Karen C. Johnston

2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Purpose— The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. When there is overlap, the recommendations made here supersede those of previous guidelines. Methods— This focused update analyzes results from 8 randomized, clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council’s Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee. Results— Evidence-based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment, for the endovascular procedure, and for systems of care to facilitate endovascular treatment. Conclusions— Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke. Systems of care should be organized to facilitate the delivery of this care.Purpose— The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. Where there is overlap, the recommendations made here supersede those of previous guidelines. Methods— This focused update analyzes results from 8 randomized clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council’s Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee (MOC). Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee. Results— Evidence-based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment, the endovascular procedure and for systems of care to facilitate endovascular treatment. Conclusions— Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke. Systems of care should be organized to facilitate the delivery of this care.

Medical and Neurological Complications of Ischemic Stroke Experience From the RANTTAS Trial

BACKGROUND AND PURPOSE Medical and neurological complications after acute ischemic stroke may adversely impact outcome and in some cases may be preventable. Limited data exist regarding the frequency of such complications occurring in the first days after the ictus and the relationship of these complications to outcome. Our objective was to identify the types, severity, and frequency of medical and neurological complications following acute ischemic stroke and to determine their role in mortality and functional outcome. METHODS Rates of serious (life-threatening) and nonserious medical and neurological complications and mortality were derived from the placebo limb of the Randomized Trial of Tirilazad Mesylate in Acute Stroke (RANTTAS) database (n=279). Complications were correlated with clinical outcome using logistic regression techniques. RESULTS Of all patients, 95% had at least one complication. The most common serious medical complication was pneumonia (5%), and the most common serious neurological complication was new cerebral infarction or extension of the admission infarction (5%). The 3-month mortality was 14%; 51% of these deaths were attributed primarily to medical complications. Outcome was significantly worse in patients with serious medical complications, after adjustment for baseline imbalances, as measured by the Barthel Index (odds ratio [OR], 6.1; 95% confidence interval [CI], 2.5 to 15.1) and by the Glasgow Outcome Scale (OR, 11.6; 95% CI, 4.3 to 30.9). After death was discounted, serious medical complications were associated with severe disability at 3 months as determined by the Glasgow Outcome Scale (OR, 4.4; 95% CI, 1.3 to 14.8). CONCLUSIONS Medical complications that follow ischemic stroke not only influence mortality but may influence functional outcome.

Infarct Volume as a Surrogate or Auxiliary Outcome Measure in Ischemic Stroke Clinical Trials

BACKGROUND AND PURPOSE Reduction in infarct volume is the standard measure of therapeutic success in animal stroke models. Reduction in infarct volume has been advocated as a biological surrogate or auxiliary outcome measure for human stroke clinical trials to replace or supplement deficit, disability, and global clinical scales. However, few studies have investigated correlations between infarct volume and clinical end points in acute ischemic stroke patients. METHODS CT scans at days 6 to 11 were acquired prospectively in 191 fully eligible patients enrolled in the Randomized Trial of Tirilazad Mesylate in Patients With Acute Stroke (RANTTAS). Patients were enrolled within 6 hours of onset of stroke in any vessel distribution. Infarct volume was measured by operator-assisted computerized planimetry. RESULTS One hundred thirty-two patients had visible new supratentorial infarcts, with median infarct volume of 28.0 cm3 (interquartile range, 9.0 to 93.0 cm3). Fifty-nine patients had no visible new infarct. Correlations with standard 3-month outcome scales and mortality were as follows: Barthel Index, r=0.43; Glasgow Outcome Scale, r=0.53; National Institutes of Health Stroke Scale, r=0.54; mortality, r=0.31. For visible infarcts alone, correlations were as follows: BI, r=0.46; GOS, r=0.59; NIHSS, r=0.56; mortality, r=0.32. CONCLUSIONS Subacute CT infarct volume correlates moderately with 3-month clinical outcome as assessed by widely used neurological and functional assessment scales. The modesty of this linkage constrains the use of infarct volume as a surrogate end point in ischemic stroke clinical trials.

Anticoagulants and Antiplatelet Agents in Acute Ischemic Stroke Report of the Joint Stroke Guideline Development Committee of the American Academy of Neurology and the American Stroke Association (a Division of the American Heart Association)

