Ep. 213: Plaque / Atherosclerosis at risk

00:00:00: Welcome to EANcast, your weekly source for education research and updates from the European Academy of Neurology.

00:00:26: Today, we are going to be talking about the latest research on serial pro-vascular risk factors and their multimodal assessment of carotid plaques at risk.

00:00:37: We will introduce a new stroke risk classification system known as Carotid Plaque Reds and how it can be applied using different imaging modalities such as ultrasound computer tomography and how to identify high-risk patients in order prevent ischemic stroke.

00:00:57: My guest today is Kristina Duka, she's a neurologist and neurosanologist at Hospital Pedro Espanol, Matasino's local health unit Portugal.

00:01:08: Welcome Kristina!

00:01:09: And thank you for joining us today.

00:01:12: Thank You Horsita.

00:01:13: It was really pleasure to be here and talk about this very relevant subject.

00:01:20: As we all know, cardiovascular diseases are the leading cause of death and disability mainly due to heart attack or stroke.

00:01:27: According to latest data, incidence of atherosclerotic cardiovascular disease has increased and is recognized as a leading determinant for over-lopal causes.

00:01:37: Let's begin our talk with terms & definitions.

00:01:41: which atherosclerotic plaques are considered plaques at risk.

00:01:45: And what does it mean for the cardiovascular risk patient?

00:01:49: To be more specific, What actually makes a plaque dangerous beyond how much it narrows their artery?

00:01:56: What structural features define vulnerability and How do they link to the risk of

00:02:03: stroke?".

00:02:05: Yeah that's really great question.

00:02:07: so The essential idea is that most carotid strokes are not caused by the artery simply being too narrow, so they're caused by embolism.

00:02:17: A plaque becomes dangerous when its surface ruptures, tromba forms on it and material embolises to the brain or the eye.

00:02:27: So their tendency to rupture has surprisingly little to do with a degree of stenosis.

00:02:35: As you said, the structural features that will define vulnerability are well described.

00:02:41: We know they're as a large lipid-rich necrotic core or thin or ruptured fibrous cap intraplac hemorrhage and also intraplacneovascularization.

00:02:56: This means there is in growth of fragile new vessels from the little vasophasorum that leak.

00:03:04: So we can add also the outward or positive remodeling where the plaque grows outward rather than into the lumen so it can stay angiographically almost hidden while becoming biologically dangerous.

00:03:19: And from data, you know and specifically from this statement of vulnerable plaque to vulnerable patient these concepts have shifted.

00:03:30: Shift has been that removes from thinking about a percentage of narrowing, to think about the biology of the plaque and ultimately also risk profile for all patients.

00:03:42: So we will say that a plaque at risk would be an unstable embologenic lipid-rich plaque And of course identifying it matters because this is patient in whom can intervene prevent first or recurrent stroke.

00:04:01: Thank you.

00:04:01: Are the locations size and number of carotid plaques also important in evaluating the atherosclerosis at risk?

00:04:10: How does the location of the stenosis differ between Caucasians and Asians,

00:04:30: singlest, tightest lesion.

00:04:33: And this concept of a carotid plex core where we sum plaque across multiple segments and on both sides will reflect these local atherosclerotic lobes.

00:04:47: That's total burden is itself predictive of vascular events independent any one stenosis.

00:04:55: So counting and measuring plaques, following them over time gives information that this single stenosis percentage does not.

00:05:06: As you said the location differs very significantly between populations And it is relevant for our clinical practice.

00:05:15: In Caucasians atherosclerosis is predominantly extrachranial.

00:05:20: so in the carotid bifurcation and in the proximal internal carotids In East Asian populations, intercranial disease is far more common.

00:05:30: It will affect distal ICA in the middle cerebral artery and this has direct consequences for us as neurosonologists.

00:05:39: so a cervical duplex study that's entirely normal would not exclude significant intracranial atherosclerosis And so in patients of specific background We need this lower threshold to study intracranial vessels with transcranial Doppler.

00:06:01: And, This is also part of why conditions like Moyamoya which as we know an intercranial stenoclusive disease will enter the differential more prominently in these populations and when you think about when or who should perform these exams, this will be of course ideally done by a trained neurosurgnologist.

00:06:29: Ideally again with the high-resolution ultrasound system and in a lab with quality standards.

00:06:37: The reality is that duplexes used widely it's widely available.

00:06:42: With proper training the detection of black and rose characterization can be performed quite broadly.

00:06:50: And this is exactly the monitoring, where ultrasound excels because it's repeatable and non-invasive.

00:06:57: so we can actually follow this plaque over time.

00:07:01: Escalate treatment if it progresses or new high risk features.

00:07:09: I totally agree with you.

00:07:11: You mentioned age when talking about the risk factors for atherosclerosis.

00:07:14: young adult, what can we find by performing cervical duplex ultrasound in younger patients?

