Physician must: Screening and treatment of asymptomatic carotid artery stenosis

*Only for medical professionals to read for reference.
Recurrence of ischemic stroke is related to plaque vulnerability, and oxidative stress affects plaque stability
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 Asymptomatic Carotid Artery Stenosis (aCAS): refers to atherosclerotic stenosis that occurs in the extracranial segment of the carotid artery and has no previous ischemic stroke, transient ischemic attack, or other neurological signs or symptoms
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aCAS is particularly important for the early diagnosis and prevention of ischemic stroke, and neurologists should improve their understanding of aCAS
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At the 24th National Neurology Conference of the Chinese Medical Association held on September 24-26, 2021, Professor Xu Yuming from the First Affiliated Hospital of Zhengzhou University gave us a lecture "Screening for Asymptomatic Carotid Stenosis" And Management", the content is wonderful, it's quick to see! Figure 1: Professor Xu Yuming's report 1 Concept points.
In clinical research, the "asymptomatic" period of aCAS is generally defined as within the past 6 months
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Most studies define a clinically significant type of stenosis as 50%-99% or 60%-99% stenosis judged on carotid ultrasound
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2aCAS Risk Factors A study of 596,469 patients in 2021 showed that risk factors related to aCAS include: age, gender, smoking, diabetes, history of stroke or transient ischemic attack (TIA), coronary heart disease, peripheral arterial disease , Systolic and diastolic blood pressure (after using antihypertensive drugs) and total cholesterol/high-density lipoprotein
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The area under the curve of the PACAS score based on the above risk factors for predicting the receiver operating characteristic curve of moderate and severe aCAS is 0.
78 (95%CI 0.
77-0.
78) and 0.
82 (95%CI 0.
81-0.
82), which has a relatively high The high predictive value helps to increase the detection rate of aCAS in the population
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Figure 2: PACAS assessment for predicting the risk of moderate and severe aCAS3aCAS stroke ■ Carotid artery stenosis A meta-analysis of 23 population studies (8419 patients) published in 2021 showed that 70%-99 at 5-year follow-up % Of patients with stenosis have a significantly higher risk of stroke than 50%-69% of patients with stenosis [10.
21% vs 4.
76%; OR 2.
1 (95% CI 1.
7-2.
5), p<0.
0001], emphasizing that the degree of arterial stenosis is closely related to the occurrence of aCAS stroke Related
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Figure 3: A meta-analysis of 23 population studies in 2021 ■ Carotid artery stenosis progression rate The 2014 ACST-1 study (1469 aCAS patients) found a faster annual stenosis progression rate (progress 2 or more grades) instead of The progression of simple stenosis is related to the occurrence of stroke
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Figure 4: ACST-1 study in 2014 ■ Microembolic monitoring The ACES study published in 2010 proposed the value of microembolic monitoring in predicting risk in aCAS
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The study included 467 patients with aCAS in 70% of 26 centers around the world.
The patients were monitored for TCD microemboli on the ipsilateral middle cerebral artery twice at baseline for 1 hour, and then at 6, 12, and 18 months.
One time 1 hour monitoring
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The results showed that at 6-month and 2-year visits, patients with microembolisms were found to have a higher risk of ipsilateral stroke and TIA than those who did not, suggesting that TCD microemboli signals can screen out higher-risk aCAS patients
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Figure 5: ACES study published in 2010 ■ The "vulnerability" of vulnerable plaque plaque has also received widespread attention in the screening of high-risk populations with aCAS stroke
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Imaging techniques including high-resolution NMR, CT angiography (CTA), PET-СТA, optical coherence tomography, and contrast-enhanced ultrasound can provide evidence of plaque stability including plaque morphology and composition characteristics.
The determination of high-risk groups provides an important reference
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Diagnostic imaging methods carotid artery 4 and the accuracy of screening for carotid stenosis include DSA, CTA, MRA, CE- MRA like
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DSA is the gold standard for diagnosing carotid artery stenosis, but it is expensive and has the risk of puncture site injury, bleeding, contrast agent allergy, nephrotoxicity, and stroke (less than 0.
2%), and it is not suitable for screening
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The diagnostic sensitivity of MRA for 70%-99% stenosis is 95% (95% Cl 92%-97%), and the specificity is 90% (95% CI 86%-93%), but there is a certain exaggerated effect.
The degree of coordination is high
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CE-MRA further improves the imaging accuracy through contrast agent injection, but the contrast agent has certain nephrotoxicity, and the inspection cost is higher
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The coincidence rate of CTA and DSA is high, but there are disadvantages such as ionizing radiation nephrotoxicity and high cost
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The advantages of low price and good accessibility of ultrasound make it the first choice for initial screening.
Meta-analysis shows that the sensitivity and specificity of ultrasound for detecting 50% or more stenosis aCAS are 98% (95% CI 97%-100%) and 88% (95% CI 76%-100%), the sensitivity and specificity for detecting 70% or more stenosis were 90% (95% CI 84%-94%) and 94% (95% CI 88%-97 %), but due to the inconsistency of the operator's technical level in the actual clinical operation, the results may be different, which increases the possibility of false positive results
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CE-MRA and CTA are less affected by the operator, and the examination results are reliable.
