Early decrease in carotid plaque lipid content as assessed by magnetic resonance imaging during treatment of rosuvastatin

MR Imaging of Carotid Artery Atherosclerosis: Updated Evidence on High-Risk Plaque Features and Emerging Trends

MR imaging is well-established as the criterion standard for carotid artery atherosclerosis imaging. The capability of MR imaging to differentiate numerous plaque components has been demonstrated, including those features that are associated with a high risk of sudden changes, thrombosis, or embolization. The field of carotid plaque MR imaging is constantly evolving, with continued insight into the imaging appearance and implications of various vulnerable plaque characteristics. This article will review the most up-to-date knowledge of these high-risk plaque features on MR imaging and will delve into 2 major emerging topics: the role of vulnerable plaques in cryptogenic strokes and the potential use of MR imaging to modify carotid endarterectomy treatment guidelines.

Efficacy of medical treatment and balloon angioplasty for severe intracranial atherosclerosis: a high-resolution MR vessel wall imaging

OBJECTIVES

To investigate the efficacy of medical treatment and balloon angioplasty for intracranial atherosclerosis using high-resolution MR vessel wall imaging (HR-MRI).

METHODS

In this prospective study, patients with symptomatic severe stenosis from January 2018 to August 2021 were treated with medical treatment or balloon angioplasty. The patients underwent HR-MRI at baseline and at 3, 6, and 12 months. Plaque characteristics at follow-up were compared with those at baseline using paired sample T-test or Wilcoxon rank sum test. The difference in the recurrence of ischemic events between two groups was compared.

RESULTS

A total of 37 patients (26 males; mean age = 60.5 ± 11.6 years) were evaluated. Of 68 plaques, 42 (61.8%) were treated with medication only. At 12 months of medical treatment, maximum plaque length (p = 0.004), maximum wall thickness (p = 0.036), and plaque enhancement (p = 0.001) were significantly reduced than baseline. At 3 months after balloon angioplasty, luminal stenosis (p = 0.048) was significantly reduced compared to baseline. At 6 months after balloon angioplasty, maximum plaque length (p = 0.011), maximum wall thickness (p = 0.003), and luminal stenosis (p = 0.001) were significantly reduced than baseline. No difference was found in the recurrence of ischemic events between two groups (p = 0.458).

CONCLUSION

Intracranial atherosclerotic plaque shrank and tended to be stable at 12 months of medical treatment. Plaque burden was significantly reduced 6 months after balloon angioplasty. This may provide evidence for the application and selection of treatment strategies for intracranial atherosclerotic disease.

KEY POINTS

• Plaque burden and plaque enhancement were significantly reduced at 12 months of medical treatment compared to baseline. • Plaque burden was significantly reduced at 6 months after balloon angioplasty compared with baseline. • No significant difference in the recurrence rate of ischemic stroke between patients treated with medication and balloon angioplasty.

Effectiveness of red yeast rice on carotid atherosclerosis: A systematic review and meta-analysis

While several studies have demonstrated the preventive and therapeutic effects of red yeast rice (RYR), a traditional Chinese medicine, on carotid atherosclerosis through the reduction of low-density lipoprotein cholesterol (LDL-C) level and other risk factors, the evidence remains inconsistent. This study aimed to further evaluate the effects of RYR in carotid atherosclerosis. Several databases were searched for original trials of RYR for the treatment of carotid atherosclerosis that reported plaque indicators. Carotid plaque area (AREA), carotid plaque score (SCORE), and intima-media thickness (IMT) were set as the primary outcomes, while lipid profile and safety indicators were set as the secondary outcomes. Meta-analyses were performed on the randomized controlled trials (RCTs) using Comprehensive Meta-analysis software. Heterogeneity was evaluated using the I2 index and Q statistic. Subgroup, sensitivity, and dose-effect analyses were conducted. Twenty RCTs with 2217 patients were included. Compared to the control group, AREA (SMD = −0.855, 95%CI: −1.259 to −0.451, p < 0.001), IMT (SMD = −0.588, 95%CI: −0.792 to −0.384, p < 0.001), SCORE (SMD = −0.708, 95%CI: −1.135 to −0.282, p = 0.001), LDL-C (SMD = −0.938, 95%CI: −1.375 to −0.502, p < 0.001), triglyceride (SMD = −0.766, 95%CI: −0.980 to −0.551, p < 0.001), and total cholesterol (SMD = −0.858, 95%CI: −1.254 to −0.462, p < 0.001) were significantly decreased and HDL-C (SMD = 0.389, 95%CI: 0.044–0.733, p = 0.027) was significantly increased following RYR therapy. The indicators for safety were not significant and did not differ between the two groups (p > 0.050). Heterogeneities mainly existed for the treatment time or control group setting. Most results showed no changes in the sensitivity analysis. Dose-effect relationships were observed for all indicators except for TC and HDL-C. We concluded that RYR therapy showed considerable efficacy and an acceptable safety profile for the treatment of carotid atherosclerosis in the Chinese population.

