Frequency-domain optical coherence tomography plaque morphology in stable coronary artery disease: sex differences

BACKGROUND: The cause for discrepancy in the clinical presentation and outcome of coronary artery disease (CAD) between men and women is not established. Different prevalences of risk factors or specific sex-related atherosclerotic aspects have been advocated as possible explanations. We investigated coronary plaque morphology looking at possible differences in plaque vulnerability between men and women with stable CAD. PATIENTS AND METHODS: We retrospectively collected and analyzed clinical data and coronary plaque morphology by frequency-domain optical coherence tomography in men and women with stable CAD. RESULTS: A total of 181 (139 were in men and 42 in women) plaques from 138 patients were analyzed. The mean age was similar between men and women. Besides an overall absence of significant differences in the vast majority of risk factors and comorbidities, men had a higher prevalence of active smoking (19 vs. 2%, P=0.006), previous myocardial infarction (17 vs. 2%, P=0.01), and previous percutaneous coronary interventions (42 vs. 17%, P=0.003). Frequency-domain optical coherence tomography in women showed significantly more plaque-vulnerability features as testified by higher percent of lipid-rich plaques (55 vs. 36%, P=0.03), macrophages (21 vs. 5%, P=0.003), and microvessels (24 vs. 8%, P=0.01). Multivariate analysis showed that female sex was associated independently with lipid-rich plaques (P=0.034) and macrophages (P=0.001). In the analysis restricted to the more severe lesions that were revascularized, women continued to be characterized by more adverse morphological features, such as macrophages (30 vs. 7%, P=0.004) and lipid-rich plaques (63 vs. 39%, P=0.045). CONCLUSION: Women with stable CAD may be characterized by plaques that have increased prevalence of vulnerability compared with men. These findings support the hypothesis of sex-specific differences in the development of atherosclerosis.