Molecular imaging of inflammation for detection of vulnerable atheromatous plaques

Abstract

This editorial refers to ‘Imaging intraplaque inflammation in carotid atherosclerosis with 11C-PK11195 positron emission tomography/computed tomography’, by O. Gaemperli et al. , doi:10.1093/eurheartj/ehr367 Inflammation plays a major pathogenic role in the development of atheromatous plaques and the progression of atherosclerosis. Disruption of the fibrous cap of atheromatous lesions has been shown to lead to acute cardiovascular events. Atheromatous plaque disruption is the mechanism most commonly associated with the occurrence of acute coronary syndrome, i.e unstable angina and acute myocardial infarction.1 Plaque disruption is directly linked to inflammation, particularly to macrophage activation,1,2 which results in the release of proinflammatory cytokines and metalloproteases that contribute to the destruction of the fibrous cap of the atheroma thus weakening its structure and leading to the development of fissures that allow a direct contact between the prothrombotic atheromatous core and the circulating blood in the affected vessel. This process can result in the development of acute thrombosis and serious clinical events.3 The early identification—in a given individual—of plaques prone to disruption (‘vulnerable plaques’) is desirable, as this may allow the implementation of preventative strategies and, possibly, effective therapeutic intervention. Vulnerable plaques often show large necrotic core volumes, positive vascular remodelling, and attenuation of fibrous plaque caps ( Figure 1 ). Figure 1 The use of combined markers of risk, i.e. imaging and circulating biomarkers, may allow the early identification of vulnerable plaques and thus help clinicians to devise more rational preventative and therapeutic strategies. Multimodal imaging of atheromatous structures with PET and CTA, as in the study of Gaemperli et al. ,15 and other diagnostic modalities combining anatomical and functional measurements are likely to allow an effective, integrated assessment of atheromatous plaques. Current evidence that molecular imaging is suited for the identification of monocyte–macrophage infiltration in the setting of acute vascular events in …