Rosuvastatin Slows Progression of Carotid Intima-Media Thickness: The METEOR-China Randomized Controlled Study

BACKGROUND

Atherosclerosis is the leading cause of cardiovascular disease worldwide, including in China. Primary prevention, through lipid-lowering, could avert development of atherosclerosis. Carotid intima-media thickness (CIMT) is a well-validated measure of atherosclerosis used in intervention studies as the primary outcome and alternative end point for cardiovascular disease events.

METHODS

This randomized, double-blind, placebo-controlled, multicenter, parallel-group study assessed the effects of rosuvastatin 20 mg/d compared with placebo on progression of CIMT over 104 weeks in Chinese people with subclinical atherosclerosis. The primary end point was the annualized rate of change in mean of the maximum CIMT measurements taken 7× over the study period from each of 12 carotid artery sites (near and far walls of the right and left common carotid artery, carotid bulb, and internal carotid artery). Secondary end points included CIMT changes at different artery sites and lipid-parameter changes. Safety was also assessed.

RESULTS

Participants were randomized (1:1) to receive rosuvastatin (n=272) or placebo (n=271). Baseline characteristics were well balanced between groups. The change in mean of the maximum CIMT of the 12 carotid sites was 0.0038 mm/y (95% CI, -0.0023-0.0100) for the rosuvastatin group versus 0.0142 mm/y (95% CI, 0.0080-0.0204) for the placebo group, with a difference of -0.0103 mm/y (95% CI, -0.0191 to -0.0016; P=0.020). For the CIMT secondary end points, the results were generally consistent with the primary end point. There were clinically relevant improvements in lipid parameters with rosuvastatin. We observed an adverse-event profile consistent with the known safety profile of rosuvastatin.

CONCLUSIONS

Rosuvastatin 20 mg/d significantly reduced the progression of CIMT over 2 years in Chinese adults with subclinical atherosclerosis and was well tolerated.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02546323.

Assessment of Therapeutic Response to Statin Therapy in Patients With Intracranial or Extracranial Carotid Atherosclerosis by Vessel Wall MRI: A Systematic Review and Updated Meta-Analysis

Background and Aims: Statin therapy is an essential component of cardiovascular preventive care. In recent years, various vessel wall MRI (VW-MRI) techniques have been used to monitor atherosclerosis progression or regression in patients with extracranial or intracranial large-artery atherosclerosis. We aimed to perform a systematic review and meta-analysis on the effects of statin therapy on plaque evolution as assessed by VW-MRI.

Materials and Methods: Prospective studies investigating carotid and intracranial atherosclerotic plaques in patients on statin therapy monitored by serial VW-MRI were systematically identified in the literature. The plaque burden and lipid-rich necrotic core (LRNC) volume of carotid plaque and the imaging features of intracranial plaques were extracted and summarized. For studies investigating carotid artery wall volume and LRNC volume, combined estimates were derived by meta-analysis.

Results: The study identified 21 studies of carotid plaque and two studies of intracranial plaque. While 16 studies investigating carotid plaques that included 780 patients by High-resolution VW-MRI were included in the meta-analysis. There was no significant change in carotid wall volume from baseline to 12 months. A significant change in LRNC volume was observed at > 12 months compared with baseline (Effect = −10.69, 95% CI = −19.11, −2.28, P < 0.01), while no significant change in LRNC volume at 3–6 months or 7–12 months after statin therapy initiation in 6 studies. Increases in fibrous tissue and calcium and reduction in neovascularization density of the plaque were seen in 2/3 studies (including 48/59 patients), 1/3 studies (including 17/54 patients), and 2/2 studies (including 71 patients) after statin therapy, respectively. Two studies with 257 patients in intracranial atherosclerosis showed that statins could effectively decrease wall volume and plaque enhancement volume.

Conclusions: Collective data indicated that statins could potentially stabilize carotid plaques by significantly reducing LRNC with 1 year of therapy as shown on serial carotid VW-MRI. There was no significant decrease in wall volume, which nonetheless indicated that plaque composition changes might be more sensitive to response monitoring than wall volume. It is likely that more sensitive, clinically relevant, and preferably quantitative indicators of therapeutic effects on intracranial vessel plaque morphology will be developed in the future.

