Nils Wahlgren

Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke.

BACKGROUND Intravenous thrombolysis with alteplase is the only approved treatment for acute ischemic stroke, but its efficacy and safety when administered more than 3 hours after the onset of symptoms have not been established. We tested the efficacy and safety of alteplase administered between 3 and 4.5 hours after the onset of a stroke. METHODS After exclusion of patients with a brain hemorrhage or major infarction, as detected on a computed tomographic scan, we randomly assigned patients with acute ischemic stroke in a 1:1 double-blind fashion to receive treatment with intravenous alteplase (0.9 mg per kilogram of body weight) or placebo. The primary end point was disability at 90 days, dichotomized as a favorable outcome (a score of 0 or 1 on the modified Rankin scale, which has a range of 0 to 6, with 0 indicating no symptoms at all and 6 indicating death) or an unfavorable outcome (a score of 2 to 6 on the modified Rankin scale). The secondary end point was a global outcome analysis of four neurologic and disability scores combined. Safety end points included death, symptomatic intracranial hemorrhage, and other serious adverse events. RESULTS We enrolled a total of 821 patients in the study and randomly assigned 418 to the alteplase group and 403 to the placebo group. The median time for the administration of alteplase was 3 hours 59 minutes. More patients had a favorable outcome with alteplase than with placebo (52.4% vs. 45.2%; odds ratio, 1.34; 95% confidence interval [CI], 1.02 to 1.76; P=0.04). In the global analysis, the outcome was also improved with alteplase as compared with placebo (odds ratio, 1.28; 95% CI, 1.00 to 1.65; P<0.05). The incidence of intracranial hemorrhage was higher with alteplase than with placebo (for any intracranial hemorrhage, 27.0% vs. 17.6%; P=0.001; for symptomatic intracranial hemorrhage, 2.4% vs. 0.2%; P=0.008). Mortality did not differ significantly between the alteplase and placebo groups (7.7% and 8.4%, respectively; P=0.68). There was no significant difference in the rate of other serious adverse events. CONCLUSIONS As compared with placebo, intravenous alteplase administered between 3 and 4.5 hours after the onset of symptoms significantly improved clinical outcomes in patients with acute ischemic stroke; alteplase was more frequently associated with symptomatic intracranial hemorrhage. (ClinicalTrials.gov number, NCT00153036.)

Thrombolysis with alteplase for acute ischaemic stroke in the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST): an observational study.

BACKGROUND The aim of the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) was to assess the safety and efficacy of intravenous alteplase as thrombolytic therapy within the first 3 h of onset of acute ischaemic stroke. Under European Union regulations, SITS-MOST was required to assess the safety profile of alteplase in clinical practice by comparison with results in randomised controlled trials. METHODS 6483 patients were recruited from 285 centres (50% with little previous experience in stroke thrombolysis) in 14 countries between 2002 and 2006 for this prospective, open, monitored, observational study. Primary outcomes were symptomatic (a deterioration in National Institutes of Health stroke scale score of >or=4) intracerebral haemorrhage type 2 within 24 h and mortality at 3 months. We compared mortality, the proportion of patients with symptomatic intracerebral haemorrhage as per the Cochrane definition, and functional outcome at 3 months with relevant pooled results from randomised controlled trials. FINDINGS Baseline characteristics of patients in SITS-MOST were much the same as those in the pooled randomised controlled trials. At 24 h, the proportion of patients with symptomatic intracerebral haemorrhage (per the SITS-MOST protocol) was 1.7% (107/6444; 95% CI 1.4-2.0); at 7 days, the proportion with the same condition as per the Cochrane definition was 7.3% (468/6438; 6.7-7.9) compared with 8.6% (40/465; 6.3-11.6) in the pooled randomised controlled trials. The mortality rate at 3 months in SITS-MOST was 11.3% (701/6218; 10.5-12.1) compared with 17.3% (83/479; 14.1-21.1) in the pooled randomised controlled trials. INTERPRETATION These data confirm that intravenous alteplase is safe and effective in routine clinical use when used within 3 h of stroke onset, even by centres with little previous experience of thrombolytic therapy for acute stroke. The findings should encourage wider use of thrombolytic therapy for suitable patients treated in stroke centres.

Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials

Summary Background Alteplase is effective for treatment of acute ischaemic stroke but debate continues about its use after longer times since stroke onset, in older patients, and among patients who have had the least or most severe strokes. We assessed the role of these factors in affecting good stroke outcome in patients given alteplase. Methods We did a pre-specified meta-analysis of individual patient data from 6756 patients in nine randomised trials comparing alteplase with placebo or open control. We included all completed randomised phase 3 trials of intravenous alteplase for treatment of acute ischaemic stroke for which data were available. Retrospective checks confirmed that no eligible trials had been omitted. We defined a good stroke outcome as no significant disability at 3–6 months, defined by a modified Rankin Score of 0 or 1. Additional outcomes included symptomatic intracranial haemorrhage (defined by type 2 parenchymal haemorrhage within 7 days and, separately, by the SITS-MOST definition of parenchymal type 2 haemorrhage within 36 h), fatal intracranial haemorrhage within 7 days, and 90-day mortality. Findings Alteplase increased the odds of a good stroke outcome, with earlier treatment associated with bigger proportional benefit. Treatment within 3·0 h resulted in a good outcome for 259 (32·9%) of 787 patients who received alteplase versus 176 (23·1%) of 762 who received control (OR 1·75, 95% CI 1·35–2·27); delay of greater than 3·0 h, up to 4·5 h, resulted in good outcome for 485 (35·3%) of 1375 versus 432 (30·1%) of 1437 (OR 1·26, 95% CI 1·05–1·51); and delay of more than 4·5 h resulted in good outcome for 401 (32·6%) of 1229 versus 357 (30·6%) of 1166 (OR 1·15, 95% CI 0·95–1·40). Proportional treatment benefits were similar irrespective of age or stroke severity. Alteplase significantly increased the odds of symptomatic intracranial haemorrhage (type 2 parenchymal haemorrhage definition 231 [6·8%] of 3391 vs 44 [1·3%] of 3365, OR 5·55, 95% CI 4·01–7·70, p<0·0001; SITS-MOST definition 124 [3·7%] vs 19 [0·6%], OR 6·67, 95% CI 4·11–10·84, p<0·0001) and of fatal intracranial haemorrhage within 7 days (91 [2·7%] vs 13 [0·4%]; OR 7·14, 95% CI 3·98–12·79, p<0·0001). The relative increase in fatal intracranial haemorrhage from alteplase was similar irrespective of treatment delay, age, or stroke severity, but the absolute excess risk attributable to alteplase was bigger among patients who had more severe strokes. There was no excess in other early causes of death and no significant effect on later causes of death. Consequently, mortality at 90 days was 608 (17·9%) in the alteplase group versus 556 (16·5%) in the control group (hazard ratio 1·11, 95% CI 0·99–1·25, p=0·07). Taken together, therefore, despite an average absolute increased risk of early death from intracranial haemorrhage of about 2%, by 3–6 months this risk was offset by an average absolute increase in disability-free survival of about 10% for patients treated within 3·0 h and about 5% for patients treated after 3·0 h, up to 4·5 h. Interpretation Irrespective of age or stroke severity, and despite an increased risk of fatal intracranial haemorrhage during the first few days after treatment, alteplase significantly improves the overall odds of a good stroke outcome when delivered within 4·5 h of stroke onset, with earlier treatment associated with bigger proportional benefits. Funding UK Medical Research Council, British Heart Foundation, University of Glasgow, University of Edinburgh.

