Determinants of Arterial Wall Remodeling During Lipid-Lowering Therapy

Coronary plaque phenotype associated with positive remodeling

BACKGROUND

Positive remodeling is an integral part of the vascular adaptation process during the development of atherosclerosis, which can be detected by coronary computed tomography angiography (CTA).

METHODS

A total of 426 patients who underwent both coronary CTA and optical coherence tomography (OCT) were included. Four machine learning (ML) models, gradient boosting machine (GBM), random forest (RF), deep learning (DL), and support vector machine (SVM), were employed to detect specific plaque features. A total of 15 plaque features assessed by OCT were analyzed. The variable importance ranking was used to identify the features most closely associated with positive remodeling.

RESULTS

In the variable importance ranking, lipid index and maximal calcification arc were consistently ranked high across all four ML models. Lipid index and maximal calcification arc were correlated with positive remodeling, showing pronounced influence at the lower range and diminishing influence at the higher range. Patients with more plaques with positive remodeling throughout their entire coronary trees had higher low-density lipoprotein cholesterol levels and were associated with a higher incidence of cardiovascular events during 5-year follow-up (Hazard ratio 2.10 [1.26-3.48], P ​= ​0.004).

CONCLUSION

Greater lipid accumulation and less calcium burden were important features associated with positive remodeling in the coronary arteries. The number of coronary plaques with positive remodeling was associated with a higher incidence of cardiovascular events.

Association of the low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and major adverse cardiac and cerebrovascular events in patients with coronary heart disease undergoing percutaneous coronary intervention: a cohort study

BACKGROUND

Although dyslipidemia increases the risk of coronary heart disease (CHD) and its adverse prognosis, the association between the ratio of low-density lipoprotein cholesterol (LDL-C) to high-density lipoprotein cholesterol (HDL-C) and major adverse cardiovascular and cerebrovascular events (MACCE) after percutaneous coronary intervention (PCI) in patients with CHD has not been adequately demonstrated. Therefore, the aim of this study was to assess the role of LDL-C/HDL-C in the risk of MACCE after PCI in patients with CHD.

METHODS

In this large cohort observational study, we enrolled 2226 patients with CHD treated with PCI. LDL-C/HDL-C was considered as an exposure variable and MACCE was considered as an outcome variable. Univariate and multivariate Logistic regression models and subgroup analyses were used to assess the relationship between LDL-C/HDL-C and the risk of MACCE.

RESULTS

A total of 2226 patients (mean age: 60.02 years; 68.00% male) were included in the analysis, and 373 patients suffered MACC. Patients who developed MACCE had higher levels of LDL-C/HDL-C compared to patients who did not develop MACCE [(2.79 ± 1.15) vs (2.64 ± 1.09), p = 0.023]. Univariate Logistic regression analysis showed a correlation between LDL-C/HDL-C and the risk of MACCE (OR: 1.121, 95% CI: 1.019-1.233, p = 0.019). Multivariate Logistic regression analysis showed that higher levels of LDL-C/HDL-C remained strongly associated with a higher risk of MACCE after stepwise adjustment for confounding variables [Model 4: T3 vs T1, OR: 1.455, 95% CI: 1.095-1.933, p = 0.010; per unit increase, OR: 1.158, 95% CI: 1.047-1.281, p = 0.004]. Further subgroup analysis showed that the association between LDL-C/HDL-C and MACCE risk remained in the subgroup ≤60 years, male, without diabetes, and with hypertension (p < 0.05).

CONCLUSION

Higher LDL-C/HDL-C was closely associated with a higher risk of MACCE after PCI in patients with CHD.

The Association between Low Levels of Low Density Lipoprotein Cholesterol and Intracerebral Hemorrhage: Cause for Concern?

Excessive levels of low-density lipoprotein cholesterol (LDL-C) in the blood are a known risk factor for atherosclerosis, and a common target of treatment for primary and secondary prevention of cerebrocardiovascular disease. As lipid lowering agents including statins, ezetimibe and anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have shown good therapeutic results, the guidelines are constantly lowering the "optimal" LDL-C goals. However, old and new data point towards an association between low LDL-C and total cholesterol and intracerebral hemorrhage (ICH). In this review we aimed to shed light on this troubling association and identify the potential risk factors of such a potential adverse reaction. With respect to the data presented, we concluded that in patients with high risk of ICH, a cautious approach and individualized therapy strategy are advised when considering aggressive LDL reduction.

Measurement of compensatory arterial remodelling over time with serial coronary computed tomography angiography and 3D metrics

AIMS

The magnitude of alterations in which coronary arteries remodel and narrow over time is not well understood. We aimed to examine changes in coronary arterial remodelling and luminal narrowing by three-dimensional (3D) metrics from serial coronary computed tomography angiography (CCTA).

METHODS AND RESULTS

From a multicentre registry of patients with suspected coronary artery disease who underwent clinically indicated serial CCTA (median interscan interval = 3.3 years), we quantitatively measured coronary plaque, vessel, and lumen volumes on both scans. Primary outcome was the per-segment change in coronary vessel and lumen volume from a change in plaque volume, focusing on arterial remodelling. Multivariate generalized estimating equations including statins were calculated comparing associations between groups of baseline percent atheroma volume (PAV) and location within the coronary artery tree. From 1245 patients (mean age 61 ± 9 years, 39% women), a total of 5721 segments were analysed. For each 1.00 mm3 increase in plaque volume, the vessel volume increased by 0.71 mm3 [95% confidence interval (CI) 0.63 to 0.79 mm3, P < 0.001] with a corresponding reduction in lumen volume by 0.29 mm3 (95% CI -0.37 to -0.21 mm3, P < 0.001). Serial 3D arterial remodelling and luminal narrowing was similar in segments with low and high baseline PAV (P ≥ 0.496). No differences were observed between left main and non-left main segments, proximal and distal segments and side branch and non-side branch segments (P ≥ 0.281).

CONCLUSIONS

Over time, atherosclerotic coronary plaque reveals prominent outward arterial remodelling that co-occurs with modest luminal narrowing. These findings provide additional insight into the compensatory mechanisms involved in the progression of coronary atherosclerosis.