Quantitative Magnetic Resonance Imaging Assessment of the Relationships Between Fat Fraction and R2* Inside Carotid Plaques, and Circulating Lipoproteins

BACKGROUND

Lipid-rich necrotic core (LRNC) and intraplaque hemorrhage (IPH) are morphological features of high-risk atherosclerotic plaques. However, their relationship to circulating lipoproteins is unclear.

PURPOSE

To study associations between changes in lipoproteins vs. changes in LRNC (represented by fat fraction [FF]) and IPH (represented by R2*).

STUDY TYPE

Prospective.

SUBJECTS

Fifty-two patients with carotid plaques, 33 males (63.5%), mean age 72 (±5).

FIELD STRENGTH/SEQUENCE

Four-point fast gradient Dixon magnetic resonance imaging (MRI) was used to quantify FF and R2* (to measure IPH) inside plaques and in vessel wall. Turbo-spin echo was used for T₁ weighted sequences to guide manual segmentation.

ASSESSMENT

Carotid MRI and serum lipid levels were assessed at baseline and at 1-year follow-up. For patients, lipid-lowering therapy was customized to reduce low-density lipoprotein (LDL) levels below 1.8 mmol/L. Segmentation was performed with one set of regions of interest for the plaque and one for the vessel wall at the location of the plaque. Thereby MRI data for FF, R2*, and volumes in plaque- and vessel-wall segmentations could be obtained from baseline and follow-up, as well as changes over the study year.

STATISTICAL TESTS

Pearson correlation coefficient for correlations. Paired samples t-test for changes over time. Significance at P < 0.05, 95% confidence interval.

RESULTS

LDL decreased significantly (2.19-1.88 mmol/L, Z - 2.9), without correlation to changes in plaque composition, nor to the significant reduction in vessel-wall volume (-106.3 mm³ ). Plaque composition remained unchanged, FF +8.5% (P = 0.366) and R2* +3.5% (P = 0.304). Compared to plaque segmentations, R2* was significantly lower in the vessel-wall segmentations both at baseline (-9.3%) and at follow-up (-9.1%).

DATA CONCLUSION

The absence of correlations between changes in lipoproteins and changes in plaque composition indicates more complex relationships between these parameters than previously anticipated. The significant differences in both R2* and volume dynamics comparing plaque segmentations and vessel-wall segmentations suggest differences in their pathobiology of atherosclerosis.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 4.

Regression in carotid plaque lipid content and neovasculature with PCSK9 inhibition: A time course study

BACKGROUND AND AIMS

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduce cardiovascular events, but their effects on atherosclerotic plaque remain elusive. Using serial magnetic resonance imaging (MRI), we studied changes in carotid plaque lipid content and neovasculature under PCSK9 inhibition with alirocumab.

METHODS

Among patients with low-density lipoprotein cholesterol (LDL-C) ≥70 mg/dl but ineligible for high-dose statin therapy, those with lipid core on carotid MRI were identified to receive alirocumab 150 mg every 2 weeks. Follow-up MRI was performed at 3, 6, and 12 months after treatment. Pre- and post-contrast MRI were acquired to measure percent lipid core volume (% lipid core). Dynamic contrast-enhanced MRI was acquired to measure the extravasation rate of gadolinium contrast (K^trans), a marker of plaque neovasculature.

RESULTS

Of 31 patients enrolled, 27 completed the study (mean age: 69 ± 9; male: 67%). From 9.8% at baseline, % lipid core was progressively reduced to 8.4% at 3 months, 7.5% at 6 months, and 7.2% at 12 months (p = 0.014 for trend), which was accompanied by a progressive increase in % fibrous tissue (p = 0.009) but not % calcification (p = 0.35). K^trans was not reduced until 12 months (from 0.069 ± 0.019 min^-1 to 0.058 ± 0.020 min^-1; p = 0.029). Lumen and wall areas did not change significantly during the study period.

CONCLUSIONS

Regression in plaque composition and neovasculature were observed under PCSK9 inhibition on carotid MRI, which provides unique insight into the biological process of plaque stabilization with disease-modifying therapies.

