Vertebral artery stenting to prevent recurrent stroke in symptomatic vertebral artery stenosis: the VIST RCT.

BACKGROUND: Symptomatic vertebral artery (VA) stenosis has been associated with a markedly increased early risk of recurrent stroke. VA stenosis can be treated with stenting; however, there are few data from randomised controlled trials evaluating the efficacy of this treatment, and recent studies in intracranial stenosis have suggested that stenting may be associated with increased risk. OBJECTIVE: The Vertebral artery Ischaemia Stenting Trial (VIST) was established to compare the risks and benefits of vertebral angioplasty and stenting with best medical treatment (BMT) alone for recently symptomatic VA stenosis. DESIGN: VIST was a prospective, randomised, open, parallel, blinded end-point clinical trial. SETTING: The trial was performed in 14 hospitals in the UK. PARTICIPANTS: Recruitment began on 23 October 2008 and follow-up ended on 1 March 2016, by which time every patient had been followed up for at least 1 year. Participants had to have symptomatic vertebral stenosis of at least 50% resulting from presumed atheromatous disease. Both patients and clinicians were aware of treatment allocation; however, an independent adjudication committee, masked to treatment allocation, assessed all primary and secondary end points. INTERVENTIONS: Participants were randomly assigned (1 : 1) to either vertebral angioplasty/stenting plus BMT (n = 91) or BMT alone (n = 88). A total of 182 patients were initially enrolled; however, three patients (two who withdrew after randomisation and one who did not attend after the initial randomisation visit) did not contribute any follow-up data and were excluded. None of these three patients had outcome events. MAIN OUTCOMES AND MEASURES: The primary end point was the occurrence of fatal or non-fatal stroke in any arterial territory during follow-up. RESULTS: The median follow-up was 3.5 (interquartile range 2.1-4.7) years. Of the 61 patients who were stented, 48 (78.7%) had extracranial stenosis and 13 (21.3%) had intracranial stenosis. No perioperative complications occurred with extracranial stenting; two strokes occurred during intracranial stenting. The primary end point occurred in five patients (including one fatal stroke) in the stent group and in 12 patients (including two fatal strokes) in the medical group (giving a hazard ratio of 0.40, 95% confidence interval 0.14 to 1.13; p = 0.08), with an absolute risk reduction of 25 strokes per 1000 person-years. LIMITATIONS: The study was underpowered because it failed to reach target recruitment. The high rate of non-confirmation of stenosis in the stented group of the trial was a second limitation. CONCLUSIONS: The trial found no difference in risk of the primary end point between the two groups. FUTURE: Post hoc analysis suggested that stenting could be associated with a reduced recurrent stroke risk in symptomatic VA and further studies are now required to confirm these findings, particularly in extracranial VA stenosis where complication rates with stenting were confirmed to be very low. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95212240. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 41. See the NIHR Journals Library website for further project information. In addition, funding for the pilot phase was provided by the Stroke Association.

About one-quarter of all strokes occur in the back of the brain, which is supplied by the vertebral and basilar arteries. An important cause of stroke is a narrowing, or stenosis, of these arteries. It is known that patients who have a minor stroke due to narrowing of a vertebral artery (VA) have a high risk of a further stroke: as much as 30% in the next year. Stenosis of the VA can be treated with stenting, in which a wire mesh is put into the narrowed artery and opens it up. Many operations to insert a vertebral stent have been carried out worldwide with good technical results; however, it is not known whether it is better to treat vertebral stenosis with stenting or only tablets. The Vertebral artery Ischaemia Stenting Trial was a randomised controlled trial comparing vertebral stenting and best medical treatment (BMT) with BMT alone in patients who had suffered a minor stroke due to vertebral stenosis. Ninety-one patients had stenting and 88 had BMT alone. Patients were followed for an average of 3.5 years. It was planned to enrol 540 patients to the trial, but recruitment was slower than expected and funding for the study was halted; therefore, recruitment was stopped at 181 patients. There was no difference in the rate of recurrent stroke between patients who had stenting and those who had BMT alone. There was some evidence that stenting might be associated with a reduced risk of recurrent stroke, but the difference was not significant. The trial was limited by the failure to recruit the anticipated sample size. The results tell us that stenting is a possible treatment for vertebral stenosis; however, further trials are required to determine whether or not it is more effective at preventing recurrent stroke than BMT alone.

Triple versus guideline antiplatelet therapy to prevent recurrence after acute ischaemic stroke or transient ischaemic attack: the TARDIS RCT.

