American Heart Association

clinical

Predicting Hemorrhagic Transformation Following tPA Using CT and CT Perfusion Images

Sami Al Kasab, MD

Batchelor C, Pordeli P, d’Esterre CD, Najm M, Al-Ajlan FS, Boesen ME, et al. Use of Noncontrast Computed Tomography and Computed Tomographic Perfusion in Predicting Intracerebral Hemorrhage After Intravenous Alteplase Therapy. Stroke. 2017

Intracerebral hemorrhage (ICH) is a known complication of intravenous alteplase. The rates of symptomatic intracerebral hemorrhage following intravenous alteplase administration have varied between 1-4% depending on the definition used and the study.

In this study, Drs. Connor et al analyze the association between multimodal CT imaging parameters, including NCCT hypo attenuation degree, vlCBV, impaired blood-brain barrier permeability surface product, clinical and laboratory data at baseline, early reperfusion status, and development of parenchymal hemorrhage (PH) on follow-up imaging. All patients received NCCT, CT angiography, and CT perfusion at baseline. A 24 to 48 hour scan (either NCCT or MRI) was obtained. Imaging analyses were performed by readers blinded to other imaging and patient outcomes. All NCCT were scored for ASPECTS scores, the degree of hypo attenuation within the ischemic region using a 3-point grading system. Functional parametric maps of cerebral blood flow (CBF), CBV, Tmax, and a modified CTP algorithm for permeability calculations were used.

Resistant Atherosclerosis

Philip Chang, MD

Spence JD, Solo K. Resistant Atherosclerosis: The Need for Monitoring of Plaque Burden. Stroke. 2017

In this study, Spence and Solo demonstrated that measurement of LDL-C levels is likely inadequate to assess a patient’s response to statin therapy. In their database of 4512 patients with 2 measurements of LDL-C and 2 carotid duplex scans measuring total plaque area, they found that neither LDL-C levels nor change in LDL-C levels predicted carotid artery plaque burden or progression of plaque area. Interestingly, they found that in the 6% of patients with low LDL-C levels (<38mg/dL), almost half experienced progression of their plaque burden. In addition, they found that it was not uncommon for patients with LDL-C levels of over 70mg/dL to experience plaque regression. This suggests that merely relying on an LDL-C level to predict plaque burden is insufficient.

Carotid Stenting vs. Endarterectomy: Vascular Anatomy Predicts Stroke Risk

Hatim Attar, MD

Müller MD, Ahlhelm FJ, von Hessling A, Doig D, Nederkoorn PJ, Macdonald S, et al. Vascular Anatomy Predicts the Risk of Cerebral Ischemia in Patients Randomized to Carotid Stenting Versus Endarterectomy. Stroke. 2017

There has been a longstanding debate on management of patients with carotid disease. In the ICSS study, patients were randomly assigned to Carotid Artery Stent (CAS) vs. Carotid Endarterectomy (CEA). CAS was related to higher peri-procedural stroke risk, but both therapies were equally effective in long-term stroke prevention. This study is a post-hoc analysis on a sub group of the ICSS study, providing the first randomized trial on vascular anatomy as an independent procedural risk factor for stroke during CAS and CEA. Studies have been completed assessing vascular anatomy for procedural risks with CAS, but none have compared the risk between CAS and CEA, making this study unique and its results invaluable.

In the ICSS MRI subgroup, brain MRI was performed before and 1-3 days after CAS or CEA; primary outcome was new diffusion restricted lesions. Patients in this study underwent Contrast Enhanced Magnetic Resonance Angiography (CE- MRA) or Computed Tomographic Angiography (CTA) to define vascular anatomy. Vascular anatomy was objectified with measurable criteria. Aortic arches were divided into three types based on origins of supra aortic arteries, and angles between all large vessels were defined, as shown below in the images.

 The authors validated the inter-rater reliability on reading these anatomic parameters. Associations were made between the laterality, stenosis length and degree, plaque ulcerations and vasculature angles.

There were 184 patients with vessel imaging; 97 were assigned to CAS, 87 to CEA. Procedural cerebral ischemia was found in 49 of the CAS group (51%), with only 14 after CEA (16%). After correcting for age, only two factors were found to be statistically significant in the CAS group—aortic arch configuration type 2 and 3, and larger ICA angulation (≥ 60 degrees). 