Measuring effects on intima-media thickness: an evaluation of rosuvastatin in Chinese subjects with subclinical atherosclerosis-design, rationale, and methodology of the METEOR-China study

BACKGROUND

The beneficial effect of statins on atherosclerosis and cardiovascular outcomes has been well established. The Measuring Effects on intima media Thickness: an Evaluation Of Rosuvastatin (METEOR) global study demonstrated that a 2-year orally administered treatment with rosuvastatin 40 mg daily significantly slowed the progression of carotid intima-media thickness (CIMT) compared to placebo. The current METEOR-China study is designed to evaluate the effect of rosuvastatin 20 mg daily versus placebo on the progression of atherosclerosis measured by CIMT in asymptomatic Chinese subjects.

METHODS

This is a phase 3, randomised, double-blind, placebo-controlled, multicentre parallel-group study. Asymptomatic Chinese subjects with a 10-year ischaemic cardiovascular disease (ICVD) risk < 10% will be recruited at 25 study sites. They will be treated with rosuvastatin 20 mg or placebo for 104 weeks. The primary endpoint is the annualised rate of change in CIMT measured by B-mode ultrasonography. Secondary endpoints include the annualised rate of change in CIMT at three different sections of the carotid artery and changes in the serum lipid profile. Safety parameters will also be assessed.

CONCLUSION

The study will evaluate whether rosuvastatin 20 mg slows the progression of CIMT in asymptomatic Chinese subjects at low risk of ICVD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02546323 . Registered on September 10, 2015.

Molecular and Nonmolecular Magnetic Resonance Coronary and Carotid Imaging

Atherosclerosis is the leading cause of cardiovascular morbidity and mortality. Over the past 2 decades, increasing research attention is converging on the early detection and monitoring of atherosclerotic plaque. Among several invasive and noninvasive imaging modalities, magnetic resonance imaging (MRI) is emerging as a promising option. Advantages include its versatility, excellent soft tissue contrast for plaque characterization and lack of ionizing radiation. In this review, we will explore the recent advances in multicontrast and multiparametric imaging sequences that are bringing the aspiration of simultaneous arterial lumen, vessel wall, and plaque characterization closer to clinical feasibility. We also discuss the latest advances in molecular magnetic resonance and multimodal atherosclerosis imaging.

Effect of high-dose strong statin for preventing periprocedural ischemic complications of carotid artery stenting

Statin therapy has been shown to induce carotid atherosclerotic plaque regression and reduce the periprocedural ischemic complications of carotid artery stenting (CAS). This study assessed the safety and usefulness of pretreatment using a high-dose strong statin (HDSS) to reduce the periprocedural ischemic complications of CAS. We analyzed 117 carotid lesions treated by CAS that were evaluated with magnetic resonance imaging (MRI) within 48 h after the procedure. For 67 lesions, an HDSS (rosuvastatin 20 mg or atorvastatin 40 mg daily) were prescribed from at least 14 days before CAS to at least 14 days after procedure (HDSS group). Clinical and angiographic data, as well as in-hospital outcomes, of the HDSS group were retrospectively compared with 50 lesions with conventional treatment without an HDSS (non-HDSS group). There were no significant differences in the baseline clinical and procedural characteristics between the two groups. There was no side effect related to the HDSS. Stroke rates were similar between the two groups (3.0% in HDSS group vs 8.0% in non-HDSS group, p = 0.22). All were minor strokes. Compared to the non-HDSS group, the HDSS group had a lower frequency of new lesions on diffusion-weighted imaging (DWI) with MRI (25.4% vs 44.0%, p = 0.0345). New ipsilateral DWI-positive rate in the HDSS group was significantly lower than in the non-HDSS group (16.4% vs 34.0%, p = 0.0275). Nonipsilateral (contralateral or posterior circulation) DWI-positive rates were similar between the two groups (13.4% vs 20.0%, p = 0.34). Pretreatment with an HDSS might reduce the periprocedural ischemic complications of CAS.

Misconceptions regarding the adequacy of best medical intervention alone for asymptomatic carotid stenosis

BACKGROUND

Medical intervention (risk factor identification, lifestyle coaching, and medication) for stroke prevention has improved significantly. It is likely that no more than 5.5% of persons with advanced asymptomatic carotid stenosis (ACS) will now benefit from a carotid procedure during their lifetime. However, some question the adequacy of medical intervention alone for such persons and propose using markers of high stroke risk to intervene with carotid endarterectomy (CEA) and/or carotid angioplasty/stenting (CAS). Our aim was to examine the scientific validity and implications of this proposal.

METHODS

We reviewed the evidence for using medical intervention alone or with additional CEA or CAS in persons with ACS. We also reviewed the evidence regarding the validity of using commonly cited makers of high stroke risk to select such persons for CEA or CAS, including markers proposed by the European Society for Vascular Surgery in 2017.

