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.

Functional MRI evaluation of the effect of carotid artery stenting: a case study demonstrating cognitive improvement

Background

The narrowing of the carotid arteries with plaque formation represents a major risk factor for ischemic stroke and cognitive impairments. Carotid angioplasty and stenting is a standard clinical treatment to reduce stroke risk. The cognitive effect of carotid angioplasty and stenting remains largely unknown.

Purpose

This study aims to provide direct evidence of possible effects of carotid angioplasty and stenting on cognition, using task-phase functional magnetic resonance imaging.

Material and Methods

This study received harmonized institutional ethics board approval (Grant number REB ID =H18-02495/FHREB 2018-058). Two patients had MRI scans pre-carotid angioplasty and stenting and two-month post-carotid angioplasty and stenting. Case 1 had severe (>95%) flow-limiting stenosis in the right carotid artery. Case 2 had 70% non-flow limiting stenosis in the left carotid artery. At each scan, patients completed two functional magnetic resonance imaging sessions while performing a working memory task. Accuracy, reaction time, and brain activation were analyzed for each patient for possible pre-post carotid angioplasty and stenting changes.

Results

Case 1 showed increased activation in the right (treated-side) frontal and temporal lobes post-carotid angioplasty and stenting; associated with improvements in accuracy (from 58% to 74%) and task completion rate (from 17% to 72%). Case 2 completed the tasks pre- and post-carotid angioplasty and stenting with >90% accuracy, while decreased functional magnetic resonance imaging activation in the contralateral (untreated) hemisphere and mildly increased activation in the left (treated -side) anterior circulation territory were observed post-carotid angioplasty and stenting.

Conclusion

These cases provided the first task-phase functional magnetic resonance imaging data demonstrating that carotid angioplasty and stenting improved cognitive function in the re-perfused vascular territory. The finding supports the role of carotid angioplasty and stenting in improving cognitive performance beyond reducing stroke risk.

Risk factors and preventive measures of cerebral hyperperfusion syndrome after carotid artery interventional therapy

This study sought to investigate the risk factors for cerebral hyperperfusion syndrome (CHS) after carotid artery interventional therapy, and to explore potential preventive measures. Three hundred and eighty-two patients treated with carotid artery stenting at the Huanhu Hospital (Tianjin, China) between January 2010 and January 2016 were divided into CHS and non-CHS groups. A retrospective analysis of patient clinical data was made. The CHS group had more patients presenting coronary heart disease, diabetes, progressive neurological disease and transient recurrent cerebral hemorrhage than the non-CHS group. More patients in the CHS group presented stenosis of the internal carotid artery siphon. More CHS group patients showed plaque formation extending >3 cm to the distal end of the internal carotid artery. Finally, more CHS group patients had pressure gradients >60 mmHg (p<0.05). Logistics regression analysis showed that preoperative diabetes mellitus and carotid pressure gradient ≥60 mmHg were independent risk factors for CHS (p<0.05). The ROC curve of carotid pressure gradients ≥60 mmHg were made to predict CHS, with the area under curve being 0.949 (p<0.05). The best cut-off value was 60 mmHg. Therefore, preoperative diabetes and a carotid pressure gradient ≥60 mmHg are risk factors for CHS, and these indicators need to be examined prior to operation.

Comparative Review of the Treatment Methodologies of Carotid Stenosis

The treatment of carotid stenosis entails three methodologies, namely, medical management, carotid angioplasty and stenting (CAS), as well as carotid endarterectomy (CEA). The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) have shown that symptomatic carotid stenosis greater than 70% is best treated with CEA. In asymptomatic patients with carotid stenosis greater than 60%, CEA was more beneficial than treatment with aspirin alone according to the Asymptomatic Carotid Atherosclerosis (ACAS) and Asymptomatic Carotid Stenosis Trial (ACST) trials. When CAS is compared with CEA, the CREST resulted in similar rates of ipsilateral stroke and death rates regardless of symptoms. However, CAS not only increased adverse effects in women, it also amplified stroke rates and death in elderly patients compared with CEA. CAS can maximize its utility in treating focal restenosis after CEA and patients with overwhelming cardiac risk or prior neck irradiation. When performing CEA, using a patch was equated to a more durable result than primary closure, whereas eversion technique is a new methodology deserving a spotlight. Comparing the three major treatment strategies of carotid stenosis has intrinsic drawbacks, as most trials are outdated and they vary in their premises, definitions, and study designs. With the newly codified best medical management including antiplatelet therapies with aspirin and clopidogrel, statin, antihypertensive agents, strict diabetes control, smoking cessation, and life style change, the current trials may demonstrate that asymptomatic carotid stenosis is best treated with best medical therapy. The ongoing trials will illuminate and reshape the treatment paradigm for symptomatic and asymptomatic carotid stenosis.

Reversible and Asymptomatic Gyral and Subarachnoid Contrast Enhancement after Carotid Stenting

The presence of sulcal hyperdensity in patients after endovascular procedures is not necessarily attributable to hemorrhage. It may frequently indicate the absolute or concomitant extravasation of contrast material into the subarachnoid spaces.This case report describes the clinical case of an 84-year-old patient with 90% stenosis of the right internal carotid who presented with a diffuse gyral and sulcal hyperdensity in the right temporal-occipital and frontal lobes at routine post-carotid stenting (CAS) brain CT scan. The patient was asymptomatic and CT findings were interpreted as contrast enhancement hyperattenuation and no therapeutic decisions were made. A 24-hour follow-up brain CT demonstrated the complete resolution of the hyperdensity, confirming the diagnosis.In this patient we considered the concomitant presence of gyral and sulcal hyperdensity as the consequence of reversible damage to the blood-brain barrier (BBB) determining a transitory extravasation of contrast material. Asymptomatic gyral and subarachnoid contrast enhancement following CAS is generally indicative of benign and transitory damage to the BBB and is not to be misinterpreted as hemorrhage.

