Effect of Hemodynamics on Stroke Risk in Symptomatic Atherosclerotic Vertebrobasilar Occlusive Disease.

Importance: Atherosclerotic vertebrobasilar (VB) occlusive disease is a significant etiology of posterior circulation stroke, with regional hypoperfusion as an important potential contributor to stroke risk.

Objective: To test the hypothesis that, among patients with symptomatic VB stenosis or occlusion, those with distal blood flow compromise as measured by large-vessel quantitative magnetic resonance angiography (QMRA) are at higher risk of subsequent posterior circulation stroke.

Design, Setting, And Participants: A prospective, blinded, longitudinal cohort study was conducted at 5 academic hospital-based centers in the United States and Canada; 82 patients from inpatient and outpatient settings were enrolled.

Extensive blooming artifact predicts no recanalization after intravenous thrombolysis.

Background And Purpose: Hemosiderin exhibits a stronger T2 shortening effect than deoxyhemoglobin. The extent of the 'blooming artifact' may therefore reflect a composition of different iron forms. Our aim was to investigate the relationship between extent of susceptibility vessel sign (SVS) width beyond the lumen and middle cerebral artery (MCA) recanalization.

Association Between CT Angiogram Collaterals and CT Perfusion in the Interventional Management of Stroke III Trial.

Background And Purpose: Collateral flow can determine ischemic core and tissue at risk. Using the Interventional Management of Stroke (IMS) III trial data, we explored the relationship between computed tomography angiogram (CTA) collateral status and CT perfusion (CTP) parameters.

Methods: Baseline CTA collaterals were trichotomized as good, intermediate, and poor, and CTP studies were analyzed to quantify ischemic core, tissue at risk, and mismatch ratios.

Enrollment Yield and Reasons for Screen Failure in a Large Prehospital Stroke Trial.

Background And Purpose: The enrollment yield and reasons for screen failure in prehospital stroke trials have not been well delineated.

Methods: The Field Administration of Stroke Therapy-Magnesium (FAST-MAG) trial identified patients for enrollment using a 2 stage screening process-paramedics in person followed by physician-investigators by cell phone. Outcomes of consecutive screening calls from paramedics to enrolling physician-investigators were prospectively recorded.

Early Magnetic Resonance Imaging Predicts Early Neurological Deterioration in Acute Middle Cerebral Artery Minor Stroke.

Background: Early neurological deterioration (END) is an important factor associated with worse clinical outcome in minor strokes. Early magnetic resonance imaging (MRI) findings can provide better sensitivity to delineate stroke pathophysiology and have diagnostic value associated with causative mechanisms. The aim of this study was to investigate the relationship between early MRI finding and the presence of END in minor stroke patients with lesions in the middle cerebral artery (MCA) territory.

New Cerebral Microbleeds After Mechanical Thrombectomy for Large-Vessel Occlusion Strokes.

The interval appearance of cerebral microbleeds (CMBs) after endovascular treatment has never been described. We investigated the frequency and predictors of new CMBs that developed shortly after mechanical thrombectomy for acute ischemic stroke, and its impact on clinical outcome.We retrospectively analyzed patients with large-vessel occlusion strokes treated with Merci Retriever, Penumbra System, or stent-retriever devices.

Innovative Interventional and Imaging Registries: Precision Medicine in Cerebrovascular Disorders.

Background: Precision medicine in cerebrovascular disorders may be greatly advanced by the use of innovative interventional and imaging-intensive registries. Registries have remained subsidiary to randomized controlled trials, yet vast opportunities exist to leverage big data in stroke.

Summary: This overview builds upon the rationale for innovative, imaging-intensive interventional registries as a pivotal step in realizing precision medicine for several cerebrovascular disorders.

Hemodynamic Impact of Systolic Blood Pressure and Hematocrit Calculated by Computational Fluid Dynamics in Patients with Intracranial Atherosclerosis.

Objective: Success in clinical trials of intracranial atherosclerosis (ICAS) is related to accurate identification of high-risk patients. Noninvasive computational fluid dynamics (CFD) of stenotic lesions may enhance therapeutic decision-making. We determined whether physiologic parameters change downstream cerebral hemodynamics in patients with ICAS.

