American Heart Association

Conference

Some Interesting Late-breaking Abstracts

European Stroke Organisation Conference (ESOC)
May 16–18, 2017

May 18, 2017
Should you restart anticoagulation after a cerebral haemorrhage? And other questions.

There are few things as devastating as a large ischaemic stroke in a patient who you had previously advised not to take anticoagulation.

As a stroke physician, I’ve been asked questions about whether I should give anticoagulation to a patient who has had an intracerebral haemorrhage (ICH). Many people who have had an ICH are at high risk of having an ischeamic stroke. At the late-breaking trials session of ESOC, there was some useful evidence that will help me sleep after these consults.

What Causes Lacunar Stroke, and How Should You Treat It?

European Stroke Organisation Conference (ESOC)
May 16–18, 2017

May 17, 2017
What if I told you that nearly 1/4 of ischaemic strokes weren’t caused by emboli at all? With the focus on retrieving clots with clever devices, and preventing them from forming with anticoagulants, it’s easy to forget that some ischeamic strokes have quite a different cause.  Lacunar strokes are caused by small vessel disease: an intrinsic disease of the small deep perforating arteries. Small vessel disease also causes vascular dementia, and is likely to  play a role in gait disturbance and falls.

At ESOC, there was an excellent session on SVD, which gave plenty of practical advice and food for thought.

Untangling Post-stroke Dementia

European Stroke Organisation Conference (ESOC)
May 16–18, 2017

May 16, 2017
It was refreshing to see a full hall at the ESOC session about the impact of stroke and cognition. In stroke research, it is easy to get distracted by exciting and dramatic things (such as thombectomy working for people who wake up with stroke) and forget some of the other things that are just as important to our patients. Fortunately, the relationship between stroke and cognitive impairment is now firmly on the research agenda.

We know that stroke increases the risk of dementia, but it’s difficult to say just HOW much. The existing data is quite confusing; if you look at patients who have had a large stroke, many will have cognitive impairment, but again many will be unable to take part in cognitive tests. The picture is quite different if we only look at patients with a mild stroke or TIA, as far fewer will have cognitive impairment. The problem is that many studies are only able to recruit patients with milder stroke. To make the problem worse, patients with severe stroke will not survive, so if you are not careful, it can seem that patients with milder stroke are more likely to have dementia at one year.

A Session for the Ages

European Stroke Organisation Conference (ESOC)
May 16–18, 2017

May 16, 2017
The 3rd European Stroke Organization Conference (ESOC) session titled “Official Welcome and Large Clinical Trials” kicked off what was to be a spectacular conference with one of the most impactful 90 minutes I have ever witnessed. The session in the Grand Hall of the Prague Conference Center was standing room only and, after a warm introduction, incorporated 8 presentations from large clinical trials each lasting 8 minutes. The conference itself drew over 4,200 participants, challenging the International Stroke Conference in impact and attendance. This is a remarkable achievement for a conference in its third year of existence.

The Nuts and Bolts of Organizing a Telestroke Network: A Challenging but Achievable Goal

International Stroke Conference (ISC)
February 17-19, 2016

February 17, 2016
The delicate intricacies of Telestroke networks were fully exposed in this interesting session at the International Stroke Conference. The discussion mainly focused on how to set-up Telestroke networks including organizing hubs and spokes, quality and outcome reporting and economic, legal, licensing and credentialing considerations. The highlights have been summarized below.

This field has grown significantly since it origins back in the 1920s. However, it wasn’t until more recent years that it became mainstream care for acute stroke patients after an inflow of literature proved this technology to be a cost-effective intervention from both a societal and hospital perspective. There are essentially three Telestroke network models. The Hub-Spoke one in which a tertiary center provides the service to satellite primary centers, the distributed model where the expertise is delivered by a third party and patients are transferred to available tertiary centers and the Hub-less model where physicians that belong to different institutions take Telestroke call on a rotatory basis to provide regional coverage. Regardless of the model, hubs and spokes may face multiple challenges while trying to institute this technology including, but not limited to, cost burden for small hospitals, commitment from staff for call coverage, access to outside hospital data, ability to interact with the patients and perform accurate physical examinations and the ability to obtain follow-up information on the cases. Often, quality maintenance may become challenging and time consuming requiring 24/7 availability of clinical and technological support, ongoing staff training, hardware and software technology updates, and imaging-sharing capabilities, among others. One topic that was highlighted by several speakers was the need to implement a signed agreement between parties that clearly delineates the type of service provided whether it is consultation only or if ownership privileges are allowed. Unfortunately, no quality measures have been created specifically for Telestroke purposes but national quality improvement strategies such as Target Stroke and Get-With-The-Guidelines can be used for this purpose. Legal and Licensing issues are most often related to the state where this technology is practiced, most importantly the state where the patient that receive care is. Overall, Telestroke has proven to be a reliable practice with minimal variation in stroke assessments (NIHSS) when compared to standard examination, which reduces door-to-needle times and increases the rate of intravenous t-PA administration and endovascular acute stroke treatment leading to better outcomes.

