Statins: An essential component in the management of carotid artery disease

Barriers to Antiplatelet and Statin Adherence Following Major Vascular Intervention

BACKGROUND

Antiplatelets and statins therapies are associated with improved cardiovascular outcomes following major vascular intervention. Many vascular surgery institutions are reporting improved prescribing rates for aspirin (ASA), P2Y12 antagonists, and statins. Nevertheless, there remains limited publication describing rates and patient-perceived barriers for postoperative adherence. The purpose of this study is to investigate patient nonadherence to antiplatelet and statin therapies following major vascular intervention.

METHODS

A retrospective review of patients who underwent major vascular intervention at a single academic center was performed. The prescribing rates of ASA, P2Y12 antagonists, and statins were reviewed. Postoperative adherence, defined as consistent intake as prescribed, was evaluated at 1, 3, 6, 9, and 12 months using electronic documentation of both follow-up clinic appointments and phone call assessments, then corroborated with pharmacy fulfilment records. Patient-reported barriers to medication adherence were also examined.

RESULTS

A total of 101 subjects underwent major vascular intervention between January 2020 and July 2020, 98% of whom were discharged on at least 1 antiplatelet or statin agent. Approximately 90% of patients were discharged with ASA, 32% with a P2Y12 antagonist, and 96% with a statin. All patients who maintained adherence up to 6 months continued to report adherence at 9 and 12 months. Consistent adherence at 12 months was documented in 76% of patients on ASA, 81% on P2Y12 antagonism therapy, and 73% on statins. New adverse drug reactions represented the most common barrier to achieving adherence (37% [n = 20]). Preoperative therapy with ASA, P2Y12 antagonists, and statins were all independently predictive of postoperative adherence to the same regimen (P ≤ 0.001). The female gender was also associated with higher rates of adherence to postoperative P2Y12 antagonism therapy (P ≤ 0.05).

CONCLUSIONS

The current prescribing rates for antiplatelet and statin agents are promising, but postoperative nonadherence remains a multifaceted issue.

Short-Term Statin Treatment Reduces, and Long-Term Statin Treatment Abolishes, Chronic Vascular Injury by Radiation Therapy

BACKGROUND

The incidental use of statins during radiation therapy has been associated with a reduced long-term risk of developing atherosclerotic cardiovascular disease. We examined whether irradiation causes chronic vascular injury and whether short-term administration of statins during and after irradiation is sufficient to prevent chronic injury compared with long-term administration.

METHODS AND RESULTS

C57Bl/6 mice were pretreated with pravastatin for 72 hours and then exposed to 12 Gy X-ray head-and-neck irradiation. Pravastatin was then administered either for an additional 24 hours or for 1 year. Carotid arteries were tested for vascular reactivity, altered gene expression, and collagen deposition 1 year after irradiation. Treatment with pravastatin for 24 hours after irradiation reduced the loss of endothelium-dependent vasorelaxation and protected against enhanced vasoconstriction. Expression of markers associated with inflammation (NFκB p65 [phospho-nuclear factor kappa B p65] and TNF-α [tumor necrosis factor alpha]) and with oxidative stress (NADPH oxidases 2 and 4) were lowered and subunits of the voltage and Ca2+ activated K+ BK channel (potassium calcium-activated channel subfamily M alpha 1 and potassium calcium-activated channel subfamily M regulatory beta subunit 1) in the carotid artery were modulated. Treatment with pravastatin for 1 year after irradiation completely reversed irradiation-induced changes.

CONCLUSIONS

Short-term administration of pravastatin is sufficient to reduce chronic vascular injury at 1 year after irradiation. Long-term administration eliminates the effects of irradiation. These findings suggest that a prospective treatment strategy involving statins could be effective in patients undergoing radiation therapy. The optimal duration of treatment in humans has yet to be determined.

What are the benefits and drawbacks of statins in carotid artery disease? A perspective review

INTRODUCTION

The prevalence of carotid artery stenosis in the general population is approximately 3%, but approximately 20% among people with acute ischemic stroke. Statins are recommended by multiple international guidelines as the drug of choice for lipid control in people with asymptomatic or symptomatic carotid artery stenosis due to their lipid-lowering and other pleiotropic effects.

AREAS COVERED

This review discusses the guidelines for statin usage as a cornerstone in the prevention and management of atherosclerotic carotid artery disease and the impact of statins on stroke incidence and mortality. Statin side effects, alternative therapy, and genetic polymorphisms are reviewed.

EXPERT OPINION

Statin therapy is associated with a decreased incidence of stroke and mortality as well as improved outcomes for patients treated with carotid revascularization. Statins are a safe and effective class of medications, but the initiation of therapy warrants close monitoring to avoid rare and potentially serious side effects. Lack of clinical efficacy or the presence of side effects suggests a need for treatment with an alternative therapy such as PCSK9 inhibitors. Understanding the interplay between the mechanisms of statins and PCSK9 inhibition therapies will allow optimal benefits while minimizing risks. Future research into genetic polymorphisms may improve patient selection for personalized therapy.

Association of Statin and Antiplatelet Use with Survival in Patients with AAA with and without Concomitant Atherosclerotic Occlusive Disease

BACKGROUND

Statin therapy has been associated with improved clinical outcomes in patients undergoing treatment for vascular disease. Current guidelines do not address statin therapy in isolated abdominal aortic aneurysm (AAA) in the absence of other atherosclerotic cardiovascular disease (ASCVD). This study aims to elucidate effects of statin therapy, either as monotherapy or combined with antiplatelet agents, on the long-term mortality of patients with and without ASCVD who undergo elective AAA repair.

