American Heart Association

Yearly Archives: 2018

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|Comments Off on Collateral Status Modulates the Effect of Glucose on Outcomes in Mechanical Thrombectomy
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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|Comments Off on Article Commentary: “Intravenous tPA in Patients With Acute Ischemic Stroke Taking Non–Vitamin K Antagonist Oral Anticoagulants Preceding Stroke”
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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|Comments Off on Bypassing Primary Stroke Centers: Are We There Yet?
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Acute Stroke Treatments for Patients with Pre-Stroke Disability: Are We Discriminating Against the Disabled?

Robert W. Regenhardt, MD, PhD
@rwregen

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|Comments Off on Acute Stroke Treatments for Patients with Pre-Stroke Disability: Are We Discriminating Against the Disabled?
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Diabetic Condition Worsens Functional Deficits After Stroke

Lin Kooi Ong, PhD
@DrLinOng

Ma S, Wang J, Wang Y, Dai X, Xu F, Gao X, et al. Diabetes Mellitus Impairs White Matter Repair and Long-Term Functional Deficits After Cerebral Ischemia. Stroke. 2018

This article by Wang and colleagues aimed to investigate the impact of diabetes on brain recovery after stroke using a preclinical model, comparing wild type male mice to diabetes (db/db) mice. The team observed a significant decrease in sensorimotor performance in diabetes mice after stroke. It should be noted that the team did not observe deficit in memory function using the Morris water maze. There was an exacerbated white matter damage at both structural and functional levels. Further, there was an enhanced inflammatory response at the white matter in diabetes mice after stroke, such as a shift of microglia/macrophage to pro-inflammatory phenotype and higher levels of IL-1β and IL-6 expression. The inflammatory environment inhibited oligodendrogenesis, a brain repair mechanism to generate new myelinating oligodendrocytes. These findings provide compelling preclinical evidence that diabetic condition exacerbates functional deficits after stroke.

By |November 12th, 2018|approved, basic sciences|Comments Off on Diabetic Condition Worsens Functional Deficits After Stroke
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Intravenous Thrombolysis in the Endovascular Mechanical Thrombectomy Era: Clot Location Determines Perfusion Outcomes

Ravinder-Jeet Singh, MBBS, DM

Kaesmacher J, Giarrusso M, Zibold F, Mosimann PJ, Dobrocky T, Piechowiak E, et al. Rates and Quality of Preinterventional Reperfusion in Patients with Direct Access to Endovascular Treatment. Stroke. 2018

Use of intravenous tissue plasminogen activator (IV-tPA) before endovascular thrombectomy (EVT) among patients with large vessel occlusion (LVO) has become controversial in recent years. The main concerns are its limited efficacy to lyse large clots in the proximal arteries, which responds excellently to EVT. Thus, tPA use adds to the total treatment cost with potentially no additional clinical benefits over and above those provided by EVT. Furthermore, there are theoretical concerns of thrombus migration and neurological worsening, and also thrombus fragmentation with lodgement in the distal region of the involved territory, which then becomes inaccessible to EVT. In contrast, IV-tPA could lead to early recanalization in a proportion of patients leading to timely reperfusion and better outcomes and may obviate the need for EVT and associated cost.

By |November 9th, 2018|clinical|Comments Off on Intravenous Thrombolysis in the Endovascular Mechanical Thrombectomy Era: Clot Location Determines Perfusion Outcomes
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World Stroke Congress Session: Advances in Stroke Imaging

World Stroke Congress
October 17-20, 2018

Ravinder-Jeet Singh, MBBS, DM

The session on advances in stroke imaging was very interesting and informative. Three speakers — Dr. Ken Butcher from Edmonton and Drs. Gregory Albers and Chitra Venkatasubramanian from Stanford — discussed some of the recent changes in the field of stroke imaging and how it is influencing the practice of stroke care.

Dr. Butcher spoke about multimodal CT based imaging paradigms in acute ischemic stroke, especially use of CTA and CTP in patient selection. It is of note that two of the “early window” EVT trials (SWIFT PRIME and EXTEND IA) and both the late window trials (DAWN and DEFUSE 3) used perfusion imaging for patient selection. He discussed various software platforms available for processing and interpreting CTP data. Options include inbuilt software provided by CT vendors and other commercially available software including RAPID (iSchemaView Inc.), MIstar (Apollo Medical Imaging Technology), and OleaSphere (Olea Medical). The key message was that clinicians should be careful in interpreting CTP images and also the outputs (core, penumbra volumes, and mismatch ratios) provided by these softwares. It is essential to look at arterial input function and venous output function curves to assess the quality of CTP data. These curves should display rapid upslopes and downslopes. Presence of any truncation of these curves should also be noted, which could lead to misestimation of core and penumbra size. In addition, the presence of motion artifacts can severely degrade image quality and, therefore, its interpretation. He also pointed out another important area in which CTP could be helpful — the stroke mimics — where a normal CTP would be reassuring in the appropriate clinical context.