Telestroke is on its way of becoming a large electronic stroke unit that allows stroke experts and tertiary centers connect to stroke patients who need quality diagnosis and treatment regardless of their location. Patient enrollment to clinical trials is another future potential application of this technology. Watch out for this developing field, much more will come and remember: “Successful Telestroke Networks pay attention to details”.

– Luciana Catanese, MD

Improving Access to Stroke Care Through Advocacy

AAN Neurology on the Hill

March 1, 2016
On Super Tuesday, March 1, 2016, members of the American Academy of Neurology met with our lawmakers to advocate for an act of congress to increase availability of acute stroke care. We were joined by a delegation of stroke patient advocates from the AHA/ASA.

The bill is called the FAST Act (Senate 1465, House 2799), which stands for Furthering Access to Stroke Telemedicine. Medicare currently only reimburses for telestroke consultation for patients presenting to hospitals in rural areas, and this bill seeks to expand coverage for patients originating in urban and suburban areas as well.

Though telemedicine has clear utility for patients in rural areas, the vast majority of patients fall victim to stroke in urban and suburban areas. Neurologists and stroke centers are more common in these areas, but this is not universally true. Increasing the availability of telestroke consultation could increase the rate and speed of acute ischemic stroke treatment in more areas.

A number of studies have examined safety, outcomes and cost-effectiveness of telestroke. Most of the data regarding telestroke come from studies in rural settings, in which telestroke systems safely and effectively aid in the treatment of stroke.1,2 Additionally, in urban Madrid, implementation of telestroke was associated with higher rates of IV-tPA administration, faster door-to-needle times, and a lower 3-month mRS scores.3 In terms of cost effectiveness, telestroke networks are at least cost-neutral and likely result in societal cost savings.2,4 Telestroke may have additional unique benefits in urban and suburban areas such as refining access to endovascular therapy.

Politically, this bill is considered a “win-win” bill. It is intended to benefit patients through expansion of coverage, yet is nonetheless expected, by AHA/ASA estimates, to generate considerable savings through the reduction of nursing home and long-term care facility use. Additionally, it has true bipartisan support with at least 25 Democrat and 25 Republican co-sponsors in the house. There is, therefore, a real possibility of this expansion becoming codified in law, whether through passage of the FAST Act or incorporation into other health care legislation.

The FAST Act would require Medicare to reimburse hospitals for telestroke regardless of geography, thereby allowing hospitals to build and strengthen the infrastructure for acute stroke care. The benefits are clear and may exceed expectations.

Concerned readers are encouraged to write to their senators and representatives. Members of the American Academy of Neurology can do so through the Action Center on the AAN website.

– Neal S. Parikh, MD

References
1. Stroke. 2014;45:2739-44.
2. Stroke. 2014;45:1876-80. [Review]
3. J Neurol. 2014;261:1768-73.
4. Am J Manag Care. 2013;19:976-85.

Appropriate Patient Selection for Endovascular Intervention: Common Clinical Challenges and Dilemmas

International Stroke Conference (ISC)
February 17-19, 2016

February 17, 2016
At the International Stroke Conference, a panel of experts discussed various clinical questions in regards to patient selection for endovascular intervention that were not addressed in recent trials. This questions include stroke severity, age, need for imaging, time, and location.

Dr. Khatri discussed stroke severity. Mild strokes were excluded from the recent endovascular trials thus leading to the ASA recommendation of endovascular intervention for strokes with NIHSS > 6. Within the trials, only 14 patients were treated with NIHSS 0-5 so treatment affect and benefit within this subset population is relatively unknown. It’s possible that such patients are mislabeled as “mild” stroke and inappropriately excluded from acute revascularization therapy. The focus should be less on absolute NIHSS number but rather on actual disability. An ACA infarct can register a low NIHSS but can be extremely disabling and should be offered revascularization therapy.