Emerging techniques in atherosclerosis imaging

Atherosclerosis is a chronic immunomodulated disease that affects multiple vascular beds and results in a significant worldwide disease burden. Conventional imaging modalities focus on the morphological features of atherosclerotic disease such as the degree of stenosis caused by a lesion. Modern CT, MR and positron emission tomography scanners have seen significant improvements in the rapidity of image acquisition and spatial resolution. This has increased the scope for the clinical application of these modalities. Multimodality imaging can improve cardiovascular risk prediction by informing on the constituency and metabolic processes within the vessel wall. Specific disease processes can be targeted using novel biological tracers and "smart" contrast agents. These approaches have the potential to inform clinicians of the metabolic state of atherosclerotic plaque. This review will provide an overview of current imaging techniques for the imaging of atherosclerosis and how various modalities can provide information that enhances the depiction of basic morphology.

Low-density lipoprotein cholesterol and risk of intracerebral hemorrhage: A prospective study

OBJECTIVE

To prospectively examine the association between low-density lipoprotein (LDL) cholesterol (LDL-C) concentrations and intracerebral hemorrhage (ICH) risk.

METHODS

The current cohort study included 96,043 participants (mean age 51.3 years) who were free of stroke, myocardial infarction, and cancer at baseline (2006). Serum LDL-C concentrations were assessed in 2006, 2008, 2010, and 2012. Cumulative average LDL-C concentrations were calculated from all available LDL-C data during that period. Incident ICH was confirmed by review of medical records.

RESULTS

We identified 753 incident ICH cases during 9 years of follow-up. The ICH risk was similar among participants with LDL concentrations of 70 to 99 mg/dL and those with LDL-C concentrations ≥100 mg/dL. In contrast, participants with LDL-C concentrations <70 mg/dL had a significantly higher risk of developing ICH than those with LDL-C concentrations of 70 to 99 mg/dL; adjusted hazard ratios were 1.65 (95% confidence interval [CI] 1.32-2.05) for LDL-C concentrations of 50 to 69 mg/dL and 2.69 (95% CI 2.03-3.57) for LDL-C concentrations <50 mg/dL.

CONCLUSIONS

We observed a significant association between lower LDL-C and higher risk of ICH when LDL-C was <70 mg/dL, and the association became nonsignificant when LDL-C ≥70 mg/dL. These data can help determination of the ideal LDL range in patients who are at increased risk of both atherosclerotic disease and hemorrhagic stroke and guide planning of future lipid-lowering studies.

Shrinkage as a potential mechanism of recurrent clinical events in patients with a large vulnerable plaque

AIMS

This study aimed to investigate the progression and vascular shrinkage of vulnerable plaque lesions with a plaque burden at least 70% among patients with coronary artery disease by optical coherence tomography (OCT) and intravascular ultrasound (IVUS).

METHODS

Fifty-six OCT-identified vulnerable plaques from 47 patients were included among coronary angiography-identified nonculprit/nontarget lesions. Serial IVUS images were used to assess plaque progression and vascular shrinkage.

RESULTS

Thirty-five small vulnerable plaques (plaque burden <70%, group A) and 21 large vulnerable plaques (plaque burden ≥70%, group B) were identified. The IVUS results at baseline show that mean plaque areas (P < 0.001) and the percentage atheroma volume (PAV) (P < 0.0001) were greater and the minimal lumen area (P < 0.0001) was smaller in group B. The absolute and relative changes in the PAV and mean plaque area from baseline to follow-up were not significantly different. However, the lesions exhibited vessel shrinkage [the mean external elastic membrane (EEM) area (P = 0.02) and mean lumen area (P = 0.03) were significantly smaller in group B] from baseline to follow-up. Patients in group B also exhibited clinical events (recurrent angina symptoms) during the follow-up period. Positive correlations were found between changes in the mean plaque area and the mean EEM area in large vulnerable plaques (r = 0.61, P < 0.0001) and between changes in the mean EEM area and the mean lumen area in large vulnerable plaques (r = 0.61, P < 0.0001).

CONCLUSION

Vulnerable plaque progression was not different between small and large vulnerable plaques. However, large vulnerable plaque lesions tended to exhibit vascular shrinkage, which is possible a cause of coronary artery lumen loss in patients with large vulnerable plaques.

Correlation Studies and Literature Review of Medullary Artery Occlusion After Intracranial Vertebral Artery Stenting

BACKGROUND

Stenosis of the target intracranial vertebral artery is one of the major causes of posterior circulation ischemic stroke. The objective of this paper is to explore methods for reducing the occurrence of medullary artery occlusion after intracranial vertebral artery stenting.

CASE DESCRIPTION

The current research presents a retrospective analysis of 48 patients who received Gateway-Wingspan stent angioplasty to treat severe stenosis of the intracranial vertebral artery, evaluates the results of stenosis remission and perfusion improvement after stent angioplasty, and explores the causes of postoperative medullary artery occlusion. A total of 49 Wingspan stents were implanted in the 48 patients, with a surgical success rate of 100%. After stent implantation, the patients' rates of intracranial vertebral artery stenosis dropped from 75.9% ± 6.3% to 28.4% ± 5.1%. Transcranial Doppler or cranial computed tomography angiography 3 months after surgery showed that none of the patients suffered from in-stent restenosis. Within 24 hours after surgery, medullary perforating artery occlusion occurred in 2 patients, probably because atherosclerotic plaque in the stenotic area became less stable and displaced under the mechanical action of postoperative saccule and stent. As a result, the medullary artery was blocked. After drug and rehabilitation therapies, the patients' symptoms were alleviated.

CONCLUSIONS

Perforating artery occlusion after intracranial vertebral artery stenting can be prevented by strict assessment and preparation before surgery, correct choices of saccule and stent during operation, and other measures. However, large sample data are needed for verification.

Dynamic Macrophages: Understanding Mechanisms of Activation as Guide to Therapy for Atherosclerotic Vascular Disease

An emerging theory is that macrophages are heterogenous; an attribute that allows them to change behavior and execute specific functions in disease processes. This review aims to describe the current understanding on factors that govern their phenotypic changes, and provide insights for intervention beyond managing classical risk factors. Evidence suggests that metabolic reprogramming of macrophages triggers either a pro-inflammatory, anti-inflammatory or pro-resolving behavior. Dynamic changes in bioenergetics, metabolome or influence from bioactive lipids may promote resolution or aggravation of inflammation. Direct cell-to-cell interactions with other immune cells can also influence macrophage activation. Both paracrine signaling and intercellular molecular interactions either co-stimulate or co-inhibit activation of macrophages as well as their paired immune cell collaborator. More pathways of activation can even be uncovered by inspecting macrophages in the single cell level, since differential expression in key gene regulators can be screened in higher resolution compared to conventional averaged gene expression readouts. All these emerging macrophage activation mechanisms may be further explored and consolidated by using approaches in network biology. Integrating these insights can unravel novel and safer drug targets through better understanding of the pro-inflammatory activation circuitry.