Impact of Collateral Status on Successful Revascularization in Endovascular Treatment: A Systematic Review and Meta-Analysis.

Background: Pre-treatment collateral status may be associated with the rates of successful revascularization in acute ischemic stroke patients receiving endovascular treatment (EVT). We conducted a systematic review and meta-analysis to synthesize relevant evidence currently available.

Methods: Relevant full-text articles published in English since January 1, 2000, reporting associations between collateral status and successful reperfusion and/or recanalization in acute ischemic stroke patients receiving EVT in cohort or case-control studies, or randomized clinical trials, were retrieved through search of PubMed.

Mechanical Thrombectomy for Isolated M2 Occlusions: A Post Hoc Analysis of the STAR, SWIFT, and SWIFT PRIME Studies.

Background And Purpose: Mechanical thrombectomy is beneficial for patients with acute ischemic stroke and a proximal anterior occlusion, but it is unclear if these results can be extrapolated to patients with an M2 occlusion. The purpose of this study was to examine the technical aspects, safety, and outcomes of mechanical thrombectomy with a stent retriever in patients with an isolated M2 occlusion who were included in 3 large multicenter prospective studies.

Materials And Methods: We included patients from the Solitaire Flow Restoration Thrombectomy for Acute Revascularization (STAR), Solitaire With the Intention For Thrombectomy (SWIFT), and Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME) studies, 3 large multicenter prospective studies on thrombectomy for ischemic stroke.

Detection of Hyperperfusion on Arterial Spin Labeling using Deep Learning.

Hyperperfusion detected on arterial spin labeling (ASL) images acquired after acute stroke onset has been shown to correlate with development of subsequent intracerebral hemorrhage. We present in this study a quantitative hyperperfusion detection model that can provide an objective decision support for the interpretation of ASL cerebral blood flow (CBF) maps and rapidly delineate hyperperfusion regions. The detection problem is solved using Deep Learning such that the model relates ASL image patches to the corresponding label (normal or hyperperfused).

DWI Lesion Patterns Predict Outcome in Stroke Patients with Thrombolysis.

Background: Lesion patterns may predict prognosis after acute ischemic stroke within the middle cerebral artery (MCA) territory; yet it remains unclear whether such imaging prognostic factors are related to patient outcome after intravenous thrombolysis.

Aims: The aim of this study is to investigate the clinical outcome after intravenous thrombolysis in acute MCA ischemic strokes with respect to diffusion-weighted imaging (DWI) lesion patterns.

Methods: Consecutive acute ischemic stroke cases of the MCA territory treated over a 7-year period were retrospectively analyzed.

Early Magnesium Treatment After Aneurysmal Subarachnoid Hemorrhage: Individual Patient Data Meta-Analysis.

Background And Purpose: Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Trials of magnesium treatment starting <4 days after symptom onset found no effect on poor outcome or DCI in SAH. Earlier installment of treatment might be more effective, but individual trials had not enough power for such a subanalysis.

Early Loss of Immediate Reperfusion While Stent Retriever in Place Predicts Successful Final Reperfusion in Acute Ischemic Stroke Patients.

Background And Purpose: Degree of stent retriever engagement with target thrombi may be reflected by (1) immediate reperfusion (IR) on first deployment, indicating displacement of clot toward the vessel wall, and (2) by early loss of IR (ELOIR), indicating penetration of retriever struts through the thrombus. The relation of these early findings to final reperfusion and clinical outcomes has not been well delineated.

Methods: We investigated IR and ELOIR in patients undergoing stent retriever mechanical thrombectomy at an academic medical center between March 2012 and June 2014.

A collaborative sequential meta-analysis of individual patient data from randomized trials of endovascular therapy and tPA vs. tPA alone for acute ischemic stroke: ThRombEctomy And tPA (TREAT) analysis: statistical analysis plan for a sequential meta-analysis performed within the VISTA-Endovascular collaboration.

