon emission computed tomography (SPECT) for equivocal findings (coronary CT angiography first), myocardial per­fusion SPECT followed by invasive coronary angiography for positive/ equivocal findings (myocardial perfusion SPECT only), myocardial perfusion SPECT followed by invasive coronary angiography for positive findings and coronary CT angiography for equivocal findings (myocardial perfusion SPECT first), and invasive coronary angiogra­phy. Analyses were conducted from the payer perspective for a near-term diagnostic period and a long-term lifetime period. The base case was a 55-year-old man with 30% risk of obstructive CAD.

Results: By using the base case for near-term cost per correct diagnosis, a cor­onary CT angiography-first strategy was the least expensive, followed by coronary CT angiography only (incremental cost-effectiveness ratio [1CER].= $17516). For long-term cost-effectiveness, a coronary CT angiography-only strategy demonstrated a favorable ICER of $20429 per quality-adjusted life-year (QALY) relative to the least expensive coronary CT angiography-first strategy. Both myocardial perfusion SPECT-only and myocardial perfusion SPECT-first strategies were more costly and less effective than either coronary CT angiographic strategy. Long-term results were sensitive to coronary CT angiographic sensitivity, myocardial perfusion SPECT sensitivity, and CAD preva­lence. Coronary CT angiography-first and coronary CT angiography-only strategies remained dominant up to a baseline coronary CT angiography test cost of $1100 and 80% CAD prevalence.

Conclusion:With a $20000 threshold level for cost per correct diagnosis and $50000 per QALY, a coronary CT angiography-only approach is the most cost-effective diagnostic strategy for evaluation of patients who have stable chest pain without known CAD with intermediate CAD prevalence.