METHODS

A retrospective review was performed on all AAA patients treated electively with endovascular (EVAR) and open aortic repair (OAR) in the Society for Vascular Surgery Vascular Quality Initiative from 2003-2020. Long-term mortality was evaluated based on the presence of statin and antiplatelet medication use at discharge stratified by those with and without a history of ASCVD. Unadjusted survival was estimated by Kaplan Meier methodology. Cox proportional hazards modeling was used to determine mortality risk after adjusting for key factors.

RESULTS

A total of 47,012 AAA repairs were selected for analysis: 80.7% EVAR (N = 40,153) and 19.3% OAR (N = 6,859). EVAR patients on combined statin/antiplatelet (AP) therapy had significantly better survival irrespective of whether they had known ASCVD. In the presence of ASCVD, EVAR patients on statin alone had improved survival compared to those not on a statin (10.9 ± 0.5 vs. 10.5 ± 0.4 years, Log Rank < 0.001), with survival being even greater among those receiving combined statin/AP therapy (12.2 ± 0.2 vs. 10.5 ± 0.4 years, Log Rank < 0.001). In the absence of ASCVD, EVAR patients on statin alone also had better mean survival compared to patients not on a statin (8.7 ± 0.5 vs. 8.4 ± 0.4 years, Log Rank<.001), with higher survival among statin/AP therapy patients (9.4 ± 0.2 years vs. 8.7 ± 0.5 years, Log Rank < 0.001). Comparison of adjusted survival via Cox multivariable regression demonstrated a protective effect of statins (HR = 0.737, P = 0.04, vs. no medication) and combined statin/AP therapy (HR = 0.659, P = 0.001, vs no medication) in patients with ASCVD history. A similar protective effect (statin: HR 0.826, P = 0.05. Combination statin/AP: HR 0.726, P < 0.001, vs. no medication) was identified in patients without ASCVD history. Within the OAR cohort, statin therapy was not associated with improved survival among patients without ASCVD; however, combined statin/AP therapy had a protective effect for patients with a known ASCVD diagnosis. Based on KM analysis, OAR patients with ASCVD on combined statin/AP therapy had significantly higher mean survival compared to isolated statin therapy (12.7 ± 0.2 vs. 10.3 ± 0.65 years) and no medical therapy (10.5 ± 0.8 years, Log Rank < 0.001). In KM analysis, OAR patients without known ASCVD indications (N = 3591) had no significant survival differences based on the presence of combined statin/AP therapy (8.4 ± .07 vs. 8.5 ± .11 years, Log Rank = 0 638).

CONCLUSION

Isolated statin therapy and combined statin/AP therapy showed significant survival benefit in all EVAR and OAR patients with ASCVD indications, as well as among EVAR patients without a known ASCVD diagnosis. OAR patients without ASCVD did not have a significant survival benefit from statin therapy, but low numbers in this group may have confounded the findings. Combined statin/AP therapy appears to have significant post-repair survival benefits even in isolated AAA without ASCVD, as demonstrated in post-EVAR patients in this study. Expansion of statin use recommendations within aneurysm treatment guidelines may be warranted.

Effects of Neck Radiation on Result of Doppler Sonography of Carotid Arteries in Head and Neck Cancer Patients

PURPOSE

The aim of this study was to assess the effects of neck radiation on the results of Doppler sonography of carotid arteries in head and neck cancer patients.

METHODS

In this prospective, cross-sectional study, 25 consecutive patients with head and neck cancers were assessed for carotid artery stenosis (CAS) by carotid color Doppler sonography before external radiotherapy and six months after external radiotherapy. Main outcome measures were peak systolic velocity (PSVs), end-diastolic velocities (EDVs) of the internal carotid artery (ICA), ICA/common carotid (CCA) ratios, and degree of stenosis.

RESULTS

The age of the enrolled patients at the initiation of radiotherapy was 57.9±11.8 years (mean±SD; range, 43-91 years), and only 4 (16%) of the 25 patients were female. The findings showed significant changes in the plaque degree and stenosis degree, and plaque size before and after external radiotherapy (P<0.05). Changes in degree of stenosis were significantly correlated with age (p=0.021).

CONCLUSION

After neck irradiation changes in the carotid artery may occur and cause subsequent neurologic events.

Cholesterol, carotid artery disease and stroke: what the vascular specialist needs to know

Hypercholesterolemia is a risk factor for carotid artery stenosis and stroke. Statins are the main drugs for the management of hypercholesterolemia and they are strongly recommended by international guidelines for the management of vascular patients. The present review will focus on the associations between cholesterol, carotid artery stenosis and stroke and will cover several topics, including the conservative and perioperative/periprocedural management of carotid patients, the effect of statins on contrast-induced nephropathy developing after endovascular carotid interventions, the role of statin loading prior to endovascular procedures, as well as the indirect beneficial effects of statin treatment on renal function. It will also discuss the topics of statin intolerance and alternative cholesterol-lowering options for statin-intolerant vascular patients. Cholesterol levels play a prognostic role in carotid patients with regards to both short- and long-term stroke and mortality rates. Physicians should keep in mind the pivotal role of cholesterol levels in determining cardiovascular outcomes and the pleiotropic beneficial effects associated with statin use and should not miss the opportunity for cardiovascular risk reduction with aggressive statin treatment.

