Prognostic value of a novel artificial intelligence-based coronary computed tomography angiography-derived ischaemia algorithm for patients with suspected coronary artery disease

Aims Coronary computed tomography angiography (CTA) imaging is used to diagnose patients with suspected coronary artery disease (CAD). A novel artificial intelligence-guided quantitative computed tomography ischaemia algorithm (AI-QCT(ischaemia)) aims to identify myocardial ischaemia directly from CTA images and may be helpful to improve risk stratification. The aims were to investigate (i) the prognostic value of AI-QCT(ischaemia) amongst symptomatic patients with suspected CAD entering diagnostic imaging with coronary CTA and (ii) the prognostic value of AI-QCT(ischaemia) separately amongst patients with no/non-obstructive CAD (<= 50% visual diameter stenosis) and obstructive CAD (>50% visual diameter stenosis).Methods and results For this cohort study, AI-QCT(ischaemia) was calculated by blinded analysts amongst patients with suspected CAD undergoing coronary CTA. The primary endpoint was the composite of death, myocardial infarction (MI), or unstable angina pectoris (uAP) (median follow-up 6.9 years). A total of 1880/2271 (83%) patients had conclusive AI-QCT(ischaemia) result. Patients with an abnormal AI-QCT(ischaemia) result (n = 509/1880) vs. patients with a normal AI-QCT(ischaemia) result (n = 1371/1880) had significantly higher crude and adjusted rates of the primary endpoint [adjusted hazard ratio (HRadj) 1.96, 95% confidence interval (CI) 1.46-2.63, P < 0.001; covariates: age/sex/hypertension/diabetes/smoking/typical angina]. An abnormal AI-QCT(ischaemia) result was associated with significantly higher crude and adjusted rates of the primary endpoint amongst patients with no/non-obstructive CAD (n = 1373/1847) (HRadj 1.81, 95% CI 1.09-3.00, P = 0.022), but not amongst those with obstructive CAD (n = 474/1847) (HRadj 1.26, 95% CI 0.75-2.12, P = 0.386) (P-interaction = 0.032).Conclusion Amongst patients with suspected CAD, an abnormal AI-QCT(ischaemia) result was associated with a two-fold increased adjusted rate of long-term death, MI, or uAP. AI-QCT(ischaemia) may be useful to improve risk stratification, especially amongst patients with no/non-obstructive CAD on coronary CTA.