Although many stroke centers worldwide have performed endovascular stroke therapy since the results of the Prolyse in Acute Cerebral Thromboembolism (PROACT) II trial were published in 1999,
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...lingering uncertainties about efficacy and the selection of patients created an uneasy equipoise. Especially nettlesome was the uncertain benefit of endovascular therapy as compared with intravenous tissue plasminogen activator (t-PA). The controversy over endovascular therapy was heightened in 2013 when the results of the Interventional Management of Stroke (IMS) III,
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Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE),
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and Local versus Systemic Thrombolysis for Acute Ischemic Stroke (SYNTHESIS Expansion)
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clinical . . .
Patients with a cryptogenic stroke or transient ischemic attack (TIA) who had a patent foramen ovale were randomly assigned to closure with a percutaneous device or to medical therapy. There was no ...significant between-group difference in the subsequent rate of stroke or TIA.
As many as 40% of acute ischemic strokes have no identifiable cause and are classified as cryptogenic.
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Some cryptogenic strokes or transient ischemic attacks (TIAs) may be the result of an embolus from the venous system traversing from the right to left atrium and into the systemic circulation through a patent foramen ovale — a phenomenon known as paradoxical embolism. Numerous studies have shown an association between patent foramen ovale and cryptogenic stroke.
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The prevalence of patent foramen ovale at autopsy ranges from 20 to 26% in the general population, and it may be as high as 56% . . .
IMPORTANCE: Patent foramen ovale (PFO)–associated strokes comprise approximately 10% of ischemic strokes in adults aged 18 to 60 years. While device closure decreases stroke recurrence risk overall, ...the best treatment for any individual is often unclear. OBJECTIVE: To evaluate heterogeneity of treatment effect of PFO closure on stroke recurrence based on previously developed scoring systems. DESIGN, SETTING, AND PARTICIPANTS: Investigators for the Systematic, Collaborative, PFO Closure Evaluation (SCOPE) Consortium pooled individual patient data from all 6 randomized clinical trials that compared PFO closure plus medical therapy vs medical therapy alone in patients with PFO-associated stroke, and included a total of 3740 participants. The trials were conducted worldwide from 2000 to 2017. EXPOSURES: PFO closure plus medical therapy vs medical therapy alone. Subgroup analyses used the Risk of Paradoxical Embolism (RoPE) Score (a 10-point scoring system in which higher scores reflect younger age and the absence of vascular risk factors) and the PFO-Associated Stroke Causal Likelihood (PASCAL) Classification System, which combines the RoPE Score with high-risk PFO features (either an atrial septal aneurysm or a large-sized shunt) to classify patients into 3 categories of causal relatedness: unlikely, possible, and probable. MAIN OUTCOMES AND MEASURES: Ischemic stroke. RESULTS: Over a median follow-up of 57 months (IQR, 24-64), 121 outcomes occurred in 3740 patients. The annualized incidence of stroke with medical therapy was 1.09% (95% CI, 0.88%-1.36%) and with device closure was 0.47% (95% CI, 0.35%-0.65%) (adjusted hazard ratio HR, 0.41 95% CI, 0.28-0.60). The subgroup analyses showed statistically significant interaction effects. Patients with low vs high RoPE Score had HRs of 0.61 (95% CI, 0.37-1.00) and 0.21 (95% CI, 0.11-0.42), respectively (P for interaction = .02). Patients classified as unlikely, possible, and probable using the PASCAL Classification System had HRs of 1.14 (95% CI, 0.53-2.46), 0.38 (95% CI, 0.22-0.65), and 0.10 (95% CI, 0.03-0.35), respectively (P for interaction = .003). The 2-year absolute risk reduction was −0.7% (95% CI, −4.0% to 2.6%), 2.1% (95% CI, 0.6%-3.6%), and 2.1% (95% CI, 0.9%-3.4%) in the unlikely, possible, and probable PASCAL categories, respectively. Device-associated adverse events were generally higher among patients classified as unlikely; the absolute risk increases in atrial fibrillation beyond day 45 after randomization with a device were 4.41% (95% CI, 1.02% to 7.80%), 1.53% (95% CI, 0.33% to 2.72%), and 0.65% (95% CI, −0.41% to 1.71%) in the unlikely, possible, and probable PASCAL categories, respectively. CONCLUSIONS AND RELEVANCE: Among patients aged 18 to 60 years with PFO-associated stroke, risk reduction for recurrent stroke with device closure varied across groups classified by their probabilities that the stroke was causally related to the PFO. Application of this classification system has the potential to guide individualized decision-making.
