BACKGROUND: The increased specificity of ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT over energy-integrating detector (EID)-CT for coronary CT angiography (CCTA) could defer unwarranted downstream tests. The objective of the study was to simulate the cost-effectiveness of UHR CCTA in stable chest pain patients with coronary calcifications. METHODS: A decision and simulation model was developed using Monte Carlo simulations with 1000 bootstrap resamples to estimate the costs associated with PCD-CT in lieu of EID-CT for CCTA and the referral for subsequent testing. The model was constructed using the diagnostic accuracy metrics of 55 coronary lesions in patients who underwent CCTA on both CT systems and subsequent invasive coronary angiography (ICA). Sensitivity and specificity were defined for each Coronary Artery Disease Reporting and Data System category. The aggregate healthcare expenditures were derived from the hospital billing system. RESULTS: Assuming a projected cohort of 15,000 patients over the lifetime of the PCD-CT, its implementation resulted in a 18.9 % reduction in the number of functional follow-up tests (6330.3 ± 59.5 vs. 5135.7 ± 60.6, p <
0.001), a 6.0 % reduction in performed ICAs (1447.7 ± 36.2 vs. 1360.2 ± 34.7, p <
0.001), and a 9.4 % decrease in major procedure-related complications. Over a 10-year expected life expectancy, PCD-CT led to an average cost saving of 94.50 ± 18.50 per patient and an overall cost difference of 1,917,500 ± 4,350,169. CONCLUSIONS: PCD-CT has the potential to reduce the financial burden on healthcare systems and procedure-related complications for stable chest pain patients with coronary calcification when compared to EID-CT.