Controlling the thickness of the atherosclerotic plaque by statin medication

Atherosclerosis, a chronic inflammatory disorder of the arterial wall, is a complex process whose dynamics are affected by multiple factors. The disease control consists of restraining it by administering statins. Slowing down or halting the plaque growth depends on the patient age at which the statin treatment begins and on the thickness of the intima-media (IMT) at that time. In this paper, we propose a mathematical model to estimate the sets of atherosclerosis states, from which the use of statins can restrain the disease. Our model is control-theoretic, and the estimated sets are the viability kernels, in the parlance of viability theory. To our best knowledge, this way of modelling the atherosclerosis progression is original. We compute two viability kernels, each for a different statin-treatment dose. Each kernel is composed of the vector [age, IMT] from which the disease can be restrained. By extension, the disease can’t be restrained from the kernel complements, this being mainly because of the disease and patient-age advancement. The kernels visualise tradeoffs between early and late treatments, which helps the clinician to decide when to start the statin treatment and which statin dose may be sufficient.

The case for statin use to reduce perioperative adverse cardiovascular and cerebrovascular events

Ischaemic heart disease and stroke are the leading causes of death worldwide at 119 per 100,000 and 85 per 100,000 population. For the USA, heart disease is leading cause of death at 165 per 100,000 population. In developed countries, strokes and acute myocardial infarction in the general population have fallen from smoking reduction, lifestyle modifications and therapeutic interventions including statins. In a population-based stroke study in the UK involving primary care practices, of in-hospital strokes 90% were ischaemic, and 37% occurred within 1 week of an operation. Approximately 50% of the patients were not on a statin. In the UK, there is a national screening initiative for the prevention of atherosclerotic cardiovascular disease (ASCVD) offered to people aged 40-74 yr old. The QRISK3 tool calculates the risk of developing heart disease or stroke over 10 yr, from which recommendations are made on interventions for the prevention of ASCVD up to age 84 yr, with similar screening and assessment tools in Europe and the US. If the QRISK3 score tool for calculating cardiovascular risk is considered sufficiently robust for population screening in primary care, should anaesthetists not use the same screening for secondary care? We present a case for statin use over the perioperative period, to reduce early vascular adverse events based on statins' early pleiotropic actions, using the primary care QRISK tool for screening of ASCVD risk.

The impact of pre-operative symptoms on carotid endarterectomy Outcomes: Analysis of the ACS-NSQIP carotid endarterectomy database

Carotid artery stenosis accounts for up to 20% of ischemic strokes. Since the 1950 s, one of the primary surgical treatment for this condition is carotid endarterectomy (CEA). Because of improvement of medical therapy for carotid artery atherosclerosis and the increased use of carotid artery stents, CEA is indicated if the risk of stroke and death are low. The goal of this study is to characterize the impact of pre-operative stroke and stroke risk factors on post-operative CEA patient outcomes, using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Targeted Vascular Module on CEA. Using the Targeted Vascular Module of the ACS-NSQIP, 22,116 patients who underwent CEA were identified from 2011 to 2016. Univariate analysis and multivariable logistic regression analyses were conducted to identify significant risk factors that predispose patients to stroke. Patients with pre-operative stroke comprise 42.1% of the group, with post-operative stroke being the second most common complication (2.1%). Pre-operative stroke patients were also at a higher risk for transient ischemic attacks, post-operative restenosis, post-operative distal embolization, and other complications. Patients with pre-operative risk factors, including stroke or stroke-like symptoms, high risk physiologic factors, high risk anatomic factors, and contralateral internal carotid artery stenosis were at a higher risk of developing post-operative stroke and other complications. Patients with these pre-operative risk factors should be closely monitored for post-operative complications in an effort to improve patient outcomes.

Hypoglycemia does not affect the progression of preclinical atherosclerosis in subjects with type 2 diabetes

Introduction

Intensive treatment aimed at achieving optimal metabolic control to prevent the development of chronic diabetic complications is often associated with an increased rate of hypoglycemic events. Hypoglycemia is believed to be responsible for acute fatal and nonfatal cardiovascular events likely as a consequence of the activation of pro-inflammatory and pro-atherothrombotic pathways. Hypoglycemia has been reported to influence the development of preclinical atherosclerosis. The present study was designed to prospectively evaluate whether hypoglycemia influences the function and the morphology of the arteries in subjects with type 2 diabetes without complications and uncontrolled diabetes.

Material and methods

Seventy-six subjects underwent a noninvasive evaluation of carotid wall thickness and brachial artery function at baseline and after one year of treatment with the intent of obtaining optimal glycemic control. At the end of the observation time, subjects were divided in two groups: with hypoglycemia (H-group) or without hypoglycemia (C-group).

Results

Baseline characteristic were comparable between groups. HbA1c significantly decreased in both groups, and fasting plasma glucose was only significant in the H-group. Subjects with hypoglycemia showed a significant reduction of carotid wall thickness after one-year of treatment (H-groups: right baseline 834±141 vs. 1-year 770±132 μ p<0.05; C-group: 757±162 vs. 767±135 μ p = ns). Endothelial function remained unchanged during the study for both groups.

Discussion

The present findings demonstrate that hypoglycemia does not affect endothelial function. Furthermore, subjects who experience more hypoglycemia show significant reduction of carotid wall thickness. Optimal metabolic control should be pursued as soon as possible.

Association Between Total Cholesterol and 5 year Mortality in Patients with Carotid Artery Stenosis and Poststroke Functional Dependence

BACKGROUND

Aggressive lipid-lowering treatment reduces the risk of cardiovascular events, but remains controversial in stroke patients. We investigate the influence of total cholesterol level on 5-year outcomes of ischemic stroke patients with high-grade internal carotid artery (ICA) stenosis and poststroke functional dependence.