The comparative effectiveness of percutaneous closure of patent foramen ovale (PFO) plus medical therapy versus medical therapy alone for cryptogenic stroke is uncertain.
The authors performed the ...first pooled analysis of individual participant data from completed randomized trials comparing PFO closure versus medical therapy in patients with cryptogenic stroke.
The analysis included data on 2 devices (STARFlex umbrella occluder NMT Medical, Inc., Boston, Massachusetts and Amplatzer PFO Occluder disc occluder AGA Medical/St. Jude Medical, St. Paul, Minnesota) evaluated in 3 trials. The primary composite outcome was stroke, transient ischemic attack, or death; the secondary outcome was stroke. We used log-rank tests and unadjusted and covariate-adjusted Cox regression models to compare device closure versus medical therapy.
Among 2,303 patients, closure was not significantly associated with the primary composite outcome. The difference became significant after covariate adjustment (hazard ratio HR: 0.68; p = 0.049). For the outcome of stroke, all comparisons were statistically significant, with unadjusted and adjusted HRs of 0.58 (p = 0.043) and 0.58 (p = 0.044), respectively. In analyses limited to the 2 disc occluder device trials, the effect of closure was not significant for the composite outcome, but was for the stroke outcome (unadjusted HR: 0.39; p = 0.013). Subgroup analyses did not identify significant heterogeneity of treatment effects. Atrial fibrillation was more common among closure patients.
Among patients with PFO and cryptogenic stroke, closure reduced recurrent stroke and had a statistically significant effect on the composite of stroke, transient ischemic attack, and death in adjusted but not unadjusted analyses.
IMPORTANCE: The Patent Foramen Ovale (PFO)–Associated Stroke Causal Likelihood classification system combines information regarding noncardiac patient features (vascular risk factors, infarct ...topography) and PFO features (shunt size and presence of atrial septal aneurysm ASA) to classify patients into 3 validated categories of responsiveness to treatment with PFO closure. However, the distinctive associations of shunt size and ASA, alone and in combination, have not been completely delineated. OBJECTIVE: To evaluate the association of PFO closure with stroke recurrence according to shunt size and/or the presence of an ASA. DESIGN, SETTING, AND PARTICIPANTS: Pooled individual patient data from 6 randomized clinical trials conducted from February 2000 to October 2017 that compared PFO closure with medical therapy. Patients in North America, Europe, Australia, Brazil, and South Korea with PFO-associated stroke were included. Analysis was completed in January 2022. EXPOSURES: Transcatheter PFO closure plus antithrombotic therapy vs antithrombotic therapy alone, stratified into 4 groups based on the combination of 2 features: small vs large PFO shunt size and the presence or absence of an ASA. MAIN OUTCOMES AND MEASURES: Recurrent ischemic stroke. RESULTS: A total of 121 recurrent ischemic strokes occurred in the pooled 3740 patients (mean SD age, 45 10 years; 1682 45% female) during a median (IQR) follow-up of 57 (23.7-63.8) months. Treatment with PFO closure was associated with reduced risk for recurrent ischemic stroke (adjusted hazard ratio aHR, 0.41 95% CI, 0.28-0.60; P < .001). The reduction in hazard for recurrent stroke was greater for patients with both a large shunt and an ASA (aHR, 0.15 95% CI, 0.06-0.35) than for large shunt without ASA (aHR, 0.27 95% CI, 0.14-0.56), small shunt with ASA (aHR, 0.36 95% CI, 0.17-0.78), and small shunt without ASA (aHR, 0.68 95% CI, 0.41-1.13) (interaction P = .02). At 2 years, the absolute risk reduction of recurrent stroke was greater (5.5% 95% CI, 2.7-8.3) in patients with large shunt and ASA than for patients in the other 3 categories (1.0% for all). CONCLUSIONS AND RELEVANCE: Patients with both a large shunt and an ASA showed a substantially greater beneficial association with PFO closure than patients with large shunt alone, patients with small shunt and ASA, and patients with neither large shunt nor ASA. These findings, combined with other patient features, may inform shared patient-clinician decision-making.