Changes in Coronary Plaque Volume: Comparison of Serial Measurements on Intravascular Ultrasound and Coronary Computed Tomographic Angiography

Serial measurements of coronary plaque volume have been used to evaluate drug efficacy in atherosclerotic progression. However, the usefulness of computed tomography for this purpose is unknown. We investigated whether the change in total plaque volume on coronary computed tomographic angiography is associated with the change in segment plaque volume on intravascular ultrasound. We prospectively enrolled 11 consecutive patients (mean age, 56.3 ± 5 yr; 6 men) who were to undergo serial invasive coronary angiographic examinations with use of grayscale intravascular ultrasound and coronary computed tomography, performed <180 days apart at baseline and from 1 to 2 years later. Subjects underwent 186 serial measurements of total plaque volume on coronary computed tomography and 22 of segmental plaque volume on intravascular ultrasound. We used semiautomated software to examine percentage relationships and changes between total plaque and segmental plaque volumes. No significant correlations were found between percentages of total coronary and segment coronary plaque volume, nor between normalized coronary plaque volume. However, in the per-patient analysis, there were strong correlations between the imaging methods for changes in total coronary and segment coronary plaque volume (r=0.62; P=0.04), as well as normalized plaque volume (r=0.82; P=0.002). Per-patient change in plaque volume on coronary computed tomography is significantly associated with that on intravascular ultrasound. Computed tomographic angiography may be safer and more widely available than intravascular ultrasound for evaluating atherosclerotic progression in coronary arteries. Larger studies are warranted.

Is High Serum LDL/HDL Cholesterol Ratio an Emerging Risk Factor for Sudden Cardiac Death? Findings from the KIHD Study

AIM

Low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c), which are components of total cholesterol, have each been suggested to be linked to the risk of sudden cardiac death (SCD). However, the relationship between LDL-c/HDL-c ratio and the risk of SCD has not been previously investigated. We aimed to assess the associations of LDL-c, HDL-c, and the ratio of LDL-c/HDL-c with the risk of SCD.

METHODS

Serum lipoprotein concentrations were assessed at baseline in the Finnish Kuopio Ischemic Heart Disease prospective cohort study of 2,616 men aged 42-61 years at recruitment. Hazard ratios (HRs) (95% confidence intervals [CI]) were assessed.

RESULTS

During a median follow-up of 23.0 years, a total of 228 SCDs occurred. There was no significant evidence of an association of LDL-c or HDL-c with the risk of SCD. In analyses adjusted for age, examination year, body mass index, systolic blood pressure, smoking, alcohol consumption, physical activity, years of education, diabetes, previous myocardial infarction, family history of coronary heart disease, and serum high sensitivity C-reactive protein, there was approximately a two-fold increase in the risk of SCD (HR 1.94, 95% CI 1.21-3.11; p=0.006), comparing the top (＞4.22) versus bottom (≤2.30) quintile of serum LDL-c/HDL-c ratio.

CONCLUSION

In this middle-aged male population, LDL-c or HDL-c was not associated with the risk of SCD. However, a high serum LDL-c/HDL-c ratio was found to be independently associated with an increased risk of SCD. Further research is warranted to understand the mechanistic pathways underlying this association.

The LargPAD Trial: Phase IIA evaluation of l-arginine infusion in patients with peripheral arterial disease

OBJECTIVE

Endothelial function is improved by l-arginine (l-arg) supplementation in preclinical and clinical studies of mildly diseased vasculature; however, endothelial function and responsiveness to l-arg in severely diseased arteries is not known. Our objective was to evaluate the acute effects of catheter-directed l-arg delivery in patients with chronic lower extremity ischemia secondary to peripheral arterial disease.

METHODS

The study enrolled 22 patients (45% male) with peripheral arterial disease (mean age, 62 years) requiring lower extremity angiography. Endothelium-dependent relaxation of patent but atherosclerotic superficial femoral arteries was measured using a combination of intravascular ultrasound (IVUS) imaging and a Doppler FloWire (Volcano Corporation, Rancho Cordova, Calif) during the infusion of incremental acetylcholine (10^-6 to 10^-4 molar concentration) doses. Patients received 50 mg (n = 3), 100 mg (n = 10), or 500 mg (n = 9) l-arg intra-arterially, followed by repeat endothelium-dependent relaxation measurement (limb volumetric flow). IVUS-derived virtual histology of the culprit vessel was also obtained. Endothelium-independent relaxation was measured using a nitroglycerin infusion. Levels of nitrogen oxides and arginine metabolites were measured by chemiluminescence and mass spectrometry, respectively.

RESULTS

Patients tolerated limb l-arg infusion well. Serum arginine and ornithine levels increased by 43.6% ± 13.0% and 23.2% ± 10.3%, respectively (P < .005), and serum nitrogen oxides increased by 85% (P < .0001) after l-arg infusion. Average vessel area increased by 6.8% ± 1.3% with l-arg infusion (acetylcholine 10^-4; P < .0001). Limb volumetric flow increased in all patients and was greater with l-arg supplementation by 130.9 ± 17.6, 136.9 ± 18.6, and 172.1 ± 24.8 mL/min, respectively, for each cohort. Maximal effects were seen with l-arg at 100 mg (32.8%). Arterial smooth muscle responsiveness to nitroglycerin was intact in all vessels (endothelium-independent relaxation, 137% ± 28% volume flow increase). IVUS-derived virtual histology indicated plaque volume was 14 ± 1.3 mm³/cm, and plaque stratification revealed a predominantly fibrous morphology (46.4%; necrotic core, 28.4%; calcium, 17.4%; fibrolipid, 6.6%). Plaque morphology did not correlate with l-arg responsiveness.

CONCLUSIONS

Despite extensive atherosclerosis, endothelial function in diseased lower extremity human arteries can be enhanced by l-arg infusion secondary to increased nitric oxide bioactivity. Further studies of l-arg as a therapeutic modality in patients with endothelial dysfunction (ie, acute limb ischemia) are warranted.

Intensive statin therapy stabilizes C-reactive protein, but not chemokine in stable coronary artery disease treated with an everolimus-eluting stent

BACKGROUND

Besides its potent plasma cholesterol-lowering activity, statin treatment has several other important effects, including lowering high-sensitive C-reactive protein (hs-CRP), levels, and stabilizing risk factors of atherosclerosis, thereby reducing the risk of cardiovascular events. Our aim in this study was to identify how intensive statin therapy can affect plasma levels of inflammatory markers over the long term.