BACKGROUND: Two antiplatelet agents are better than one for preventing recurrent stroke after acute ischaemic stroke or transient ischaemic attack (TIA). Therefore, intensive treatment with three agents might be better still, providing it does not cause undue bleeding. OBJECTIVE: To compare the safety and efficacy of intensive therapy with guideline antiplatelet therapy for acute ischaemic stroke and TIA. DESIGN: International prospective randomised open-label blinded end-point parallel-group superiority clinical trial. SETTING: Acute hospitals at 106 sites in four countries. PARTICIPANTS: Patients > 50 years of age with acute non-cardioembolic ischaemic stroke or TIA within 48 hours of ictus (stroke). INTERVENTIONS: Participants were allocated at random by computer to 1 month of intensive (combined aspirin, clopidogrel and dipyridamole) or guideline (combined aspirin and dipyridamole, or clopidogrel alone) antiplatelet agents, and followed for 90 days. MAIN OUTCOME MEASURES: The primary outcome was the incidence and severity of any recurrent stroke (ischaemic, haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days by blinded telephone follow-up. Analysis using ordinal logistic regression was by intention to treat. Other outcomes included bleeding and its severity, death, myocardial infarction (MI), disability, mood, cognition and quality of life. RESULTS: The trial was stopped early on the recommendation of the Data Monitoring Committee after recruitment of 3096 participants (intensive, n = 1556; guideline, n = 1540) from 106 hospitals in four countries between April 2009 and March 2016. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy in 3070 (99.2%) participants with data [93 vs. 105 stroke/TIA events; adjusted common odds ratio 0.90, 95% confidence interval (CI) 0.67 to 1.20; p = 0.47]. Major (encompassing fatal) bleeding was increased with intensive as compared with guideline therapy [39 vs. 17 participants; adjusted hazard ratio (aHR) 2.23, 95% CI 1.25 to 3.96; p = 0.006]. There were no differences between the treatment groups in all-cause mortality, or the composite of death, stroke, MI and major bleeding (aHR 1.02, 95% CI 0.77 to 1.35; p = 0.88). LIMITATIONS: Patients and investigators were not blinded to treatment. The comparator group comprised two guideline strategies because of changes in national guidelines during the trial. The trial was stopped early, thereby reducing its statistical power. CONCLUSIONS: The use of three antiplatelet agents is associated with increased bleeding without any significant reduction in recurrence of stroke or TIA. FUTURE WORK: The safety and efficacy of dual antiplatelet therapy (combined aspirin and clopidogrel) versus aspirin remains to be defined. Further research is required on identifying individual patient response to antiplatelets, and the relationship between response and the subsequent risks of vascular recurrent events and bleeding complications. TRIAL REGISTRATION: Current Controlled Trials ISRCTN47823388. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 48. See the NIHR Journal Library website for further project information. The Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke (TARDIS) vanguard phase was funded by the British Heart Foundation (grant PG/08/083/25779, from 1 April 2009 to 30 September 2012) and indirect funding was provided by the Stroke Association through its funding of the Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK. There was no commercial support for the trial and antiplatelet drugs were sourced locally at each site. The trial was sponsored by the University of Nottingham.

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial.

BACKGROUND: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy. METHODS: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388. FINDINGS: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67-1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05-3·16, p<0·0001). INTERPRETATION: Among patients with recent cerebral ischaemia, intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding. Triple antiplatelet therapy should not be used in routine clinical practice. FUNDING: National Institutes of Health Research Health Technology Assessment Programme, British Heart Foundation.

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection.

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.

User experience of a centralized hyperacute stroke service: a prospective evaluation.

BACKGROUND AND PURPOSE: Centralizing hyperacute stroke unit (HASU) care services allows improved access to thrombolysis but could be associated with worse patient experience, particularly when early repatriation to a local stroke recovery unit occurs as this may result in discontinuity of care. A centralized model of care was introduced in London, United Kingdom, with 8 HASUs providing acute care for the whole 8.3 million population, with repatriation on day 3 to a local stroke recovery unit. The patient and carer experience of this model of care has not been previously reported. METHODS: We undertook a prospective observational study of the new model of care in the South West London sector. Patient and carer experiences were evaluated using a modified Picker Questionnaire. Separate questionnaires were used for patients discharged directly home from the HASU, those repatriated to local stroke recovery units, and for carers of patients admitted to the HASU. RESULTS: Despite moving from a selected to nonselected admission pattern, thrombolysis rates increased from 6% to 9%. High satisfaction rates were reported among both patients and carers. Patients discharged directly home had higher satisfaction levels than those requiring repatriation to their local stroke unit, who were older and had more severe stroke. A total of 47% of carers expressed anxiety over the repatriation from the HASU back to the local stroke recovery unit, but few patients and carers reported an impact of this move on patient recovery. CONCLUSION: Centralized HASU care is associated with good levels of patient and carer satisfaction.

Can transcranial Doppler discriminate between solid and gaseous microemboli? Assessment of a dual-frequency transducer system.

BACKGROUND AND PURPOSE: Transcranial Doppler ultrasound can reliably detect both gaseous and solid cerebral emboli. However, conventional equipment is unable to discriminate between gaseous and solid emboli. This is a major limitation in situations in which the 2 coexist, because they may have very different clinical relevance. Recently, a novel Embo-Dop system, using insonation at 2 ultrasound transducer frequencies, has been developed. An initial study with a small sample size suggested it provided excellent discrimination. We performed a validation study in subjects with embolic signals of known nature. METHODS: Gaseous embolic signals were obtained in 7 patients with known patient foramen ovale by intravenous injection of agitated saline injections. Solid embolic signals were obtained in patients with symptomatic carotid stenosis (N=23). Discrimination of the 2 using the Embo-Dop system dual-frequency system was assessed. It was compared with discrimination using embolic signal maximum intensity with an intensity threshold. RESULTS: One hundred forty-five solid embolic signals were recorded from carotid stenosis patients. Seventy-three were classified as solid and 72 as gaseous by the Embo-Dop system. Six hundred forty-eight gaseous embolic signals were recorded from 7 patients with patent foramen ovale. Six hundred twenty-five were classified as gaseous and 23 as solid. This gave a sensitivity of 50.3% and specificity of 96.5% for detecting solid embolic signals. Discrimination was better than using a simple intensity threshold. CONCLUSIONS: The Embo-Dop dual-frequency system allows better discrimination than a simple intensity threshold but it is not accurate enough for use in clinical or research studies. Further work is needed to develop reliable clinical systems for discrimination of emboli.