The National Institutes of Health (NIH) estimates that stroke costs now exceed 45 billion dollars per year. Stroke is the third leading cause of death and one of the leading causes of adult ...disability in North America, Europe, and Asia. A number of well-designed randomized stroke trials and case series have now been reported in the literature to evaluate the safety and efficacy of thrombolytic therapy for the treatment of acute ischemic stroke. These stroke trials have included intravenous studies, intra-arterial studies, and combinations of both, as well as use of mechanical devices for removal of thromboemboli and of neuroprotectant drugs, alone or in combination with thrombolytic therapy. At this time, the only therapy demonstrated to improve outcomes from an acute stroke is thrombolysis of the clot responsible for the ischemic event. There is room for improvement in stroke lysis studies. Divergent criteria, with disparate reporting standards and definitions, have made direct comparisons between stroke trials difficult to compare and contrast in terms of overall patient outcomes and efficacy of treatment. There is a need for more uniform definitions of multiple variables such as collateral flow, degree of recanalization, assessment of perfusion, and infarct size. In addition, there are multiple unanswered questions that require further investigation, in particular, questions as to which patients are best treated with thrombolysis. One of the most important predictors of clinical success is time to treatment, with early treatment of <3 hours for intravenous tissue plasminogen activator and <6 hours for intra-arterial thrombolysis demonstrating significant improvement in terms of 90-day clinical outcome and reduced cerebral hemorrhage. It is possible that improved imaging that identifies the ischemic penumbra and distinguishes it from irreversibly infarcted tissue will more accurately select patients for therapy than duration of symptoms. There are additional problems in the assessment of patients eligible for thrombolysis. These include being able to predict whether a particular site of occlusion can be successfully revascularized, predict an individual patient's prognosis and outcome after revascularization, and in particular, to predict the development of intracerebral hemorrhage, with and without clinical deterioration. It is not clear to assume that achieving immediate flow restoration due to thrombolytic therapy implies clinical success and improved outcome. There is no simple correlation between recanalization and observed clinical benefit in all ischemic stroke patients, because other interactive variables, such as collateral circulation, the ischemic penumbra, lesion location and extent, time to treatment, and hemorrhagic conversion, are all interrelated to outcome.
This article was written under the auspices of the Technology Assessment Committees for both the American Society of Interventional and Therapeutic Neuroradiology and the Society of Interventional Radiology. The purpose of this document is to provide guidance for the ongoing study design of trials of intra-arterial cerebral thrombolysis in acute ischemic stroke. It serves as a background for the intra-arterial thrombolytic trials in North America and Europe, discusses limitations of thrombolytic therapy, defines predictors for success, and offers the rationale for the different considerations that might be important during the design of a clinical trial for intra-arterial thrombolysis in acute stroke. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are mainly intended for research trials; however, they should also be helpful in clinical practice and applicable to all publications. This article serves to standardize reporting terminology and includes pretreatment assessment, neurologic evaluation with the NIH Stroke Scale score, imaging evaluation, occlusion sites, perfusion grades, follow-up imaging studies, and neurologic assessments. Moreover, previously used and established definitions for patient selection, outcome assessment, and data analysis are provided, with some possible variations on specific end points. This document is therefore targeted to help an investigator to critically review the scales and scores used previously in stroke trials. This article also seeks to standardize patient selection for treatment based on neurologic condition at presentation, baseline imaging studies, and utilization of standardized inclusion/exclusion criteria. It defines outcomes from therapy in phase I, II, and III studies. Statistical approaches are presented for analyzing outcomes from prospective, randomized trials with both primary and secondary variable analysis. A discussion on techniques for angiography, intra-arterial thrombolysis, anticoagulation, adjuvant therapy, and patient management after therapy is given, as well as recommendations for posttreatment evaluation, duration of follow-up, and reporting of disability outcomes. Imaging assessment before and after treatment is given. In the past, noncontrast CT brain scans were used as the initial screening examination of choice to exclude cerebral hemorrhage. However, it is now possible to quantify the volume of early infarct by using contiguous, discrete (nonhelical) images of 5 mm. In addition, CT angiography by helical scanning and 100 mL of intravenous contrast agent can be used expeditiously to obtain excellent vascular anatomy, define the occlusion site, obtain 2D and 3D reformatted vascular images, grade collateral blood flow, and perform tissue-perfusion studies to define transit