The POST trial: initial post-market experience of the Penumbra system: revascularization of large vessel occlusion in acute ischemic stroke in the United States and Europe.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the initial post-market experience of the device and how it is compared with the Penumbra Pivotal trial used to support the 510k application. METHODS: A retrospective case review of 157 consecutive patients treated with the Penumbra system at seven international centers was performed. Primary endpoints were revascularization of the target vessel (TIMI score of 2 or 3), good functional outcome as defined by a modified Rankin scale (mRS) score of ≤2 and incidence of procedural serious adverse events. Results were compared with those of the Penumbra pivotal trial. RESULTS: A total of 157 vessels were treated. Mean baseline values at enrollment were: age 65 years, NIHSS score 16. After use of the Penumbra system, 87% of the treated vessels were revascularized to TIMI 2 (54%) or 3 (33%) as compared with 82% reported in the Pivotal trial. Nine procedural serious adverse events were reported in 157 patients (5.7%). All-cause mortality was 20% (32/157), and 41% had a mRS of ≤2 at 90-day follow-up as compared with only 25% in the Pivotal trial. Patients who were successfully revascularized by the Penumbra system had significantly better outcomes than those who were not. CONCLUSION: Initial post-market experience of the Penumbra system revealed that the revascularization rate and safety profile of the device are comparable to those reported in the Pivotal trial. However, the proportion of patients who had good functional outcome was higher than expected.

'Stroke Room': Diagnosis and Treatment at a Single Location for Rapid Intraarterial Stroke Treatment.

BACKGROUND: For patients with acute ischemic stroke, intra-arterial treatment (IAT) is considered to be an effective strategy for removing the obstructing clot. Because outcome crucially depends on time to treatment ('time-is-brain' concept), we assessed the effects of an intervention based on performing all the time-sensitive diagnostic and therapeutic procedures at a single location on the delay before intra-arterial stroke treatment. METHODS: Consecutive acute stroke patients with large vessel occlusion who obtained IAT were evaluated before and after implementation (April 26, 2010) of an intervention focused on performing all the diagnostic and therapeutic measures at a single site ('stroke room'). RESULT: After implementation of the intervention, the median intervals between admission and first angiography series were significantly shorter for 174 intervention patients (102 min, interquartile range (IQR) 85-120 min) than for 81 control patients (117 min, IQR 89-150 min; p < 0.05), as were the intervals between admission and clot removal or end of angiography (152 min, IQR 123-185 min vs. 190 min, IQR 163-227 min; p < 0.001). However, no significant differences in clinical outcome were observed. CONCLUSION: This study shows for the, to our knowledge, first time that for patients with acute ischemic stroke, stroke diagnosis and treatment at a single location ('stroke room') saves crucial time until IAT.

Is prehospital treatment of acute stroke too expensive? An economic evaluation based on the first trial.

BACKGROUND: Recently, a strategy for treating stroke directly at the emergency site was developed. It was based on the use of an ambulance equipped with a scanner, a point-of-care laboratory, and telemedicine capabilities (Mobile Stroke Unit). Despite demonstrating a marked reduction in the delay to thrombolysis, this strategy is criticized because of potentially unacceptable costs. METHODS: We related the incremental direct costs of prehospital stroke treatment based on data of the first trial on this concept to one year direct cost savings taken from published research results. Key parameters were configuration of emergency medical service personnel, operating distance, and population density. Model parameters were varied to cover 5 different relevant emergency medical service scenarios. Additionally, the effects of operating distance and population density on benefit-cost ratios were analyzed. RESULTS: Benefits of the concept of prehospital stroke treatment outweighed its costs with a benefit-cost ratio of 1.96 in the baseline experimental setting. The benefit-cost ratio markedly increased with the reduction of the staff and with higher population density. Maximum benefit-cost ratios between 2.16 and 6.85 were identified at optimum operating distances in a range between 43.01 and 64.88 km (26.88 and 40.55 miles). Our model implies that in different scenarios the Mobile Stroke Unit strategy is cost-efficient starting from an operating distance of 15.98 km (9.99 miles) or from a population density of 79 inhabitants per km2 (202 inhabitants per square mile). CONCLUSION: This study indicates that based on a one-year benefit-cost analysis that prehospital treatment of acute stroke is highly cost-effective across a wide range of possible scenarios. It is the highest when the staff size of the Mobile Stroke Unit can be reduced, for example, by the use of telemedical support from hospital experts. Although efficiency is positively related to population density, benefit-cost ratios can be greater than 1 even in rural settings.