00:07:23: Yes, age is very important.

00:07:26: it changes what we call the pre-test probability enormously.

00:07:34: if alterations in the Doppler ultrasound, we have to interrogate if it's truly atherosclerosis.

00:07:46: because we can see on ultrasounds several non-atherosclerotic causes that are more common than young people.

00:07:53: That will have distinctive signatures.

00:07:57: To say for example of course carotid dissection.

00:08:00: We'll produce immural hematoma with a tapering lumen sometimes a flap.

00:08:08: If we see fibromuscular dysplasia can give this beaded appearance mostly in the mid to distal ICA, carotid web that it's more and more recognized itself as variant of the fibromoscular dysphagia considered will appear has thin shelf or projection on posterior wall And this will be a very important cause of cryptogenic stroke in young.

00:08:39: Of course, if the disease is intracranial and progressive we have to consider Moyamoya.

00:08:46: In older patients there are overwhelming likelihood that it would be atherosclerosis.

00:08:54: we know from ancillary studies, from the Rotterdam study and others that age, hypertension in smoking will drive of course this prevalence of carotid disease.

00:09:05: And this progression at a population level.

00:09:10: Thank you!

00:09:11: You already mentioned that patients with vulnerable blacks were described as vulnerable.

00:09:18: At first it was made for coronary arteries.

00:09:22: It was pointed out that these plaques may contribute to converting chronic coronary atherosclerosis into acute coronary artery disease.

00:09:33: And in recent years, coronary arteries disease reporting and data system CAT-RES was developed to standardize the reporting of coronary CTA.

00:09:42: What is newly introduced carotid plaque res?

00:09:46: how are the categories structured, and what does it add?

00:09:51: Would they be applicable in everyday clinical

00:09:53: practices?".

00:09:54: In addition to Stanoza's grading by NASA.

00:09:59: Is black rats ready to guide intervention decisions or perhaps is still a research and stratification tool?

00:10:09: That's very important too.

00:10:11: discuss because this parallel with the cave rats the right way in cardiology, recognize that this writing freely on CTA reports would lead to inconsistency.

00:10:26: So the CAD-RED standardize these into reproducible categories... In the end a most important thing is guide management.

00:10:36: so we know now there has been established carotid plaques reds applied same philosophy but to the carotide plaque.

00:10:47: So it runs from category one to five, being one with no plaque.

00:10:52: Category two would be a predominantly stable plaque.

00:10:58: We go through three that will mix Four... It's going to be more unstable plaque With more lipid-rich components But without this surface disruption.

00:11:13: and this final fifth category where it's the higher risk plaques that are complex, they have ulceration hemorrhage or other of these high-risk features we can access through Doppler ultrasound.

00:11:30: Another very important aspect is that this categorization is designed to work across modalities.

00:11:39: Ultrasonic CT and MRI to the point that, in the same language we'll describe the plaque wherever it is or however it's imaged.

00:11:51: What it adds over an asset that we use more for quantification... ...is a sort of second axis of information.

00:12:00: An asset as we know will tell you how tight the stenosis is and plaque grads would actually tell us how dangerous this plaque is and used together, so they should be use-together in the sense that there will be far more informative than alone of course especially this gray area at the moderate stenosis.

00:12:22: I think currently it is not yet a decision maker for surgery or stenting with black rats.

00:12:34: we really do lack these prospective trials.

00:12:37: that category alone should decide intervention or no.

00:12:43: So it's a powerful stratification and research tool, and its really structured way to feed this vulnerable plaque concept into the clinical decision of course alongside symptoms and stenosis.

00:13:00: That's interesting!

00:13:01: Are you already using carotid lacrosse in your hospital?

00:13:06: I would like.

00:13:08: And could lack of time, lack of experiences sonographers or lack of high resolution ultrasound systems negatively influence the implementation of carotid lacrosse into clinical practices?

00:13:21: How do you think

00:13:23: we are beginning to apply these principles.

00:13:26: So doing this systematic characterization and try to do a structured description I think that for most centers, including ours is it's still being integrated rather than already fully embedded.

00:13:43: The barriers you name are exactly the important.

00:13:47: one time a proper plaque characterization will take longer then simply reporting velocity and percentage.

00:13:56: so we all know all in busy labs where time pressure is really significant.

00:14:04: So this would be one limitation, the other one which is transversal to all the neurosonology field is that expertise.

00:14:14: it's very important.

00:14:14: so reproducible plaque classification will require trained experienced sonographers This variability between observers Without the training and even sometimes in very trained specialists, we need good equipment.

00:14:35: We need a machine that can assess surface features And this fine morphology.

00:14:43: That requires high resolution systems which is very important.

00:14:50: also the contrast capability, so the possibility to do contrast-enhanced ultrasound.

00:14:57: To check for neurovascularization.

