Carotid Artery Stenosis: A Look Into the Diagnostic and Management Strategies, and Related Complications

Carotid stenosis (CS) is a buildup of atherosclerotic plaque within the artery leading to a wide range of symptoms, from mild symptoms, including blurred vision and confusion, to much more life-threatening presentations, including paralysis due to stroke. The presentation is insidious, with symptoms exhibiting predominantly at severe stenosis; hence the emphasis is placed on the importance of early diagnosis, treatment, and lifestyle modifications. CS is seen undergoing almost the same pathogenesis of any atherosclerotic plaque formation, from endothelial damage of the artery lumen to the formation of a fibrous cap with a foam cell, lipid-filled core. The findings of our review article were consistent with the recent literature, depicting that comorbid hypertension, diabetes, and chronic kidney disease (CKD), and lifestyle aspects, including smoking and diet, played the most salient role in plaque development. Among several imaging modalities, duplex ultrasound (DUS) imaging is the widely preferred method in clinical practice. Carotid endarterectomy (CEA) and carotid stenting are the primarily advocated procedures for symptomatic severe stenosis, with similar long-term outcomes. Although, earlier clinical trials showed promising results in mitigating the risk of stroke among asymptomatic severe CS with surgical intervention. However, recent advancements have shifted the focus to medical management alone due to comparable results among the asymptomatic population. Both surgical and medical regimens are beneficial in treating patients, but it is still an ongoing debate as to which is predominantly superior. The currently advancing trials and research will help elucidate definitive guidelines. However, the massive impact of lifestyle modifications advocates some degree of individualized multidisciplinary management strategies.

Early Atherosclerotic Inflammatory Pathways in Children with Obstructive Sleep Apnea

OBJECTIVE

To evaluate structural and functional carotid changes and inflammatory profiles in children with obstructive sleep apnea (OSA) and healthy controls.

STUDY DESIGN

Patients with OSA and matched controls (ages 5-13 years) were recruited. Proinflammatory cytokines and acute phase reactants were measured at 6:00 p.m. Common carotid artery measures were determined using ultrasound. Confirmatory factor analysis was used to determine subgroups of cytokines and their effects on carotid measures.

RESULTS

Ninety-six patients participated (53 healthy controls, 43 patients with OSA). OSA was associated with increased proinflammatory cytokines (cluster of differentiation-40 ligand [CD40-L], interleukin [IL]-6, and IL-8) and high sensitivity C-reactive protein (P < .05 for all). One cytokine subgroup (IL-6 and IL-8) was negatively associated with markers of carotid function, indicating reduced arterial distensibility and increased stiffness (P < .05 for 3 ultrasound measures); and tumor necrosis factor-α had an opposing effect on carotid function compared with this cytokine subgroup (P < .05 for 2 ultrasound measures). Linear regression demonstrated significant associations between and tumor necrosis factor- α and 2 measures of carotid function (P < .05 for each). Children with OSA did not have functional or structural carotid changes compared with controls.

CONCLUSION

OSA was not directly associated with structural and functional carotid changes but was associated with upregulation of key proinflammatory cytokines (sCD40-L, IL-6, and IL-8). Together, IL-6 and IL-8 were associated with changes in carotid function. Longitudinal studies are needed to demonstrate that the inflammatory milieu observed in our population is a precursor of atherosclerosis in children.

Choosing the right therapy for a patient with asymptomatic carotid stenosis

Introduction: Most patients with asymptomatic carotid stenosis (ACS) now have a lower risk with intensive medical therapy than with stenting (CAS) or endarterectomy (CEA); the annual risk of stroke or death with intensive medical therapy is ~ 0.5%, vs. a periprocedural risk with CAS of ~ 2.5-4.1% with CAS, and ~ 1.4-1.8% with CEA. The excess risk of CAS is greater in older patients.Areas covered: Discussed are the need for intensive medical therapy, the nature of intensive medical therapy, approaches to identifying the few patients with ACS who could benefit from CEA or CAS, and which patients would be better suited to CEA vs. CAS.Expert opinion: All patients with ACS are at high risk of cardiovascular events, soshould receive intensive medical therapy including lifestyle modification, intensive lipid-lowering, B vitamins to lower homocysteine (using methylcobalamin rather than cyanocobalamin), and appropriate antithrombotic therapy. High-risk patients who could benefit from intervention can be identified by clinical and imaging features including transcranial Doppler embolus detection, ulceration, intraplaque hemorrhage, reduced cerebrovascular reserve, plaque echolucency, silent infarction on brain imaging, and progression of stenosis. Most patients whose risk of stroke warrants intervention would be better treated with CEA than with CAS.