RESULTS

Randomized trials of medical intervention alone versus additional CEA showed a definite statistically significant CEA stroke prevention benefit for ACS only for selected average surgical risk men aged less than 75 to 80 years with 60% or greater stenosis using the North American Symptomatic Carotid Endarterectomy Trial criteria. However, the most recent measurements of stroke rate with ACS using medical intervention alone are overall lower than for those who had CEA or CAS in randomized trials. Randomized trials of CEA versus CAS in persons with ACS were underpowered. However, the trend was for higher stroke and death rates with CAS. There are no randomized trial results related to comparing current optimal medical intervention with CEA or CAS. Commonly cited markers of high stroke risk in relation to ACS lack specificity, have not been assessed in conjunction with current optimal medical intervention, and have not been shown in randomized trials to identify those who benefit from a carotid procedure in addition to current optimal medical intervention.

CONCLUSIONS

Medical intervention has an established role in the current routine management of persons with ACS. Stroke risk stratification studies using current optimal medical intervention alone are the highest research priority for identifying persons likely to benefit from adding a carotid procedure.

Effects of Simvastatin on Augmentation Index Are Transient: Outcomes From a Randomized Controlled Trial

Background

Statins improve endothelial function, but their effects on arterial stiffness and aortic blood pressure in middle‐aged adults are uncertain.

Methods and Results

This was a prospective, randomized, double‐blind, placebo‐controlled trial of middle‐aged (40‐72 years old) adults who were randomly assigned to receive simvastatin 40 mg (n=44) or placebo (n=44) daily for 18 months to evaluate impact on dementia‐related biomarkers (primary end points) and measures of vascular health (secondary end points). This analysis focuses on the predetermined secondary end points of changes in central aortic blood pressure, aortic augmentation index, and brachial artery flow‐mediated dilation. Measurements were performed at baseline and after 6, 12, and 18 months. Multivariable models were used to identify predictors of these prespecified vascular end points. Study groups were similar at baseline; low‐density lipoprotein cholesterol declined in the statin group but not in the placebo group (P<0.01). There were no significant differences in changes in central blood pressure parameters or flow‐mediated dilation (all P>0.2). After 12 months, augmentation index decreased from baseline in the statin group compared with the placebo group (−2.3% [5.5%] versus 1.2% [5.7%], P=0.007), but by 18 months the response in both groups trend toward baseline (−1.1% [5.8%] versus 0.2% [4.8%], P=0.3). Low‐density lipoprotein cholesterol was not associated with changes in augmentation index at any time point.

Conclusions

Statin therapy led to a short‐term reduction in augmentation index after 12 months, but this effect did not persist after 18 months despite continued reduction in low‐density lipoprotein cholesterol levels. These findings suggest that statins may have a transient effect on aortic stiffness.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT00939822.

Rapid improvement in carotid adventitial angiogenesis and plaque neovascularization after rosuvastatin therapy in statin treatment-naïve subjects

BACKGROUND

Statin therapy can improve plaque stability. However, the time course of effects of statin on adventitial angiogenesis and plaque neovascularization has not been studied.

OBJECTIVE

The objective of the study was to investigate whether statin therapy reduces plaque neovascularization, associated with adventitial angiogenesis, over 24 months as assessed by using carotid dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

METHODS

Forty-three lipid treatment-naïve subjects with asymptomatic carotid atherosclerosis received rosuvastatin (5-20 mg/d) to lower low-density lipoprotein cholesterol to <80 mg/dL for 24 months. Carotid DCE-MRI was performed at baseline, 3, 12 and 24 months. Vascularity (V_p = fractional plasma volume) and vascular permeability (K^trans = transfer constant) derived from kinetic modeling of DCE-MRI were measured in both adventitia and plaque.

RESULTS

Adventitia V_p and adventitia K^trans were significantly correlated with plaque V_p and plaque K^trans at baseline. Rosuvastatin significantly reduced both adventitial and plaque V_p significantly at 3 months from 0.121 ± 0.064 to 0.085 ± 0.049 (P = .008) and from 0.096 ± 0.052 to 0.067 ± 0.043 (P = .013). Adventitial and plaque V_p continued to decrease by 43% and 34% at 12 months and by 49% and 45% at 24 months. However, the continued reductions from 3 to 12 months and from 12 to 24 months were not statistically significant. Adventitial and plaque K^trans showed similar trends, but nonstatistically significant decreases during the 24 months of treatment.

CONCLUSIONS

Rosuvastatin therapy rapidly and significantly decreased adventitial and plaque neovascularization at 3 months followed by continued, but nonstatistically significant, decreases at 12 and 24 months.