Use of Antiplatelet Agents Is Associated With Intraplaque Hemorrhage on Carotid Magnetic Resonance Imaging: The Plaque at Risk Study.

BACKGROUND AND PURPOSE Intraplaque hemorrhage (IPH), visualized by magnetic resonance imaging, has shown to be associated with the risk of stroke in patients with carotid artery stenosis. The mechanisms of IPH development are poorly understood. In this study, we investigated the association between clinical patient characteristics and carotid IPH on high-resolution magnetic resonance imaging. METHODS Patients participate in the Plaque at Risk (PARISK) study. This prospective, multicenter cohort study included patients with recent amaurosis fugax, hemispheric transient ischemic attack, or nondisabling stroke in the internal carotid artery territory and an ipsilateral carotid stenosis of <70%, who were not scheduled for carotid revascularization procedure. One hundred patients, recruited between 2010 and 2012, underwent a 3-T high-resolution carotid magnetic resonance imaging. We documented clinical patient characteristics and performed multivariable logistic regression analysis to investigate their association with IPH. RESULTS IPH was observed in 45 patients (45%) in 1 or both carotid arteries. Male sex and the use of antiplatelet agents before the index event were associated with IPH in univariable analysis. In a multivariable analysis, only previous use of antiplatelet agents was significantly associated with IPH (odds ratio, 2.71; 95% confidence interval, 1.12-6.61). Risk factors of atherosclerotic arterial disease, including a history of symptomatic arterial diseases, were not associated with IPH. CONCLUSIONS In this cohort of 100 patients with recently symptomatic carotid stenosis, the previous use of antiplatelet agents is associated with carotid IPH on magnetic resonance imaging. Antiplatelet therapy may increase the risk of IPH, but our findings need to be confirmed in larger patient cohorts. The implications for risk stratification remain to be determined.