METHODS

One-hundred and ninety-six acute ischemic stroke patients with high-grade ICA stenosis and modified Rankin Scale score ≥ 3 upon discharge were enrolled and prospectively observed for 5 years. Patients were divided into 2 groups according to total cholesterol level at admission: ≥200 mg/dL or <200 mg/dL. Demographic features, vascular risk factors, co-morbidities, and outcomes were compared between the 2 groups.

RESULTS

117 (59.7%) patients had higher and 79 (40.3%) patients had lower total cholesterol levels. The prevalence of older age and atrial fibrillation was significantly higher in patients with lower total cholesterol; the prevalence of diabetes mellitus was higher in patients with higher total cholesterol. After adjusting for the established clinical predictors of adverse outcomes, the multivariate Cox regression revealed that lower total cholesterol level is a significant predictor of 5-year mortality (HR (hazard ratio) = 1.88, 95% CI (confidence interval) = 1.09-3.23, P = .023).

CONCLUSIONS

Lower total cholesterol level is associated with increased risk of 5-year mortality in ischemic stroke patients with high-grade ICA stenosis and post-stroke functional dependence. Aggressive treatment of hyperlipidemia should be carefully considered in these patients although it could reduce the risk of atherosclerotic cardiovascular diseases and stroke recurrence in some stroke patients.

Clinical Effect and Cost-Effectiveness of Screening for Asymptomatic Carotid Stenosis: A Markov Model

OBJECTIVE/BACKGROUND

The cost-effectiveness of screening depends on the cost of screening, prevalence of asymptomatic carotid artery stenosis (ACAS), and the potential effect of medical intervention in reducing the risk of stroke. The aim of the study was to determine the threshold values for these parameters in order for screening for ACAS to be cost-effective.

METHODS

The clinical effect and cost-effectiveness of ultrasound screening for ACAS with subsequent initiation of preventive therapy versus not screening was assessed in a Markov model with a lifetime perspective. Key parameters, including stroke risk, all cause mortality, and costs, were based on contemporary published data, population statistics, and data from an ongoing screening program in Uppsala county (population 300,000), Sweden. Prevalence of ACAS (2%) and the rate of best medical treatment (BMT; 40%) were based on data from a male Swedish population recently screened for ACAS. The required stroke risk reduction from BMT, incremental cost-efficiency ratio (ICER), absolute risk reduction for stroke (ARR), and number needed to screen (NNS) were calculated.

RESULTS

Screening was cost-effective at an ICER of €5744 per incremental quality adjusted life year (QALY) gained. ARR was 135 per 100,000 screened, NNS was 741, and QALYs gained were 6700 per 100,000 invited. At a willingness to pay (WTP) threshold of €50,000 per QALY the minimum required stroke risk reduction from BMT was 22%. The assumed degree of stroke risk reduction was the most important determinant of cost-efficiency.

CONCLUSION

A moderate (22%) reduction in the risk of stroke was required for an ACAS screening strategy to be cost-effective at a WTP of €50,000/QALY. Targeting populations with a higher prevalence of ACAS could further improve cost-efficiency.

Changes in the Common Carotid Artery after Radiotherapy: Wall Thickness, Calcification, and Atherosclerosis

BACKGROUND AND PURPOSE

Since the long-term survival rate has improved in laryngeal cancer patients who receive radiotherapy, concerns about postradiation complications (including carotid atherosclerosis) have increased. We followed changes in the common carotid artery (CCA) after radiotherapy and identified the underlying risk factors.

METHODS

Consecutive patients with laryngeal cancer who underwent radiotherapy between January 1999 and December 2009 and who had received computed tomography (CT) both pre- and postradiotherapy were enrolled. Changes in the wall thickness and in the vessel and lumen areas as well as the presence of calcification or atherosclerosis were investigated. Demographics and risk factors were compared between patients with and without atherosclerosis at follow-up CT.

RESULTS

In total, 125 patients were enrolled. The wall thickness had increased and the lumen area had decreased several months after radiotherapy. These changes were not associated with vascular risk factors and were not progressive. Calcification and atherosclerosis were observed in 37 (29.6%) and 71 (56.8%) patients, respectively. Diabetes was associated with calcification (p=0.02). The prevalence of hyperlipidemia was higher in patients with atherosclerosis (28.2% vs. 11.1%, p=0.02) and for a longer period postradiation [62.7±32.1 vs. 40.0±24.2 months (mean±SD), p<0.001]. Atherosclerosis occurred mostly in the middle portion of the CCA (n=31, 24.6%), followed by the proximal CCA at the intrathoracic level (n=26, 20.6%) and the distal CCA (n=6, 4.8%). Positive remodeling was also observed, but this was less common in patients with calcification (p=0.02).

CONCLUSIONS

Various types of postradiation changes occur in the CCA and can be easily observed in postradiation CT. The prevalence and burden of postradiation atherosclerosis increased in a close relationship with baseline cholesterol levels and the time after radiotherapy. Postradiation atherosclerosis was observed at unusual sites of the CCA.

An update on the incidence of perioperative outcomes after carotid endarterectomy, stratified by type of preprocedural neurologic symptom

OBJECTIVE

Perioperative complications after carotid endarterectomy (CEA) have decreased over time. Therefore, we aimed to provide an update on 30-day outcomes after CEA, stratified by type of preprocedural neurologic symptom.

