Kennedy R. Lees

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.

Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials

BACKGROUND Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis. METHODS We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patients symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis. FINDINGS Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.71) for 181-270 min, and 1.49 (1.00-2.21) for 271-360 min. INTERPRETATION Patients with ischaemic stroke selected by clinical symptoms and CT benefit from intravenous alteplase when treated up to 4.5 h. To increase benefit to a maximum, every effort should be taken to shorten delay in initiation of treatment. Beyond 4.5 h, risk might outweigh benefit. FUNDING None.

The Desmoteplase in Acute Ischemic Stroke Trial (DIAS) A Phase II MRI-Based 9-Hour Window Acute Stroke Thrombolysis Trial With Intravenous Desmoteplase

Background and Purpose— Most acute ischemic stroke patients arrive after the 3-hour time window for recombinant tissue plasminogen activator (rtPA) administration. The Desmoteplase In Acute Ischemic Stroke trial (DIAS) was a dose-finding randomized trial designed to evaluate the safety and efficacy of intravenous desmoteplase, a highly fibrin-specific and nonneurotoxic thrombolytic agent, administered within 3 to 9 hours of ischemic stroke onset in patients with perfusion/diffusion mismatch on MRI. Methods— DIAS was a placebo-controlled, double-blind, randomized, dose-finding phase II trial. Patients with National Institute of Health Stroke Scale (NIHSS) scores of 4 to 20 and MRI evidence of perfusion/diffusion mismatch were eligible. Of 104 patients, the first 47 (referred to as Part 1) were randomized to fixed doses of desmoteplase (25 mg, 37.5 mg, or 50 mg) or placebo. Because of an excessive rate of symptomatic intracranial hemorrhage (sICH), lower weight-adjusted doses escalating through 62.5 &mgr;g/kg, 90 &mgr;g/kg, and 125 &mgr;g/kg were subsequently investigated in 57 patients (referred to as Part 2). The safety endpoint was the rate of sICH. Efficacy endpoints were the rate of reperfusion on MRI after 4 to 8 hours and clinical outcome as assessed by NIHSS, modified Rankin scale, and Barthel Index at 90 days. Results— Part 1 was terminated prematurely because of high rates of sICH with desmoteplase (26.7%). In Part 2, the sICH rate was 2.2%. No sICH occurred with placebo in either part. Reperfusion rates up to 71.4% (P=0.0012) were observed with desmoteplase (125 &mgr;g/kg) compared with 19.2% with placebo. Favorable 90-day clinical outcome was found in 22.2% of placebo-treated patients and between 13.3% (62.5 &mgr;g/kg; P=0.757) and 60.0% (125 &mgr;g/kg; P=0.0090) of desmoteplase-treated patients. Early reperfusion correlated favorably with clinical outcome (P=0.0028). Favorable outcome occurred in 52.5% of patients experiencing reperfusion versus 24.6% of patients without reperfusion. Conclusions— Intravenous desmoteplase administered 3 to 9 hours after acute ischemic stroke in patients selected with perfusion/diffusion mismatch is associated with a higher rate of reperfusion and better clinical outcome compared with placebo. The sICH rate with desmoteplase was low, using doses up to 125 &mgr;g/kg.

Interatrial septal abnormalities and stroke A meta-analysis of case-control studies