Stroke remains a common and costly problem worldwide, but substantial advances have been made in recent decades in understanding stroke mechanisms, risk factors, and therapies. Because thrombosis plays an important role in the pathogenesis of ischemic stroke, drugs that interfere with hemostasis and clot formation such as anticoagulants and platelet antiaggregants commonly are used in the management of cerebrovascular disease. Considerable evidence supports the use of certain antithrombotic drugs in stroke prevention. However, because of limited supportive data, the use of these agents in patients with acute ischemic stroke remains controversial. In this report, we examine the published evidence relevant to the effects of anticoagulants and antiplatelet agents on acute ischemic stroke mortality, morbidity, and recurrence rates as well as associated ancillary benefits and risks of those treatments on the rates of deep vein thrombosis, pulmonary embolus, and cardiovascular complications. As part of these analyses, we also sought to determine whether there was evidence supporting differential efficacy of these drugs according to ischemic stroke subtypes. To prepare this report, experienced neurologists with a special interest in stroke diagnosis and management were appointed by the Quality Standards Subcommittee (QSS) and the Therapeutics and Technology Assessment (TTA) Subcommittee of the American Academy of Neurology, and the Stroke Council and Science Advisory and Coordinating Committee (SACC) of the American Heart Association (AHA). The QSS, TTA, Stroke Council and SACC are each charged with the responsibility of preparing evidence-based reports pertaining to medical practice issues including stroke. To facilitate the process of joint guideline development, a Steering Committee, chaired by representatives of the AAN and the American Stroke Association of the AHA, was appointed to discuss potential topics of wide interest to the stroke community. Choosing the role of anticoagulants and antiplatelet agents in acute ischemic stroke as the first topic, a Joint Writing …

A Predictive Risk Model for Outcomes of Ischemic Stroke

BACKGROUND AND PURPOSE The great variability of outcome seen in stroke patients has led to an interest in identifying predictors of outcome. The combination of clinical and imaging variables as predictors of stroke outcome in a multivariable risk adjustment model may be more powerful than either alone. The purpose of this study was to determine the multivariable relationship between infarct volume, 6 clinical variables, and 3-month outcomes in ischemic stroke patients. METHODS Included in the study were 256 eligible patients from the Randomized Trial of Tirilazad Mesylate in Acute Stroke (RANTTAS). Six clinical variables and 1-week infarct volume were the prespecified predictor variables. The National Institutes of Health Stroke Scale, Barthel Index, and Glasgow Outcome Scale were the outcomes. Multivariable logistic regression techniques were used to develop the model equations, and bootstrap techniques were used for internal validation. Predictive performance of the models was assessed for discrimination with receiver operator characteristic (ROC) curves and for calibration with calibration curves. RESULTS The predictive models had areas under the ROC curve of 0.79 to 0.88 and demonstrated nearly ideal calibration curves. The areas under the ROC curves were statistically greater (P<0.001) with both clinical and imaging information combined than with either alone for predicting excellent recovery and death or severe disability. CONCLUSIONS Combined clinical and imaging variables are predictive of 3-month outcome in ischemic stroke patients. Demonstration of this relationship with acute clinical variables and 1-week infarct information supports future attempts to predict 3-month outcome with all acute variables.

A Pilot Dose-Escalation Safety Study of Tenecteplase in Acute Ischemic Stroke

Background and Purpose— Recombinant tissue-type plasminogen activator (rtPA) is the only approved treatment in acute ischemic stroke. However, intracerebral hemorrhage (ICH) occurs in 6.4% of patients treated with rtPA and limits its use. Tenecteplase (TNK) is a modified form of rtPA, with longer half-life and greater fibrin specificity. Patients after myocardial infarction had fewer systemic hemorrhages when treated with TNK compared with rtPA. This open-label, dose-escalation safety study was conducted to develop initial experience with TNK in the treatment of ischemic stroke. Methods— Eligible patients were treated with an intravenous bolus infusion of TNK within 3 hours of stroke onset. The dose escalation was conducted in tiers of 25 patients, starting at 0.1 mg/kg, to a planned maximum of 0.6 mg/kg. The primary endpoint was symptomatic intracranial hemorrhage within 36 hours of treatment. All patients were followed-up for 3 months. Results— Eighty-eight (88) patients were treated in 4 dosing tiers. In the first 3 tiers (0.1, 0.2, 0.4 mg/kg) of 25 patients each, no symptomatic and 2 (8%), 8 (32%), and 7 (28%) asymptomatic ICHs occurred. Enrollment into the fourth tier at 0.5 mg/kg was closed after 2 of 13 patients (15%) had symptomatic and 3 (23%) had asymptomatic ICHs. Overall, modified Rankin scores at 3 months were similar to those of historical controls treated with rtPA and not significantly different between treatment groups. Conclusions— TNK doses of 0.1 to 0.4 mg/kg are safe in ischemic stroke. Future trials are needed to compare the effect of TNK on neurological outcome and safety as compared with rtPA.

Levels of evidence: Taking Neurology to the next level.

