XI. European Stroke Conference
Geneva, Switzerland
29 May - 1 June 2002

New Issues
Date: 1.6.2002   Time: 11:00-11:15 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

01
The Natural History of Unruptured Intracranial Aneurysms: Prospective Data from The International Study of Unruptured Intracranial Aneurysms
R.D. Brown, Jr.                                                                
For the International Study of Unruptured Intracranial Aneurysms Investigators

Mayo Clinic

USA

Background: The International Study of Unruptured Intracranial Aneurysms (ISUIA) reported the natural history of 1449 patients with UIAs entered retrospectively, but there have not been conclusive prospective natural history data available. Methods: Starting in 1991, ISUIA prospectively entered patients with UIAs into the natural history aspect of the study. Demographic, and past medical/family history data were prospectively collected. All patients had arteriograms sent for central review, and had yearly follow-up. Endpoints were comprehensively adjudicated. The risk of aneurysm rupture was determined, and Cox proportional hazards regression analysis was used to define predictors of rupture. Results: 1705 patients with UIAs were entered into the prospective natural history component of ISUIA; 1081 without a prior history of SAH (group 1) and 624 with a prior history of SAH from some other source (group 2). Arteriogram review by a neuroradiologist determined the aneurysm diameter and site. In the prospective cohort, the risk of hemorrhage among group 1 patients was dependent on aneurysm diameter, with the highest risk being those >25 mm. Independent predictors of hemorrhage included posterior communicating and basilar tip sites, and larger size. In group 2 patients, hemorrhage risk was minimally higher in those with 10-24 mm aneurysms compared to those <10 mm in size, and size was not an independent predictor of hemorrhage. Discussion: UIAs <7 mm in diameter are extremely unlikely to rupture, and risk increases with size among people without prior hemorrhage. Detailed site- and size-specific aneurysm rupture rates may be used in comparing the observation risks to the intervention risks as one defines the optimal management for patients with UIAs.

New Issues
Date: 1.6.2002   Time: 11:15-11:30 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

02
Assessing risks of treating patients with unruptured intracranial aneurysms: The International Study of Unruptured Intracranial Aneurysms
D.O.Wiebers                                                               
for the ISUIA Investigators

Mayo Clinic, Rochester, MN

USA

Background: The International Study of Unruptured Intracranial Aneurysms (ISUIA) has previously reported limited outcomes data involving 1,172 surgically treated patients with unruptured intracranial aneurysms (UIAs) but patient numbers were insufficient to allow definitive judgments regarding predictors of outcome. Methods: From 1991 to 1999 patients with UIAs were prospectively entered into the treatment aspect of ISUIA from 60 participating centers in North America and Europe. Patients were assessed at hospital discharge and at 7 and 30 days post-procedure with subsequent yearly follow-up by questionnaire and telephone interview. Cox proportional hazards regression analysis was used to define predictors of surgical risk. Results: A total of 2415 patients were entered into the treatment component of ISUIA. Intracranial aneurysm surgery was performed in 1725 patients (71%), endovascular procedures in 332 (13%) and multiple/other procedures in 351 (13%). Mean age at diagnosis was 51 years and approximately ¾ of the patients were women. The mean size of treated UIAs was 10.8 mm and approximately 90% were located in the anterior circulation. Independent predictors of surgical morbidity and mortality included patient age, aneurysm size and location, and history of prior cerebral infarction. Age and history of prior cerebral infarction were not as important for predicting endovascular treatment risk. Discussion: Operative risk increases with increasing patient age, increasing aneurysmal size, posterior circulation location (particularly basilar tip) and a history of prior cerebral infarct. Age-specific intervention morbidity and mortality rates by aneurysm size and location may be used for comparison to natural history risks to optimize management of patients with UIAs.

New Issues
Date: 1.6.2002   Time: 11:30-11:40 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

03
The Canadian Activase for Stroke Effectiveness Study (CASES): Final Results
A.V.Hachinski    M.D.Hill    A.M.Buchan                                                 
the CASES Investigators

