Coronary calcium to rule out obstructive coronary artery disease in patients with non-anginal chest pain

Abstract Background Recent North American and European chest pain/chronic coronary syndrome (CCS) guidelines recommend the use of coronary artery calcium score (CACS) to determine the need for further cardiac testing in patients with low clinical likelihood of coronary artery disease (CAD). A large proportion of patients referred for coronary computed tomography angiography (CCTA) due to suspected CCS present with non-anginal chest pain. Among such patients, CACS may be particularly efficacious in identifying those who can be safely deferred from further testing. Purpose This study aimed to investigate the ability of CACS = 0 to rule out obstructive CAD in a large cohort of patients presenting with non-anginal chest pain. Methods Consecutive patients with non-anginal chest pain who were referred for CCTA from 2013 to 2024 were included. Obstructive CAD was defined as ≥1 vessel with ≥50% stenosis on CCTA. To assess the diagnostic accuracy of CACS = 0 to rule out obstructive CAD, we calculated the negative predictive value (NPV) and negative likelihood ratio (LR-). Results The study included 3267 patients (mean age: 57.3 ± 10.0 years; 59% male). Among the 1415 patients (43.3%) with CACS = 0, only 7 (0.5%) exhibited obstructive CAD. By contrast, among the 1852 patients (56.7%) with CACS >0, 653 (35.3%) had obstructive CAD. The NPV and LR- of CACS = 0 to rule out obstructive CAD were 99.5% (95% CI, 99.0% to 99.8%) and 0.02 (95% CI, 0.01 to 0.04), respectively. Only 1 patient with CACS = 0 (0.07%) underwent revascularization. The NPV for identifying patients who needed revascularization was 99.9% (95% CI, 99.5% to 100%). Among patients with CACS = 0, the number needed to test with CCTA was 202 to detect one patient with obstructive CAD, and 1415 to detect one patient who needed revascularization. Conclusions In patients with non-anginal chest pain, a CACS = 0 exhibits nearly perfect rule-out capabilities for obstructive CAD and may be used to safely defer patients from further testing. The application of CACS as a gatekeeper in this patient population could substantially reduce the need for additional testing by CCTA and associated cost, radiation and contrast exposure.