They can be used to further confirm the diagnosis after initial screening with ultrasound
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5 Medical treatment of asymptomatic carotid artery stenosis ■ The medical treatment of aspirin aCAS mainly includes antiplatelet drugs, lipid-lowering therapy, hypertension and diabetes, management of risk factors and life>
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Figure 6: RCT study in 1995 An RCT study in 1995 did not prove that aspirin (325 mg/d) can reduce the risk of stroke in patients with aCAS (>50%) at 2.
3 years of follow-up compared with placebo group
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Figure 7: ACES study in 2013 A follow-up study of 477 patients with aCAS (70%-99%) from the ACES study in 2013 showed that antiplatelet drugs and antihypertensive drugs were associated with the risk of ipsilateral stroke/TIA during the 2-year follow-up And any stroke/cardiovascular death risk reduction is positively correlated
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■ Statins Figure 8: Post-mortem analysis of the ACST-1 study The post-mortem analysis from the ACST-1 study showed that medical treatment or CEA intervention for aCAS patients had more strokes and strokes than 10 years before using statins without the use of statins.
The risk of death is significantly increased
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6 Surgical treatment of asymptomatic carotid stenosis In 2014, a meta-analysis of 3 aCAS treatment interventions (ACAS, ACST, VACS) involving a total of 5226 people showed that CEA was more effective than medical treatment at the 5-year follow-up.
Both endpoint indicators showed a significant decrease in absolute risk
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Stenting (CAS) VS Endarterectomy (CEA): There are currently 5 main trials (Lexington, Mannheim, SPACE-2, ACT-1 and CREST-1) in the "carotid artery Among patients with "moderate risk", CAS and CEA were compared, and there was no significant difference between CAS and CEA treatment
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7 Recommendations in recent years ■ The 2017 European Vascular Surgery Guidelines (ESVS) 1.
The 2017 ESVS guidelines do not recommend screening for aCAS in the routine population, but for patients with multiple risk factors for vascular disease, selective screening (such as combined Peripheral arterial disease or patients older than 65 years old with a history of coronary heart disease, smoking or hyperlipidemia), the purpose of screening is to reduce the late cardiovascular complications through risk factor management and drug treatment in patients with aCAS who are screened Disease and mortality
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2.
Under the premise that the perioperative stroke/mortality rate is less than 3% and the life expectancy is more than 5 years, for asymptomatic patients with 60%-99% stenosis "average surgical risk", if there are one or more possibilities with For imaging features (plaque vulnerability, etc.
) related to the increased risk of ipsilateral stroke in late stage, CEA or CAS may be considered
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■ 2019 China Primary Prevention Guidelines 1.
Patients with asymptomatic carotid artery stenosis can take statins and/or aspirin, screen for other treatable stroke risk factors, conduct reasonable treatment and change unhealthy life>
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2.
For patients with asymptomatic carotid artery stenosis (stenosis degree> 70%), in the case of life expectancy greater than 5 years, qualified hospitals (perioperative stroke and death rate <3%) may consider CEA or CAS (level I recommendation, level B evidence); patients undergoing CEA or CAS, if there are no contraindications, should be given antiplatelet therapy during and after the operation (level I recommendation, level C evidence)
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3.
For patients with asymptomatic carotid stenosis greater than 50%, it is recommended to conduct regular ultrasound screening and follow-up in qualified hospitals to assess the progression of stenosis and the risk of stroke (level I recommendation, level C evidence)
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■ Chinese Stroke Society Clinical Management Guidelines for Cerebrovascular Disease 1.
It is recommended that patients with asymptomatic carotid artery stenosis (stenosis> 50%) take statins and aspirin daily (Class IIa recommendation; Level C evidence)
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2.
It is recommended that patients with asymptomatic carotid artery stenosis (stenosis> 50%) be screened for other treatable stroke risks, reasonable treatments and life>
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3.
Patients with asymptomatic carotid artery stenosis (stenosis 60%-99%) and life expectancy greater than 5 years can be treated with CEA in qualified hospitals (hospitals with a perioperative stroke and death rate of less than 3%) ( Class IIa recommendation; Level B evidence).
For patients undergoing CEA, if there are no contraindications, it is recommended to take aspirin during the perioperative period and after the operation (Class I recommendation; Level C evidence)
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4.
Asymptomatic carotid artery stenosis with a higher risk of CEA surgery (stenosis 60%-99%), and life expectancy greater than 5 years, in a hospital with conditions (a hospital with a perioperative stroke and death rate of <3%) ) Preventive CAS (Class IIb recommendation; Level B evidence) can be considered, but the effectiveness of CAS compared with drug therapy alone has not been fully proven
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5.
Patients with carotid artery stenosis with symptoms of more than 2 risk factors are recommended to undergo regular ultrasound screening and follow-up in qualified hospitals to assess the progression of the stenosis and the risk of stroke (Class IIa recommendation; Level C evidence)
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8 Future development direction In the future, more research is needed to assess the disease burden of aCAS in the general adult population in China; aCAS high-risk population and aCAS stroke risk assessment tools suitable for Chinese are developed and well verified
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The benefits and risks of aCAS treatment, especially in the Chinese population
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Including: comparing the effects of CEA or CAS combined with the best drug therapy and drug therapy alone, and carrying out long-term trials (follow-up> 5 years).
The ongoing studies of CREST-2, CREST-H, ECST-2, ACTRIS, etc.
are expected to be resolved Long-term controversy in this field
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