METHODS AND RESULTS

We used a prospective, randomized, open blinded-endpoint design. A total of 30 patients with stable coronary artery disease treated with everolimus-eluting stent implantation were randomized to receive rosuvastatin 2.5 (standard therapy group) or 10 mg (intensive therapy group) for 12 months. Plasma levels of hs-CRP, pentraxin-3, monocyte chemoattractant protein-1, and CXC chemokine ligand 4 were measured after a percutaneous coronary intervention, at 1, 3, 6, 9, and 12 months. Levels of LDL cholesterol (LDL-C) and HDL cholesterol were also measured. We investigated short-term and long-term clinical outcomes. After 12 months of therapy, the intensive therapy group had lower levels of LDL-C than the standard therapy group. Plasma levels of hs-CRP largely fluctuated in the standard therapy group, whereas they were stable in the intensive therapy group during the follow-up period. There were no significant differences in serum pentraxin-3, monocyte chemoattractant protein-1, and CXC chemokine ligand 4 levels, or in the incidence of any clinical adverse events, between the standard and the intensive therapy groups.

CONCLUSION

Intensive rosuvastatin therapy stabilizes hs-CRP levels, but not chemokine levels, besides lowering LDL-C levels. Thus, this therapy may inhibit the progression of atherosclerosis by stably inhibiting the inflammatory cascade.

Associations of cardiovascular and all-cause mortality events with oxygen uptake at ventilatory threshold

BACKGROUND

Oxygen uptake (VO₂) at ventilatory threshold (VT), is a cardiopulmonary exercise testing parameter which may be a proxy for peak VO₂. We aimed to assess the associations of VO₂ at VT with sudden cardiac death (SCD), fatal coronary heart disease (CHD) and cardiovascular disease (CVD), and all-cause mortality.

METHODS AND RESULTS

VO₂ at VT was assessed during a submaximal exercise test using respiratory gas analyzers in the Kuopio Ischemic Heart Disease cohort of 1639 middle-aged men. Hazard ratios (HRs) (95% CIs) were assessed. During a median follow-up of 25.6years, 121 SCDs, 202 fatal CHDs, 312 fatal CVDs, and 703 all-cause mortality events occurred. VO₂ at VT was correlated with peak VO₂ (r=0.90) and linearly associated with each outcome. Comparing extreme quartiles of VO₂ at VT, the HRs (95% CIs) for SCD, fatal CHD, fatal CVD, and all-cause mortality on adjustment for established risk factors were 0.37 (0.18-0.78), 0.32 (0.18-0.57), 0.45 (0.30-0.69), and 0.50 (0.38-0.64) respectively. The HRs were 1.02 (0.36-2.91), 1.43 (0.63-3.25), 1.46 (0.79-2.71), and 1.02 (0.69-1.51) respectively on further adjustment for peak VO₂. Addition of VO₂ at VT to a CVD mortality risk prediction model containing established risk factors significantly improved risk discrimination and reclassification at 25years.

CONCLUSIONS

There are linear and inverse associations of VO2 at VT with fatal cardiovascular and all-cause mortality events, which are dependent on peak VO₂. Inclusion of VO₂ at VT in the standard established risk factors panel significantly improves the prediction and classification of long-term CVD mortality risk.

Significance of the percentage of cholesterol efflux capacity and total cholesterol efflux capacity in patients with or without coronary artery disease

We hypothesized that cholesterol efflux capacity is more useful than the lipid profile as a marker of the presence and the severity of coronary artery disease (CAD). Therefore, we investigated the associations between the presence and the severity of CAD and both the percentage of cholesterol efflux capacity and total cholesterol efflux capacity and the lipid profile including the high-density lipoprotein cholesterol (HDL-C) level in patients who underwent coronary computed tomography angiography (CTA). The subjects consisted of 204 patients who were clinically suspected to have CAD and underwent CTA. We isolated HDL from plasma by ultracentrifugation and measured the percentage of cholesterol efflux capacity using ³H-cholesterol-labeled J774 macrophage cells and calculated total cholesterol efflux capacity as follows: the percentage of cholesterol efflux capacity/100× HDL-C levels. While the percentage of cholesterol efflux capacity was not associated with the presence or the severity of CAD, total cholesterol efflux capacity and HDL-C in patients with CAD were significantly lower than those in patients without CAD. In addition, total cholesterol efflux capacity and HDL-C, but not the percentage of cholesterol efflux capacity, significantly decreased as the number of coronary arteries with significant stenosis increased. Total cholesterol efflux capacity was positively correlated with HDL-C, whereas the percentage of cholesterol efflux capacity showed only weak association. In a logistic regression analysis, the presence of CAD was independently associated with total cholesterol efflux capacity, in addition to age and gender. Finally, a receiver-operating characteristic curve analysis indicated that the areas under the curves for total cholesterol efflux capacity and HDL-C were similar. In conclusion, the percentage of cholesterol efflux capacity using the fixed amount of isolated HDL was not associated with CAD. On the other hand, the calculated total cholesterol efflux capacity that was dependent of HDL-C levels had a significant correlation with the presence of CAD.

Clinical guidelines on hyperlipidaemia: recent developments, future challenges and the need for an Australian review

Large reductions in cardiovascular disease (CVD) mortality have been achieved over the last 50 years in developed countries. The health policies that have contributed so much to this success have largely been coordinated by means of expert guidelines for the management of the classic modifiable risk factors such as blood pressure, diabetes and blood lipids. National and international guidelines for lipid management have demonstrated a high degree of consistency between numerous sets of recommendations. It has been argued that some important components of the consensus that has been established over the past decade have been challenged by the latest guidelines of the American Heart Association - American College of Cardiologists (AHA-ACC). Clinicians can be reassured that continued reliance on extensive scientific evidence has reaffirmed the importance of lipid metabolism as a modifiable risk factor for atherosclerotic cardiovascular disease. On the other hand, the recent AHA-ACC guidelines suggest changes in the strategies by which metabolic risk factors may be modified. This small number of important changes should not be sensationalised because these differences usefully reflect the need for guidelines to evolve to accommodate different contexts and changing perspectives as well as emerging issues and new information for which clinical trial evidence is incomplete. This article will consider the recent policies and responses of national and supranational organisations on topics including components of CVD risk assessment, sources of CVD risk information and re-appraisal of lipid-lowering interventions. Timely review of Australian lipid management guidelines will require consideration of these issues because they are creating a new context within which new guidelines must evolve.

