Sex differences in coronary artery plaque composition detected by coronary computed tomography: quantitative and qualitative analysis

BACKGROUND: Sex differences in the calculation of coronary heart disease risk have been analysed extensively. However, data on coronary plaque morphology diverge. We analysed plaque characteristics in patients with suspected coronary artery disease (CAD) and defined prognostic factors using coronary computed tomography angiography (CCTA). METHODS: A total of 6,050 consecutive patients underwent CCTA and were enrolled in the registry. Patients with known CAD were excluded. The patients were propensity score matched (1:1 male:female) for age and known coronary risk factors. Coronary arteries were evaluated for stenosis, plaque types (non-calcified, mixed and calcified) and high-risk plaque features (napkin-ring sign, low-attenuation plaque, spotty calcifications, positive remodelling). Clinical follow-up was performed. RESULTS: A total of 1,050 patients (525 female, 525 male) in matched cohorts were selected for analysis. CCTA showed significantly higher calcium scores for males (mean 180.5 vs 67.8 AU, p < 0.0001) and a higher rate of CAD (66.0% vs 34.1%, p < 0.0001). In a total of 16,800 segments, males had significantly more plaques (861 vs 752, p < 0.0001) with a significantly larger proportion of calcified plaques, while females had more mixed and non-calcified plaques (33.5% vs 24.4%, p = 0.006 and 24.1% vs 13.6%, p = 0.22, respectively). After a mean follow-up of 5.6 years, major adverse cardiac event (MACE) rate was 5.3% in male and 1.9% in female patients (p < 0.05). The relative odds ratio for high-risk plaque features to predict MACE was higher in females. CONCLUSION: Based on a higher relative risk for women with high-risk plaque features, the findings of our study support the increased importance of a differentiated qualitative plaque analysis to improve the risk stratification for both sexes.