CT coronary angiography in the lipid clinic: a pilot study and lipidologist survey

Guidelines recommend considering coronary calcium score (CCS) in asymptomatic patients to aid risk stratification. However, calcification occurs late in atherosclerosis. Coronary CT angiography (CCTA) can detect non-calcific plaque and inflammation before calcification develops, but impact on clinical management is not well documented. We compare coronary artery disease (CAD) detection and grading between CCS and CCTA, impact on management, and explore CCTA-derived inflammation biomarker (pericoronary fat attenuation index [FAI]) in the lipid clinic. Exploratory analysis of a prospectively maintained database of lipid clinic patients with CCS and CCTA (2018-2020). CCS grade was compared with CCTA stenosis, presence of high-risk plaque (HRP) and FAI-score analysis. UK Consultant Lipidologists completed an anonymised survey, documenting lipid target and management after sequential unblinding of CCS and CCTA data. In 45 asymptomatic patients (49% female, mean age 55 ± 9), CCTA re-classified CAD presence in 22% (p = 0.002) and severity in 62% (p = 0.005) vs. CCS. HRP was observed in 20% (9/45), including 56% with CCS ≤ 100. Median LDL target with clinical vignette was 101 mg/dL (IQR 77-120), reducing to 89 mg/dL (77-120) after CCS, and 77 mg/dL (70-116) after CCTA unblinding. CCS altered LDL target in 12%, and CCTA a further 19% (χ2 57.0, p < 0.005). High FAI-score was demonstrated in 20%, including 22% of those with CCS ≤ 100 and 75% of those with ≤ mild CAD on CCTA. CCTA increased CAD prevalence and re-classified severity versus CCS, altering hypothetical management. High FAI-scores were observed across CCS and CCTA severity grades, including patients with no overt CAD.