Prevalence of Sleep Apnea in Patients with Carotid Artery Stenosis

Obstructive sleep apnea (OSA) is a common disease affecting about 13% of men and 6% of women, usually having severe cardiovascular sequalae. OSA is responsible for the systemic inflammatory response and oxidative stress and results in endothelial injury being a risk factor for atherosclerosis. The aim of this study was to estimate the prevalence of OSA among patients with severe carotid artery stenosis. Fifty-five patients (F/M-24/31, mean age 70 ± 7 years, body mass index 28.3 ± 6.3 kg/m²) were enrolled into the study. The patients were qualified for elective surgical treatment of carotid artery stenosis. Polysomnography was performed in all patients the night before surgery. Thirty-six patients underwent surgical endarterectomy and nineteen patients underwent carotid artery stenting. Sleep apnea was diagnosed in 44 (80%) of all patients. The mean apnea-hypopnea index (AHI) was 14.5 ± 12.9. The OSA severity distribution was as follows: 22 mild, 16 moderate, and 6 severe cases. We found that the percentage of carotid endarterectomies was the greatest in mild and moderate OSA. It was approximately twofold greater than that in non-OSA patients. Carotid artery stenting was performed in nearly half of the patients in each of these groups. We conclude that OSA is highly prevalent in patients with carotid artery stenosis scheduled for carotid surgery. Nonetheless, the exact pathogenetic mechanisms underlying mutual interaction between OSA and vascular wall damage remain elusive. OSA is not routinely diagnosed among patients with advanced atherosclerosis. The study results might be an argument for performing polysomnography in patients with carotid artery stenosis.

Sleep and Stroke: New Updates on Epidemiology, Pathophysiology, Assessment, and Treatment

PURPOSE OF REVIEW

This review aims to discuss the most recent data on sleep disorders and stroke, highlighting relevant findings for the practicing neurologist or health providers who encounter patients with sleep disorders and stroke.

RECENT FINDINGS

Sleep apnea and abnormal sleep duration have the strongest association with stroke risk. Possible mechanisms include non-dipping of blood pressure during sleep, hypoxemia or reoxygenation leading to sympathetic activation, hypertension, atrial fibrillation and impaired cerebral hemodynamics. Treatment studies suggest that continuous positive airway pressure (CPAP) for sleep apnea could improve primary prevention of stroke, but data is equivocal for secondary prevention. However, CPAP could improve functional outcomes after stroke.

SUMMARY

Sleep disorders present an opportunity to improve stroke risk and functional outcomes. However, new strategies are needed to determine the patients at high-risk who would most likely benefit from targeted care. Novel methods for phenotyping sleep disorders could provide personalized stroke care to improve clinical outcomes and public health strategies.

Association Between Systemic Inflammation, Carotid Arteriosclerosis, and Autonomic Dysfunction

Systemic inflammation is associated with arteriosclerotic disease progression and worse stroke outcome in patients with carotid arteriosclerotic disease. We hypothesize that systemic inflammation is mediated by impaired carotid baroreceptor and chemoreceptor function induced by carotid arteriosclerosis rather than by the generalized inflammatory arteriosclerotic process.Heart rate variability (HRV), serum levels of inflammatory markers, demographic and life style factors, and concomitant diseases with potential impact on systemic inflammation were determined in 105 patients with asymptomatic carotid stenosis of varying degree. Multivariate linear regression analyses were performed to ascertain independent determinants of carotid stenosis severity, autonomic function, and inflammation.Systemic inflammation (C-reactive protein, beta = .255; P = .014), age (beta = .232; P < .008), and arterial hypertension (beta = .206; P = .032) were associated with carotid stenosis severity. Only carotid stenosis severity and not generalized arteriosclerotic disease, concomitant diseases (arterial hypertension, diabetes mellitus, dyslipidemia, hypothyroidism), life style factors (smoking, obesity), or age was associated with a reduction in vagal tone (HRV HF band power beta = - .193; P < 0.049). Systemic inflammation was related to a reduction in vagal tone (HRV HF band power, beta = - .214; P = .031), and not to generalized arteriosclerotic disease, concomitant diseases (arterial hypertension, diabetes mellitus, dyslipidemia), life style factors (smoking, obesity), and age.In conclusion, systemic inflammation is associated with carotid rather than with generalized arteriosclerotic disease. The association between systemic inflammation and carotid arteriosclerosis is mediated by a reduction in vagal tone which indicates a major role of carotid arteriosclerosis-mediated autonomic dysfunction in the pathogenesis of systemic inflammation in arteriosclerotic disease.

