PURPOSE: This study aimed to test whether the coronary artery calcium (CAC) burden on attenuation correction computed tomography (CTac), measured using artificial intelligence (AI-CACac), correlates with coronary flow capacity (CFC) and prognosis. MATERIALS AND METHODS: We retrospectively enrolled patients who underwent [ RESULTS: In total, 289 patients were included in this study. Significant negative correlations were found between AI-CACac and stress MBF (ρ = -0.363, p <
0.001) and MFR (ρ = -0.305, p <
0.001). AI-CACac >
10 was associated with a significantly higher prevalence of impaired CFC (31% vs. 7%, p <
0.001) and significant ischaemia (20% vs. 7%), which remained significant after adjusting for other risk factors. MACE occurred in 49 (17%) patients (median follow-up, 284 days), and those who experienced MACE had significantly higher AI-CACac (median, 166 vs. 56
p = 0.039). However, multivariable analysis revealed an independent prognostic association among impaired CFC, diabetes, smoking, but not for AI-CACac. CONCLUSION: AI-measured CACac correlates well with PET-measured MBF and CFC, but its prognostic significance requires further validation.