00:15:00: not every center will have this ability.

00:15:03: I think that none of these limitations are impossible to overcome but they mean that this adoption probably gradual it'll depend on training programs And of course, on the results of studies that prove this effort really changes outcomes.

00:15:28: Thank

00:15:28: you!

00:15:29: Would you like to point out how do CT and geography MRI and digital subtraction geography compare for vulnerable black imaging?

00:15:41: How would you compare these images?

00:15:46: When we use B mode... using ultrasound.

00:15:50: We know that it's a really high temporal resolution, in real time It is widely available and doesn't have radiation And...it is good at echogenicity.

00:16:04: so distinguishing this ecolucent lipid-rich more dangerous plaque from ecogenic and caustified for surface details and for ulceration would be harder to check, and of course we know that if there's a classification We can have an acoustic shadow.

00:16:24: That will difficult our assessment.

00:16:29: When you use this contrast ultrasound Will add something that be more canned so?

00:16:38: We used microwabels that penetrate the plaque reveal this new vascularization and it has a strong correlation with intraplac hemorrhage, the large lipid core.

00:16:51: It's not used that common because of its timed cost or need for trained operator.

00:16:57: And it is not embedded in guidelines.

00:17:00: so it's a selective tool rather than I would say routine one.

00:17:06: maybe we hope time changes.

00:17:09: If we think about other modalities that were used to study atherosclerosis and the unstable plaque, We know that CT angiography is fast.

00:17:19: It's excellent for classification To grade the stenosis Sort of an anatomical roadmap.

00:17:27: So the trade-offs would be radiation The contrast And sometimes this calcium blooming can obscure the lumen When... We think and know more about vessel wall MRI, which will be strongest for composition.

00:17:45: It'll allow us to really study the hemorrhage cap integrity so too detailing the plaque characteristics.

00:17:58: Not all centers would have this availability And it's also slower in motion sensitive.

00:18:05: And of course, angiography remains the reference for lumen and hemodynamics.

00:18:10: It's invasive.

00:18:11: it has a small procedural risk so we use only in inconclusive cases or when planning intervention.

00:18:21: So I would summarize this as ultrasound and contrast is first line MRI for composition CTA for the map and angiography for problem solving.

00:18:37: Thank you very much for such detailed explanation, I would like to return to the ICA stenosis grading according to NASA criteria.

00:18:49: do we need to add ESCT criteria very shortly or not?

00:18:56: The important thing is that which method are we using?

00:19:03: and to be consistent because they're not interchangeable.

00:19:07: We know that NASA will compare the lumen to normal distal ICA, SEST compares it with the estimated original diameter at level of stenosis.

00:19:20: so this means that ECST will overestimate a higher number for same lesion.

00:19:27: The trials that we use, set are threshold for intervention.

00:19:34: Use the Nashit methodology.

00:19:37: so you have to know this and it would be standard reporting And I wouldn't add ECSTs because they will create a bit of confusion sometimes over treatment.

00:19:51: if numbers are mixed and know how to interpret it, be consistent.

00:20:02: You are right!

00:20:04: In your opinion what is the difference between a standard kerotid ultrasound versus point-of-care ultrasound opacus?

00:20:11: And what questions could Pocosans were in symptomatic patients in the emergency department IQ or ambulatory room?

00:20:20: Could they change their management of stroke patients?

00:20:23: talking about kerotids artery stenosis and flex, in stable flex.

00:20:30: Yeah, Pocos ultrasound.

00:20:32: it's very important that we talk about this and reflect on this because the difference is really one of scope and question when we do.

00:20:44: a standardized or carotid ultrasound will be comprehensive bilateral systematic idealina acute stroke patient to study intracranial vessels as well.

00:20:58: But we are doing full stenosis quantification and Pocos is focused.

00:21:04: so, We're asking a specific time critical question at the bedside.

00:21:10: So for example in asymptomatic patients In the emergency department or in the ICU.

00:21:16: The question is Is there a culprit lesion ipsilateral that changes what I will do in the next hour, a significant typsilateral plaque and your occlusion an occlusion, a dissection.

00:21:33: These findings will generally change management In the sense we'll decide on urgency of definite imaging treatment options And if this patient needs an urgent vascular assessment.

00:21:50: And of course, after Amarose's fugaz in a TIA in an outpatient setting.

00:21:55: A focused look that the ipsilateral carotid will rapidly confirm our suspicion have significant symptomatic stenosis.

00:22:06: That at end we'll set pace for workup and I think what a non-specialy can reliably do is assess present inside of a significant plug, a gross morphological category, peak velocity estimate that can flag a significance to noses and the color flow that will spot obvious seclusion.

00:22:35: what they cannot do will be greater stenosis or characterize the service for alteration, the TETA web or exclude the session.

00:22:47: So this would be a bit more specialized.

