American Heart Association

Monthly Archives: November 2018

Mechanical Thrombectomy in Patients with Minor Strokes and Large Vessel Occlusion: The “Too Good to Intervene” Dilemma

Victor J. Del Brutto, MD

Nagel S, Bouslama M, Krause LU, Küpper C, Messer M, Petersen M, et al. Mechanical Thrombectomy in Patients With Milder Strokes and Large Vessel Occlusions: A Multicenter Matched Analysis. Stroke. 2018

Over half of acute ischemic strokes in the U.S. present with mild deficits as defined by an initial NIHSS score of 5 or less. Despite having deficits perceived as “minor”, around 30% of these patients will not achieve a good functional outcome at follow-up. Large vessel occlusion (LVO) is found in 10 to 20% of patients with minor strokes. Presence of LVO has been associated with early neurological deterioration, as well as decreased likelihood of good recovery. Minor symptoms in the setting of a major occluded vessel pictures good collateral flow maintaining tissue perfusion. On the other hand, frequent early clinical deterioration and worse functional outcomes expose the potential failure of aforementioned collaterals and infarct expansion.

Mechanical thrombectomy  (MT) is the current standard of care for selected patients with LVO and initial NIHSS score ≥6; however, the benefit of MT in patients with milder symptoms remains uncertain. Recanalization is an appealing solution to prevent clinical deterioration and improve long-term functional outcome in these patients. Nonetheless, the treatment effect might not provide a significant benefit and could add potential risk for complications related to the procedure, such as hemorrhagic conversion, emboli to new vascular territories, failure of collaterals due to transient hypotension related to anesthesia, etc.

By |November 30th, 2018|clinical|0 Comments

The Modified Treatment in Cerebral Ischemia Score: Does It Matter Who is Scoring It?

Mohammad Anadani, MD

Zhang G, Treurniet KM, Jansen IGH, Emmer BJ, van den Berg R, Marquering HA, et al. Operator Versus Core Lab Adjudication of Reperfusion After Endovascular Treatment of Acute Ischemic Stroke. Stroke. 2018

Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke treatment. The goal of MT is to restore perfusion to the affected area. Hence, its efficiency is evaluated by the degree of reperfusion at the end of the procedure. The Modified Treatment in Cerebral Ischemia (mTICI) score is the most widely used reperfusion score, and it was used in most of the recent intra-arterial treatment landmark trials to assess the efficacy of mechanical thrombectomy. It was also used to compare different thrombectomy techniques, especially contact aspiration and stent retriever techniques. The mTICI score ranges from 0-3, where 0 means no perfusion and 3 means complete perfusion. In the randomized trial settings, mTICI is usually assessed by core laboratories to avoid overestimation. However, this notion of overestimation by local operators has not been supported by research studies.

By |November 28th, 2018|clinical|0 Comments

Observational Study Data on the Utility of EVT for Acute Ischemic Stroke Patients with LVO and Mild Neurological Deficits: Shivering Lights Through the Mist!

Aristeidis H. Katsanos, MD, PhD

Nagel S, Bouslama M, Krause LU, Küpper C, Messer M, Petersen M, et al. Mechanical Thrombectomy in Patients With Milder Strokes and Large Vessel Occlusions: A Multicenter Matched Analysis. Stroke. 2018

Sarraj A, Hassan A, Savitz SI, Grotta JC, Cai C, Parsha KN, et al. Endovascular Thrombectomy for Mild Strokes: How Low Should We Go? A Multicenter Cohort Study. Stroke. 2018

According to the current guidelines from the American Heart Association/American Stroke Association, endovascular thrombectomy (EVT) should be implemented in the treatment of acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) who have a measurable neurological deficit of at least 6 points in the National Institutes of Health Stroke Scale (NIHSS) on admission, providing however weak support for the use of EVT in AIS patients with internal carotid artery (ICA) or proximal middle cerebral artery (MCA-M1) occlusion and a baseline NIHSS score less than 6. In the October issue of Stroke, two independent multicenter study groups aimed to answer the question on the utility of EVT in patients with LVO and mild AIS severity (NIHSS <6).

By |November 27th, 2018|clinical|0 Comments

How Long Should We Give Dual Antiplatelet Therapy After Minor Acute Ischemic Stroke?

World Stroke Congress
October 17-20, 2018

Danielle de Sa Boasquevisque, MD

Following a Transient Ischemic Attack (TIA) or minor ischemic stroke, the risk of having another ischemic stroke or vascular events within the next three months is 10-20%. The Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) Trial was a randomized, double-blind study designed to evaluate the benefit of dual antiplatelet therapy (DAPT) compared to aspirin alone during the first 90 days after a minor ischemic stroke or transient ischemic attack. The primary efficacy outcome was major ischemic events, and the primary safety outcome was major hemorrhage.