Streamlining of prehospital stroke management: the golden hour.

Thrombolysis with alteplase administered within a narrow therapeutic window provides an effective therapy for acute ischaemic stroke. However, mainly because of prehospital delay, patients often arrive too late for treatment, and no more than 1-8% of patients with stroke obtain this treatment. We recommend that all links in the prehospital stroke rescue chain must be optimised so that in the future more than a small minority of patients can profit from time-sensitive acute stroke therapy. Measures for improvement include continuous public awareness campaigns, education of emergency medical service personnel, the use of standardised, validated scales for recognition of stroke symptoms and for triaging to the appropriate institution, and advance notification to the receiving hospital. In the future, use of telemedicine technologies for interaction between the emergency site and hospital, and the strategy of treatment directly at the emergency site (mobile stroke unit concept), could contribute to more efficient use of resources and reduce the time taken to instigate treatment to within 60 min--the golden hour--of the onset of the symptoms of stroke.

Mechanical recanalization with flow restoration in acute ischemic stroke: the ReFlow (mechanical recanalization with flow restoration in acute ischemic stroke) study.

OBJECTIVES: This study sought to assess the feasibility and safety of a recently described technique of mechanical recanalization with the help of a stent-like device. BACKGROUND: In the special group of acute stroke patients with an intracranial large vessel occlusion, intravenous tissue-type plasminogen activator on its own leads to a good clinical outcome (mRS ≤ 2) in only 15% to 25% of cases. The aforementioned technique of mechanical recanalization showed very promising clinical results. METHODS: Forty patients presenting within 6 h from stroke symptom onset were enrolled. Mechanical recanalization was performed using a Solitaire FR revascularization device. The primary endpoint of the study was the clinical outcome rated with the help of the modified Rankin Scale (mRS) after 90 days. RESULTS: Twenty-four patients (60%) showed a good clinical outcome (mRS ≤ 2) at 90 days. One symptomatic hemorrhage was detected on follow-up computed tomography. The death rate was 12.5% (5 patients). Successful recanalization (Thrombolysis In Cerebral Infarction score ≥ 2b) of the target vessel was achieved in 95% of the patients with a mean of 1.8 runs with the device. CONCLUSIONS: The ReFlow (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke) study shows that mechanical recanalization with flow restoration is highly effective in stroke patients with a large intracranial vessel occlusion presenting within 4.5 h after symptom onset. (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke [ReFlow]; NCT01210729).

Diagnosis and treatment of patients with stroke in a mobile stroke unit versus in hospital: a randomised controlled trial.

BACKGROUND: Only 2-5% of patients who have a stroke receive thrombolytic treatment, mainly because of delay in reaching the hospital. We aimed to assess the efficacy of a new approach of diagnosis and treatment starting at the emergency site, rather than after hospital arrival, in reducing delay in stroke therapy. METHODS: We did a randomised single-centre controlled trial to compare the time from alarm (emergency call) to therapy decision between mobile stroke unit (MSU) and hospital intervention. For inclusion in our study patients needed to be aged 18-80 years and have one or more stroke symptoms that started within the previous 2·5 h. In accordance with our week-wise randomisation plan, patients received either prehospital stroke treatment in a specialised ambulance (equipped with a CT scanner, point-of-care laboratory, and telemedicine connection) or optimised conventional hospital-based stroke treatment (control group) with a 7 day follow-up. Allocation was not masked from patients and investigators. Our primary endpoint was time from alarm to therapy decision, which was analysed with the Mann-Whitney U test. Our secondary endpoints included times from alarm to end of CT and to end of laboratory analysis, number of patients receiving intravenous thrombolysis, time from alarm to intravenous thrombolysis, and neurological outcome. We also assessed safety endpoints. This study is registered with ClinicalTrials.gov, number NCT00153036. FINDINGS: We stopped the trial after our planned interim analysis at 100 of 200 planned patients (53 in the prehospital stroke treatment group, 47 in the control group), because we had met our prespecified criteria for study termination. Prehospital stroke treatment reduced the median time from alarm to therapy decision substantially: 35 min (IQR 31-39) versus 76 min (63-94), p<0·0001; median difference 41 min (95% CI 36-48 min). We also detected similar gains regarding times from alarm to end of CT, and alarm to end of laboratory analysis, and to intravenous thrombolysis for eligible ischaemic stroke patients, although there was no substantial difference in number of patients who received intravenous thrombolysis or in neurological outcome. Safety endpoints seemed similar across the groups. INTERPRETATION: For patients with suspected stroke, treatment by the MSU substantially reduced median time from alarm to therapy decision. The MSU strategy offers a potential solution to the medical problem of the arrival of most stroke patients at the hospital too late for treatment. FUNDING: Ministry of Health of the Saarland, Germany, the Werner-Jackstädt Foundation, the Else-Kröner-Fresenius Foundation, and the Rettungsstiftung Saar.