METHODS

We included all CEAs from the Targeted Vascular module of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP, 2011-2015) and stratified patients based on type of preprocedural neurologic symptom, that is, asymptomatic, ocular transient ischemic attack (TIA), hemispheric TIA, and stroke. We compared 30-day outcomes across the groups, with 30-day stroke/death as our primary endpoint.

RESULTS

Of 16,739 CEA patients, 9784 were asymptomatic (58%). Among the 6955 symptomatic patients, 1216 (17%) had a preprocedural ocular TIA, 2635 (38%) a preprocedural hemispheric TIA, and 3104 (45%) a preprocedural stroke. Preprocedural stroke patients had higher 30-day stroke/death rates compared with those with a preprocedural hemispheric TIA, or ocular TIA, or asymptomatic patients (5.0% vs 3.3%, 1.9%, and 1.8%, respectively; all P < .001), primarily owing to differences in perioperative 30-day stroke rates, with 4.1% vs 2.5%, 1.4%, and 1.3%, respectively (all P < .001).

CONCLUSIONS

Among symptomatic CEA patients, those with a preprocedural stroke had a high perioperative 30-day stroke/death rate, compared with those patients with either a preprocedural hemispheric or ocular TIA. Therefore, the common stratification applied to CEA patients, which groups all symptomatic patients, should be avoided, especially as the relative proportion of symptomatic patients with a preprocedural stroke vs those with a hemispheric or ocular TIA will affect the overall outcome for all symptomatic patients after CEA.

2017 Position Paper of the Italian Society for Cardiovascular Prevention (SIPREC) for an Updated Clinical Management of Hypercholesterolemia and Cardiovascular Risk: Executive Document

The benefits achieved by implementing cardiovascular prevention strategies in terms of reduced incidence of atherosclerotic diseases and mortality are accepted, worldwide. In particular, the clinical management of hypercholesterolemia has a fundamental role for all preventive strategies, both in primary and secondary prevention, at each stage of cardiovascular risk. Since the net clinical benefit of lipid-lowering therapy largely depends on baseline individual cardiovascular risk profile, the assessment of individual risk is essential to establish type and intensity of both preventive and therapeutic strategies. Thus, the real challenge in a setting of clinical practice is not only to identify whom to treat among individuals at low-to-moderate risk, but mostly how much and how long to treat high or very-high risk patients. This manuscript, which reflects concepts and positions that have been published in a more extensive document of the Italian Society for Cardiovascular Prevention (SIPREC), deals with the diagnostic and therapeutic management of patients with dyslipidaemia, with an evidence-based approach adapted and updated from recent guidelines of the European Society of Cardiology and very recent results of randomized clinical trials. The purpose is to suggest a multidimensional and integrated actions aimed at eliminating or minimizing the impact of cardiovascular diseases and their related disabilities and mortality in patients with hypercholesterolemia.

Evidence-Based Carotid Interventions for Stroke Prevention: State-of-the-art Review

Carotid artery stenosis is responsible for between 10-20% of all ischaemic strokes. Interventions, such as carotid endarterectomy and carotid stenting, effectively reduce the risk of stroke in selected individuals. This review describes the history of carotid interventions, and summarises reliable evidence on the safety and efficacy of these interventions gained from large randomised clinical trials.Early trials comparing carotid endarterectomy to medical therapy alone in symptomatic patients, and asymptomatic patients, demonstrated that endarterectomy halved the risk of stroke and perioperative death in these two unique populations. The absolute risk reduction was smaller in the asymptomatic carotid trials, consistent with their lower absolute stroke risk. More recent trials in symptomatic patients, suggest that carotid stenting has similar long term durability to carotid endarterectomy, but possibly has higher procedural hazards dominated by non-disabling strokes. The Asymptomatic Carotid Surgery Trial-2, along with individual patient data meta-analysis of all asymptomatic trials, will provide reliable evidence for the choice of intervention in asymptomatic patients in whom a decision has been made for carotid revascularisation. Given improvements in effective cardiovascular medical therapy, in particular lipid-lowering medications, there is renewed uncertainty as to whether carotid interventions still provide meaningful net reductions in stroke risk in asymptomatic populations. Four large trials in Europe and the US are currently underway, and are expected to report long-term results in the next decade.It is essential that surgeons, interventionalists, and physicians continue to randomise large numbers of patients from around the world to clarify current uncertainty around the management of asymptomatic carotid stenosis.

Appropriate Patient Selection for Carotid Revascularization Procedures is Urgently Needed

The identification/selection of appropriate patient subgroups with asymptomatic carotid artery stenosis and the performance of prophylactic carotid endarterectomy (CEA)/carotid artery stenting (CAS) exclusively on these asymptomatic patient subgroups is currently one of the "hottest" topics in vascular surgery. It is now clear that offering CEA/CAS to asymptomatic carotid patients based only on the degree of carotid stenosis is unjustified and scientifically flawed. On the other hand, offering only best medical therapy to every asymptomatic patient, irrespective of certain high-risk criteria (such as the detection of microemboli by transcranial Doppler, intraplaque hemorrhage, silent embolic infarcts on brain computed tomography/magnetic resonance imaging, elevated biomarkers, family history), is equally wrong. The validation of specific measures to identify those asymptomatic patients at high risk for developing symptoms is crucial to achieve optimal use of carotid interventions and avoid wasting stroke prevention resources.

Simplified ultrasound protocol for the exclusion of clinically significant carotid artery stenosis

OBJECTIVES

To evaluate a simplified ultrasound protocol for the exclusion of clinically significant carotid artery stenosis for screening purposes.