Rationale: Endovascular treatment has been shown to restore blood flow effectively. Second-generation medical devices such as stent retrievers are now showing overwhelming efficacy in clinical trials, particularly in conjunction with intravenous recombinant tissue plasminogen activator.

Aims And Design: This statistical analysis plan utilizing a novel, sequential approach describes a prospective, individual patient data analysis of endovascular therapy in conjunction with intravenous recombinant tissue plasminogen activator agreed upon by the Thrombectomy and Tissue Plasminogen Activator Collaborative Group.

Feasibility and Safety of Using External Counterpulsation to Augment Cerebral Blood Flow in Acute Ischemic Stroke-The Counterpulsation to Upgrade Forward Flow in Stroke (CUFFS) Trial.

Background: External counterpulsation (ECP) increases perfusion to a variety of organs and may be helpful for acute stroke.

Methods: We conducted a single-blinded, prospective, randomized controlled feasibility and safety trial of ECP for acute middle cerebral artery (MCA) ischemic stroke. Twenty-three patients presenting within 48 hours of symptom onset were randomized into one of two groups.

Determinants of Intracranial Hemorrhage Occurrence and Outcome after Neurothrombectomy Therapy: Insights from the Solitaire FR With Intention For Thrombectomy Randomized Trial.

Background And Purpose: Intracranial hemorrhage is the most dreaded complication of neurothrombectomy therapy for acute ischemic stroke. The determinants of intracranial hemorrhage and its impact on clinical course remain incompletely delineated. The purpose of this study is to further investigate the clinical and procedural factors leading to intracranial hemorrhage and to define the clinical impact of different hemorrhagic subtypes.

Imaging of prehospital stroke therapeutics.

Despite significant quality improvement efforts to streamline in-hospital acute stroke care in the conventional model, there remain inherent layers of treatment delays, which could be eliminated with prehospital diagnostics and therapeutics administered in a mobile stroke unit. Early diagnosis using telestroke and neuroimaging while in the ambulance may enable targeted routing to hospitals with specialized care, which will likely improve patient outcomes. Key clinical trials in telestroke, mobile stroke units with prehospital neuroimaging capability, prehospital ultrasound and co-administration of various classes of neuroprotectives, antiplatelets and antithrombin agents with intravenous thrombolysis are discussed in this article.

Routing Ambulances to Designated Centers Increases Access to Stroke Center Care and Enrollment in Prehospital Research.

Background And Purpose: Emergency medical services routing of patients with acute stroke to designated centers may increase the proportion of patients receiving care at facilities meeting national standards and augment recruitment for prehospital stroke research.

Methods: We analyzed consecutive patients enrolled within 2 hours of symptom onset in a prehospital stroke trial, before and after regional Los Angeles County Emergency Medical Services implementation of preferentially routing patients with acute stroke to approved stroke centers (ASCs). From January 2005 to mid-November 2009, patients were transported to the nearest emergency department, whereas from mid-November 2009 to December 2012, patients were preferentially transported to first 9, and eventually 29, ASCs.

Outcome Differences between Intra-Arterial Iso- and Low-Osmolality Iodinated Radiographic Contrast Media in the Interventional Management of Stroke III Trial.

Background And Purpose: Intracarotid arterial infusion of nonionic, low-osmolal iohexol contrast medium has been associated with increased intracranial hemorrhage in a rat middle cerebral artery occlusion model compared with saline infusion. Iso-osmolal iodixanol (290 mOsm/kg H2O) infusion demonstrated smaller infarcts and less intracranial hemorrhage compared with low-osmolal iopamidol and saline. No studies comparing iodinated radiographic contrast media in human stroke have been performed, to our knowledge.

"Sudden Drop" in Blood Pressure is Associated With Recanalization After Thrombolysis.

We aim to investigate whether the phenomenon of "sudden drop" in blood pressure (BP) within the first 2 hours is associated with vessel recanalization.We retrospectively examined clinical and imaging data from a consecutive series of patients with stroke with large vessel occlusion treated with intravenous thrombolysis (IVT). BP was monitored every 15 minutes during the first 2 hours, then every 30 minutes for 6 hours, and then every hour for 16 hours.