Dr. Powers discussed the important risk factor of age and whether there should be an upper limit. The data suggests limited benefit beyond age > 80 but there are no controls. What is clear from the data that untreated patients do worse and the focus should be on relative benefit rather than absolute benefit. A consensus is age alone should not be a contraindication and treatment decisions should factor baseline health and functional status. There are sufficient anecdotal evidence of successful endovascular treatment with good clinical outcome in octogenarians with a normal functional status at baseline.

Dr. Yoo discussed perhaps one of the more controversial topics of how much imaging is actually required before proceeding with intervention. Many hospitals have adopted CT and CTA scan as their “default” imaging in order to determine eligibility and this has also been adopted within guidelines as well. The dilemma becomes when there are CT hypodensities and more data is needed for ASPECTS of 0-4. In this scenario, it is reasonable to proceed with perfusion imaging to assess for penumbra. DEFUSE-2 is on-going study addressed to determine if perfusion imaging can identify patients for clot retrieval.

Dr. Jovin addressed the important factor of time and when is it getting too late for intervention. It has been well established that collaterals determine rate of infarct growth. Furthermore, patients with good collaterals have also been shown to do well without intervention as well. Therefore, selecting patients based solely on collaterals may be a self-fulfilling prophecy. Two trials are currently underway evaluating outcomes in patients with delayed presentation.

Lastly, Dr. Noguiera discussed the influence of site of occlusion on treatment. Vast majority of patients treated in the trials were large proximal artery occlusion (ICA, M1). With improving technology, clot retrieval is achievable for other sites including ACA, PCA, and M3. However, data on such infarcts are sparse. Only 3 ACA occlusions were included within MR CLEAN. The decision to intervene upon smaller vessels should be based upon risk and benefit. There is greater risk to intervene upon smaller vessels, especially as tortuousity increases, and decision should be based upon other factors including stroke syndrome and anatomy.

– Jay Shah, MD

Regional Pre-hospital Triage and Treatment of Stroke Patients in the New Era of Endovascular Therapy

International Stroke Conference (ISC)
February 17-19, 2016

February 17, 2016
This ISC session focused on a hot-topic: pre-hospital stroke triage and care. We learned about optimizing EMS triage protocols by learning from trauma and MI models, improving EMS providers’ clinical recognition of stroke, when to bypass local PSCs in favor of a CSC, and the role of technology in the pre-hospital setting.

Dr. McMullan from Cincinnati began the session discussing his personal experience as a prior EMT, and described the various levels of training that emergency responders may have. While the advanced technology we are coming up with is great, we can’t realistically have that everywhere and so we need to do our best in getting patients to the most appropriate location with the resources we have. We know that there are better outcomes at high volume/specialty centers, and that delays from secondary transfer decrease outcomes. However, we must recognize the limits of comprehensive centers, in terms of number of patients that can be accommodated. In the trauma example given, we learned that up to a 40% “overtriage” rate is acceptable (sending a lower level trauma to a higher level of care based on initial assessment) but that the acceptable rate of “undertriage” is zero. He ended with the recommendation to “put patients first.” While this sounds obvious, I took it to mean that we should create and use algorithms and protocols to improve patient care, but not allow the rules to impede achievement of this goal. Triage algorithms can be complicated and if there is any hesitation on where to send the patient, keeping this mantra at the forefront of our minds will ensure the best care for our patients.

Dr. Katz, also from Cincinnati, followed with a discussion on EMS identification of severe strokes. He acknowledged that there is no consensus on the definition of a large vessel occlusion based on NIHSS, but that certain features are more suggestive. Multiple stroke scales have been created and tested, including the LMAS, 3ISS, C-STAT (previously the CPSS), and RACE scales. We have not yet decided on a universal scale to use, and further testing needs to be done. Ultimately, the scale has to be predictive of a large vessel occlusion in order for EMS to use it to triage patients who should bypass PSCs. The optimal scale will be easy to administer, have good inter-rater reliability, be validated for LVO prediction, and tested in a large real life population of patients by real EMS providers.