Heart Failure Associated With All Types of Strokes at Long-term Follow Up

Peggy Nguyen, MD

Adelborg K, Szépligeti S, Sundbøll J, Horváth-Puhó E, Henderson VW, Ording A, et al. Risk of Stroke in Patients With Heart Failure: A Population-Based 30-Year Cohort Study. Stroke. 2017

Heart failure has previously been identified in association with ischemic stroke, with previous literature citing thrombus formation, hypercoagulable state, endothelial dysfunction and impaired cerebral autoregulation as possible mechanisms underlying ischemia. Additionally, heart failure and stroke share several common etiological conditions, including hypertension and dyslipidemia (Stroke. 2011;42:2977-2982). However, the association between heart failure and hemorrhagic stroke, and the long-term implications of heart failure on all-stroke risk, remained to be clearly elucidated. Here, patients with heart failure (n = 289,353) were compared to an age and gender matched control group (n = 1,446,765), for the outcomes of ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) evaluated at 30 days, 1 year, and 30 years, providing a far more extensive follow up than previous studies.

Breakthroughs in Neurorehabilitation: Using Brain Computer Interfaces for Stroke Recovery

Gurmeen Kaur, MBBS
@kaurgurmeen

Bundy DT, Souders L, Baranyai K, Leonard L, Schalk G, Coker R, et al. Contralesional Brain–Computer Interface Control of a Powered Exoskeleton for Motor Recovery in Chronic Stroke Survivors. Stroke. 2017

Brain computer interfaces (BCIs) are defined as systems which take biological signal from a person and predict some abstract aspect of the person’s cognitive state. The goal of the BCI technology is to give severely paralyzed people a way to communicate.

While BCIs can use several input-signals, including EEG, EMG, and fMRIs, the BCI technology developed for chronic stroke rehabilitation has been focused on demonstrating motor improvement with the use of EEG input. Recent studies have shown that BCI-controlled orthoses or functional electric stimulators can lead to improvements in motor function in chronic stroke survivors.

In this study, the authors recruited 10 subjects with chronic hemiparesis involving the upper extremity for a home-based BCI powered exoskeleton. Previous experimenters had used EEG signals derived from “perilesional” cortex, contralateral to the arm involvement—which means the area next to that affected by the stroke. The problem with use of perilesional cortex was that if the infarct size is large, with extensive cortical damage, the perilesional cortex was not able to produce sufficient EEG signal to power the exoskeleton. To overcome this, the authors used “contralesional” cortex, ipsilateral to the affected arm. This is the first study to look at the use of the unaffected hemicortex in chronic stroke recovery and aimed to see if plasticity could be triggered.

An Update on Poststroke Fatigue

Stephen Makin, PhD
@StephenMakin

Hinkle JL, Becker KJ, Kim JS, Choi-Kwon S, Saban KL, McNair N, et al, on behalf of the American Heart Association Council on Cardiovascular and Stroke Nursing and Stroke Council. Poststroke Fatigue: Emerging Evidence and Approaches to Management: A Scientific Statement for Healthcare Professionals From the American Heart Association. Stroke. 2017

After a stroke, fatigue is a big deal; even my patients who make an excellent physical recovery can be very limited by the fatigue. From my clinical practice, it appears to be very common and often very disabling. So, I was interested to read this interesting review on poststroke fatigue.

The prevalence of poststroke fatigue varies depending on different methods used to measure it, but it’s estimated at 40%. It’s associated with a reduced quality of life, so it’s something we should all be aware of. Although it’s more common after stroke, some people who have a TIA also suffer from fatigue.

When I first heard about poststroke fatigue I thought it was simply depression, which is also common poststroke. However, only 38% of fatigued patients are depressed, and anti-depressant medication doesn’t seem to be effective.

Resuming Anticoagulation After Intracranial Hemorrhage: The Tides are Shifting

Danny R. Rose, Jr., MD

Murthy SB, Gupta A, Merkler AE, Navi BB, Mandava P, Iadecola C, et al. Restarting Anticoagulant Therapy After Intracranial Hemorrhage: A Systematic Review and Meta-Analysis. Stroke. 2017

For most clinicians, intracerebral hemorrhage (ICH) is the most feared potential complication of anticoagulation therapy, carrying significant morbidity and mortality. Clinical decision-making regarding the resumption of anticoagulation for patients for whom it is indicated is complex, as many of these patients have significant risk of ischemic and hemorrhagic events. Traditionally, providers have been reluctant to restart anticoagulation after ICH, especially for patients with atrial fibrillation as compared to mechanical valves.

