Showing papers by "Peter D. Schellinger published in 2012"

Statistical Analysis of the Primary Outcome in Acute Stroke Trials

Abstract: Common outcome scales in acute stroke trials are ordered categorical or pseudocontinuous in structure but most have been analyzed as binary measures. The use of fixed dichotomous analysis of ordered categorical outcomes after stroke (such as the modified Rankin Scale) is rarely the most statistically efficient approach and usually requires a larger sample size to demonstrate efficacy than other approaches. Preferred statistical approaches include sliding dichotomous, ordinal, or continuous analyses. Because there is no best approach that will work for all acute stroke trials, it is vital that studies are designed with a full understanding of the type of patients to be enrolled (in particular their case mix, which will be critically dependent on their age and severity), the potential mechanism by which the intervention works (ie, will it tend to move all patients somewhat, or some patients a lot, and is a common hazard present), a realistic assessment of the likely effect size, and therefore the necessary sample size, and an understanding of what the intervention will cost if implemented in clinical practice. If these approaches are followed, then the risk of missing useful treatment effects for acute stroke will diminish.

Contemporary Outcome Measures in Acute Stroke Research: Choice of Primary Outcome Measure

Abstract: Background and Purpose—The diversity of available outcome measures for acute stroke trials is challenging and implies that the scales may be imperfect. To assist researchers planning trials and to aid interpretation, this article reviews and makes recommendations on the available choices of scales. The aim is to identify an approach that will be universally accepted and that should be included in most acute trials, without seeking to restrict options for special circumstances. Methods—The article considers outcome measures that have been widely used or are currently advised. It examines desirable properties for outcome measures such as validity, relevance, responsiveness, statistical properties, availability of training, cultural and language issues, resistance to comorbidity, as well as potential weaknesses. Tracking and agreement among outcomes are covered. Results—Typical ranges of scores for the common scales are described, along with their statistical properties, which in turn influence optimal analy...

Assessment of additional endpoints for trials in acute stroke - what, when, where, in who?

Abstract: Functional outcome in acute stroke trials among others is usually measured on the modified Rankin Scale. However, new onset of depression, cognitive decline, and communication deficits alone or in combination affect more than 25% of patients. This report summarizes the findings and conclusions of a workshop by the European Stroke Organization held in February 2011 We propose that assessment of mood disorders, cognitive impairment/dementia, language or communication dysfunction, and quality of life should supplement outcome measures after acute stroke.

Safety and Feasibility of NeuroFlo Use in Eight- to 24–Hour Ischemic Stroke Patients:

Abstract: BackgroundAcute treatment of ischemic stroke patients presenting more than eight-hours after symptom onset remains limited and largely unproven. Partial aortic occlusion using the NeuroFlo catheter can augment cerebral perfusion in animals. We investigated the safety and feasibility of employing this novel catheter to treat ischemic stroke patients eight-hours to 24 h following symptom onset.MethodsA multicenter, single-arm trial enrolled ischemic stroke patients at nine international academic medical centers. Eligibility included age 18–85 years old, National Institutes of Health stroke scale (NIHSS) score between four and 20, within eight-hours to 24 h after symptom onset, and perfusion–diffusion mismatch confirmed by magnetic resonance imaging. The primary outcome was all adverse events occurring from baseline to 30 days posttreatment. Secondary outcomes included stroke severity on neurological indices through 90 days. This study is registered with ClinicalTrials.gov, number NCT00436592.ResultsA total ...

Current acute stroke trials and their potential impact on the therapeutic time window.

Abstract: Several trials in acute stroke are underway or have been completed recently. Among the latter, ECASS 3 was a milestone regarding the extension of the rigid 3-h time window out to 4.5 h for intravenous thrombolysis with recombinant tissue plasminogen activator. Several other approaches are being tested for thrombolytic therapy, among them modern imaging-based patient selection of patients and interventional approaches. Other pharmaceutical strategies include neuroprotection, and restoration, biophysical approaches, such as near infrared laser therapy, hemodynamic augmentation, and sphenopalatine ganglion stimulation. This perspective will cover the recently completed and currently recruiting acute stroke trials with respect to their potential role in expanding the therapeutic time window for acute ischemic stroke.

[Industry-funded therapy studies: what is in the pipeline?].

Abstract: Several acute stroke trials are underway or have been recently completed. Among the latter are the ICTUS trial and the IST-3 trial. Several other approaches are being tested for thrombolytic therapy among them modern imaging-based patient selection and new thrombolytic agents, such as desmoteplase and tenecteplase. Other strategies include neuroprotection and neurorestoration, biophysical approaches, such as near infrared laser therapy, hemodynamic augmentation and sphenopalatine ganglion stimulation. Mechanical thrombectomy is practiced in many centers although randomized trials are pending and the IMS-3 trial was stopped. This overview will cover the very recently completed and currently recruiting acute ischemic stroke trials.

Letter to the Editor by Köhrmann and Schellinger Regarding Article, “Current Status of Endovascular Stroke Treatment”

Abstract: To the Editor: We have read “Current Status of Endovascular Stroke Treatment” by Meyers and colleagues1 with great interest, and congratulate the authors for their comprehensive and very balanced overview of recent studies on interventional treatment of stroke. However, there are 2 aspects that in our opinion need clarification. As the authors correctly state, “In any review of endovascular stroke therapy, there are important reasons to initiate the discussion with intravenous therapy ….”1 Intravenous recombinant tissue-type plasminogen activator remains the only Food and Drug Administration–approved recanalization therapy for acute ischemic stroke, and thus any novel therapy needs to be compared with this standard approved treatment. This was done in the present review in which data from the pivotal National Institute of Neurological Disorders and Stroke (NINDS) trial were compared with data from recent interventional trials. However, in a table and figure, data …