Comparison of coronary artery calcium score-based and all-coronary computed tomography angiography strategies in patients with stable chest pain and risk factor-weighted clinical likelihood of 5–15%

BACKGROUND: For patients with stable chest pain (SCP) and risk factor-weighted clinical likelihood (RF-CL) of 5–15%, the most appropriate strategy to defer or refer further testing is important but remains debatable. This study aimed to compare two coronary artery calcium score (CACS)-based strategies and all-coronary computed tomography angiography (CCTA) strategy in these patients. METHODS: 19682 patients with RF-CL of 5%-15% referred to CCTA for SCP were classified into referral and deferral groups according to CACS strategy and CACS-weighted clinical likelihood model-based strategy (CACS-CL strategy), respectively. The associations of coronary artery disease (CAD), major adverse cardiovascular event (MACE) and subsequent clinical management with groups, as well as net reclassification improvement (NRI) and number needed to test (NNT) with CACS were evaluated to compare the performance of strategies. RESULTS: Compared to CACS strategy, CACS-CL strategy indicated stronger associations between groups and CAD, MACE (hazard ratios: 5.30 versus 4.09), more intensive subsequent clinical management and positive NRIs (varying between 6.72% and 18.69%). When comparing CACS-CL to all-CCTA strategy, all metrics (such as diagnostic yield of CCTA) significantly (p < 0.001) improved, except rate of omission diagnosis, leading to an NNT to reduce one CCTA of 2.10 and to miss one necessary CCTA of 16.27, respectively. CONCLUSION: In patients with SCP and RF-CL of 5%-15%, CACS-CL strategy was associated with greater effectiveness and safety than CACS strategy did. Compared to all-CCTA strategy, CACS-CL strategy dramatically improved the classification of patients to deferral group but slightly compromised safety, which should be investigated in further study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04691037; Registration Date: 12/29/2020.