times of a contrast bolus through specific tissue beds and regions of interest in the brain. Dynamic CT perfusion scans to assess the whole dynamics of a contrast agent transit curve can now be routinely obtained at many hospitals involved in these studies. The rationale, current status of this technology, and potential use in future clinical trials are given. Many hospitals are also performing MR brain studies at baseline in addition to, or instead of, CT scans. MRI has a high sensitivity and specificity for the diagnosis of ischemic stroke in the first several hours from symptom onset, identifies arterial occlusions, and characterizes ischemic pathology noninvasively. Case series have demonstrated and characterized the early detection of intraparenchymal hemorrhage and subarachnoid hemorrhage by MRI. Echo planar images, used for diffusion MRI and, in particular, perfusion MRI are inherently sensitive for the susceptibility changes caused by intraparenchymal blood products. Consequently, MRI has replaced CT to rule out acute hemorrhage in some centers. The rationale and the potential uses of MR scanning are provided. In addition to established criteria, technology is continuously evolving, and imaging techniques have been introduced that offer new insights into the pathophysiology of acute ischemic stroke. For example, a better patient stratification might be possible if CT and/or MRI brain scans are used not only as exclusion criteria but also to provide individual inclusion and exclusion criteria based on tissue physiology. Imaging techniques might also be used as a surrogate outcome measure in future thrombolytic trials. The context of a controlled study is the best environment to validate emerging imaging and treatment techniques. The final section details reporting standards for complications and adverse outcomes; defines serious adverse events, adverse events, and unanticipated adverse events; and describes severity of complications and their relation to treatment groups. Recommendations are made regarding comparing treatment groups, randomization and blinding, intention-to-treat analysis, quality-of-life analysis, and efficacy analysis. This document concludes with an analysis of general costs associated with therapy, a discussion regarding entry criteria, outcome measures, and the variability of assessment of the different stroke scales currently used in the literature is also featured.
In summary, this article serves to provide a more uniform set of criteria for clinical trials and reporting outcomes used in designing stroke trials involving intra-arterial thrombolytic agents, either alone or in combination with other therapies. It is anticipated that by having a more uniform set of reporting standards, more meaningful analysis of the data and the literature will be able to be achieved.
Summary Background Previous studies have suggested that desmoteplase, a novel plasminogen activator, has clinical benefit when given 3–9 h after the onset of the symptoms of stroke in patients with ...presumptive tissue at risk that is identified by magnetic resonance perfusion imaging (PI) and diffusion-weighted imaging (DWI). Methods In this randomised, placebo-controlled, double-blind, dose-ranging study, patients with acute ischaemic stroke and tissue at risk seen on either MRI or CT imaging were randomly assigned (1:1:1) to 90 μg/kg desmoteplase, 125 μg/kg desmoteplase, or placebo within 3–9 h after the onset of symptoms of stroke. The primary endpoint was clinical response rates at day 90, defined as a composite of improvement in National Institutes of Health stroke scale (NIHSS) score of 8 points or more or an NIHSS score of 1 point or less, a modified Rankin scale score of 0–2 points, and a Barthel index of 75–100. Secondary endpoints included change in lesion volume between baseline and day 30, rates of symptomatic intracranial haemorrhage, and mortality rates. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov , NCT00111852. Findings Between June, 2005, and March, 2007, 193 patients were randomised, and 186 patients received treatment: 57 received 90 μg/kg desmoteplase; 66 received 125 μg/kg desmoteplase; and 63 received placebo. 158 patients completed the study. The median baseline NIHSS score was 9 (IQR 6–14) points, and 30% (53 of 179) of the patients had a visible occlusion of a vessel at presentation. The core lesion and the mismatch volumes were small (median volumes were 10·6 cm3 and 52·5 cm3 , respectively). The clinical response rates at day 90 were 47% (27 of 57) for 90 μg/kg desmoteplase, 36% (24 of 66) for 125 μg/kg desmoteplase, and 46% (29 of 63) for placebo. The median changes in lesion volume were: 90 μg/kg desmoteplase 14·0% (0·5 cm3 ); 125 μg/kg desmoteplase 10·8% (0·3 cm3 ); placebo −10·0% (−0·9 cm3 ). The rates of symptomatic intracranial haemorrhage were 3·5% (2 of 57) for 90 μg/kg desmoteplase, 4·5% (3 of 66) for 125 μg/kg desmoteplase, and 0% for placebo. The overall mortality rate was 11% (5% 3 of 57 for 90 μg/kg desmoteplase; 21% 14 of 66 for 125 μg/kg desmoteplase; and 6% 4 of 63 for placebo). Interpretation The DIAS-2 study did not show a benefit of desmoteplase given 3–9 h after the onset of stroke. The high response rate in the placebo group could be explained by the mild strokes recorded (low baseline NIHSS scores, small core lesions, and small mismatch volumes that were associated with no vessel occlusions), which possibly reduced the potential to detect any effect of desmoteplase. Funding PAION Deutschland GmbH; Forest Laboratories.
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