Carotid Plaque Lipid Content and Fibrous Cap Status Predict Systemic CV Outcomes

Abstract

Objectives We sought to investigate whether and what carotid plaque characteristics predict systemic cardiovascular outcomes in patients with clinically established atherosclerotic disease. Background Advancements in atherosclerosis imaging have allowed assessment of various plaque characteristics, some of which are more directly linked to the pathogenesis of acute cardiovascular events compared to plaque burden. Methods As part of an event-driven clinical trial (AIM-HIGH), subjects with clinically established atherosclerotic disease underwent multicontrast carotid MRI to detect plaque tissue composition and high-risk features. Prospective associations between MRI measurements and the AIM-HIGH primary endpoint (fatal and non-fatal myocardial infarction, ischemic stroke, hospitalization for acute coronary syndrome, and symptom-driven revascularization) were analyzed using Cox proportional hazard models. Results Of 232 subjects recruited, 214 (92.2%) with diagnostic image quality constituted the study population (mean age: 61±9 years; males: 82%; statin use: 94%). During a median follow-up of 35.1 months, 18 (8.4%) subjects reached the AIM-HIGH endpoint. High lipid content (hazard ratio per one-standard-deviation increase in % lipid core volume: 1.57, p=0.002) and thin/ruptured fibrous cap (hazard ratio: 4.31, p=0.003) in carotid plaques were strongly associated with the AIM-HIGH endpoint. Intraplaque hemorrhage had a low prevalence (8%) and was marginally associated with the AIM-HIGH endpoint (hazard ratio: 3.00, p=0.053). High calcification content (hazard ratio per one-standard-deviation increase in % calcification volume: 0.66, p=0.20), plaque burden metrics, and clinical risk factors were not significantly associated with the AIM-HIGH endpoint. The associations between carotid plaque characteristics and the AIM-HIGH endpoint changed little after adjusting for clinical risk factors, plaque burden, or AIM-HIGH randomized treatment assignment. Conclusions Among patients with clinically established atherosclerotic disease, carotid plaque lipid content and fibrous cap status were strongly associated with systemic cardiovascular outcomes. Markers of carotid plaque vulnerability may serve as novel surrogate markers for systemic atherothrombotic risk.

Combined spatiotemporal and frequency-dependent shear wave elastography enables detection of vulnerable carotid plaques as validated by MRI

“…Imaging protocol. Carotid bifurcation MRI was performed at 3 T with a carotid phase-array surface 6-channel coil (Neocoil LLC, Pewaukee, WI, USA) using a previously described multi-contrast protocol 26 . In brief, the sequences included 3D time-of-flight MR angiography (TOF-MRA), a 3D black-blood sequence optimized to detect IPH (magnetization-prepared rapid acquisition gradient echo, MPRAGE), 2D pre-contrast black-blood T1 weighting (T1W), 2D T2 weighting (T2W), and contrast-enhanced 2D black-blood T1W (CE-T1W).…”

Co-existing cerebrovascular atherosclerosis predicts subsequent vascular event: a multi-contrast cardiovascular magnetic resonance imaging study

“…Zavodni et al [20] showed that a lipid core at CMR imaging confers increased risk for subsequent cardiovascular events in asymptomatic individuals. Sun et al [21] reported that high lipid content (HR per one-standarddeviation increase in % lipid core volume: 1.57, P = 0.002) in carotid plaques was strongly associated with the cardiovascular outcomes. The LRNC within atherosclerotic plaque, particularly its size, has been believed to be a key feature of vulnerable plaque [22,23].…”

“…Third, in the present study, the size of the intraplaque compositions of co-existing intracranial and extracranial artery atherosclerosis was not assessed. Previous evidences showed that the size of LRNC [18,21] and IPH [18] was associated with future vascular events. Fourth, the longitudinal coverage of current carotid imaging protocol is 32 mm centered to carotid bifurcation.…”

Visualization of carotid vessel wall and atherosclerotic plaque: T1-SPACE vs. compressed sensing T1-SPACE

“…The characteristics of carotid plaque provided by plaque imaging on MR can serve a surrogate marker for risk management of patients with atherosclerosis [5]. The characteristics of carotid plaque such as intraplaque hemorrhage, calcification, and lipid-rich necrotic core are evaluated by threedimensional (3D) T1-weighted fast spin echo (T1-FSE) in combination with T2WI, time-of-flight MR angiography, magnetization-prepared rapid acquisition gradient echo sequences [6].…”