Association of traditional risk factors with coronary artery disease in nonagenarians: the primary role of hypertension

BACKGROUND

Previous studies have shown different relationships between traditional cardiovascular risk factors for coronary artery disease (CAD) in very elderly people. Although new associations with CAD have been reported, there is also evidence of the possibility of new therapeutic strategies for the treatment or prevention of CAD.

DESIGN

This article retrospectively examines the possible association of traditional cardiovascular risk factors with CAD in very elderly people aged >90 years. This study represents the hypothesis that the elderly aged >90 years have a different cardiovascular profile with respect to CAD than patients <90 years old.

METHODS

Data on all patients aged >90 years who received a cardiac catheterization were collected from hospital charts from the Department of Internal Medicine, Saarland University Medical Center, Germany, within the study period of 2004-2013. The cardiovascular risk profiles were compared in patients aged >90 years with and without CAD after cardiac catheterization.

RESULTS

One hundred and six out of 67,976 (0.2%, mean age 91.6±1.8 years, 40 female [37.7%]; 95% confidence interval [CI]: 0.1-0.2), and out of a total of 114 of the very elderly patients, were found to have CAD. From the results of this study, the author could establish only a causal relationship between hypertension and CAD in very elderly people (P=0.005). At best, this is just an association with a higher risk of CAD in this age group. Several studies with similar outcomes are needed to establish causality.

CONCLUSION

This study could find no link between CAD and traditional risk factors, except for hypertension.

Weak prediction power of the Framingham Risk Score for coronary artery disease in nonagenarians

Background

Coronary artery disease (CAD) is caused by an acute myocardial infarction and is still feared as a life-threatening heart disease worldwide. In order to identify patients at high risk for CAD, previous studies have proposed various risk assessment scores for the prevention of CAD. The most commonly used risk assessment score for CAD worldwide is the Framingham Risk Score (FRS). The FRS is used for middle-aged people; hence, its appropriateness has not been demonstrated to predict the likelihood of CAD occurrence in very elderly people. This article examines the possible predictive value of FRS for CAD in very elderly people over 90 years of age.

Methods

Data on all patients over 90 years of age who received a cardiac catheter were collected from hospital charts from the Department of Internal Medicine, Saarland University Medical Center, and HELIOS Hospital Wuppertal, Witten/Herdecke University Medical Center, Germany, within a study period from 2004 to 2013. The FRSs and cardiovascular risk profiles of patients over 90 years of age with and without CAD after cardiac catheterization were compared.

Results

One hundred and seventy-five (91.15%, mean age 91.51±1.80 years, 74 females [42.29%]; 95% confidence interval [CI], 0.87–0.95) of a total 192 of the very elderly patients were found to have CAD. Based on the results of our study, the FRS seems to provide weak predictive ability for CAD in very elderly people (P = 0.3792).

Conclusion

We found weak prediction power of FRS for CAD in nonagenarians.

High-intensity statin therapy alters the natural history of diabetic coronary atherosclerosis: insights from SATURN

OBJECTIVE

Although statins can induce coronary atheroma regression, this benefit has yet to be demonstrated in diabetic individuals. We tested the hypothesis that high-intensity statin therapy may promote coronary atheroma regression in patients with diabetes.

RESEARCH DESIGN AND METHODS

The Study of Coronary Atheroma by Intravascular Ultrasound: Effect of Rosuvastatin Versus Atorvastatin (SATURN) used serial intravascular ultrasound measures of coronary atheroma volume in patients treated with rosuvastatin 40 mg or atorvastatin 80 mg for 24 months. This analysis compared changes in biochemistry and coronary percent atheroma volume (PAV) in patients with (n = 159) and without (n = 880) diabetes.

RESULTS

At baseline, patients with diabetes had lower LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels but higher triglyceride and CRP levels compared with patients without diabetes. At follow-up, diabetic patients had lower levels of LDL-C (61.0 ± 20.5 vs. 66.4 ± 22.9 mg/dL, P = 0.01) and HDL-C (46.3 ± 10.6 vs. 49.9 ± 12.0 mg/dL, P < 0.001) but higher levels of triglycerides (127.6 [98.8, 163.0] vs. 113.0 mg/dL [87.6, 151.9], P = 0.001) and CRP (1.4 [0.7, 3.3] vs. 1.0 [0.5, 2.1] mg/L, P = 0.001). Both patients with and without diabetes demonstrated regression of coronary atheroma as measured by change in PAV (-0.83 ± 0.13 vs. -1.15 ± 0.13%, P = 0.08). PAV regression was less in diabetic compared with nondiabetic patients when on-treatment LDL-C levels were >70 mg/dL (-0.31 ± 0.23 vs. -1.01 ± 0.21%, P = 0.03) but similar when LDL-C levels were ≤70 mg/dL (-1.09 ± 0.16 vs. -1.24 ± 0.16%, P = 0.50).

CONCLUSIONS

High-intensity statin therapy alters the progressive nature of diabetic coronary atherosclerosis, yielding regression of disease in diabetic and nondiabetic patients.

Computational fluid dynamics in coronary artery disease

Computational fluid dynamics (CFD) is a widely used method in mechanical engineering to solve complex problems by analysing fluid flow, heat transfer, and associated phenomena by using computer simulations. In recent years, CFD has been increasingly used in biomedical research of coronary artery disease because of its high performance hardware and software. CFD techniques have been applied to study cardiovascular haemodynamics through simulation tools to predict the behaviour of circulatory blood flow in the human body. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of coronary artery geometry, thus, identifying risk factors for development and progression of coronary artery disease. This review aims to provide an overview of the CFD applications in coronary artery disease, including biomechanics of atherosclerotic plaques, plaque progression and rupture; regional haemodynamics relative to plaque location and composition. A critical appraisal is given to a more recently developed application, fractional flow reserve based on CFD computation with regard to its diagnostic accuracy in the detection of haemodynamically significant coronary artery disease.

Coronary CT angiography in the quantitative assessment of coronary plaques

Coronary computed tomography angiography (CCTA) has been recently evaluated for its ability to assess coronary plaque characteristics, including plaque composition. Identification of the relationship between plaque composition by CCTA and patient clinical presentations may provide insight into the pathophysiology of coronary artery plaque, thus assisting identification of vulnerable plaques which are associated with the development of acute coronary syndrome. CCTA-generated 3D visualizations allow evaluation of both coronary lesions and lumen changes, which are considered to enhance the diagnostic performance of CCTA. The purpose of this review is to discuss the recent developments that have occurred in the field of CCTA with regard to its diagnostic accuracy in the quantitative assessment of coronary plaques, with a focus on the characterization of plaque components and identification of vulnerable plaques.