MATERIAL AND METHODS

A total of 9,493 carotid arteries in 4,748 persons underwent carotid ultrasound examination. Most subjects were 65-year-old men attending screening for abdominal aortic aneurysm. The presence of a stenosis on B-mode and/or a mosaic pattern in post-stenotic areas on colour Doppler and maximum peak systolic velocity (PSV) in the internal carotid artery (ICA) were recorded. A carotid stenosis was defined as The North American Symptomatic Carotid Endarterectomy Trial (NASCET) >20% and a significant stenosis as NASCET >50%. The kappa (κ) statistic was used to assess agreement between methods. Sensitivity, specificity, positive predictive (PPV), and negative predictive (NPV) values were calculated for the greyscale/mosaic method compared to conventional assessment by means of PSV measurement.

RESULTS

An ICA stenosis was found in 121 (1.3%) arteries; 82 (0.9%) were graded 20%-49%, 16 (0.2%) were 50%-69%, and 23 (0.2%) were 70%-99%. Eighteen (0.2%) arteries were occluded. Overall, the greyscale/mosaic protocol showed a moderate agreement with ICA PSV measurements for the detection of carotid artery stenosis, κ = 0.455. The sensitivity, specificity, PPV, and NPV for detection of >20% ICA stenosis were 91% (95% CI 0.84-0.95), 97% (0.97-0.98), 31% (0.26-0.36), and 97% (0.97-0.97), respectively. The corresponding figures for >50% stenosis were 90% (0.83-0.95), 97% (0.97-0.98), 11% (0.08-0.15), and 100% (0.99-1.00).

CONCLUSION

Compared with PSV measurements, the simplified greyscale/mosaic protocol had a high negative predictive value for detection of >50% carotid stenosis, suggesting that it may be suitable as a screening method to exclude significant disease.

Risk Factors for Silent Lacunar Infarction in Patients with Transient Ischemic Attack

Background

Lacunar infarctions represent 25% of ischemic strokes. Lacunar stroke and transient ischemic attack (TIA) share a number of symptoms. This study aimed to assess the potential risk factors for lacunar infarction in patients with TIA.

Material/Methods

This was a retrospective study performed at the Beijing Military General Hospital in patients with TIA admitted between March 2010 and December 2011. Patients were grouped according to lacunar vs. no lacunar infarction. All patients were diagnosed using diffusion-weighted imaging (DWI) on brain magnetic resonance imaging (MRI). Brain angiography (computed tomography and MRI) was used to measure intracranial stenosis. Carotid artery stenosis was measured by ultrasound.

Results

Patients with TIA and lacunar infarction (n=298) were older than those without lacunar infarction (n=157) (69.4±10.0 vs. 58.9±9.0 years, P<0.001) and showed a higher frequency of males (51.7% vs. 41.4%, P=0.037), hypertension (75.3% vs. 45.9%, P<0.001), diabetes (32.6% vs. 21.0%, P=0.010), hyperlipidemia (53.4% vs. 29.3%, P<0.001), carotid stenosis (73.2% vs. 40.1%, P<0.001), and intracranial stenosis (55.6% vs. 31.9%, P<0.001), but a lower frequency of alcohol drinking (8.1% vs. 14.0%, P=0.045). Lacunar infarction mostly involved the anterior circulation (62.8%). Multivariate analysis showed that age (odds ratio (OR)=1.085, 95% confidence interval (95%CI): 1.054–1.117, P<0.001), hypertension (OR=1.738, 95%CI: 1.041–2.903, P=0.035), hyperlipidemia (OR=2.169, 95%CI: 1.307–3.601, P=0.003), and carotid stenosis (OR=1.878, 95%CI: 1.099–3.206, P=0.021) were independently associated with lacunar infarction.

Conclusions

Age, hypertension, hyperlipidemia, and carotid stenosis were independently associated with silent lacunar infarction in patients with TIA.

Definition of Best Medical Treatment in Asymptomatic and Symptomatic Carotid Artery Stenosis

Implementation of best medical treatment (BMT) is the cornerstone of the management of patients with either asymptomatic or symptomatic carotid artery stenosis. We review the literature to define the components of BMT. Smoking cessation, maintaining a healthy body weight, moderate exercise, and a Mediterranean diet are essential lifestyle measures. Moderate alcohol consumption may also be beneficial but recommending it to patients may be hazardous if they consume too much. The importance of lifestyle measures is largely underestimated by both physicians and patients. Blood pressure and diabetes control, antiplatelet agents, and lipid-lowering treatment with statins/ezetimibe comprise the pharmacological components of BMT. Initiation of an intensive regimen of BMT is a sine qua non for patients with carotid artery stenosis whether or not they are offered or undergo an invasive revascularization procedure.

Issues to Be Addressed and Hopefully Resolved in the Carotid Revascularization Endarterectomy Versus Stenting Trial 2

The superiority of carotid endarterectomy (CEA) plus best medical treatment (BMT) over BMT alone for the management of patients with asymptomatic carotid stenosis is based on randomized controlled trials that recruited patients up to 30 years ago. Best medical treatment has improved considerably since that time with respect to stroke prevention. Furthermore, a new carotid intervention has emerged during the last 2 decades and has gradually become established, that is, carotid artery stenting (CAS). Consequently, the efficacy of current BMT alone needs to be compared not only with CEA plus BMT but also with CAS plus BMT to determine which strategy achieves the optimal stroke prevention rates. This article highlights the purpose of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) 2 and discusses the issues that CREST-2 will hopefully provide answers to.