Carotid artery stenting in acute stroke.

OBJECTIVES: The purpose of this study is to demonstrate the technical success of carotid artery stenting in acute extracranial internal carotid artery (ICA) occlusion as well as the benefit in clinical outcome. BACKGROUND: Stroke caused by acute occlusion of the ICA is associated with a significant level of morbidity and mortality. For this type of lesion, treatment with standard intravenous thrombolysis alone leads to a good clinical outcome in only 17% of the cases, with a death rate as high as 55%. Recanalization of the occluded ICA can lead to an improvement in acute symptoms of stroke, prevent possible deterioration, and reduce long-term stroke risk. At present, there is no consensus treatment for patients with acute ischemic stroke presenting with severe clinical symptoms due to atherosclerotic occlusion of the extracranial ICA. METHODS: Carotid artery stenting was performed in 22 patients with acute atherosclerotic extracranial ICA occlusion within 6 h of stroke symptom onset. In 18 patients, there was an additional intracranial occlusion at the level of the terminal segment of the ICA (n = 4) and at the level of the middle cerebral artery (n = 14). Intracranial occlusions were either treated with the Penumbra system or the Solitaire stent-based recanalization system, or a combination of mechanical recanalization and intra-arterial thrombolysis. Recanalization results were assessed by angiography immediately after the procedure. The neurologic status was evaluated before and after the treatment with a follow-up as long as 90 days using the National Institutes of Health Stroke Scale and the modified Rankin Scale. RESULTS: Successful revascularization of extracranial ICA with acute stent implantation was achieved in 21 patients (95%). There was no acute stent thrombosis. After successful recanalization of the origin of the ICA, the intracranial recanalization with Thrombolysis In Myocardial Infarction flow grade 2/3 was achieved in 11 of the 18 patients (61%). The overall recanalization rate (extracranial and intracranial) was 14 of 22 patients (63%). Nine patients (41%) had a modified Rankin Scale score of ≤2 at 90 days. The mortality rate was 13.6% at 90 days. CONCLUSIONS: Carotid artery stenting in acute atherosclerotic extracranial ICA occlusion with severe stroke symptoms is feasible, safe, and useful within the first 6 h after symptom onset.

Point-of-care laboratory halves door-to-therapy-decision time in acute stroke.

Currently, stroke laboratory examinations are usually performed in the centralized hospital laboratory, but often planned thrombolysis is given before all results are available, to minimize delay. In this study, we examined the feasibility of gaining valuable time by transferring the complete stroke laboratory workup required by stroke guidelines to a point-of-care laboratory system, that is, placed at a stroke treatment room contiguous to the computed tomography, where the patients are admitted and where they obtain neurological, laboratory, and imaging examinations and treatment by the same dedicated team. Our results showed that reconfiguration of the entire stroke laboratory analysis to a point-of-care system was feasible for 200 consecutively admitted patients. This strategy reduced the door-to-therapy-decision times from 84 ± 26 to 40 ± 24 min (p < 0.001). Results of most laboratory tests (except activated partial thromboplastin time and international normalized ratio) revealed close agreement with results from a standard centralized hospital laboratory. These findings may offer a new solution for the integration of laboratory workup into routine hyperacute stroke management.

Bringing the hospital to the patient: first treatment of stroke patients at the emergency site.

