Figure 1. Patients with carotid plaques with high vulnerability index have higher risk for future cardiovascular events.

A, Histological stains used for vulnerability index: ratio between the sum of cluster of differentiation 68 (CD68; macrophages stained in brown), Oil red O (ORO; neutral lipids stained in red), glycophorin A (intraplaque hemorrhage stained in brown), and the sum of alpha‐actin (vascular smooth muscle cells stained in brown) and collagen (stained in yellow). All histological components were assessed as % of total plaque area. Scale bar, 2 mm. B, Kaplan‐Meier curve showing the higher risk for cardiovascular events for patients with highest plaque vulnerability index in fourth quartile (red) compared with the first–third quartile (blue, log‐rank test, P=0.0002). C, Multiple linear regression analysis showing the influence of the 5 different histological components on the vulnerability index. Vulnerability index was used as the dependent variable.