Abstract 9789: Gender is Strongly Associated with the Presence of Atherosclerotic Plaque Hemorrhage and an Effect Modifier in the Relation between Plaque Hemorrhage and Cardiovascular Outcome

Background Plaque hemorrhage may lead to accelerated progression of atherosclerotic disease. In patients who undergo carotid or femoral endarterectomy, the presence of local plaque hemorrhage predicts future cardiovascular events in any vascular territory. We assessed the hypothesis that gender has an effect on the prevalence of local plaque hemorrhage and the predictive value of plaque hemorrhage for the occurrence of cardiovascular events. Methods Atherosclerotic plaques from 1008 patients (688 male, 320 female) who underwent carotid endarterectomy were analyzed histologically for the presence of plaque hemorrhage. All patients were followed-up for cardiovascular events (non-fatal stroke, non-fatal myocardial infarction, vascular death, vascular intervention) during 3 years. Results Plaques from male patients showed a significantly higher prevalence of plaque hemorrhage compared to women (75% vs. 61%, p<0.001). After a median follow-up of 2.97 years, 208 events had occurred in males (30%) and 80 in females (25%). In a multivariable Cox proportional hazards model, there was a significant interaction between gender and plaque hemorrhage. Cumulative event rate of males with plaque hemorrhage was 32.3% [95% CI=29.1-37.5] compared to 19.1% [95% CI=12.9-24.8] in males without plaque hemorrhage. In females, this event rate was 23.4% [95% CI=17.1-29.3] versus 25.4% [95% CI=17.0-32.9] respectively. Gender-stratified analysis showed that plaque hemorrhage was a strong predictor for events in males (HR 1.8, [95% CI=1.3-2.7]), but this relationship was completely abolished in females (HR 1.1, [95% CI=0.71-1.8]). Conclusions In conclusion, atherosclerotic carotid plaques obtained from females reveal a lower prevalence of plaque hemorrhage compared with males. Local plaque hemorrhage is a strong predictor for secondary manifestations of cardiovascular disease in males but not in females.