Thrombolysis with alteplase 3–4·5 h after acute ischaemic stroke (SITS-ISTR): an observational study

BACKGROUND Intravenous alteplase is approved for use within 3 h of ischaemic stroke onset, although a meta-analysis of randomised controlled trials suggests treatment benefit up to 4.5 h. We compared outcome in patients treated between 3 h and 4.5 h versus those treated within 3 h, who were recorded in the in the Safe Implementation of Treatments in Stroke (SITS), a prospective internet-based audit of the International Stroke Thrombolysis Registry (ISTR). METHODS We compared 664 patients presenting with ischaemic stroke and given intravenous altepase (0.9 mg/kg total dose) between 3 h and 4.5 h with 11 865 patients treated within 3 h. All patients were otherwise compliant with European summary of product characteristics criteria and had been documented in the international stroke treatment registry between Dec 25, 2002, and Nov 15, 2007. Outcome measures were symptomatic intracerebral haemorrhage within 24 h (haemorrhage type 2 associated with National Institutes of Health Stroke Scale [NIHSS] > or = 4 points deterioration), and mortality and independence (modified Rankin scale of 0-2) at 3 months. FINDINGS In the 3-4.5-h cohort, treatment was started at a median of 55 min later after symptom onset (195 min [IQR 187-210] vs 140 min [115-165], p<0.0001), median age was 3 years younger (65 years [55-73] vs 68 years [58-74], p<0.0001), and stroke severity was lower (NIHSS score 11 [7-16] vs 12 [8-17], p<0.0001) than in the 3-h cohort. We recorded no significant differences between the 3-4.5-h cohort and the within 3-h cohort for any outcome measure--rate of symptomatic intracerebral haemorrhage: 2.2% (14 of 649) versus 1.6% (183 of 11 681) (odds ratio [OR] 1.18 [95% CI 0.89-1.55], p=0.24; adjusted OR 1.32 [1.00-1.75], p=0.052); mortality: 12.7% (70 of 551) versus 12.2% (1263 of 10 368) (OR 1.02 [0.90-1.17]; p=0.72; adjusted OR 1.15 [1.00-1.33]; p=0.053); and independence: 58.0% (314 of 541) versus 56.3% (5756 of 10231) (OR 1.04 [0.95-1.13], p=0.42; adjusted OR 0.93 [0.84-1.03], p=0.18). INTERPRETATION Alteplase remains safe when given at 3-4.5 h after ischaemic stroke, offering an opportunity for patients who cannot be treated within the standard 3-h timeframe. FUNDING Boehringer-Ingelheim, European Union Public Health Executive Authority.

Multivariable analysis of outcome predictors and adjustment of main outcome results to baseline data profile in randomized controlled trials: Safe Implementation of Thrombolysis in Stroke-MOnitoring STudy (SITS-MOST).

Background and Purpose— The Safe Implementation of Thrombolysis in Stroke-MOnitoring STudy (SITS-MOST) unadjusted results demonstrated that intravenous alteplase is well tolerated and that the effects were comparable with those seen in randomized, controlled trials (RCTs) when used in routine clinical practice within 3 hours of ischemic stroke onset. We aimed to identify outcome predictors and adjust the outcomes of the SITS-MOST to the baseline characteristics of RCTs. Methods— The study population was SITS-MOST (n=6483) and pooled RCTs (n=464) patients treated with intravenous alteplase within 3 hours of stroke onset. Multivariable, backward stepwise regression analyses (until P≤0.10) were performed to identify the outcome predictors for SITS-MOST. Variables appearing either in the final multivariable model or differing (P<0.10) between SITS-MOST and RCTs were included in the prediction model for the adjustment of outcomes. Main outcome measures were symptomatic intracerebral hemorrhage, defined as National Institutes of Health Stroke Scale deterioration ≥1 within 7 days with any hemorrhage (RCT definition), mortality, and independency as defined by modified Rankin Score of 0 to 2 at 3 months. Results— The adjusted proportion of symptomatic intracerebral hemorrhage for SITS-MOST was 8.5% (95% CI, 7.9 to 9.0) versus 8.6% (6.3 to 11.6) for pooled RCTs; mortality was 15.5% (14.7 to 16.2) versus 17.3% (14.1 to 21.1); and independency was 50.4% (49.6 to 51.2) versus 50.1% (44.5 to 54.7), respectively. In the multivariable analysis, older age, high blood glucose, high National Institutes of Health Stroke Scale score, and current infarction on imaging scans were related to poor outcome in all parameters. Systolic blood pressure, atrial fibrillation, and weight were additional predictors of symptomatic intracerebral hemorrhage. Current smokers had a lower rate of symptomatic intracerebral hemorrhage. Disability before current stroke (modified Rankin Score 2 to 5), diastolic blood pressure, antiplatelet other than aspirin, congestive heart failure, patients treated in new centers, and male sex were related to high mortality at 3 months. Conclusions— The adjusted outcomes from SITS-MOST were almost identical to those in relevant RCTs and reinforce the conclusion drawn previously in the unadjusted analysis. We identified several important outcome predictors to better identify patients suitable for thrombolysis.