Dr. Asimos from Charlotte, NC, continued the discussion with a review of different stroke triage models and the factors which influence our decision to bypass local PSCs for a CSC. Realizing that there is no “easy” tool for in-the-field determination of LVO, and that some patients will arrive at a CSC without an amenable lesion, we need to determine the NNB (number needed to bypass) for taking patients directly to a CSC in lieu of stopping at a local PSC. Based on a trial conducted in Florida, for every 8 patients who bypassed PSCs, 1 received endovascular therapy. Dr. Asimos recommended that we look at the door to needle times of PSCs (often slower than CSCs), and include that in our decision model. There is also variation in the time it takes to image patients at PSCs, and we should consider which imaging is actually necessary prior to transfer. A study at Emory found that doing CTA and CTP prior to transfer added an hour to the time it took the patient to arrive at the CSC. He concluded by stating that we need target metrics, both for pre-hospital and inter-hospital transfers. I think we need to identify each component of the transfer process to determine where there are time delays and whether skipping that component (i.e. CTA CTP which will most likely be repeated at the CSC prior to taking the patient to endovacscular) is possible. If that reduction in time delay is enough to improve outcomes, we can streamline and standardize the expectations we set for transfer protocols.

Dr. Heinrich Audebert concluded the session with a discussion of the role of technology in pre-hospital triage and care. He pointed out that while only 1-5% of stroke patients are eligible for endovascular therapy, and about 20% are eligible for tPA, almost all patients are eligible for specialized stroke ward treatment. He described the results of the PHANTOM-S trial, in which the CT-equipped STEMO ambulance was compared to standard of care. Fewer stroke patients were transported to hospitals without a stroke unit during STEMO weeks (~4%) than during control weeks (~10%). Dr. Audebert recommended a preliminary triage system before deploying STEMO, as well as an on-call telestroke physician to do an evaluation in the ambulance. While it would be ideal to have a CT scanner in each ambulance, or at least have one available for a larger area which can be deployed after some preliminary triage, this may not be possible given the resources required. I think it is much more feasible to employ affordable telemedicine options, which have previously been explored, to better triage patients to the right place and ensure optimal care.

Overall, a great session on a rapidly growing aspect of stroke care. This same session will likely be very different next year – looking forward to it.

– Ilana Spokoyny, MD

Beyond Atrial Fibrillation: Atrial Cardiopathies as a Cause of Unexplained Stroke (Diagnosis of Stroke Etiology)

International Stroke Conference (ISC)
February 17-19, 2016

February 17, 2016
At an invited symposium at the ISC, attendees were treated to a thorough discussion regarding extended monitoring for AF, biomarkers for AF, and atrial cardiopathy.

First, Dr. Bernstein reviewed recent trials demonstrating the importance and yield of prolonged cardiac monitoring to detect AF in patients with cryptogenic stroke. As we know, approximately 30% of stroke remains cryptogenic after a standard stroke work-up. In EMBRACE, patients with cryptogenic stroke or TIA were randomized to standard of care of 30 days of monitoring. Prolonged monitoring doubled the rate of AF diagnosis (14.8% at 4 weeks as compared to 2.2% after 24 hours and 7.4% after 1 week) and led to an increase in appropriate therapy. In CRYSTAL AF, a similar population was randomized to standard of care and an insertable cardiac monitor. AF diagnosis increased in a time-dependent manner. At ISC 2016, FIND-AF was presented, which randomized all-comer stroke patients to standard of care or 3 10-day monitoring episodes. 4.5% of patients in the control were found to have AF, versus 13.5% at 6 months with up to 3 10-day sessions.

These trials all suggest the importance of prolonged cardiac monitoring. Dr. Bernstein astutely conveyed the opportunities inherent to this data: we may be able to determine the dose-dependence and thresholds of toxicity with regards to AF and stroke.

Second, we were treated to a discussion of structural and serum biomarkers of AF. The goal of biomarker development is to guide early detection of AF in order to initiate early therapy to prevent early recurrent cerebrovascular events. Noteworthy potential biomarkers include cardiac MRI (delayed enhancement reveals atrial fibrosis), atrial blood flow dynamics, and BNP and ANP, for which there are a range of potential cut-offs.

Third, Hooman Kamel provided an overview of electrocardiographic markers of atrial dysfunction that may be independent of AF. He argues that it is important to search for occult AF because 70% of patients with cryptogenic stroke (e.g. in EMBRACE) do not have AF even after prolonged study, suggesting that other mechanisms of disease may have a role. He notes that endothelial dysfunction, fibrosis, impaired myocyte function, and chamber dilation are noted in patients with AF. He conducted multiple studies in various, large cohorts (MESA, Cardiovascular Health Study, ARIC, NOMAS) to demonstrate that the P-wave terminal force on EKG (lead V1) is associated with ischemic stroke and, more specifically, cryptogenic and non-lacunar stroke. This association suggests that atrial cardiopathy may independently be a risk for cardioembolic stroke, with AF perhaps indicating more severe atrial cardiopathy.