US nationwide trends in carotid revascularization: hospital outcome and predictors of outcome from 1998 to 2007

OBJECTIVES

The goals of the study were to assess US nationwide trends in hospital outcome following carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) and to determine potential predictors of outcome.

METHODS

The Nationwide Inpatient Sample, constituting a 20% representative and stratified sample of non-federal US hospitals, was analyzed retrospectively from years 1998 to 2007.

RESULTS

The annual number of CEA decreased (137,877-111,658) and increased for CAS (2318-14,415). Inhospital mortality following CEA decreased from 0.4% to 0.3% (P < 0.001), whereas long-term facility (LTF) discharge increased from 8.2% to 10.5% (P < 0.001). Discharge outcome improved for CAS in both categories (mortality 2-0.5%; LTF discharge 10.7-8.3%; both P < 0.001). The trend analysis revealed an increase in patient age and a worsening comorbid profile over time. Age, women, length of stay, atrial fibrillation, and carotid stenosis with infarction were important determinants of unfavorable hospital outcome.

CONCLUSION

From a nationwide practice perspective, the number of carotid revascularizations fell by 10%. CEA has resulted in stable hospital mortality rates. Meanwhile, CAS has been increasingly utilized with overall improvement in short-term outcome. Our results further suggest a decrease in the number of patients with treatment-eligible carotid disease over time. However, the increasing prevalence of high-risk comorbidity in the aging population may pose a challenge to revascularization strategies.

US nationwide trends in carotid revascularization: is there a clinical opportunity cost associated with the introduction of novel medical devices?

OBJECTIVES

Nationwide practice patterns during the implementation of novel technology, such as carotid angioplasty and stenting (CAS) and embolic protection devices (EPD), and the clinical impact thereof have received less attention.

METHODS

The Nationwide Inpatient Sample, constituting a 20% representative sample of non-federal US hospitals, was analyzed from years 1998 to 2007. Hospital outcome was stratified into in-hospital mortality (IHM), long-term facility discharge, and home/ short-term facility discharge (HSF).

RESULTS

Discharge outcome improved for CAS over the decade. However, this improvement occurred in two phases with a period of worsening (2003-2005) in between. During this transition period, the risk of IHM following CAS was increased (RR 1.29-2.43) and was lower for good outcome (HSF: RR 0.97-0.99) when compared with 2002/2003. During the same transition period, carotid endarterectomy (CEA) was associated with a lower risk of IHM (RR 0.75-1.00), but also a lower risk of HSF (RR 0.98-0.99).

CONCLUSIONS

The results lead to the hypothesis that the nationwide introduction of CAS-EPD may have been associated with temporary increases in in-hospital mortality and discharge morbidity. If such 'clinical opportunity costs' exist with the widespread introduction and adoption of new medical technology with proven efficacy in randomized trials, effective mechanisms are needed for mitigation or prevention during the transition period.

Hemodynamic instability during carotid angioplasty and stenting-relationship of calcified plaque and its characteristics

PURPOSE

During carotid angioplasty and stenting (CAS), hemodynamic instability (HDI) can occur, possibly causing post-procedural ischemic complications. The goal of this study was to investigate the risk factors of HDI focusing on characteristics of plaque.

MATERIALS AND METHODS

Thirty nine CAS patients were retrospectively evaluated for HDI. Prolonged HDI that lasted over 30 minutes was analyzed in relation to characteristics of calcified plaque.

RESULTS

Nineteen (48.7%) patients had HDI. Ten of the 19 had both bradycardia and hypotension, and nine had only bradycardia. All bradycardia was treated well with a transcutaneous temporary cardiac pacemaker. But eight patients presented with prolonged hypotension in spite of recovery of bradycardia. Calcified plaque was a related factor associated with HDI (odds ratio, 8.571; 95% confidence interval, 1.321-55.62; p=0.024). Extensive and eccentric type calcified plaques were associated with prolonged hypotension (p=0.04, and p=0.028, respectively).

CONCLUSION

The calcification of plaque is a predictable factor of HDI during CAS, and its extensive and eccentric calcified plaques may be related to prolonged HDI.

Haemodynamic depression during carotid angioplasty and stenting

Haemodynamic depression is commonly defined as a change in arterial pressure (hypotension with systolic pressure values of less than 90 mmHg) and heart rate (bradycardia, heart rate of less than 60 beats per minute). Carotid angioplasty and stenting (CAS) can result in many complications, particularly in the perioperative period. Apart from the most serious complications, such as stroke and temporary ischaemic attack (TIA), as well as local complications (related to the puncture of the femoral artery), the researchers are especially interested in haemodynamic depression. It is closely related to the interventional treatment area. The region of the common carotid artery bifurcation and the initial section of the internal carotid artery are abundant in baroreceptors and mechanoreceptors. Various prophylactic measures were introduced to clinical practice due to possible complications, such as hypotension and perioperative bradycardia. They include preoperative fluid infusion, atropine administration, infusion of 'pressor' amines and provision of an intracardiac electrode for the time of the procedure.