Abstract 25: Carotid Plaque Thickness, Stenosis, Ulceration, Age And Male Sex Optimally Predict Carotid Intraplaque Hemorrhage

Abstract

Background and Purpose: MRI-detected intraplaque hemorrhage (IPH) is associated with acute and future stroke. IPH can be detected with a high sensitivity, specificity and accuracy using heavily T1-weighted sequences such as the magnetization-prepared rapid acquisition gradient echo (MPRAGE) sequence. This sequence is not always available in screening of potential carotid sources of stroke. The purpose of this study was to determine the discriminatory power of clinical and imaging markers in predicting carotid IPH. Methods: In this retrospective cross sectional study, patients undergoing stroke workup were imaged with magnetic resonance imaging (MRI) and IPH detection. A total of 726 carotid plaques were imaged. Carotid imaging characteristics were recorded, including percent diameter and mm stenosis, plaque thickness, ulceration, intraluminal thrombus and IPH. Clinical confounders were recorded and a multivariable logistic regression model was fitted. Backward-elimination was used to determine essential predictors of IPH with a threshold two-sided p<.10. Receiver operating characteristic (ROC) analysis was performed to determine discriminatory value. Results: Significant predictors of carotid IPH included plaque thickness (Odds ratio, OR=2.20, p<.001), mm stenosis (OR=0.46, p<.001), ulceration (OR=4.25, p=.020), age (OR=1.11, p=.001) and male sex (OR=3.23, p=.077). Percent diameter stenosis (OR=31.0, p=.001) could be used nearly interchangeably with mm stenosis. The final model discriminatory value was excellent (Area under the curve, AUC=0.932). This was significantly higher than models using only plaque thickness (AUC=0.881), only mm stenosis (AUC=0.830) or only ulceration (AUC=0.715) p<.001. Conclusions: Optimal discrimination of carotid IPH required information on plaque thickness, mm stenosis, ulceration, age and male sex. When these factors are recorded, IPH can be predicted with a high discriminatory power.