University of Calgary

CANADA

Background: Therapy for acute stroke using rtPA was approved in Canada in February 1999. The Canadian Activase for Stroke Effectiveness Study Group was formed to study the use of rtPA in Canada in a 30-month post-marketing study (Feb 1999-June 2001). Purpose: To both prospectively assess the safety of rtPA in the Canadian context, to examine whether the efficacy of rtPA for acute stroke, demonstrated in the NINDS trial, can be translated into effectiveness in routine clinical practice across Canada and to develop a prognostic index for patients treated with alteplase. Methods: The CASES group is a collaboration among the Canadian Stroke Consortium (CSC), the Canadian Stroke Society, the Heart & Stroke Foundation of Canada, Hoffmann-La Roche Canada, the Canadian Stroke Network and physicians across the country. The study protocol was approved by the research ethics board at each centre. Demographics, stroke risk factors, blood pressure, biochemistry, hematology, and CT scans have been collected. NIHSS and mRS scores have been collected prospectively. CT scans are being scored centrally using ASPECTS. Outcomes have been monitored at discharge and at 3 months. Results: 60 centres participated in the study. 1099 patients were recruited. The median NIHSS score is 15 (range 2-40). 30% of patients have minimal or no neurological deficit (NIHSS 0-1) and 46% are independent (mRS 0-2) at 90 days. The symptomatic hemorrhage rate is 4.6% (95%CI 3.4% to 6.0%). The rate of protocol violations is 15%, the majority of which are time window violations. Predictors of good outcome include baseline NIHSS score, baseline ASPECT score, age, baseline serum glucose, atrial fibrillation. Predictors of symptomatic intracerebral hemorrhage included baseline mean arterial blood pressure and baseline serum glucose. Conclusions: CASES was a prospective evaluation of the effectiveness of rtPA in acute stroke. The symptomatic hemorrhage rate is low (4.6%). Alteplase for ischemic stroke is safe and effective in Canada.

New Issues
Date: 1.6.2002   Time: 11:40-11:50 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

04
Long-term durability of carotid endarterectomy: ten year risks and risk factors for late post-operative stroke in the European Carotid Surgery Trial
R. Bond    E.J.Cunningham    M.R.Mayberg    C.P.Warlow    P.M.Rothwell                                   
European Carotid Surgery Trialists’ Collaborative Group

Radcliffe Infirmary, Oxford

UNITED KINGDOM

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is a potential alternative to endarterectomy (CEA) for symptomatic severe carotid stenosis. Case series and small randomised trials of CEA vs PTA have focused primarily on the 30-day procedural risks. However, long-term durability is also important. We determined the long-term risk of stroke after CEA, and related risk factors, in the European Carotid Study Trial (ECST) - the largest CEA cohort followed-up by neurologists. METHODS: Actuarial risks of ipsilateral carotid territory ischaemic stroke were calculated from the 30th day after CEA in 1728 patients. Risk factors were determined by Cox regression. For comparison we determined the “background” risk of stroke on medical treatment in the territory of 558 previously asymptomatic contralateral carotid arteries with <30% angiographic stenosis (ECST method). RESULTS: The risks of disabling ipsilateral ischaemic stroke and any ipsilateral ischaemic stroke were constant after CEA, reaching 4.4% (95%CI=3.0-5.8) and 9.7% (95%CI=7.6-11.7) respectively by 10 years. The equivalent risks distal to contralateral <30% asymptomatic carotid stenosis were 2.0% (95%CI=0.8–3.2) and 4.5% (95%CI=1.5–7.4) Presentation with cerebral symptoms, diabetes, peripheral vascular disease and elevated systolic blood pressure were associated with an increased risk of stroke after CEA, but pre-operative % stenosis, plaque morphology and use of a patch graft were not. CONCLUSION: Although the risk of stroke after CEA for symptomatic stenosis is greater than the calculated “background” risk, it is still only about 1% per year, and remains low for at least 10 years. Ideally, alternative treatments should be equally durable. Several risk factors identify patients at risk of late post-operative stroke.

New Issues
Date: 1.6.2002   Time: 11:50-12:00 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

05
Effect of Intravenous Thrombolysis on MRI Parameters and Functional Outcome in Acute Stroke < 6 Hours
J. Roether    P.D.Schellinger    A. Gass    M. Siebler    A. Villringer    J.B.Fiebach    J.F.Fiehler    O. Jansen    T. Kucinski       
 

University Hospitals Hamburg Eppendorf, Heidelberg, Mannheim, Düsseldorf , Berlin Charite, University Hospitals and Kiel

GERMANY

Aim: To examine MRI baseline characteristics of patients with acute ischemic stroke (AIS) and to study the influence of intravenous tissue plasminogen activator (tPA) on MR parameters and functional outcome within a multicenter approach. Methods: Consecutive AIS patients with suspected anterior circulation stroke that finished a multiparametric stroke MRI protocol (diffusion and perfusion weighted MRI (DWI, PWI); magnetic resonance angiography (MRA)) within 6 hours after symptom onset and on follow-up (days 1 and 7) were included. Patients were either treated with tPA (thrombolysis group) or conservatively (Æ thrombolysis group). Functional outcome was assessed on day 90 (modified Rankin Score; mRS). Findings: We enrolled 139 AIS patients (no thrombolysis group, n=63; thrombolysis group, n=76). Patients treated with tPA were more severely affected (NIHSS 10 vs. 13; p=0.002). In the thrombolysis group, T2w lesion volume on day 7 was smaller (35 ml [1.6-377] - median [range] vs. 73 ml [0-685]; p=0.44) and recanalisation rates (TIMI 1-3 on day 1) were higher (66.2% vs. 32.7%; p<0.001). Proximal vessel occlusions resulted in larger infarct volumes and a worse outcome (p=0.02). Thrombolysis was associated with a better outcome regardless of the time point of tPA treatment [£ 3h or 3-6h] (univariate analysis mRS £2: p=0.017; mRS £1: p=0.023). Age (p=0.003), thrombolytic therapy 0-6h (p=0.01), recanalisation (p=0.016), lesion volume on day 7 (p=0.001) and initial NIHSS (p=0.001) affected functional outcome (mRS90) positively. The time point of tPA therapy affected the recanalisation rate (p=0.024) but not the final infarct volume. Interpretation: tPA therapy had a beneficial effect on final infarct volumes and on functional outcome. Multiparametric MRI delineates tissue at risk of infarction in AIS patients that may be helpful for the selection of patients for tPA therapy. tPA therapy appeared safe and effective in this study beyond a 3-hour time window.