Effect of chronic statin treatment on vascular remodeling determined by intravascular ultrasound in patients with acute myocardial infarction

Early statin treatment of patients with acute coronary syndrome results in vascular changes and improved clinical outcomes. However, the influence of chronic statin treatment on the culprit vessel in acute coronary syndrome is not fully understood. The aim of this study was to investigate the morphologic features of the culprit vessel in acute myocardial infarction by comparing patients with and without chronic statin treatment. We enroled consecutive patients with AMI, who had hyperlipidemia and primary percutaneous coronary intervention guided by intravascular ultrasound within 24 hours of symptom onset. Of 155 patients, 73 patients were stratified to the chronic statin group and 82 to the nonstatin group. Intravascular ultrasound in both the groups showed that positive remodeling was significantly less frequent in the chronic statin group (46.6%) compared with the nonstatin group (70.7%; p = 0.001). Necrotic core area was significantly smaller in the chronic statin group (2.2 ± 1.3 mm(2)) compared with the nonstatin group (3.2 ± 2.1 mm(2); p <0.001). Multivariate logistic regression analysis revealed that chronic statin treatment was significantly associated with less positive remodeling (odds ratio 0.283, 95% confidence interval 0.111 to 0.723, p = 0.008). In conclusion, chronic statin treatment reduced positive remodeling in the culprit lesions of patients with acute myocardial infarction.

Treatment of intracranial arterial stenosis

Intracranial stenosis accounts for 8-10% of ischemic strokes in the USA. Treatment of intracranial stenosis with extracranial-to-intracranial bypass surgery was investigated as a therapy in the 1980s, but was shown to be no better than aspirin alone. The Warfarin vs Aspirin for Symptomatic Intracranial Disease study found a 12% per year risk of recurrent stroke for symptomatic lesions of 50% or higher, with the majority of strokes occurring in the first year. Warfarin was no better than aspirin in the prevention of recurrent stroke and had a higher risk of serious bleeding and death. Subgroup analysis showed that patients with the highest risk of recurrent stroke included those with 70% or more stenosis and/or recent symptoms and women. Angioplasty and stenting of intracranial stenosis have been undergoing rapid evolution in technology and are emerging as a promising therapy. Current treatment recommendations include antiplatelet agents, with consideration for angioplasty alone or angioplasty and stenting in cases refractory to medical therapy.

In vivo assessment of endothelial function in human lower extremity arteries

OBJECTIVE

Endothelial function has been measured in preclinical studies in human brachial and coronary arteries but not in lower extremity arteries affected by atherosclerosis. We describe a novel, first-in-man evaluation of endothelial function of the superficial femoral arteries (SFAs) in patients with peripheral arterial disease (PAD).

METHODS

Enrolled were 25 patients with PAD requiring lower extremity angiography. Endothelial-dependent relaxation was measured using intravascular ultrasound (IVUS) imaging and a Doppler flow wire after the infusion of acetylcholine (Ach). IVUS-derived virtual histology of the same vessel was calculated. Endothelial-independent relaxation was measured with an infusion of nitroglycerin (200 μg). Levels of nitric oxide and serum nitric oxide metabolites were determined by laboratory analysis.

RESULTS

Patients (48% male; mean age, 62 years) had a history of hypertension (80%), coronary disease (36%), and diabetes (40%). The mean SFA diameter was 5.2 ± 1 mm (range, 3.2-6.9 mm). Patients tolerated Ach infusion with no adverse events. Endothelial-dependent relaxation increased over baseline for all patients with Ach infusion of 10(-6) to 10(-4). At Ach 10(-4), diameter (0.5%) and area (1.8%) changes in the diseased SFAs were modest and insignificant; however, average peak velocity of blood flow significantly increased 26%, 46%, and 63% with an Ach 10(-6) to 10(-4) infusion. Calculations of limb volumetric flow (68% at Ach 10(-4)) were significantly increased after Ach infusion. Lower extremity nitric oxide levels were slightly lower than systemic venous levels (P = .04). Nitroglycerin infusion indicated normal smooth muscle responsiveness (3% diameter, 9% area, and 116% velocity change over baseline). IVUS-virtual histology plaque stratification indicated predominantly fibrous morphology (46%; necrotic core, 29%; calcium, 18%). Atheroma burden was 14.9 ± 5.5 mm(3)/cm and did not correlate with endothelial responsiveness.

CONCLUSIONS

Endothelial function can be measured directly in human lower extremity arteries at the sites of vascular disease. Despite extensive atherosclerosis, endothelial function is still intact. These data support the application of regional endothelial-specific biologic therapies in patients with PAD.

A novel mouse model of atherosclerotic plaque instability for drug testing and mechanistic/therapeutic discoveries using gene and microRNA expression profiling

RATIONALE

The high morbidity/mortality of atherosclerosis is typically precipitated by plaque rupture and consequent thrombosis. However, research on underlying mechanisms and therapeutic approaches is limited by the lack of animal models that reproduce plaque instability observed in humans.

OBJECTIVE

Development and use of a mouse model of plaque rupture that reflects the end stage of human atherosclerosis.

METHODS AND RESULTS

On the basis of flow measurements and computational fluid dynamics, we applied a tandem stenosis to the carotid artery of apolipoprotein E-deficient mice on high-fat diet. At 7 weeks postoperatively, we observed intraplaque hemorrhage in ≈50% of mice, as well as disruption of fibrous caps, intraluminal thrombosis, neovascularization, and further characteristics typically seen in human unstable plaques. Administration of atorvastatin was associated with plaque stabilization and downregulation of monocyte chemoattractant protein-1 and ubiquitin. Microarray profiling of mRNA and microRNA (miR) and, in particular, its combined analysis demonstrated major differences in the hierarchical clustering of genes and miRs among nonatherosclerotic arteries, stable, and unstable plaques and allows the identification of distinct genes/miRs, potentially representing novel therapeutic targets for plaque stabilization. The feasibility of the described animal model as a discovery tool was established in a pilot approach, identifying a disintegrin and metalloprotease with thrombospondin motifs 4 (ADAMTS4) and miR-322 as potential pathogenic factors of plaque instability in mice and validated in human plaques.

CONCLUSIONS

The newly described mouse model reflects human atherosclerotic plaque instability and represents a discovery tool toward the development and testing of therapeutic strategies aimed at preventing plaque rupture. Distinctly expressed genes and miRs can be linked to plaque instability.

