American Heart Association

Cerebral Microbleeds: A Risk Factor for Intracranial Hemorrhage and Worse Outcomes After Thrombolytic Therapy for Acute Ischemic Stroke

Mark R. Etherton, MD PhD

Charidimou A, Turc G, Oppenheim C, Yan S, Scheitz JF, Erdur H, et al. Microbleeds, Cerebral Hemorrhage, and Functional Outcome After Stroke Thrombolysis: Individual Patient Data Meta-Analysis. Stroke. 2017

In this entry, I discuss the recent meta-analysis, using individual patient data, by Andreas Charidimou and colleagues on cerebral microbleeds (CMB) and the risk of intracerebral hemorrhage (ICH) and poor functional outcomes after intravenous thrombolytic therapy for acute ischemic stroke.

Prior to this study, a recent meta-analysis had demonstrated that the mere presence of pre-treatment CMBs was associated with increased odds of symptomatic intracerebral hemorrhage (sICH) after intravenous thrombolytic therapy for acute ischemic stroke (Charidimou et al. Stroke. 2015). Building on this study, the authors performed a pooled, individual patient data meta-analysis to evaluate several hypotheses pertaining to the presence, quantity, and location of pre-treatment CMBs in relation to ICH risk and post-stroke outcomes.

By |September 20th, 2017|clinical|0 Comments

Beyond Drip and Ship: The Role of Baseline Vascular Imaging for Referring Hospitals in Acute Ischemic Stroke Triage for the Endovascular Era

Danny R. Rose, Jr. MD

Boulouis G, Siddiqui K, Lauer A, Charidimou A, Regenhardt R, Viswanathan A, et al.  Immediate Vascular Imaging Needed for Efficient Triage of Patients With Acute Ischemic Stroke Initially Admitted to Nonthrombectomy Centers. Stroke. 2017

The landmark publication of multiple positive endovascular thrombectomy (EVT) trials in 2015 was a pivotal moment for treatment of acute ischemic stroke. The most significant development in acute stroke treatment in the nearly twenty years since the FDA approval of tissue plasminogen activator in 1996 has led to much discussion with respect to improving stroke systems of care to be able to provide this treatment to as many eligible patients as possible. Reflecting this new development in acute stroke treatment, the American Heart Association released a focused update to their guidelines on acute stroke treatment that recommended endovascular therapy be offered to patients who present within 6 hours of last known normal and have a favorable imaging profile and a National Institutes of Health Stroke Scale (NIHSS) of 6 or greater.

Just as the time-sensitive nature of intravenous thrombolytic administration led to the development of prehospital stroke scales and the stroke alert process, the most effective way to triage and treat patients with suspected emergent large vessel occlusions (LVO) amenable to endovascular treatment is a topic of ongoing research and debate. An important facet of this discussion concerns the most effective method to triage and transfer patients with suspected LVO to a thrombectomy-capable stroke center. A cohort by Sarraj et al. presented at the 2017 International Stroke Conference showed comparably good outcomes for patients transferred to thrombectomy-capable centers as compared to patients who presented directly to the facility, suggesting that the “drip and ship” transfer paradigm can be successfully augmented to accommodate endovascular therapy.

Author Interview: Søren Bache, MD

Søren Bache

Søren Bache

A conversation with Søren Bache, MD, from the Neurointensive Care Unit, Department of Neuroanaesthesiology and Centre for Genomic Medicine, Rigshospitalet, University of Copenhagen, Denmark, about microRNA changes after subarachnoid hemorrhage.

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

They will be discussing the paper, “MicroRNA Changes in Cerebrospinal Fluid After Subarachnoid Hemorrhage,” published in the September 2017 issue of Stroke.

​Dr. Merino: Thank you for agreeing to the interview. First, I would like you to explain some things about delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) for our readers: How common is it? How soon after SAH does it develop? How does it affect outcome after SAH?

Dr. Bache: The reported prevalence of DCI after SAH varies, but newer randomized clinical trials have found a risk of 21–38% in patients who survive the initial bleeding and aneurism-securing surgery. The variation in calculated risk may be due to discrepancies both in case definition (i.e. the numerator) and in the definition of which patients are entered into the denominator. Today, most researchers base their case definition of DCI on the criteria suggested by Vergouwen et al. (Vergouwen MD, et al. Stroke. 2010). Before this consensus work, the definition varied even more, and many used their own criteria for DCI, delayed ischemic neurological deficits (DIND) or cerebral vasospasm. However, not all patients are conscious enough to be assessed clinically for a deterioration in consciousness, and such patients may be either included or excluded in the total number of patients; hence, the variation in the denominator. Based on Vergouwen’s criteria, in our center, we found a prevalence of 23% in 450 patients admitted from 2009–12 with SAH (unpublished data). These patients all receive prophylactic nimodipine, which lowers the risk of DCI; therefore, one should expect publications from the pre-nimodipine era to report a higher prevalence of DCI (Dorhout Mees SM, et al. Cochrane Database of Systematic Reviews. 2007).