00:22:50: Pocos is triage.

00:22:52: it guides urgency.

00:22:54: It will not replace formal study and I think that knowing its boundary makes it safe.

00:23:04: Yes, that's very important.

00:23:06: Thank you!

00:23:07: Sometimes performing pokus we can detect micro-embolic signals... Have you done it already or not?

00:23:18: Several micro-embolic signals may signalize about the physiology of a stroke.

00:23:26: What do you think about this?

00:23:28: Yeah, it's another high-risk feature of any plaque and we know from previous studies that can even help us to guide our decision on the antiplatelet regimen.

00:23:41: So if you are able do a study of microimbalic signals spontaneous one in an acute setting during stroke unit admittance our decision and to characterize a bit more the risk, the symbolic risks of that patient.

00:24:04: Of course we can see micro-embolic signals not only from plaques but they come from carotid plaques or from the heart.

00:24:16: so it can help us guide this initial study.

00:24:22: Neurologist

00:24:23: with Cerebroascular Anatomy Knowledge Baggage has a privilege to know where to look at when using target ultrasound according the presented neurological symptoms and signs as you mentioned.

00:24:36: Would we teach non-neurologists?

00:24:39: how do that?

00:24:40: What's your opinion

00:24:41: on this?

00:24:43: I think... We can, but of course Many, at least in my context many internal medicine doctors that act as the primary line and care also for stroke patients.

00:25:02: The neurologist advantage is exactly how he describes so it's symptom-driven.

00:25:08: we do a hypothesis lead scanning We localize from these clinical pictures So I know which vessel and which territory to study and that clinical reasoning is teachable.

00:25:22: I think with the structure curriculum, we define competencies.

00:25:29: a clear understanding of this focus protocols in cerebral vascular anatomy.

00:25:36: so i think that general focus training will teach people to operate the machine with proper orientation would be very helpful.

00:25:51: That's so important!

00:25:53: And how do you see the future of ultrasound diagnostic and stroke management?

00:25:58: What will be most changed, how we stratify carotid-stroke risk in next few years... ...and what about using AI?

00:26:11: I think that on one hand We should really converge this standardized reporting.

00:26:24: And I think that AI will have a role in this, of course because as we said before the main limitation of black characterization is inter-observer variability.

00:26:36: so even two skilled readers can classify the same plaque differently and that can undermine any risk system.

00:26:47: So maybe this AI analysis, trained on physiologically validated data can make that assessment reproducible and quantitative in real time directly even from the B-mode imaging.

00:27:00: if we combine these with enhancement using contrast for neovascularization also we will move from a largely collective exercise towards something that it's reproducible, a risk score that is repeatable and allows us to set up of course other big studies, longitudinal studies.

00:27:30: And in the end this will lead us to identify the truly vulnerable patient and not just the vulnerable plaque.

00:27:39: so again through large multi-center multimodal research with also comparison with other MRI vessel imaging events and also PET scans can prove the value in cost-effectiveness before this will eventually reach into routine guidelines.

00:28:02: Thank you, Kristina for such an interesting talk!

00:28:05: And now it's time to summarize our talk.

00:28:08: Carotid plaques at risk are unstable, embolicenic, lipid-rich atherosclerotic plaques characterized by a thin fibrosis gap prone to rupture, intraplac hemorrhage, interplac neoasculorization and outward remodeling.

00:28:25: It may remain angiographically silent while dangerous due to possible local tombosuperposition and arterial embolization to the brain and eye causing acute ischemic stroke.

00:28:39: And we present a standardized evaluation of carotid plaques.

00:28:43: using our new Stroke Risk Classification System, Carotid Plaquettes could help accurately identify patients at risk of TIAO stroke.

00:28:54: as Christina told us it was recommended to grade the stenosis according to NASA's criteria And in addition, try to apply the standardized carotid plaques to optimize medication treatment and if indicated to perform appropriate endovascular treatment in a timely manner before stroke occurs.

00:29:18: And

00:29:18: non-invasive cervical colocody duplex ultrasonography with or without contrast agent is recommended for detection assessment monitoring of carotide plaques at risk And furthermore, as Kristina told us larger multi-central research on vulnerable carotid plaques including ultrasound and

00:29:41: II

00:29:42: assisted plaque analysis is needed to demonstrate the importance of focus in standard neurological examination for their integration into cerebral vascular disease prevention.

00:29:58: And stroke guidelines.

00:30:00: Kristina, would you like to add something for this?

00:30:03: summarizing?

00:30:05: I think this... You summarize it pretty well and i think that's important.

00:30:09: That we use Doppler not only in the lab or our patients Not all in the stroke unit but also in the emergency room In outpatient clinics so really is a tool which has to be at all times present for our stroke patients and it can allow us to really individualize treatment in the follow-up, prevent new strokes.

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