Effect of Intravenous Nimodipine on Blood Pressure and Outcome After Acute Stroke

BACKGROUND AND PURPOSE The Intravenous Nimodipine West European Stroke Trial (INWEST) found a correlation between nimodipine-induced reduction in blood pressure (BP) and an unfavorable outcome in acute stroke. We sought to confirm this correlation with and without adjustment for prognostic variables and to investigate outcome in subgroups with increasing levels of BP reduction. METHODS Patients with a clinical diagnosis of ischemic stroke (within 24 hours) were consecutively allocated to receive placebo (n=100), 1 mg/h (low-dose) nimodipine (n=101), or 2 mg/h (high-dose) nimodipine (n=94). The correlation between average BP change during the first 2 days and the outcome at day 21 was analyzed. RESULTS Two hundred sixty-five patients were included in this analysis (n=92, 93, and 80 for placebo, low dose, and high dose, respectively). Nimodipine treatment resulted in a statistically significant reduction in systolic BP (SBP) and diastolic BP (DBP) from baseline compared with placebo during the first few days. In multivariate analysis, a significant correlation between DBP reduction and worsening of the neurological score was found for the high-dose group (beta=0.49, P=0. 048). Patients with a DBP reduction of > or =20% in the high-dose group had a significantly increased adjusted OR for the compound outcome variable death or dependency (Barthel Index <60) (n/N=25/26, OR 10. 16, 95% CI 1.02 to 101.74) and death alone (n/N=9/26, OR 4.336, 95% CI 1.131 16.619) compared with all placebo patients (n/N=62/92 and 14/92, respectively). There was no correlation between SBP change and outcome. CONCLUSIONS DBP, but not SBP, reduction was associated with neurological worsening after the intravenous administration of high-dose nimodipine after acute stroke. For low-dose nimodipine, the results were not conclusive. These results do not confirm or exclude a neuroprotective property of nimodipine.

Intravenous Nimodipine West European Stroke Trial (INWEST) of Nimodipine in the Treatment of Acute Ischaemic Stroke

A randomised, double-blind, placebo-controlled trial of intravenous nimodipine was conducted in 295 patients with acute ischaemic stroke. Nimodipine was given as an intravenous infusion of 1 or 2 mg/h for 5 days followed by an oral dose of 120 mg daily for a total treatment period of 21 days. Patients with a clinical diagnosis of ischaemic stroke in the carotid artery territory within 24 h entered the study at 34 centres, involving 11 European countries: 100 were randomly assigned to placebo, 101 to nimodipine with an initial intravenous dose of 1 mg/h and 94 patients to an initial dose of 2 mg/h. The trial, initially aiming at a patient inclusion of 600, was terminated because of concerns arising from safety monitoring. Primary efficacy variables were neurological outcome according to the Orgogozo scale and functional outcome according to the Barthel scale at day 21. There were apparent differences between the groups in neurological and functional outcome with a better outcome in the placebo group. The differences between the placebo group and the 2-mg/h group were statistically significant (p = 0.0005 for the Orgogozo scale and p = 0.0033 for the Barthel scale). The differences were even more pronounced at the final follow-up at 24 weeks (p = 0.0001 and p = 0.0002, respectively). There were no statistically significant differences in mortality between the groups. There were statistically significant differences between the groups regarding the effect of the first few days of intravenous treatment on systolic and diastolic blood pressure with the most pronounced reduction in the 2-mg/h nimodipine treatment group at day 2 (p = 0.0001). An explorative analysis indicated a correlation between diastolic blood pressure reduction in the nimodipine-treated groups and unfavourable neurological outcome (p = 0.0005). A potential neuroprotective effect of nimodipine by preventing calcium overload in ischaemic neurons may thus have been outweighed by detrimental haemodynamic effects in the ischaemic area.