Beyond Coronary Stenosis: Coronary Computed Tomographic Angiography for the Assessment of Atherosclerotic Plaque Burden

Coronary computed tomographic angiography (CCTA) is emerging as a key non-invasive method for assessing cardiovascular risk by measurement of coronary stenosis and coronary artery calcium (CAC). New advancements in CCTA technology have led to the ability to directly identify and quantify the so-called "vulnerable" plaques that have features of positive remodeling and low density components. In addition, CCTA presents a new opportunity for noninvasive measurement of total coronary plaque burden that has not previously been available. The use of CCTA needs also to be balanced by its risks and, in particular, the associated radiation exposure. We review current uses of CCTA, CCTA's ability to measure plaque quantity and characteristics, and new developments in risk stratification and CCTA technology. CCTA represents a quickly developing field that will play a growing role in the non-invasive management of cardiovascular disease.

Effect of intensive versus moderate lipid-lowering therapy on epicardial adipose tissue in hyperlipidemic post-menopausal women: a substudy of the BELLES trial (Beyond Endorsed Lipid Lowering with EBT Scanning)

OBJECTIVES

This study sought to evaluate the effect of intensive and moderate statin therapy on epicardial adipose tissue (EAT).

BACKGROUND

EAT has been associated with coronary artery disease severity and outcome. It is currently unknown whether EAT volume changes over time when patients are exposed to statin therapy.

METHODS

Subanalysis of a randomized study of atorvastatin 80 mg/day versus pravastatin 40 mg/day for 1 year in a clinical trial designed to assess the progression of coronary artery calcium (CAC) in hyperlipidemic post-menopausal women. Patients underwent cardiac computed tomography scans at the start and end of the trial period.

RESULTS

Of 420 patients, 194 received atorvastatin and 226 pravastatin; the median low-density lipoprotein change was -53.3% and -28.3% with atorvastatin and pravastatin, respectively (p < 0.001). Baseline EAT correlated with age, body mass index, hypertension, diabetes mellitus, high-density lipoprotein, triglyceride levels, and CAC (p < 0.001). At the end of follow-up, EAT regressed more in the atorvastatin than in the pravastatin group (median, -3.38% vs. -0.83%, p = 0.025). The EAT percent change from baseline was significant in the atorvastatin, but not the pravastatin group (p < 0.001 and p = 0.2, respectively). There was no correlation between lipid lowering and EAT regression. CAC progressed significantly in both groups from baseline.

CONCLUSIONS

In hyperlipidemic post-menopausal women, statin therapy induced EAT regression, although intensive therapy was more effective than moderate-intensity therapy. This effect does not seem linked to low-density lipoprotein lowering and may be secondary to other actions of statins such as anti-inflammatory effects.

Early differential changes in coronary plaque composition according to plaque stability following statin initiation in acute coronary syndrome: classification and analysis by intravascular ultrasound-virtual histology

PURPOSE

The aim of this study was to demonstrate the early effects of statin treatment on plaque composition according to plaque stability on Intravascular Ultrasound- Virtual Histology at 6 months after a coronary event. Previous trials have demonstrated that lipid lowering therapy with statins decreases plaque volume and increases plaque echogenicity in patients with coronary artery disease.

MATERIALS AND METHODS

Fifty-four patients (54 lesions) with acute coronary syndrome were prospectively enrolled. We classified and analyzed the target plaques into two types according to plaque stability: thin-cap fibroatheroma (TCFA, n=14) and non-TCFA (n=40). The primary end point was change in percent necrotic core in the 10-mm subsegment with the most disease.

RESULTS

After 6 months of statin therapy, no change was demonstrated in the mean percentage of necrotic core (18.7±8.5% to 20.0±11.0%, p=0.38). There was a significant reduction in necrotic core percentage in patients with TCFA (21.3±7.2% to 14.4±8.9%, p=0.017), but not in patients with non-TCFA. Moreover, change in percent necrotic core was significantly correlated with change in high-sensitivity C-reactive protein levels (r=0.4, p=0.003). Changes in low-density lipoprotein cholesterol levels and lipid core percentage demonstrated no significant associations.

CONCLUSION

A clear reduction of lipid core was observed only for the TCFA plaque type, suggesting that changes in plaque composition following statin therapy might occur earlier in vulnerable plaque than in stable plaque; the effect may be related to the anti-inflammatory effects of statins.

Coronary CT angiography and high-risk plaque morphology

Computed tomography angiography (CTA) is commonly employed for exclusion of coronary artery disease and demonstration of the extent of coronary vascular involvement. It has been recently proposed that coronary artery plaques could be visualized noninvasively. This review article focused on the high risk plaque detected by CTA. Plaque characteristics of acute coronary syndrome (ACS) was compared to sable angina pectoris (SAP). The presence of positive remodeling (ACS 87 %, SAP 12 %, p < 0.0001), low attenuation plaque (LAP) (ACS 79 %, SAP 9 %, p < 0.0001), and spotty calcification (ACS 63 %, SAP 21 %, p = 0.0005) were significantly more frequent in the culprit ACS lesions. Furthermore, in asymptomatic patients, presence of positively remodeling and LAP portends a greater risk for development of acute coronary events (hazard ratio = 22.8, CI = 6.9-75.2, p < 0.001). Possibility of drug intervention to high risk plaque was also reported. Serial CTA assessment allows for evaluation of interval change in morphological plaque characteristics and can be employed for assessment of efficacy of therapeutic intervention. Use of statin results in substantial reduction in LAP volume (follow-up: 4.9 ± 7.8 versus baseline: 1.3 ± 2.3 mm(3), p = 0.02) forwards stabilization of plaques. Although not recommended currently as a population-based strategy, CT angiographic examination may help identify very high risk asymptomatic subjects.

Comparison of arterial remodeling and changes in plaque composition between patients with progression versus regression of coronary atherosclerosis during statin therapy (from the TRUTH study)

Statin therapy produces regression of coronary artery plaques and reduces the incidence of coronary artery disease. However, not all patients show regression of coronary atherosclerosis after statin therapy. The purpose of the present study was to identify differences in clinical characteristics, serum lipid profiles, arterial remodeling, and plaque composition between patients with progression and those with regression of coronary atherosclerosis during statin therapy. The effects of 8-month statin therapy on coronary atherosclerosis were evaluated in the Treatment With Statin on Atheroma Regression Evaluated by Intravascular Ultrasound With Virtual Histology (TRUTH) study using intravascular ultrasound-virtual histology. One hundred nineteen patients were divided into 2 groups according to atheroma volume increase (progressors) or decrease (regressors) during an 8-month follow-up period. Fifty-one patients (43%) were categorized as progressors and the remaining 68 (57%) as regressors. External elastic membrane volume increased, although not significantly (0.8%, p = 0.34), and luminal volume decreased significantly (-5.3%, p = 0.0003) in progressors, while external elastic membrane volume decreased significantly (-3.2%, p <0.0001) and luminal volume increased (2.2%, p = 0.13) in regressors. The fibrous component increased significantly in progressors, while this component decreased in regressors. A strong positive correlation was observed between change in atheroma volume and change in fibrous volume (r = 0.812, p <0.0001). In conclusion, coronary arteries showed negative remodeling during statin-induced plaque regression. The difference in plaque composition between patients with progression and those with regression of coronary atherosclerosis during statin therapy arose from the difference in the change in fibrous component.