The POINT Trial was halted after 84% of the anticipated number of participants had been enrolled. They found that patients enrolled in 3 months of DAPT had fewer major ischemic events than patients given aspirin alone (5% versus 6.5%, respectively; hazard ratio, 0.75; 95% confidence interval [CI], 0.59 to 0.95; p=0.02). However, the DAPT also seemed to increase chances of major hemorrhage compared to the aspirin controls (0.9% versus 0.4%, respectively; hazard ratio 2.32; 95% CI, 1.10-4.87; p=0.02).

A secondary analysis of POINT Trial data was presented by Jordan J. Elm at the World Stroke Congress in October in Montreal. It aimed to identify the time course of risks versus benefits of clopidogrel and aspirin in acute minor ischemic stroke and high-risk TIA patients and determine if there is an optimal time when patients would benefit most from using both aspirin and clopidogrel.

Article Commentary: “Resting-State Functional Connectivity Magnetic Resonance Imaging and Outcome after Acute Stroke”

Alexis N. Simpkins, MD, PhD

Puig J, Blasco G, Alberich-Bayarri A, Schlaug G, Deco G, Biarnes C, et al. Resting-State Functional Connectivity Magnetic Resonance Imaging and Outcome After Acute Stroke. Stroke. 2018

Many ischemic stroke patients will have residual disability from their stroke even if they receive thrombolysis or endovascular therapy. In fact, stroke is and is projected to continue to be one of the leading causes of long-term disability in adults. Identifying tools that can be used to accurately predict expected stroke recovery can change the way the patient is medically managed and can be used as an outcome measure in clinical trials. Changes in NIHSS, infarct volume, and stroke lesion have been shown to predict early neurologic outcome, but there are still limitations with each of these predictors. As a result, there are continued efforts to provide more sensitive and specific predictive models. Here, the authors assessed whether resting state-functional MRI (rs-fMRI) is associated with projected neurologic outcome at 90 days and can be combined with other frequently used predictors to improve accuracy. The selection of rs-fMRI was supported by previous studies that demonstrated an association between resting state and task-oriented functional connectivity and previous reports of the role of interhemispheric connectivity in stroke recovery.

Acute Intracranial Atherosclerosis–Related Large Vessel Occlusion: Recanalization as a Starting Point

Elena Zapata-Arriaza, MD

Baek JH, Kim BM, Heo JH, Kim DJ, Nam HS, Kim YD. Outcomes of Endovascular Treatment for Acute Intracranial Atherosclerosis–Related Large Vessel Occlusion. Stroke. 2018

In this entry, I discuss a recent publication by Jang-Hyun Baek and colleagues regarding the endovascular and clinical outcomes of patients with Acute Intracranial Atherosclerosis–Related Large Vessel Occlusion, treated with endovascular therapy.

The introduction of retrievable stents as first choice technique for endovascular therapy in acute ischemic stroke has allowed a high recanalization rate, and has been associated with a good clinical outcome. However, the etiology of stroke may affect the success of the mentioned recanalization technique.

By |November 20th, 2018|clinical|0 Comments

Collateral Status Modulates the Effect of Glucose on Outcomes in Mechanical Thrombectomy

Lina Palaiodimou, MD

Kim J-T, Liebeskind D, Jahan R, Menon B, Goyal M, Nogueira R, et al. Impact of Hyperglycemia According to the Collateral Status on Outcomes in Mechanical Thrombectomy. Stroke. 2018

Hyperglycemia upon admission is a common phenomenon in acute ischemic stroke and is an independent predictor of poor outcome in both diabetic and non-diabetic stroke patients. More specifically, previous studies have shown that hyperglycemia is independently associated with infarct expansion, early hemorrhagic transformation, impaired recanalization and increased rates of symptomatic intracranial hemorrhage after intravenous thrombolysis. Increased admission and fasting glucose are associated with unfavorable short-term outcome in patients with large vessel occlusion treated with endovascular reperfusion therapies, especially in the subgroup of patients not achieving complete reperfusion following mechanical thrombectomy. However, aggressive serum glucose lowering in clinical studies failed to translate into improvements in functional outcomes, indicating heterogeneity of the biological effects of glucose and the different ways that can modify prognosis in different clinical settings. Accordingly, case-specific glucose management appears to be important.