New Issues
Date: 1.6.2002   Time: 12:00-12:10 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

06
THE PROGNOSIS OF ACUTE CEREBRAL VEIN AND DURAL SINUS THROMBOSIS. ISCVT RESULTS
J.M.Ferro    J. Stam    M.G.Bousser    F. Barinagarrementeria    P. Canhão                                   
ISCVT Collaborators

Hospital Santa Maria

PORTUGAL

Background: The information on the prognosis of cerebral vein and dural sinus thrombosis (CVDST) was not previously addressed by adequately powered prospective studies. Purpose: ISCVT is a multinational (21 countries), multicentre (89 centres) prospective, observational study aiming to describe the acute and long term prognosis of CVDST and to identify its predictors. Results: From 5/98 to 5/2001, 624 adult cases of CVDST (confirmed by appropriate imaging) were registered. Mean age was 39 years, mean admission GCS was 14, median delay from onset to admission was 4 days. At discharge (median stay 16 days) the modified Rankin grade was: 0-27% of the patients, 1-39%, 2-15%, 3-7%, 4-5%, 5-2%, and 6 (death)-4%. 21 (3,4%) patients died within 30 days. Multivariate predictors of death within 30 days were GCS score (GCS between 3 and 8, OR=13; GCS between 9 and 13, OR=8.6), mental status disorder (OR=2.9), haemorrhage on admission CT (OR=4.0) and thrombosis of the deep venous system (OR=6.1). Multivariate predictors of death or dependency (Rankin>2) at discharge were GCS score (GCS between 3 and 8, OR=6.9; GCS between 9 and 13, OR=3.5), age (between 27 and 49 years old, OR=2.8; more than 50 years old, OR=3.4), mental status disorder (OR=1.8), hemiparesis (OR=2.8), haemorrhage on admission CT (OR=2.7), thrombosis of the deep venous system (OR=2.4) and CNS disorder (OR=2.8) or cancer (OR=2.2) as a predisposing condition. Conclusion: In this large multicentre cohort the prognosis of CVDST was better than previously reported. We identified a number of factors in the acute phase that were associated with poor prognosis. This subgroup of high-risk patients could be the target for trials of more aggressive interventions.

New Issues
Date: 1.6.2002   Time: 12:10-12:20 -  Room: 2
Chair: N.Wahlgren, Sweden ; J.P. Mohr, USA

07
Simvastatin for aymptomatic patients with middle cerebral artery steonsis: a randomised, double-blind, placebo-controlled study
K.S.Wong    P.W.Ng    T.H.Tsoi    V. Yeung                                          
ROCAS Study Group

Chinese University of Hong Kong

HONG-KONG

There has been no published randomized clinical trial on the medical treatment of patients with middle cerebral artery (MCA) stenosis. Objectives: to test the hypothesis that simvastatin 20 mg daily retards progression of MCA and prevents clinical events in patients with asymptomatic MCA stenosis. Subjects and methods: From August 1996 till June 1999, we screened 3882 patients with transcranial Doppler. Inclusion criteria included LDL-cholesterol between 3 – 5 mmol/L, no history of ischemic heart or cerebrovascular disease (including stroke or transient ischemic attack). MCA stenosis was confirmed by magnetic resonance angiography (MRA). Stenosis severity as % stenosis on MRAs were measured by a blind investigator before and after treatment. Results: We recruited 143 women and 74 men. The mean age was 61 ± 9.1 years. The mean LDL-cholesterol levels is 3.93 mmol/l. For the primary outcome measure of the % stenosis on MRA, there was a non-significant trend of more regression in the simvastatin group (-9%) versus the placebo group (-2%, P = 0.3). Similarly, the TCD results showed that there was a trend of less progression of systolic velocity in the simvastatin group (mean 1.7 cm/sec) than the placebo group (mean 9.8 cm/sec, P= 0.09). For clinical events, there were significant reductions of total mortality in the simvastatin group (0 death) than the placebo (7 deaths, P = 0.014). There were also a trend for reduction of stroke (2 vs. 4) and acute coronary syndrome (2 vs. 4). For any vascular event, there was a border significant reduction (5 vs. 13, P = 0.08). Conclusion: Simvastatin 20 mg daily has minimal effects on the regression of occlusive lesion in MCA but the beneficial effects are somewhat more apparent in clinical event reduction.