Prognostic Value of a Coronary Computed Tomography Angiography–Derived Ischemia Algorithm: Comparison Against Hybrid Coronary Computed Tomography Angiography/Positron Emission Tomography Imaging

Abstract

<h3>Background</h3><p>Artificial intelligence–guided quantitative computed tomography ischemia (AI‐QCT_ischemia) is a novel machine‐learning method for predicting myocardial ischemia from coronary computed tomography angiography (CCTA). This observational cohort study aimed to compare the long‐term prognostic value of AI‐QCT_ischemia with hybrid CCTA/positron emission tomography (PET) myocardial perfusion imaging in suspected coronary artery disease (CAD).</p><h3>Methods</h3><p>Symptomatic patients with suspected CAD underwent CCTA with selective downstream PET to detect ischemic CAD. Blinded reanalysis of CCTA images was done using the AI‐QCT_ischemia algorithm, providing a binary result (normal versus abnormal).</p><h3>Results</h3><p>In the full analysis set (n=2271), hybrid CCTA/PET imaging was successful in 94% of the patients and AI‐QCT_ischemia evaluation was feasible in 83%, resulting in a per‐protocol set of 1772 patients (19% with ischemic CAD on hybrid CCTA/PET and 25% with abnormal AI‐QCT_ischemia). There was moderate‐to‐substantial agreement between the methods (Cohen’s κ=0.61). During a median follow‐up of 7.0 years, 177 (10%) patients experienced the composite end point of all‐cause death, myocardial infarction, or unstable angina. Ischemic CAD on hybrid CCTA/PET was predictive of the composite end point (hazard ratio [HR], 2.35 [95% CI, 1.62–3.40]; <em>P</em><0.001), after adjustment for clinical variables and early (6‐month) myocardial revascularization. Similarly, an abnormal (ischemic) AI‐QCT_ischemia result was independently predictive of adverse outcomes (adjusted HR, 1.98 [95% CI, 1.39–2.80]; <em>P</em><0.001). The adjusted models, including either hybrid CCTA/PET or AI‐QCT_ischemia, demonstrated similar discriminative ability (C‐index 0.734 versus 0.729; <em>P</em>=0.53).</p><h3>Conclusions</h3><p>The AI‐QCT_ischemia algorithm demonstrated long‐term prognostic value comparable to hybrid CCTA/PET perfusion imaging in suspected CAD.</p>