Association of clinical risk scores with coronary atherosclerotic plaque burden and progression assessed by coronary computed tomography angiography

Background Atherosclerotic cardiovascular disease (ASCVD) risk scores are widely used to guide preventative therapies and referral of patients for non-invasive imaging, yet lack diagnostic and prognostic precision at the individual level. Coronary computed tomography angiography (CCTA) enables direct visualisation, quantification and characterization of atherosclerotic disease burden and progression. Purpose To examine the association between ASCVD risk scores and CCTA-derived measures of plaque burden and progression in patients with stable coronary artery disease (CAD). Methods Retrospective, single-centre study of consecutive adults undergoing clinically indicated CCTA at an interscan interval of ≥2 years. Conventional ASCVD risk scores including the Framingham Risk Score (FRS), Pooled Cohort Equation (PCE), Predicting Risk of Cardiovascular Events (PREVENT), Systematic Coronary Risk Evaluation (SCORE2) and Australian CVD Risk (AusCVDRisk) were calculated using published algorithms. Plaque volumes were quantified from CCTA using automated software (Autoplaque v3.0). Multivariable linear regression was used to examine the association of baseline ASCVD risk scores with temporal change in plaque volumes, with adjustment for baseline plaque volume, statin use, and interscan interval. Results The final study population comprised 335 patients (mean age 58.3 ± 9.9 years; 53.3% male; mean interscan interval 4.6 ± 2.1 years; 62.9% statin-treated). The mean estimated cardiovascular risk according to FRS, PCE, PREVENT, and AusCVDRisk was 10.8 ± 7.6%, 7.5 ± 6.4%, 4.0 ± 3.0%, and 3.7 ± 3.0%, respectively. Mean total plaque volume at baseline was 87.1 ± 103.7 mm³, with an annualised increase of 8.5 ± 15.0 mm³ per year. FRS, PCE, and AusCVDRisk were positively associated with total plaque volume and calcified plaque volume at baseline (β 1.13 to 5.17; SE 0.25 to 1.86; all p<0.05). No associations were observed between any of the risk scores and change in total plaque volume (all p>0.05). PCE, PREVENT, and AusCVDRisk were negatively and weakly associated with progression of calcified plaque (β = −0.13 to −0.34, SE 0.04 to 0.12; all p<0.05). Only the PCE was associated with progression of noncalcified plaque (β = 0.12, SE 0.06; p=0.04). Conclusion In patients with stable CAD undergoing serial CCTA, conventional ASCVD risk scores including FRS, PCE, and AusCVD exhibited positive associations with total and calcified plaque volume at baseline, however negligible associations with subsequent plaque progression. This underlines the limited utility of clinical risk scores to guide referral for initial or repeat CCTA imaging, and a need for more reliable and personalised measures of coronary atherosclerosis