By |November 7th, 2018|clinical, Conference|Comments Off on World Stroke Congress Session: Advances in Stroke Imaging
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Collaterals vs. Time in the Natural History of Acute Ischemic Stroke

Raffaele Ornello, MD

Vagal A, Aviv R, Sucharew H, Reddy M, Hou Q, Michel P, et al. Collateral clock is more important than time clock for tissue fate – A natural history study of acute ischemic strokes. Stroke. 2018

The endovascular treatment of ischemic stroke is beneficial up to 24 hours from symptom onset, provided that neuroimaging studies show the presence of ischemic penumbra, i.e., the hypoperfused brain region which has not progressed to infarction. Over time, the ischemic penumbra progresses to infarction, thus limiting the possibility of treating ischemic stroke; however, current literature suggests that the presence of robust collateral vessels delays that progression.

By |November 6th, 2018|clinical, diagnosis and imaging|Comments Off on Collaterals vs. Time in the Natural History of Acute Ischemic Stroke
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Transcranial Stimulation for Aphasia Recovery in Subacute Stroke Patients

Danielle de Sa Boasquevisque, MD

Spielmann K, van de Sandt-Koenderman WME, Heijenbrok-Kal MH, Ribbers GM. Transcranial Direct Current Stimulation Does Not Improve Language Outcome in Subacute Poststroke Aphasia. Stroke. 2018

Trancranial direct current stimulation (tDCS) is a non-invasive neuromodulation therapy with the potential to enhance recovery after ischemic stroke. This technique uses a weak electrical current that ultimately leads to a polarity specific change in excitability: increasing cortical excitability (anodal tDCS), decreasing cortical excitability (cathodal tDCS), or a combination of both effects (bihemispheric). Many studies demonstrated benefit in chronic aphasia, but research within the early phase after stroke, when the mechanisms of neuroplasticity are more active, are still scarce.

In this article, the authors aimed to investigate the effects of online anodal tDCS applied over the left inferior frontal gyrus on aphasia recovery in the subacute phase after stroke. This study was a multi-center double-blinded clinical trial that enrolled patients with aphasia after ischemic or hemorrhagic stroke between 3 weeks and 3 months poststroke. Participants were randomized to 2 parallel groups: anodal tDCS (1mA, 20 minutes) and sham tDCS. They also received online tDCS while on 2 weeks (5 sessions/week) of 45-min word-finding language therapy session.

By |November 5th, 2018|clinical, treatment|Comments Off on Transcranial Stimulation for Aphasia Recovery in Subacute Stroke Patients
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Alteplase in Minor Stroke: A Daily Dilemma

Alejandro Fuerte, MD

Levine SR, Weingast SZ, Weedon J, Stefanov DG, Katz P, Hurley D, et al. To Treat or Not to Treat? Exploring Factors Influencing Intravenous Thrombolysis Treatment Decisions for Minor Stroke. Stroke. 2018

The activase/alteplase package insert from the Food and Drug Administration was updated in February 2015. Despite this, controversy continues over the criteria for the use of this drug in minor stroke, defined as National Institutes of Health Stroke Scale (NIHSS) score 1 to 5. In this article, Levine et al explore clinical factors influencing alteplase treatment decisions for patients with ictus minor.

This is a descriptive study. A committee of stroke experts identified the key factors in making decisions about the use of alteplase. The most prominent factors on the basis of which the study was developed were the following: all patient-dependent: National Institutes of Health Stroke Scale (NIHSS), NIHSS area of primary deficit, baseline functional status, previous ischemic stroke (IS), previous intracerebral hemorrhage (ICH), recent anticoagulation, and temporal pattern of symptoms in first hour of care. A fractional factorial design was used to provide unconfounded estimates of the effect of the 7 main factors, plus first-order interactions for the NIHSS. A joint statistical analysis was then applied.

By |November 2nd, 2018|clinical, treatment|Comments Off on Alteplase in Minor Stroke: A Daily Dilemma
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