Abstract:
Objective To evaluate the applicability of three cardiovascular risk assessment models as primary screening tools for vulnerable carotid plaques.
Methods Using a cross-sectional design, we enrolled 986 local residents from Liuzhou, Guangxi surveyed between 2019 and 2023 as participants. The 10-year cardiovascular disease risk values were calculated using the assessment models of prediction for atherosclerotic cardiovascular disease risk in China (China-PAR), Framingham risk score (FRS), and World Health Organization cardiovascular disease risk charts (WHO laboratory-based model). The model performance was assessed using the area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow goodness-of-fit test, calibration plots, sensitivity, specificity and positive predictive value, and the optimal cut-offs for each model were explored by maximizing the Youden's index.
Results The 3 models exhibited good discriminatory ability for vulnerable carotid plaques (AUC: 0.71–0.72), but showed poor calibration (P < 0.001). At the original cut-offs of each model, the FRS showed high sensitivity (89.6%), low specificity (32.2%) and low positive predictive value (27.6%). The other two models showed low sensitivity (WHO laboratory-based model: 39.8%; China-PAR model: 53.4%), high specificity (WHO laboratory-based model: 84.2%; China-PAR model: 72.5%), and high positive predictive value (WHO laboratory-based model: 42.1%; China-PAR model: 35.9%). After cut-off optimization, the WHO laboratory-based model at the optimal cut-off of 4.5% exhibited a higher sensitivity than the FRS model (74.2% vs. 67.0%, P=0.003) and the China-PAR model (74.2% vs. 67.9%, P=0.018), and exhibited a lower specificity than the China-PAR model (61.7% vs. 65.2%, P=0.006) and the FRS model (61.7% vs. 66.5%, P < 0.001). No statistically significant differences in positive predictive value were observed between the WHO laboratory-based model (35.9%) and either the China-PAR model (36.1%) or the FRS model (36.6%)(P > 0.05).
Conclusion The 3 models exhibit satisfactory discriminatory performance in identifying vulnerable carotid plaques. However, when directly applying the original development cut-offs for initial screening, it is difficult to balance missed diagnoses and misdiagnoses. After cut-off optimization, the WHO laboratory-based model achieves the best overall performance. These conclusions suggest that primary medical institutions in Guangxi region can initially use the cut-off risk (4.5%) optimized by the WHO laboratory-based model for initial screening and conduct further carotid ultrasonography for high-risk individuals.