Delayed cerebral ischemia occurs a median of 6–7 days after hemorrhage, but this varies, with a typical reported range from 3 to 14 days. DCI may be reversible, but in some cases it progresses to permanent brain injury, thereby affecting outcome.

Predicting Stroke Outcome with Multimodality CT

Kevin S. Attenhofer, MD

Dankbaar JW, Horsch AD, van den Hoven AF, Kappelle LJ, van der Schaaf IC, van Seeters T, et al. Prediction of Clinical Outcome After Acute Ischemic Stroke: The Value of Repeated Noncontrast Computed Tomography, Computed Tomographic Angiography, and Computed Tomographic Perfusion. Stroke. 2017

A significant aspect of stroke care is the long-term ramifications with respect to a patient’s ability to manage their activities of daily living. Part of the physician’s role is to help the patient navigate this challenge to maintain as much independence as possible. Understanding likely outcomes helps set the stage for realistic expectations and goals. Today, the most commonly used metric to score outcomes is the modified Rankin scale (mRS) performed well after the index event (often 90 days).

In stroke research, follow-up imaging markers such as computed tomographic angiography (CTA) recanalization and computed tomographic perfusion (CTP) reperfusion are sometimes used as proxy measurements for clinical outcomes. In this study, Dankbaar et al. used multimodality commuted tomography to predict mRS at 90 days.

By |September 11th, 2017|clinical, prognosis|0 Comments

Taking Patients Directly to Comprehensive Stroke Centers May Be Feasible for Patients and Hospitals

Neal S. Parikh, MD 

Katz BS, Adeoye O, Sucharew H, Broderick JP, McMullan J, Khatri P, et al. Estimated Impact of Emergency Medical Service Triage of Stroke Patients on Comprehensive Stroke Centers. An Urban Population-Based Study. Stroke. 2017

Whether all acute stroke patients should be taken to a comprehensive stroke center (CSC) remains unclear. However, there is mounting computer modeling and clinical data that support transporting acute stroke patients directly to CSCs, especially when the additional travel time is not excessive. The American Heart Association recommends transporting patients directly to CSCs if additional travel time does not exceed 15–20 minutes.

Brian Katz and colleagues performed an analysis to examine real-world EMS transport practices in the Greater Cincinnati/Northern Kentucky (GCNK) region. They performed computer modeling to evaluate the implications of adhering more closely to AHA recommendations. The authors identified patients with acute stroke from the GCNK Study who were transported by EMS in 2010. The GCNK region has 1 CSC and a total of 14 primary stroke centers (PSC) and acute stroke ready hospitals (ASRH). Patients’ addresses were geocoded, and software was used to estimate travel distances to each patient’s initial presenting hospital and also to the CSC.

Understanding Changing Temporal Trends in Dementia — Does Improving Vascular Health Have a Role?

Gurmeen Kaur, MBBS

Pase MP, Satizabal C, Seshadri S. Role of Improved Vascular Health in the Declining Incidence of Dementia. Stroke. 2017

It is projected that 13.8 million Americans will have dementia by the year 2050, making it a major public health epidemic. While the overall prevalence is on a rise, every individual’s chance of developing dementia per year is decreasing. The authors used the Framingham Heart Study (FHS) to demonstrate nearly a 20% decrease in developing dementia by a specific age over the past 30 years and have explored the temporal trends of this change.

Improved cardiovascular health and better management of stroke and vascular risk factors may be the reason for this observed decrease. Vascular risk factors have also been implicated in the pathophysiology of both vascular dementia and Alzheimer’s type dementia. A meta-analysis of 14,730 adults, including 862 with a history of stroke and 13,868 controls, demonstrated that a history of stroke increased the risk of AD dementia by 59%. Leukoariosis or increased burden of small vessel disease suggests silent ischemia. Many large databases show that the incidence of strokes is decreasing, which may be a contributing factor to decreased rates of dementia.