BACKGROUND: Early treatment with rt-PA is critical for favorable outcome of acute stroke. However, only a very small proportion of stroke patients receive this treatment, as most arrive at hospital too late to be eligible for rt-PA therapy. METHODS AND FINDINGS: We developed a "Mobile Stroke Unit", consisting of an ambulance equipped with computed tomography, a point-of-care laboratory system for complete stroke laboratory work-up, and telemedicine capabilities for contact with hospital experts, to achieve delivery of etiology-specific and guideline-adherent stroke treatment at the site of the emergency, well before arrival at the hospital. In a departure from current practice, stroke patients could be differentially treated according to their ischemic or hemorrhagic etiology even in the prehospital phase of stroke management. Immediate diagnosis of cerebral ischemia and exclusion of thrombolysis contraindications enabled us to perform prehospital rt-PA thrombolysis as bridging to later intra-arterial recanalization in one patient. In a complementary patient with cerebral hemorrhage, prehospital diagnosis allowed immediate initiation of hemorrhage-specific blood pressure management and telemedicine consultation regarding surgery. Call-to-therapy-decision times were 35 minutes. CONCLUSION: This preliminary study proves the feasibility of guideline-adherent, etiology-specific and causal treatment of acute stroke directly at the emergency site.

Recurrent stroke after cervical artery dissection.

OBJECTIVE: Cervical artery dissection (CAD) accounts for 10-20% of all strokes in young adults, but no randomised controlled trial has investigated the best secondary prevention after ischaemic stroke or transient ischaemic attack (TIA). Because only small numbers of patient with CAD have been prospectively documented and followed up, the authors aimed to investigate the prognosis under various prevention regimens. METHODS: 30 German departments of neurology with acute stroke units prospectively documented 250 patients with acute ischaemic stroke or TIA due to CAD. A central follow-up (median 31 months) assessed recurrent stroke, recurrent CAD and death in 198 patients. RESULTS: CAD was found more often in the carotid arteries (52.0%) than in the vertebral arteries (46.8%). Thirteen patients (5.2%, CI 3.1% to 8.6%) suffered a recurrent stroke during the acute hospital stay. The rate of recurrent CAD during the first year was 1.7% (95% CI 0.3% to 3.6%). The cumulative recurrent stroke rate during the first year was 10.7% (95% CI 6.5% to 14.9%) and 14.0% (95% CI 8.9% to 19.1%) over 3 years. After discharge, the rate of recurrent stroke up to 6 months in patients treated with anticoagulants was 2.0% (95% CI 0.6% to 7.1%) and in those treated with antiplatelets 16.7% (95% CI 5.8% to 39.2%), which was statistically significant (HR 0.11; CI 0.02 to 0.69, p=0.02). CONCLUSIONS: This observational study confirms a high risk of early recurrent stroke following acute IS or TIA due to CAD. Whether anticoagulation provides any benefit over antiplatelets needs to be investigated in a randomised controlled trial.

Quality monitoring of acute stroke care in Rhineland-Palatinate, Germany, 2001-2006.

BACKGROUND AND PURPOSE: Quality monitoring projects are useful tools to improve the quality and to assess temporal trends of stroke care in larger populations. METHODS: In Rhineland-Palatinate, Germany, a statewide, hospital-based, acute stroke care quality monitoring project was started in 2001. Initially, participation was mandatory for all hospitals with dedicated stroke units and from 2006 onward was mandatory for all hospitals. Quality monitoring included a structured data assessment and quality indicators for procedural measures. RESULTS: Between 2001 and 2006, the numbers of patients registered annually (N=6389 vs N=10 610), admission <3 hours after stroke onset (28.2% vs 34.6%), admission via emergency medical systems (38.1% vs 50.3%), and treatment in stroke units (44.3% vs 59.5%) increased significantly (P<0.0001, respectively). In ischemic stroke, use of thrombolytic therapy increased (for patients admitted <3 hours after onset, 6.5% vs 14.1%), whereas therapy with high-dose heparin declined (24.5% vs 6.0%, P<0.0001). Several quality indicators (performance of neuroimaging and Doppler/duplex sonography, neuroimaging <3 hours after admission) showed stable results at a high level; more patients received echocardiography (62.2% vs 74.0%), but fewer patients were rapidly examined by extracranial Doppler/duplex sonography (68.7% vs 62.8%, P<0.0001). Diagnosis and treatment of hypertension and hyperlipidemia, use of aspirin and combined aspirin/dipyridamole, and diagnosis of atrial fibrillation increased (P<0.0001, respectively). Use of oral anticoagulation remained stable at approximately 38% of patients with cardioembolism. CONCLUSIONS: Although these results reflect high standards of acute stroke care and improvements regarding early admission, thrombolytic therapy, and several secondary preventive measures, there is still the potential for further improvement regarding thrombolysis, use of oral anticoagulation and statins, and admission to stroke units, for example.