Last, Shadhi Yaghi reviewed the therapeutic implications of the atrial cardiopathy model. He has also discussed some of these views in an article in Neurology (2015). A major advantage of the atrial cardiopathy model is that it shrinks the cryptogenic stroke population, which allows more targeted, individualized therapy for secondary stroke prevention. Studies to evaluate the effectiveness of anti-coagulation for secondary prevention in patients with stroke or TIA and markers of atrial dysfunction should be considered. Additionally, this model may allow for prediction of AF, which could, prompt a search for therapies to halt or reverse atrial cardiopathy and also prompt trials for primary prevention of stroke.

In summary, patients with cryptogenic stroke and TIA should undergo prolonged cardiac monitoring to prompt appropriate secondary prevention (anti-coagulation). Structural and serum biomarkers of AF may help us identify patients who can be initiated on anti-coagulation earlier after a stroke, before AF is conclusively diagnosed. AF may be a marker of severe atrial cardiopathy, which may be independently associated with ischemic stroke; emerging data will inform approaches to primary and secondary stroke prevention in patients with risk for cardioembolic stroke in the absence of documented AF.

– Neal S. Parikh, MD

By |February 24th, 2016|Conference|0 Comments

Stroke Controversies: Debate

International Stroke Conference (ISC)
February 17-19, 2016

February 19, 2016
Another standing room only session at the ISC 2016, the Stroke Controversies: Debate was a spirited back and forth session exploring three topics of clinical equipoise between thought leaders in their respective fields, of which there are no easy answers.
 
Debate #1: Should we bypass primary stroke centers (PSC)? Arguing in favor, Dr. Goyal points out that tPA does not work very well for proximal large vessel occlusions, the NNT is as low as 2.6 for endovascular therapy, time is brain and we lose time (and therefore brain) transferring from a PSC to a comprehensive stroke center (CSC). Dr. Johnston agreed that in some cases, i.e. if the patient does not qualify for tPA, it may be reasonable, but endovascular treatment is only proven safe and efficacious for a minority of patients. As of now, there is no way to effectively screen patients in the field, and bypassing a PSC may in these situations delay treatment with tPA.

I interpreted this as a debate between pragmatism and idealism. The ideal might be bypassing a PSC, but pragmatically, within our current system of stroke care, this may lead to saving time for a subset of patients with large vessel occlusion at the expense of delaying tPA for the majority of patients, especially within the context of the resources that we have. We need a better work flow to minimize delays in transfers if we continue to rely on PSCs, or alternatively, better screening measures in the field if we want to bypass them.

Debate #2: Embolic stroke, atrial fibrillation, and cerebral microbleeds: Is there a role for anticoagulation? Dr. Diener presented the pro side, arguing that afib increases the risk of stroke and while some microbleeds, such as with amyloid angiopathy, may be a contraindication, others are markers of small vessel disease. NOACs have a more favorable profile for ICH than warfarin and has been demonstrated to not increase microbleeds. Dr. Greenberg, however, iterated the dismal outcome of anticoagulation related ICH (up to 50%), and pointed out that microbleeds lead to 5 ICH events/100 person years. A decision analysis modeling the risk/benefit ratio of anticoagulation has previously identified an ICH risk of 1.4% as the tipping point where risk of anticoagulation outweighed benefits.

There is no easy resolution to this debate. With safer NOACs being introduced, it would seem reasonable to anticoagulate, even in the presence of microbleeds. In parallel, as treatments of ICH continue to advance, the mortality of anticoagulation related ICH will hopefully decline to the point where we will no longer fear it.

Debate #3: Should we assess the outcome of severe strokes early (3 months) or late in clinical trial? Both Dr. Dawson, who argued in favor of an early assessment, as well as Dr. Broderick, who argued in favor or a late assessment, used data from the MISTIE II and IMS III to support their points, which perhaps points to the true equipoise in this question. Dr. Dawson’s point was that in general, the longer a trial is conducted, the more confounders are introduced and often, additional time does not add information that significantly changes the interpretation of the results. Given the resources available, a better approach may be to recruit more patients within a shorter trial rather than follow less patients for a longer time frame. Dr. Broderick argued that especially with severe strokes, there are patients who recover later, and delayed follow up allows for better cost effect analysis.

Much like the first debate, some of this is a question of what is practical vs what is ideal. Delayed recovery is still important for the patient and the physician, and a later assessment allows us to fully capture all of these patients; it will allow us to answer the question of the sustainability of recovery. However, with limited funds for trials, it may be difficult to implement this. 

– Peggy Nguyen, MD