Do the Effects of Secondary Prevention of Cardiovascular Events in PAD Patients Differ from Other Atherosclerotic Disease?

Atherosclerosis is considered a generalized disease. Similar or identical etiopathogenetic mechanisms and risk factors are involved in various atherosclerotic diseases, and the positive effects of preventive measures on atherogenesis in different parts of the arterial system were shown. However, until know, great emphasis has been placed on the aggressive pharmacological management of coronary artery disease (CHD), while less attention has been devoted to the management of peripheral arterial disease (PAD), despite its significant morbidity and mortality. Data on the efficacy of preventive measures in PAD patients have mostly been gained from subgroup analyses from studies devoted primarily to the management of coronary patients. These data have shown that treatment of risk factors for atherosclerosis with drugs can reduce cardiovascular events also in patients with PAD. The effects of some preventive procedures in PAD patients differ from coronary patients. Aspirin as a basic antiplatelet drug has been shown to be less effective in PAD patients than in coronary patients. The latest Antithrombotic Trialists' Collaboration (ATC) meta-analysis demonstrates no benefit of aspirin in reducing cardiovascular events in PAD. Statins reduce cardiovascular events in all three of the most frequently presented cardiovascular diseases, including PAD to a comparable extent. Recent studies indicate that in PAD patients, in addition to a reduction in cardiovascular events, statins may have some hemodynamic effects. They prolong walking distance and improve quality of life. Similarly, angiotensin enzyme inhibitors are also effective in the prevention of cardiovascular events in coronary, cerebrovascular, as well as PAD patients and show positive effects on the walking capacity of patients with intermittent claudication. In PAD patients, the treatment of hypertension and diabetes also effectively prevents cardiovascular morbidity and mortality. As PAD patients are at a highest risk of cardiovascular complications, the risk factors of atherosclerosis should be treated intensively in this group of patients. Most of the preventive measures, including the drugs used for prevention of CHD, are also effective in PAD patients.

HIV-associated large-vessel vasculopathy: a review of the current and emerging clinicopathological spectrum in vascular surgical practice

An established relationship exists between human immunodeficiency virus (HIV) and the vascular system, which is characterised by clinical expressions of aneurysmal and occlusive disease that emanate from a common pathological process. The exact pathogenesis is currently unknown; attempts to implicate opportunistic pathogens have been futile. Theories converge on leucocytoclastic vasculitis with the vaso vasora as the vasculopathic epicentre. It is thought that the virus itself or viral proteins trigger the release of inflammatory mediators that cause endothelial dysfunction and smooth muscle proliferation leading to vascular injury and thrombosis. The beneficial effects of highly active anti-retroviral therapy alter the natural history of the disease profile and promote longevity but are negated by cardiovascular complications. Atherosclerosis is an emerging challenge. Presently patients are managed by standard surgical protocols because of non-existent universal surgical interventional guidelines. Clinical response to treatment is variable and often compounded by complications of graft occlusion, sepsis and poor wound healing. The clinical, imaging and pathological observations position HIV-associated large-vessel vasculopathy as a unique entity. This review highlights the spectrum of HIV-associated large-vessel aneurysmal, occlusive and atherosclerotic disease in vascular surgical practice.

Best evidence for medical therapy for carotid artery stenosis

Carotid atheromatous disease is an important cause of stroke and represents a key target in stroke prevention. Randomized trials have shown the efficacy of carotid endarterectomy in secondary stroke prevention. Carotid stenting presents a less invasive alternative to surgical intervention. Advances in medical management, if compliance can be ensured, are leading to improvement in outcomes when implemented as sole therapy in the treatment of atherosclerotic carotid stenosis. This includes lifestyle modification, blood pressure control, and antiplatelet and statin therapy. Over the last 20 years, the annual rate of ipsilateral stroke associated with asymptomatic carotid stenosis has decreased from 2% to 4% to less than 1%. This is largely due to improvements in medical therapy. However, despite numerous trials and years of clinical research, the optimal management of symptomatic and asymptomatic carotid disease remains controversial. This article presents and summarizes the evidence supporting best medical treatment for carotid artery stenosis.

Optimal statin type and dosage for vascular patients

Statins are an essential component of the management of patients suffering from vascular diseases. As there is neither any consensus nor any guidelines regarding this issue, we aimed to define the optimal statin type and dosage for these patients. MEDLINE was searched for studies comparing different statin types and dosages for vascular patients. In the absence of adverse effects, rosuvastatin or atorvastatin ≥ 20 mg/d is the optimal statin type and dosage for vascular patients. The management of statin-induced adverse events and the options for statin-intolerant patients are also discussed. Routine statin treatment is associated with several beneficial effects in vascular patients whether managed conservatively or undergoing open vascular surgery/endovascular interventions. If possible, statins should not be discontinued before open or endovascular procedures and treatment should be resumed as soon as possible. Future studies should evaluate the effects of an increased statin loading dose prior to vascular procedures.

Serum leptin levels in patients undergoing carotid endarterectomy: a pilot study

INTRODUCTION

Elevated serum leptin levels are associated with cardiovascular events. We investigated the role of serum leptin in patients undergoing carotid endarterectomy (CEA).

METHODS

A total of 74 patients (55 men; 38 symptomatic and 36 asymptomatic; mean age 66.9 +/- 8.2 years) undergoing CEA for >70% carotid artery stenosis were enrolled.