New mechanical recanalization devices - the future in pediatric stroke treatment?

OBJECTIVE: To evaluate the recanalization rate and clinical outcome in children with acute ischemic stroke following treatment with innovative mechanical thrombectomy devices. PATIENTS AND METHODS: Three subjects aged 7-16 years presenting with acute cerebral vascular occlusions (thrombolysis in myocardial infarction [TIMI] 0) were treated with either the Penumbra System, operating on an aspiration platform, or the Phenox clot retriever device, a flexible wire compound with perpendicularly-oriented polyamid microfilaments. Target vessels were the internal carotid artery, the middle cerebral artery and the basilar artery. RESULTS: Successful recanalization (TIMI 3) was attained in all cases. No device-related complications or intracranial hemorrhage occurred. Follow up was conducted for up to 30 days. A 10- to 26-point improvement in the National Institutes of Health Stroke Scale (NIHSS) score was achieved. CONCLUSIONS: Mechanical thrombectomy devices possess a dual advantage whereby they can achieve instant recanalization as well as minimize the number of bleeds that customarily accompany intravenous and intra-arterial therapy. These new devices could contribute greatly to treatment decisions in a field not yet clearly defined by current guidelines.

The POST trial: initial post-market experience of the Penumbra system: revascularization of large vessel occlusion in acute ischemic stroke in the United States and Europe.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the initial post-market experience of the device and how it is compared with the Penumbra Pivotal trial used to support the 510k application. METHODS: A retrospective case review of 157 consecutive patients treated with the Penumbra system at seven international centers was performed. Primary endpoints were revascularization of the target vessel (TIMI score of 2 or 3), good functional outcome as defined by a modified Rankin scale (mRS) score of ≤2 and incidence of procedural serious adverse events. Results were compared with those of the Penumbra pivotal trial. RESULTS: A total of 157 vessels were treated. Mean baseline values at enrollment were: age 65 years, NIHSS score 16. After use of the Penumbra system, 87% of the treated vessels were revascularized to TIMI 2 (54%) or 3 (33%) as compared with 82% reported in the Pivotal trial. Nine procedural serious adverse events were reported in 157 patients (5.7%). All-cause mortality was 20% (32/157), and 41% had a mRS of ≤2 at 90-day follow-up as compared with only 25% in the Pivotal trial. Patients who were successfully revascularized by the Penumbra system had significantly better outcomes than those who were not. CONCLUSION: Initial post-market experience of the Penumbra system revealed that the revascularization rate and safety profile of the device are comparable to those reported in the Pivotal trial. However, the proportion of patients who had good functional outcome was higher than expected.

Influence of carotid artery stenting on cognitive function.

INTRODUCTION: There have only been a few studies on cognitive changes in patients with carotid occlusive disease, and the results of these show major discrepancies in the extent to which treatment affects neuropsychological function. We sought to clarify these discrepancies by evaluating the effects of carotid artery stenting (CAS) on the cognitive function. METHODS: Forty-one asymptomatic CAS patients were administered a test battery of neuropsychological tests measuring cognitive speed and memory function before and 3 months after the procedure. A control group was also evaluated. To test for thromboembolic lesions, diffusion-weighted imaging was used. RESULTS: CAS led to a significant increase in cognitive speed (p<0.001) but did not afford any change in memory function. This was regardless of the degree or side of stenosis or patient age or gender. CONCLUSION: CAS significantly improved functions that involve cognitive speed. Earlier studies did not differentiate between speed and memory tests and thus might have missed these changes. Further studies correlating changes in brain perfusion with increase in cognitive speed are needed.