1. Gender-related differences in carotid plaque features: focus on instability and inflammation Giuseppe Biondi Zoccai, MD University of Modena and Reggio Emilia, Modena, Italy On behalf of Giuseppe Sangiorgi, Sara Roversi, Francesca Servadei, Doriana Liotti, Luigi Giusto Spagnoli, Alessandro Mauriello, Maria Grazia Modena

2. BACKGROUND Severe carotid stenosis is a frequent cause of atherothrombotic stroke in both men and women. Several sex-related comparisons are available on coronary plaque features, suggesting that males have higher thrombotic burden and females a more severe inflammatory substrate. However, there are few data appraising gender-specific features of atherosclerotic carotid plaques.

3. GOAL We aimed to systematically compare the pathology of carotid plaques in males versus females, with a specific emphasis on features of thrombosis and inflammation.

4. METHODS Carotid plaque specimens were collected from patients undergoing surgical thromboendoarterectomy (TEA) for asymptomatic (>80% diameter) or symptomatic (>50% diameter) carotid stenosis. Standard pathologic analyses were performed, as well as sophisticated measurements for plaque hemorrhage, inflammation and foam cells.

5. RESULTS A total of 457 patients were included (132 women, 325 men). Baseline analyses showed a greater prevalence of hypercholesterolemia and hypertension in women, and higher prevalence of current smoking, despite a raised Framingham Heart score in men (all p<0.05). Women had a lower prevalence of thrombotic plaques, and smaller percentage area of necrotic core and hemorrhage extension (all p<0.05).

6. RESULTS Plaque inflammation analysis showed a lower concentration of inflammatory and foam cells in the plaque cap of females (both p<0.05). Even at multivariable analysis adjusting for smoking status, hypercholesterolemia, hypertension, Framingham Heart Score, plaque classification, percentage area of necrotic lipid core, hemorrhage extension, women had a significantly lower concentration of foam cells and/or lymphocytes in the cap (p=0.032).

7. BASELINE FEATURES Females (N=132)Males (N=325)P value Age (Years) 69.9±7.269.6±7.0 0.768 Smoking history Current Former Ever 32 (24.2%) 71 (53.8%) 29 (22.0%) 96 (29.5%) 117 (36.0%) 112 (34.5%) 0.002 Hypercholesterolemia89 (67.4%)183 (56.3%)0.028 Hypertension61 (67.0%)121 (53.1%)0.023 Total number of risk factors 2.9±1.42.7±1.5 0.228 Framingham Heart Score 17.3±7.427.3±11.3 <0.001 Statin therapy42 (35.6%)87 (29.6%)0.277 Symptomatic status Asymptomatic Transient ischemic attack Stroke 71 (53.8%) 27 (20.5%) 34 (25.8%) 149 (45.8%) 92 (28.3%) 84 (25.8%) 0.178 Serum fibrinogen (mg/dL)365.1±140.6335.3±93.00.420

8. PLAQUE PATHOLOGY Females (N=132)Males (N=325)P value Plaque location Common carotid Bifurcation Internal carotid 12 (28.6%) 22 (52.4%) 8 (19.0%) 28 (21.7%) 75 (58.1%) 24 (18.6%) 0.687 Area stenosis (%) 46.8±16.750.6±17.1 0.387 Plaque classification With luminal thrombus With organized thrombus Ulceration Erosion Non-thrombotic thin-cap fibro-atheroma With calcified nodules Healed Stable fibro-calcific 11 (8.3%) 7 (5.3%) 19 (14.4%) 0 22 (16.7%) 7 (5.3%) 15 (11.4%) 51 (38.6%) 25 (7.7%) 37 (11.4%) 67 (20.6%) 1 (0.3%) 50 (15.4%) 7 (2.2%) 52 (16.0%) 86 (26.5%) 0.034

9. PLAQUE PATHOLOGY Females (N=132)Males (N=325)P value Thrombotic plaque44 (40.0%)137 (49.8%)0.013 Any vulnerable plaque32 (24.2%)93 (28.6%)0.342 Multiple vulnerable plaques4 (3.0%)20 (6.2%)0.195 Minimum cap thickness (μm) 143.2±117.8131.7±94.1 0.612 Percentage area of necrotic lipid core 49.2±18.756.2±17.7 0.010 Calcium-lumen distance (μm) 866.7±721.51458.5±1461.6 0.144 Calcified area >5% of plaque area 1-5% of plaque area no calcifications 41 (64.1%) 11 (17.2%) 12 (18.8%) 85 (51.5%) 40 (24.2%) 0.227 Hemorrhagic area >10% of plaque 1-10% of plaque no hemorrhage 26 (63.2%) 15 (24.6%) 20 (32.8%) 98 (63.2%) 23 (14.8%) 34 (21.9%) 0.022

10. PLAQUE INFLAMMATION Females (N=132) Males (N=325) P value Plaque inflammation (HPF; 40x magnification) 20.2±13.825.0±14.1 0.017 CD68+CD3 positive cells in the plaque/mm 2 29.3±20.036.3±20.4 0.017 Foam cells in the cap/mm 2 19.3±16.027.1±22.7 0.009 T lymphocytes in the cap/mm 2 8.5±9.97.4±6.1 0.541 Foam cells or lymphocytes in the cap/mm 2 26.0±20.234.1±25.80.028

11. MULTIVARIABLE ANALYSIS* R2R2 Regression coefficient (95% CI) P value Plaque inflammation (HPF; 40x magnification) 2.4%2.5 (-5.6; 10.5)0.537 CD68+CD3 positive cells in the plaque/mm 2 2.4%3.6 (-1.6; 10.9)0.537 Foam cells in the cap/mm 2 2.3%15.6 (1.5; 29.8)0.032 T lymphocytes in the cap/mm 2 0.4%3.3 (-3.7; 10.2)0.343 Foam cells or lymphocytes in the cap/mm 2 2.8%18.9 (4.6; 32.3)0.012 *exploring the association between gender and plaque inflammation features AND adjusting for all variables associated at bivariate analyses with gender with p<0.10: smoking status, hypercholesterolemia, hypertension, Framingham Heart Score, plaque classification, thrombotic plaque, percentage area of necrotic lipid core, hemorrhage extension, R 2 was computed using as gender as the only independent variable; female gender was coded as 2, and male gender as 1

12. CONCLUSIONS Carotid plaques are significantly different in women and men. In contrast to findings observed in coronary vessels, females have a lower degree of inflammation and thrombosis, and more frequently stable plaques. Further studies are warranted to demonstrate whether such gender-related differences in carotid pathology may have implications for the clinical management and revascularization of patients with carotid artery disease.

13. Thank you for your attention For any correspondence: gbiondizoccai@gmail.com For these and further slides on these topics feel free to visit the metcardio.org website: http://www.metcardio.org/slides.html gbiondizoccai@gmail.com http://www.metcardio.org/slides.html