Implementation and outcome of thrombolysis with alteplase 3–4·5 h after an acute stroke: an updated analysis from SITS-ISTR

BACKGROUND In September, 2008, the European Acute Stroke Study III (ECASS III) randomised trial and the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Registry (SITS-ISTR) observational study reported the efficacy and safety of the extension of the time window for intravenous alteplase treatment from within 3 h to within 4.5 h after stroke onset. We aimed to assess the implementation of the wider time window, its effect on the admission-to-treatment time, and safety and functional outcome in patients recorded in SITS-ISTR. METHODS Patients treated according to the criteria of the European Summary of Product Characteristics, except for the time window, were included. Patients were grouped according to whether they were registered into SITS-ISTR before or after October, 2008. We measured admission-to-treatment time and rates of symptomatic intracerebral haemorrhage, mortality, and functional independence at 3 months. FINDINGS 23 942 patients were included in SITS-ISTR between December, 2002, and February, 2010, of whom 2376 were treated 3-4.5 h after symptom onset. The proportion of patients treated within 3-4.5 h by the end of 2009 was three times higher than in the first three quarters of 2008 (282 of 1293 [22%] vs 67 of 1023 [7%]). The median admission-to-treatment time was 65 min both for patients registered before and after October, 2008 (p=0.94). 352 (2%) of 21 204 patients treated within 3 h and 52 (2%) of 2317 treated within 3-4.5 h of stroke had symptomatic intracerebral haemorrhage at 3 months (adjusted odds ratio [OR] 1.44, 95% CI 1.05-1.97; p=0.02). 2287 (12%) of 18 583 patients who were treated within 3 h and 218 (12%) of 1817 who were treated within 3-4.5 h had died by the 3-month follow-up (adjusted OR 1.26, 95% CI 1.07-1.49; p=0.005); 10 531 (57%) of 18 317 patients treated within 3 h of stroke and 1075 (60%) of 1784 who were treated within 3-4.5 h were functionally independent at 3 months (adjusted OR 0.84, 95% CI 0.75-0.95; p=0.005). INTERPRETATION Since October, 2008, thrombolysis within 3-4.5 h after stroke has been implemented rapidly, with a simultaneous increase in the number of patients treated within 3 h; admission-to-treatment time has not increased. Safety and functional outcomes are less favourable after 3 h, but the wider time window now offers an opportunity for treatment of those patients who cannot be treated earlier. Thrombolysis should be initiated within 4.5 h after onset of ischaemic stroke, although every effort should be made to treat patients as early as possible after symptom onset. FUNDING Boehringer Ingelheim, Ferrer, the European Union Public Health Executive Authority, and Medical Training and Research (ALF) from Stockholm County Council and Karolinska Institutet.

Neuroprotection in Cerebral Ischaemia: Facts and Fancies – The Need for New Approaches