Κim et al. conducted a post-hoc analysis using data from the Triple-S database, in order to explore the potential association between poor collaterals at presentation and hyperglycemia and the interaction between pretreatment collaterals and glucose upon admission on outcomes. They obtained data from 3 prospective clinical trials (SWIFT, SWIFT PRIME and STAR) and included 309 patients who had acute ischemic stroke with moderate to severe neurological deficit and angiographically confirmed large vessel occlusion and were treated with mechanical thrombectomy within 8 hours of onset. Pretreatment collaterals grades were scored according to the American Society of Interventional and Therapeutic Neuroradiology collateral grading (AGC) system, and reperfusion was evaluated using modified TICI score.

By |November 19th, 2018|clinical|0 Comments

Article Commentary: “Intravenous tPA in Patients With Acute Ischemic Stroke Taking Non–Vitamin K Antagonist Oral Anticoagulants Preceding Stroke”

Muhammad Zeeshan Memon, MD

Jin C, Huang RJ, Peterson ED, Laskowitz DT, Hernandez AF, Federspiel JJ, et al. Intravenous tPA (Tissue-Type Plasminogen Activator) in Patients With Acute Ischemic Stroke Taking Non–Vitamin K Antagonist Oral Anticoagulants Preceding Stroke. Stroke. 2018

The 2018 AHA stroke council guidelines caution against potential harm in administrating intravenous tPA to patients taking Non–Vitamin K Antagonist Oral Anticoagulants (NOACs) unless sensitive laboratory tests are normal or the last intake of NOACs is >48 hours before stroke (Class III: harm; level of evidence C-expert opinion). However, this recommendation is complex to implement because of the lack of rapidly available sensitive tests. Global coagulation tests such as PT, aPTT, and INR are not specific for NOACs and commonly unable to be obtained in the hyperacute stroke presentation setting. In the absence of any confirmatory data, patients with atrial fibrillation and DVT/PE on NOACs are excluded from IV t-PA administration.

By |November 16th, 2018|clinical|0 Comments

Bypassing Primary Stroke Centers: Are We There Yet?

Richard Jackson, MD

Suzuki K, Nakajima N, Kunimoto K, Hatake S, Sakamoto Y, Hokama H, et al. Emergent Large Vessel Occlusion Screen Is an Ideal Prehospital Scale to Avoid Missing Endovascular Therapy in Acute Stroke. Stroke. 2018

Kentaro Suzuki et al. developed a new prehospital stroke scale called the Emergent Large Vessel Occlusion (ELVO) screen for use by paramedics to identify large vessel occlusions (LVO) for diversion of transport to the nearest thrombectomy-capable location.

In the introduction, they comment that transport of patients without LVO is “unwise, time consuming, and expensive” and, therefore, the need has arisen for better emergent stroke transportation systems.  They base this on data that showed, in their words, unacceptable negative predictive values (NPV) and a possible 20% of missed LVO eligibility.

They comprised their scale based on cortical symptoms with simplicity in mind. The scale consists of paramedic observation of eye deviation, a question regarding naming of eye glasses or a watch, and a question about neglect regarding naming of the number of fingers being held up for visual confrontation. A positive result was an abnormality on any of the three items.

By |November 14th, 2018|clinical|0 Comments

Acute Stroke Treatments for Patients with Pre-Stroke Disability: Are We Discriminating Against the Disabled?

Robert W. Regenhardt, MD, PhD

Ganesh A, Luengo-Fernandez R, Pendlebury ST, Rothwell PM. Long-Term Consequences of Worsened Poststroke Status in Patients With Premorbid Disability: Implications for Treatment. Stroke. 2018

Goldhoorn R-JB, Verhagen M, Dippel DWJ, van der Lugt A, Lingsma HF, Roos YBWEM, et al. Safety and Outcome of Endovascular Treatment in Prestroke-Dependent Patients: Results From MR CLEAN Registry. Stroke. 2018

Robust, randomized trial evidence exists supporting the efficacy of thrombolysis and thrombectomy to reduce disability after acute ischemic stroke for select patients. However, there is a paucity of evidence for patients with pre-stroke disability since patients with baseline mRS 2-5 are often excluded from trials. Like many acute stroke care providers, I have found myself in several situations in which our team pauses as we learn the pre-stroke mRS is not perfect. It spurs some debate, as in many cases the pre-stroke disability seems to have little implications for hemorrhage risk, procedural risk, or treatment efficacy. Ganesh et al. point out that exclusion of patients with mRS 2-5 is not based on mechanistic hypotheses about reduced benefit for this population necessarily, but reflects that pre-stroke disability prevents patients from contributing to the typical dichotomized mRS analyses. They further discuss that patients with mRS 2-4 would likely consider retaining their pre-stroke status a favorable outcome, but pre-stroke disability is often cited as a reason for withholding treatment.

By |November 13th, 2018|clinical|0 Comments