AHA guidelines reflect the lack of clarity on this matter, with current recommendations (Class IIa) to avoid anticoagulation after spontaneous lobar ICH in patients with non-valvular atrial fibrillation (NVAF), and to consider resuming antiplatelet therapy after all ICH and anticoagulation in patients with non-lobar ICH (Class IIb). Selection and timing for resumption of anticoagulation has been the topic of ongoing research, with the results of pertinent studies presented at the International Stroke Conference, as well as the European Stroke Organisation Conference in 2017. In addition to this, a recent meta-analysis published in Stroke by Drs. Murthy et al. sought to address this clinical challenge by reviewing available studies with respect to the safety and efficacy of restarting anticoagulation after ICH. To understand the significance of this study in the context of evolving concepts regarding anticoagulation after ICH, we will start by reviewing a previous study with similar aims.

Key to Identifying the Culprit Aneurysm Among Multiple Aneurysms in Patients with Subarachnoid Hemorrhage

Tapan Mehta, MBBS, MPH

Björkman J, Frösen J, Tähtinen O, Backes D, Huttunen T, Harju J, et al. Irregular Shape Identifies Ruptured Intracranial Aneurysm in Subarachnoid Hemorrhage Patients With Multiple Aneurysms. Stroke. 2017

Endovascular therapy has become the treatment of choice for the majority of ruptured saccular intracranial aneurysms (sIAs). About 15–30% of patients can present with more than one sIA. Identification of ruptured sIA could sometimes be difficult without direct visualization (micro surgically) when more than one sIA is located in close proximity to the site of the hemorrhage on the computed tomography (CT). It is important to identify the ruptured aneurysm correctly to aid definitive endovascular management. This article adds to the literature on the importance of aneurysm shape in addition to size in determining rupture status of sIAs.

Author Interview: Santosh Murthy, MD, MPH

Santosh Murthy

Santosh Murthy

A conversation with Santosh Murthy, MD, MPH, Assistant Professor of Neurology and Neuroscience, Weill Cornell Medicine, about the decision on when to restart anticoagulation after intracranial hemorrhage.

Interviewed by José G. Merino, MD, Associate Professor of Neurology, University of Maryland School of Medicine.

They will be discussing the paper “Restarting Anticoagulant Therapy After Intracranial Hemorrhage: A Systematic Review and Meta-Analysis,” published in the June 2017 issue of Stroke.

Dr. Merino: Can you please summarize the key findings of your study and place them in context of what was already known on the topic?

Dr. Murthy: There is a lack of standardized recommendations regarding the use of anticoagulant therapy after intracerebral hemorrhage (ICH). Our meta-analysis of observational studies suggests that compared with withholding anticoagulation, resumption of anticoagulant therapy after ICH significantly lowers the risk of ischemic stroke and myocardial infarction (MI) with no discernable elevation in the risk of ICH recurrence. While our results help summarize the existing literature and may serve as a guide to clinicians in making informed decisions, randomized clinical trials are needed to determine the true risk-benefit profile of anticoagulation resumption after ICH.

Author Interview: Colin Derdeyn, MD

Colin Derdeyn

Colin Derdeyn

A conversation with Colin Derdeyn, MD, Chair and Departmental Executive Officer of the Department of Radiology, University of Iowa Carver College of Medicine, about the late complications of stenting for intracranial atherosclerotic disease and the challenges posed by new stroke treatments.

Interviewed by José G. Merino, MD, Associate Professor of Neurology, University of Maryland School of Medicine.

They will be discussing the paper, “Nonprocedural Symptomatic Infarction and In-Stent Restenosis After Intracranial Angioplasty and Stenting in the SAMMPRIS Trial (Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis),” published in the June 2017 issue of Stroke.

Dr. Merino: Good afternoon. Can you tell us what prompted this secondary analysis of the SAMMPRIS data?
Dr. Derdeyn: From SAMMPRIS, we learned that there’s potentially great value for dual antiplatelets and statins, along with aggressive risk factor management for patients with intracranial atherosclerotic disease (ICAD).  We also learned that in this setting, there is a much higher complication rate from stenting than we thought, mainly due to a lot of perforator strokes, particularly in the basilar territory, and that the procedure is associated with a risk of intracranial hemorrhage, perhaps due to reperfusion. These short-term complications limit the value of stenting for ICAD.