Low density lipoprotein-cholesterol/high density lipoprotein-cholesterol ratio predicts plaque vulnerability in patients with stable angina

BACKGROUND AND OBJECTIVES

The relationship between lipid profile and coronary plaque tissue characteristics in patients with stable angina pectoris (SAP) is unclear. The aim of this study was to evaluate the relationship between tissue characteristics and lipid profile and predictors of unstable plaques (UPs) in patients with SAP by virtual histology intravascular ultrasonography (VH-IVUS).

SUBJECTS AND METHODS

VH-IVUS was performed for target lesions in patients with SAP (61.7±9.2 years, 174 males, n=266) at the time of coronary angiography. UPs are characterized by thin-cap fibroatheroma, ruptured plaque, or remaining thrombus with VH-IVUS.

RESULTS

The present study showed that 34 SAP patients had UPs (61.6±9.2 years, 24 males, 12.8%). The percentage of plaque area in the minimum luminal area in high low density lipoprotein-cholesterol (LDL-C)/high density lipoprotein-cholesterol (HDL-C) ratio patients was significantly higher than in low LDL-C/HDL-C ratio patients (72.7±9.5% vs. 69.9±9.3%, p=0.035). An LDL-C/HDL-C ratio >2.0 was an independent predictor for UPs in SAP patients (odds ratio 5.252, 95% confidence interval 1.132-24.372, p=0.034).

CONCLUSION

An elevated LDL-C/HDL-C ratio is a positive predictor for coronary plaque vulnerability in patients with SAP.

Relationship of antihypertensive treatment to plasma markers of vascular inflammation and remodeling in the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis study

BACKGROUND

Antihypertensive agents lower the risk of cardiovascular events, but whether they affect pathways important in inflammation and plaque remodeling in atherosclerosis is uncertain. We assessed whether 2 commonly used antihypertensive agents affected plasma biomarkers reflecting specific inflammatory and remodeling processes over 2 years in the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis (CAMELOT) study.

METHODS

The study was a randomized controlled trial of 2 antihypertensives (amlodipine and enalapril) compared with placebo in patients with coronary artery disease and diastolic blood pressure less than 100 mm Hg. In 196 subjects who had baseline and 2-year intravascular coronary ultrasound examinations, we measured plasma interleukin 18, interleukin 1 receptor antagonist, matrix metalloproteinase 9, neopterin, and C-reactive protein. Results for both treatment groups were pooled and compared with placebo.

RESULTS

Antihypertensive treatment with either agent significantly lowered diastolic blood pressure (-4.7 vs placebo 1.3 mm Hg, P = .002) and progression of coronary atheroma (Δ percent atheroma volume 0.6 vs placebo 2.1, P = .031). Antihypertensive therapy did not affect plasma biomarkers of inflammation or plaque remodeling in the 135 subjects with baseline and 2-year biomarker samples. Progression in percent atheroma volume was significantly less in subjects taking statins at baseline (-2.5%, P = .0008).

CONCLUSIONS

In patients with coronary artery disease and well-controlled risk factors, antihypertensive therapy lowered blood pressure and progression of coronary atherosclerosis but did not affect plasma biomarkers of inflammation and remodeling. Antihypertensives may decrease atheroma progression by mechanisms other than those reflected by these plasma biomarkers.

Statin treatment for coronary artery plaque composition based on intravascular ultrasound radiofrequency data analysis

BACKGROUND

Systemic therapy with statin has been shown to lower the risk of coronary events; however, the in vivo effects of statin therapy on plaque volume and composition are less understood.

METHODS

We conducted a prospective, open-labeled, randomized, multicenter study in 11 centers in Japan. A total of 164 patients were randomized to receive either 4 mg/d of pitavastatin (intensive lipid-lowering therapy) or 20 mg/d of pravastatin (moderate lipid-lowering therapy). Analyzable intravascular ultrasound data were obtained for 119 patients at baseline and at 8-month follow-up. The primary end point was the difference of volume changes in each of the 4 main plaque components (fibrosis, fibrofatty, calcium, and necrosis), assessed by virtual histology intravascular ultrasound, between the 2 groups.

RESULTS

The mean low-density lipoprotein cholesterol level at follow-up was significantly lower in the pitavastatin than in the pravastatin group (74 vs 95 mg/dL, P < .0001). During the 8-month follow-up period, statin therapy reduced the absolute and relative amount of fibrofatty component (pitavastatin: from 1.09 to 0.81 mm(3)/mm, P = .001; pravastatin: from 1.05 to 0.83 mm(3)/mm, P = .0008) and increased in the amount of calcium (pitavastatin: from 0.42 to 0.55 mm(3)/mm, P < .0001; pravastatin: from 0.44 to 0.55 mm(3)/mm, P = .005), whereas volume changes in both plaque components were not statistically different between the 2 groups.

CONCLUSIONS

Both pitavastatin and pravastatin altered coronary artery plaque composition by significantly decreasing the fibrofatty plaque component and increasing the calcified plaque component.

Current management of symptomatic intracranial stenosis

Intracranial arterial stenosis (IAS) is the cause of about 10% of all ischemic strokes in the United States, but may account for about 40% of strokes in some populations. After a stroke or transient ischemic attack due to IAS, patients face a 12% annual risk of recurrent stroke on medical therapy, with most strokes occurring in the first year. Warfarin is no better than aspirin in preventing recurrent strokes but poses a higher risk of serious bleeding and death. Groups with the highest risk of recurrent stroke are those with high-grade (≥ 70%) stenosis, those with recent symptom onset, those with symptoms precipitated by hemodynamic maneuvers, and women. Endovascular treatment of IAS is a rapidly evolving therapeutic option. Antiplatelet agents are currently recommended as the primary treatment for symptomatic IAS, with endovascular therapy reserved for appropriate high-risk cases refractory to medical therapy.