Obstructive sleep apnea causes impairment of the carotid artery in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND

Obstructive sleep apnea (OSA) prevalence is high among patients with hypertrophic cardiomyopathy (HCM). OSA can cause increase in carotid intima-media thickness (CIMT) in the general population. However, whether this phenomenon is applicable to patients with HCM is unclear.

METHODS

A total of 130 consecutive patients with a confirmed diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) at Fuwai Hospital between September 2017 and May 2018 were analyzed.

RESULTS

72 patients (55.4%) were diagnosed with OSA. Patients with OSA were older. Compared to those in patients without OSA, the left, right, and mean CIMTs were significantly increased in patients with OSA. In the multiple linear regression model, age (β = 0.341, p < 0.001), apnea-hypopnea index (AHI) (β = 0.421, p < 0.001), and fasting glucose level (β = 0.167, p < 0.03) were independently associated with mean CIMT increase (adjusted R² = 0.458, p < 0.001). In the receiver operating characteristic curve analysis, the area under the curve for CIMT was 0.813 (95% CI, 0.717-0.909, p < 0.001) with a sensitivity and specificity of 0.84 and 0.70 for unexplained syncope, respectively. In the multivariate logistic regression model, we found that the mean CIMT (OR = 10.4, 95% CI = 3.16-34.11, p < 0.001), left ventricular ejection fraction (LVEF) (OR = 0.90, 95% CI = 0.83-0.99, p = 0.03), and amaurosis (OR = 5.07, 95% CI = 1.47-17.49, p = 0.01) were independently associated with unexplained syncope occurrence.

CONCLUSIONS

In patients with HOCM, CIMT increased with OSA severity. Age, AHI, and fasting plasma glucose level were independently associated with mean CIMT increase. Moreover, amaurosis, LVEF, and higher mean CIMT were independently associated with unexplained syncope in patients with HOCM.

Ideal Cardiovascular Health Metrics Associated with Reductions in the Risk of Extracranial Carotid Artery Stenosis: a Population-based Cohort Study

The cardiovascular health (CVH) metrics are closely related to the risk of stroke. Extracranial carotid artery stenosis (ECAS) represents an important risk factor for ischemic stroke. The present study aims to explore the longitudinal effect of the baseline CVH metrics on the development of ECAS. Totally 5,440 participants were randomly enrolled in the Asymptomatic Polyvascular Abnormalities Community study from 2010 to 2011. Information regarding the seven CVH metrics was collected at baseline. ECAS was assessed by performing carotid duplex sonography at baseline (2010-2011) and during the follow-up (2012-2013). Finally 3,487 subjects were included, and 976 participants developed ECAS during the 2-year follow-up. The optimum CVH status was associated with a 42% (95% confidence interval: 0.40-0.85) decreased risk of the incidence of ECAS after adjusting for age, sex, weight, education, income, alcohol use, waist-hip ratio, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, uric acid, homocysteine, and C-reactive protein. Ideal physical activity, total cholesterol and fasting blood glucose were independent protective factors of ECAS. In this cohort study, the ideal baseline CVH status was negatively associated with the occurrence of ECAS during the follow-up. This study provides practical insight for further developing effective screening strategies or implementing the best medical treatment.

Self-reported obstructive sleep apnea is associated with nonresponse to antidepressant pharmacotherapy in late-life depression

BACKGROUND

Obstructive sleep apnea (OSA) is frequently comorbid with late-life depression. The purpose of this project was to determine, using a sample of older adults with major depressive disorder, whether patient-reported diagnosis of OSA was associated with rate of response to venlafaxine.

METHODS

Participants from this multisite study were adults ≥60 years old (n = 468) with major depressive disorder and a Montgomery Asberg Depression Rating Scale (MADRS) score of ≥15. Depression response was the outcome variable, defined as a MADRS score of ≤10 for two consecutive assessments at the end of 12 weeks of open-label treatment with venlafaxine 300 mg/day. To assess OSA, participants were asked if they had been diagnosed with OSA using polysomnography.

RESULTS

Eighty participants (17.1%) reported a diagnosis of OSA prior to baseline. Participants with OSA were more likely to be male, report greater impairment on measures of health, experience a longer duration of the index episode, and receive an adequate antidepressant trial prior to entering the study. During the 12 weeks of treatment, 40.8% responded to treatment with venlafaxine (43.6%, n = 169/388 of the no OSA group, and 27.5%, n = 22/80 of the OSA group). Participants without OSA were 1.79 times more likely to respond to treatment (HR: 1.79 [95%CI: 1.13-2.86], P < .05) compared to those with OSA.

CONCLUSIONS

OSA may impair response to antidepressant pharmacotherapy in depressed older adults. Future studies of antidepressant response rates among depressed older adults with OSA should both prospectively diagnose OSA and monitor adherence to treatments such as continuous positive airway pressure.