Prognostic significance of bilateral carotid plaque asymmetry for major cardiovascular events in high-risk patients: a 3-year retrospective cohort study.

Carotid atherosclerotic plaque burden and asymmetry may reflect systemic vascular instability, but their prognostic value for major adverse cardiovascular events (MACE) in high-risk patients remains unclear. In this retrospective cohort study, 200 high-risk patients (age ≥ 65 years, ≥ 2 cardiovascular risk factors) who underwent bilateral carotid ultrasound between January 2015 and December 2019 were included and followed for 3 years to assess incident MACE. Baseline clinical and imaging variables (asymmetry index) were collected. A predictive model and corresponding nomogram were developed using multivariate logistic regression techniques. Internal validation was performed using bootstrap resampling, and external validation was conducted in a separate cohort of 70 patients screened in 2020. Among the 200 patients in the derivation cohort, 70 (35.0%) developed MACE during follow-up. Compared with the event-free group, the MACE group had a higher age (median 72 vs. 68 years, P < 0.001), a more frequent smoking history (52.9% vs. 32.3%, P = 0.008), lower eGFR (72.0 vs. 86.0 mL/min/1.73 m², P = 0.001), and higher plaque asymmetry index (0.38 vs. 0.21, P < 0.001). The final logistic regression model included four variables: age (for each increase in year, OR 1.06; 95% CI 1.01-1.12), smoking history (ever smoked vs. never smoked, OR 2.17; 95% CI 1.08-4.37), eGFR (for 10 mL/min decrement, OR 0.73; 95% CI 0.60-0.88), and AI (for 0.1 increase in AI; OR 2.28; 95% CI 1.32-3.96). The nomogram demonstrated an AUC of 0.88 (95% CI 0.82-0.94) in the derivation cohort and 0.81 in the external validation cohort, with good calibration and non-significant Hosmer - Lemeshow tests. While bilateral carotid plaque asymmetry and burden may add prognostic value for MACE, this will need to be validated in larger and multicenter studies.