Coronary Artery Calcium Score-Weighted Clinical Likelihood Model Performance in Patients with Stable Chest Pain and Coronary Artery Calcium Scores of Zero

Background: For individuals with persistent stable chest pain (SCP) and a coronary artery calcium score (CACS) of 0, it might be challenging to establish the best risk assessment method for determining the individuals who will not benefit from further cardiovascular imaging testing (CIT). Thus, we investigated the CACS-weighted clinical likelihood (CACS-CL) model in SCP patients with a CACS of 0. Methods: Thus, to assess SCP, we originally enrolled 14,232 individuals for CACS and coronary computed tomography angiography (CCTA) scans between January 2016 and January 2018. Finally, patients with a CACS of 0 were included and followed up until January 2022. According to the established CACS-CL cutoffs of 15% and 5%, the associations between coronary artery disease (CAD) and major adverse cardiovascular events (MACEs) in risk groups were evaluated, alongside the net reclassification improvement (NRI). Results: Of the 6689 patients with a CACS of 0, the prevalence of CAD increased significantly (p < 0.0001) in patients with higher CACS-CL. However, there was no significant difference in the CAD distribution (p = 0.0637) between patients with CACS-CL <5% and 5-15%. The association between the CACS-CL = 15% -determined risk groups and the occurrence of MACEs was stronger than for a CACS-CL = 5% (adjusted hazard ratio (HR): 7.24 (95% CI: 1.93-16.42) versus 3.68 (95% CI: 1.50-8.26)). Compared with the cutoff for CACS-CL = 5%, the NRI was 10.61% when using a cutoff for CACS-CL = 15%. Conclusions: Among patients with an SCP and CACS of 0, the CACS-CL model provided accurate predictions of CAD and MACEs. Compared to the cutoff for CACS-CL = 5%, the cutoff for CACS-CL = 15% seemed to be more effective and safer for deferring further CIT. Clinical Trial registration: NCT04691037.