RESULTS

Serum leptin levels were lower in symptomatic compared with asymptomatic patients (7.1 +/- 1.3 vs 14.4 +/- 4.7 ng/dL; P < .001). Interleukin-6 (IL-6) levels were higher in symptomatic compared with asymptomatic patients (4.3 +/- 1.7 vs 3.3 +/- 1.1 pg/dL; P = .017). Symptomatic patients had more intense macrophage accumulation (0.7% +/- 0.1% vs 0.3% +/- 0.1%; P < .001). Serum leptin and serum IL-6 levels were independently associated with the presence of symptoms in multivariate analysis.

CONCLUSION

Serum leptin levels were decreased in symptomatic carotid artery disease. This finding requires further investigation in larger studies.

The GALA Trial: Will It Influence Clinical Practice?

The General Anesthesia vs. Local Anesthesia for Carotid Surgery (GALA) trial did not show a difference in 30-day postoperative stroke, myocardial infarction and death rates between patients undergoing carotid endarterectomy (CEA) under local vs. general anesthesia. The present article discusses some limitations of the GALA trial. Firstly, the expected stroke and death rates following CEA is so low, that it was unlikely that the GALA trial would show any significant difference between local and general anesthesia. Secondly, preoperative statin use was not recorded. Thirdly, intraoperative shunt usa ge rates (a possible parameter for the development of stroke) varied considerably between the 2 groups (43% vs. 14%, for general vs. local anesthesia, respectively; P < .0001), as well as between UK and non-UK surgeons who always (73.6% vs. 20.8%, respectively; P < .0001), never (4.2% vs. 26%, respectively; P < .0002), or selectively (22.2% vs. 53.2%, respectively; P < .0001) used a shunt. Furthermore, no information was provided regarding the type of shunts used; for example, atraumatic shunts may be associated with lower perioperative stroke rates. These limitations could influence the interpretation of the results of the GALA trial. Due to lack of differences between the 2 groups and the presence of the above limitations, it seems likely that this trial will have little effect on clinical practice.

Statins and venous thromboembolism: a novel effect of statins?

Statins play a key role in the management of hypercholesterolemia and other dyslipidemias. However, statins exert several other actions, often referred to as 'pleiotropic'. This Editorial looks at the JUPITER trial (Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin), examining, in particular, the occurrence of venous thromboembolism in the rosuvastatin and placebo groups, and discussing these findings in the context of the current literature. The authors conclude that statin use could perhaps be associated with reductions in the risk of venous thromboembolism, and call for further appropriately designed studies.

Effect of pravastatin on experimental diabetic wound healing

BACKGROUND

Impaired wound healing in diabetes has been associated with abnormalities in wound nitric oxide (NO) and nitric oxide synthase (NOS) availability. Efforts to alter the profile of NO expression in the wound microenvironment have proven to be successful in partially restoring wound healing deficits. We investigated the effects of pravastatin, a HMG Co A reductase inhibitor on endothelial nitric oxide synthase (eNOS) expression, NO production, and wound healing in a diabetic acute wound healing model.

MATERIALS AND METHODS

Of 70 male Sprague Dawley rats injected with streptozocin, 62 were confirmed diabetic after 1 wk. Animals were randomized into two groups: (1) diabetic control and (2) diabetic treated with pravastatin. Pravastatin sodium was gavaged at 0.4 mg/kg/d for 5 d, after which all animals underwent dorsal incision with insertion of subcutaneous sponges. Breaking strengths and hydroxyproline were measured on days 1, 3, and 10 post-wounding. Wound fluid was analyzed for nitrate/nitrite production. Tissue samples were analyzed for eNOS expression.

RESULTS

We demonstrated enhanced wound breaking strengths, hydroxyproline accumulation, an up-regulation in eNOS expression, and elevated NO levels in the pravastatin treated group.

CONCLUSION

We have shown that pravastatin, in an experimental model of diabetes may through up-regulation of eNOS and NO expression improve wound healing.

Prevalence of hypoechoic carotid plaques in coronary artery disease: relationship with coexistent peripheral arterial disease and leukocyte number

Abstract

In coronary artery disease (CAD), a concomitant peripheral arterial disease (PAD) entails a more severe coronary atherosclerosis. We hypothesized that the severity of carotid artery disease is greater in CAD+PAD than in CAD alone. In 90 CAD and 79 CAD+PAD patients, carotid plaque echolucency was measured by gray-scale median (GSM), and the degree of carotid stenosis by routine Doppler criteria. Plaques were absent in 20 (22.2%) CAD and 8 (10.1%) CAD+PAD patients ( p = 0.035), while the prevalence of carotid stenosis ≥ 50% was 16.7% and 25.3%, respectively ( p = 0.166). The GSM score was 45.1 [21.7–67.7] in CAD+PAD vs 60.1 [44.9–83.1] in CAD alone ( p < 0.001). Consistently, hypoechoic plaques (GSM < 25th percentile) were more common in CAD+PAD than in CAD patients (38.0% vs 11.4%, p < 0.001). On multivariate analysis, CAD+PAD was the only variable significantly associated with hypoechoic plaques (OR = 4.16, 95% CI 1.68–10.28). However, when the leukocyte count was added to the model, it showed the strongest association with hypoechoic plaques (OR = 6.70, 95% CI 2.13–21.10). In conclusion, compared with CAD alone patients, those with concomitant PAD showed a greater prevalence of plaques with characteristics of instability. Thus, our data suggest that in CAD+PAD, evaluation of carotid plaque echogenicity could contribute to improve clinical decision-making and differentiate treatments for individual patients.