Performance of the coronary calcium score in an outpatient chest pain clinic and strategies for risk stratification.
BACKGROUND
Coronary artery calcium score (CAC) is an objective marker of atherosclerosis. The primary aim is to assess CAC as a risk classifier in stable coronary artery disease (CAD).


HYPOTHESIS
CAC improves CAD risk prediction, compared to conventional risk scoring, even in the absence of cardiovascular risk factor inputs.


METHODS
Outpatients presenting to a cardiology clinic (n = 3518) were divided into two cohorts: derivation (n = 2344 patients) and validation (n = 1174 patients). Adding logarithmic transformation of CAC, we built two logistic regression models: Model 1 with chest pain history and risk factors and Model 2 including chest pain history only without risk factors simulating patients with undiagnosed comorbidities. The CAD I Consortium Score (CCS) was the conventional reference risk score used. The primary outcome was the presence of coronary artery disease defined as any epicardial artery stenosis≥50% on CT coronary angiogram.


RESULTS
Area under curve (AUC) of CCS in our validation cohort was 0.80. The AUC of Models 1 and 2 were significantly improved at 0.88 (95%CI 0.86-0.91) and 0.87 (95%CI 0.84-0.90), respectively. Integrated discriminant improvement was >15% for both models. At a pre-specified cut-off of ≤10% for excluding coronary artery disease, the sensitivity and specificity were 89.3% and 74.7% for Model 1, and 88.1% and 71.8% for Model 2.


CONCLUSION
CAC helps improve risk classification in patients with chest pain, even in the absence of prior risk factor screening.
['Huang|Weiting|W|https://orcid.org/0000-0003-3453-2374', 'Lim|Leon Ming Hsien|LMH|', 'Aurangzeb|Amirzeb S/O|AS|https://orcid.org/0000-0002-3536-9145', 'Wong|Cheney Jianlin|CJ|', 'Koh|Natalie Si Ya|NSY|', 'Huang|Zijuan|Z|', 'Teo|Hooi Khee|HK|', 'Chua|Terrance Siang Jin|TSJ|', 'Tan|Swee Yaw|SY|']
D002118:Calcium D002637:Chest Pain D017023:Coronary Angiography D003324:Coronary Artery Disease D006801:Humans D010045:Outpatients D018710:Pain Clinics D011237:Predictive Value of Tests D018570:Risk Assessment D012307:Risk Factors
chest pain coronary artery calcium coronary artery disease risk score