When you pick up an issue of Neurology ® and scan its contents, how do you decide what to read? And how do you decide if what you read should change your clinical practice? The value of a scientific study can be assessed by a variety of objective and subjective measures and its value will depend on your perspective. Do you view the results as a researcher or as a practicing neurologist seeking the best evidence on which to make clinical decisions? Readers will naturally assess whether the article’s focus aligns with their interests, either investigative or care-based; whether the findings answer a question relevant to those pursuits; and whether the results are robust enough to serve as a definitive basis for informing their work. In short, readers will be assessing the strength of evidence presented. We might all agree in principle with the notion that the practice of medicine ought to be based on evidence; yet there are situations for which there is little to no evidence, and others for which the evidence is of varying strength. A simple standardized system that can organize the evidence would make such an assessment easier. At Neurology , we are dedicated to bringing our readers the most relevant and sound scientific research, focusing largely although not exclusively on human subjects. We also publish Practice Parameters and Clinical Guidelines that assess the primary literature and allow readers to see a summary of the strengths and limitations of those studies. In turn, those analyses …

Predicting Major Neurological Improvement With Intravenous Recombinant Tissue Plasminogen Activator Treatment of Stroke

Background and Purpose— In the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study, major neurological improvement within 24 hours (MNI) occurred significantly more frequently with recombinant tissue plasminogen activator (rtPA) treatment than with placebo. We explored the relationship between MNI and 3-month favorable outcome and sought clinical predictors of MNI. Methods— Data from 312 rtPA-treated patients from the NINDS trial were used to assess the ability of MNI to predict favorable outcome at 3 months as defined by a modified Rankin Scale score of 0 to 1. Next, a multivariable predictive model was developed for MNI within the same data set. Clinical variables examined included age, time to treatment (TTT), diabetes, pretreatment glucose, baseline National Institutes of Health Stroke Scale score, pretreatment blood pressure, history of atrial fibrillation, weight >100 kg, and a dense artery sign. Finally, this model was used to forecast into the placebo group of the NINDS trial to assess the uniqueness of the predictors in the rtPA-treated group. Results— MNI had a positive predictive value and negative predictive value of 0.70 for predicting favorable 3-month outcome. Only age [odds ratio (OR), 0.68; 95% confidence interval (CI), 0.47 to 0.99] and TTT (OR, 0.56; 95% CI, 0.34 to 0.91) appear to be independently associated with MNI. The model performed only moderately well (area under the receiver-operating characteristic curve, 0.66). Age (OR, 0.67; 95% CI, 0.45 to 0.99) but not TTT was associated with MNI in the placebo group. Conclusions— MNI may be a useful surrogate for thrombolytic activity and is predictive of favorable 3-month outcome. When rates of MNI in different populations of stroke patients treated with thrombolysis are compared, adjustments for age and TTT may be necessary.

Stroke Therapy Academic Industry Roundtable (STAIR) Recommendations for Extended Window Acute Stroke Therapy Trials

The Stroke Therapy Academic Industry Roundtable (STAIR) meetings focus on helping to advance the development of acute stroke therapies. Further extending the time window for acute stroke therapies is an important endeavor for increasing the number of stroke patients who might benefit from treatment. The STAIR group recommends that future extended time window trials initially should focus on selected patient groups most likely to respond to investigational therapies and that penumbral imaging is one tool that may identify such patients. The control group in these trials should receive best locally available medical care; if regulatory approval for intravenous (i.v.) tPA is extended to 4.5 hours, then tPA will become the most appropriate comparator in trials conducted within this time window. In future well-designed extended window clinical trials randomization is appropriate and should not be precluded by using unproven treatment with intraarterial (i.a.) thrombolysis or mechanical devices. For proof of concept, extended time window, phase II trials of i.v. thrombolysis, or mechanical devices in which early recanalization/reperfusion is the primary end point, rescue therapy/bailout treatment with i.a. thrombolysis or devices may be acceptable. Statistical considerations and definitions of successful recanalization/reperfusion are suggested for these trials.

Glucose Regulation in Acute Stroke Patients (GRASP) Trial A Randomized Pilot Trial

Background and Purpose— Hyperglycemia is associated with worse outcome in patients with acute stroke. Methods— We conducted a prospective, randomized, multicenter, 3-arm trial (tight control [target 70 to 110 mg/dL], loose control [target 70 to 200 mg/dL], and control usual care [70 to 300 mg/dL]) to assess the feasibility and safety of 2 insulin infusion protocol targets in patients with acute ischemic stroke. The planned sample was 72 subjects. Results— A total of 74 subjects were enrolled. Seventy-two (97%) had data available for the primary analyses and 73 (99%) had 3-month clinical outcome data. Median age was 67 years, median National Institutes of Health Stroke Scale score was 8, median glucose was 163 mg/dL, and median time to randomization was 10.7 hours. Fifty-nine percent of patients were diabetic, 35% received thrombolysis, and 14% of subjects died within 3 months. The loose control and usual care groups had median glucose concentrations of 151 mg/dL. The tight control group had a median glucose concentration of 111 mg/dL. The loose control group spent 90% of the first 24 hours in target and the tight group 44% of time in target. There was only one symptomatic patient with hypoglycemia in the loose control group (4%) and zero in the tight control group. The overall rates of hypoglycemia (<55 mg/dL) were 4% in control, 4% in loose, and 30% in tight. Exploratory efficacy analysis was conducted. Conclusions— Insulin infusion for patients with acute ischemic stroke is feasible and safe using the insulin infusion protocol in the Glucose Regulation in Acute Stroke Patients (GRASP) trial. Exploratory efficacy analysis supports further comparative study.