Statins and Carotid Artery Stenting

Tapan Mehta, MBBS, MPH

Hong JH, Sohn SI, Kwak J, Yoo J, Chang HW, Kwon OK, et al. Dose-Dependent Effect of Statin Pretreatment on Preventing the Periprocedural Complications of Carotid Artery Stenting. Stroke. 2017

In this entry, I discuss a recent publication by Dr. Jeong-Ho Hong and colleagues regarding effectiveness of statin pretreatment on preventing the periprocedural complications of carotid artery stenting (CAS).

CAS as a procedure has evolved significantly in the past two decades. Previous studies have shown increased periprocedural complication risk with CAS compared to carotid endarterectomy (CEA). Invention of new endovascular devices, distal embolization protection systems and antiplatelet medications, along with increasing operator experience, have contributed in reduction of periprocedural complications. Recently published CREST trial data can be considered an important example of this. As there is already data available on statin pretreatment reducing periprocedural complication risk for CEA and percutaneous coronary intervention, this study importantly extends the possibility of benefit with pre-procedural statin use for patients undergoing CAS.

Baseline Blood Pressure and Intra-Arterial Therapy Outcomes

Brian Marcus, MD

Mulder MJHL, Ergezen S, Lingsma HF, Berkhemer OA, Fransen PSS, Beumer D, et al. Baseline Blood Pressure Effect on the Benefit and Safety of Intra-Arterial Treatment in MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands). Stroke. 2017

It is known that extremes in blood pressure lead to worse functional outcomes in stroke patients. This article by Mulder et al. looks to see if similar extremes in blood pressure lead to worse outcomes in patients receiving intra-arterial treatment. They performed a post hoc analysis of the MR CLEAN study in the Netherlands and measured blood pressure at baseline and before intra-arterial treatment and compared this with the patient’s modified Rankin scale at 90 days. In addition to looking at modified Rankin scale, the authors also looked to see how blood pressure prior to therapy was related to imaging findings, changes in the NIHSS, TICI score, and the Barthel index.

By |August 28th, 2017|clinical|0 Comments

Author Interview: George Ntaios, MD

George Ntaios

George Ntaios

A conversation with George Ntaios, MD, MSc (ESO Stroke Medicine), PhD, Assistant Professor of Internal Medicine, Department of Medicine, University of Thessaly

Interviewed by Stephen Makin, PhD, Clinical Lecturer at Glasgow University

They will be discussing the paper, “Real-World Setting Comparison of Nonvitamin-K Antagonist Oral Anticoagulants Versus Vitamin-K Antagonists for Stroke Prevention in Atrial Fibrillation: A Systematic Review and Meta-Analysis,” being published in the September 2017 issue of Stroke.

Dr. Makin: Thank you for taking the time to talk to us.

Prof. Ntaios: Thank you for the invitation to discuss our study.

Dr. Makin: Could I begin by asking you to summarize your study and its findings?

Prof. Ntaios: We aimed to summarize all available evidence from high-quality real-world observational studies about the efficacy and safety of non-vitamin-K-oral-anticoagulants (NOACs) compared to vitamin-K-antagonists (VKAs) in patients with atrial fibrillation (AF). Based on 28 identified studies, we found that dabigatran, rivaroxaban and apixaban, as compared to VKAs, are associated with lower risk of intracranial haemorrhage and similar risk of ischemic stroke and ischemic stroke or systemic embolism; apixaban and dabigatran with lower risk of mortality; apixaban with fewer gastrointestinal and major haemorrhages; dabigatran and rivaroxaban with higher risk of gastrointestinal haemorrhage; and dabigatran and rivaroxaban with a similar rate of myocardial infarction.

Does Head Positioning Matter in Acute Stroke?

Philip Chang, MD

Anderson CS, Arima H, Lavados P, Billot L, Hackett ML, Olavarría VV, et al. Cluster-Randomized, Crossover Trial of Head Positioning in Acute Stroke. N Engl J Med. 2017

This article by Anderson et al investigates the role of supine bedrest positioning after acute stroke and weighed it against the risk of aspiration pneumonia. In this trial, 11,093 patients were randomized to supine or head-up (defined as at least 30 degrees head of bed elevation) initiated after hospital admission and maintained for 24 hours. The primary outcome was mRS scores at 90 days. The results of the article showed that people who were supine were less likely to maintain a supine position for 24 hours (87% vs. 95%, p<0.001), and there was no difference in mRS scores at 90 days. In addition, there were no significant differences in serious adverse events between the two groups, including the rates of aspiration pneumonia. The authors of the trial suggest that any modification of cerebral blood flow that may have occurred as a result of head positioning initiated within 24 hours was insufficient to reduce neurologic deficit associated with acute stroke.

By |August 21st, 2017|clinical|0 Comments