‘Neuroprotection’ is a term used to describe the putative effect of interventions protecting the brain from pathological damage. In occlusive stroke, the concept of neuroprotection involves inhibition of a cascade of pathological molecular events occurring under ischaemia and leading to calcium influx, activation of free radical reactions and cell death. This article will summarize neuroprotection trials to date, some facts and fancies about neuroprotection, ischaemic pathophysiology and possible reasons for the apparent failure of human neuroprotective stroke trials. Facts: In the acute stage of occlusive stroke, moderate reduction of blood flow results in a ‘penumbra’ of brain cells, often surrounding a core infarct, in which brain cells survive for a few hours but gradually die if reperfusion is not established. Increased knowledge of the complex pathophysiology in acute ischaemic stroke has led to the development of a great number of candidates for neuroprotective interventions. Many neuroprotective agents have proven efficacious in animal models, but so far no human study has shown a statistically significant benefit in patients with acute ischaemic stroke on primary endpoint measures. Some neuroprotective agents show beneficial effects on post hoc analyses, and some studies are still ongoing. Fancies: In the early years of neuroprotective studies in stroke, it was thought that a drug with almost no adverse effects could be given by ambulance staff on the way to hospital and induce a clinically significant effect on outcome. Since there were only benefits and no risks, diagnostic skills by neurologists and neuroradiological evaluations would no longer be required. Why Have Neuroprotective Agents Failed in Human Stroke Trials? There are several possible explanations why neuroprotective trials have been unable to prove an effect in addition to the eventuality that the basic concept is wrong. The effects of neuroprotective agents on infarct size are time dependent, and treatment has often been initiated much later than in successful experimental stroke models. Insufficient doses of the drugs and slow availability of the drug at the target area may be other explanations. Too small sample sizes in trials and imbalance of prognostically important baseline variables are examples of shortcomings in trial methodology. What Can Be Done? Future New Approaches: In animal models, preclinical testing of neuroprotective candidates should be standardized. Conventional stroke models with young and healthy animals may be replaced by older animals with common co-morbidity such as atherosclerosis. Highly effective new neuroprotective agents need to be discovered, and combination therapies should be tried. In clinical trials, the greatest chances of success may be with neuroprotective concepts involving mechanisms in both ischaemic and reperfusion pathophysiology, in combination with a thrombolytic therapy protocol. Neuroprotective agents, possibly combinations of agents, should preferably approach several of these mechanisms. Treatments should be initiated early, at least within 3 h after stroke onset, by an intravenous route. The selected compound(s) should easily pass the blood-brain barrier. Neuroprotective agents shown to be highly effective in stroke models should be preferred, and doses used experimentally should be used also in the clinical setting. Trials should use randomization techniques, which reduce imbalances of prognostically important baseline variables, and the estimated sample size of a trial should be based on expectations of a modest clinical effect.

Thrombolysis in very elderly people: controlled comparison of SITS International Stroke Thrombolysis Registry and Virtual International Stroke Trials Archive

Objective To assess effect of age on response to alteplase in acute ischaemic stroke. Design Adjusted controlled comparison of outcomes between non-randomised patients who did or did not undergo thrombolysis. Analysis used Cochran-Mantel-Haenszel test and proportional odds logistic regression analysis. Setting Collaboration between International Stroke Thrombolysis Registry (SITS-ISTR) and Virtual International Stroke Trials Archive (VISTA). Participants 23 334 patients from SITS-ISTR (December 2002 to November 2009) who underwent thrombolysis and 6166 from VISTA neuroprotection trials (1998-2007) who did not undergo thrombolysis (as controls). Of the 29 500 patients (3472 aged >80 (“elderly,” mean 84.6), data on 272 patients were missing for baseline National Institutes of Health stroke severity score, leaving 29 228 patients for analysis adjusted for age and baseline severity. Main outcome measures Functional outcomes at 90 days measured by score on modified Rankin scale. Results Median severity at baseline was the same for patients who underwent thrombolysis and controls (median baseline stroke scale score: 12 for each group, P=0.14; n=29 228). The distribution of scores on the modified Rankin scale was better among all thrombolysis patients than controls (odds ratio 1.6, 95% confidence interval 1.5 to 1.7; Cochran-Mantel-Haenszel P<0.001). The association occurred independently among patients aged ≤80 (1.6, 1.5 to 1.7; P<0.001; n=25 789) and in those aged >80 (1.4, 1.3 to 1.6; P<0.001; n=3439). Odds ratios were consistent across all 10 year age ranges above 30, and benefit was significant from age 41 to 90; dichotomised outcomes (score on modified Rankin scale 0-1 v 2-6; 0-2 v 3-6; and 6 (death) v rest) were consistent with the results of the ordinal analysis. Conclusions Outcome in patients with acute ischaemic stroke is significantly better in those who undergo thrombolysis compared with those who do not. Increasing age is associated with poorer outcome but the association between thrombolysis treatment and improved outcome is maintained in very elderly people. Age alone should not be a barrier to treatment.