Objective: To examine the association between patent foramen ovale (PFO) and atrial septal aneurysm (ASA) and stroke. Method:— Data from case-control studies that examined the relative frequency of PFO, ASA, or both, in all patients with ischemic stroke, cryptogenic stroke, and known stroke cause as well as control subjects were included. Trials were categorized by age, clinical comparison, and abnormality. Combined OR were calculated using fixed effect (FE) and random effect (RE) methods. Results: Comparing patients with ischemic stroke with control subjects using RE, OR for all ages was 1.83 (95% CI, 1.25 to 2.66) for PFO (15 studies), 2.35 (95% CI, 1.46 to 3.77) for ASA (nine studies), and 4.96 (95% CI, 2.37 to 10.39) for PFO plus ASA (four studies). Homogeneous results were found within the group younger than age 55: using FE, OR was 3.10 (95% CI, 2.29 to 4.21) for PFO, 6.14 (95% CI, 2.47 to 15.22) for ASA, and 15.59 (95% CI, 2.83 to 85.87) for PFO plus ASA. For patients older than age 55, using FE, OR was 1.27 (95% CI, 0.80 to 2.01) for PFO, 3.43 (95% CI, 1.89 to 6.22) for ASA, and 5.09 (95% CI, 1.25 to 20.74) for PFO plus ASA. Comparing cryptogenic stroke with known stroke cause, heterogeneous results were derived from total group examination using RE: OR was 3.16 (95% CI, 2.30 to 4.35) for PFO (22 studies), 3.65 (95% CI, 1.34 to 9.97) for ASA (five studies), and 23.26 (95% CI, 5.24 to 103.20) for PFO plus ASA (two studies). In patients younger than age 55, using FE the OR was 6.00 (95% CI, 3.72 to 9.68) for PFO; only one study examined ASA or PFO plus ASA. In patients aged 55 years or older, three studies produced heterogeneous results for PFO: using RE, OR was 2.26 (95% CI, 0.96 to 5.31); no data were available on ASA prevalence. Conclusions: PFO and ASA are significantly associated with ischemic stroke in patients younger than 55 years. Further studies are needed to establish whether an association exists between PFO and ischemic stroke in those older than 55.

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.

Dual Antiplatelet Therapy With Clopidogrel and Aspirin in Symptomatic Carotid Stenosis Evaluated Using Doppler Embolic Signal Detection The Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) Trial

Background—Evidence for efficacy of dual antiplatelet therapy in stroke is limited. Symptomatic carotid stenosis patients are at high risk of early recurrent stroke. In this group, asymptomatic microembolic signals (MES), detected by transcranial Doppler ultrasound (TCD), are markers of future stroke and transient ischemic attack (TIA) risk. They offer a surrogate marker to evaluate antiplatelet therapy, but no multicenter study has evaluated the feasibility of this approach. Methods and Results—Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) is a randomized, double-blind study in subjects with recently symptomatic ≥50% carotid stenosis. Patients were screened with TCD, and if MES were detected, they were randomized to clopidogrel and aspirin or aspirin monotherapy. Repeated TCD recordings were made on days 2 and 7. MES were detected in 110 of 230 patients by online analysis at baseline, of whom 107 were randomized. Intention-to-treat analysis revealed a significant reduction in the primary end point: 43.8% of dual-therapy patients were MES positive on day 7, as compared with 72.7% of monotherapy patients (relative risk reduction 39.8%; 95% CI, 13.8 to 58.0; P=0.0046). The secondary end point of MES frequency per hour was reduced (compared with baseline) by 61.4% (95% CI, 31.6 to 78.2; P=0.0013) in the dual-therapy group at day 7 and by 61.6% (95% CI, 34.9 to 77.4; P=0.0005) on day 2. There were 4 recurrent strokes and 7 TIAs in the monotherapy group versus no stroke and 4 TIAs in the dual-therapy group that were treatment emergent and ipsilateral to the qualifying carotid stenosis; 2 additional ipsilateral TIAs occurred before treatment started. MES frequency was greater in the 17 patients with recurrent ipsilateral events compared with the 90 without (mean±SD: 24.4±27.7 versus 8.9±11.5 per hour; P=0.0003). Conclusions—In patients with recently symptomatic carotid stenosis, combination therapy with clopidogrel and aspirin is more effective than aspirin alone in reducing asymptomatic embolization. Doppler MES detection is a feasible method to evaluate the efficacy of antiplatelet therapy in multicenter studies.

Clinical Experience With Excitatory Amino Acid Antagonist Drugs

BACKGROUND Excitotoxic damage due to excess release of neuronal glutamate is hypothesized to play a pivotal role in the pathogenesis of focal cerebral ischemia. Drugs that antagonize excitatory amino acid function are consistently neuroprotective in preclinical models of stroke, and many are now entering clinical trials. SUMMARY Antagonists of the N-methyl-D-aspartate (NMDA) receptor are furthest advanced in clinical development for stroke. Both noncompetitive (aptiganel hydrochloride, dextrorphan) and competitive (selfotel, d-CPPene) antagonists have undergone tolerability studies in acute stroke and traumatic brain injury. These agents all cause a similar spectrum of neuropsychological symptoms, and several have important cardiovascular effects. Other modulatory sites on the NMDA receptor complex, notably the polyamine and magnesium ion sites, are also the subject of clinical trials. Glycine site antagonists are in early clinical development. Non-NMDA glutamate receptor antagonists remain in preclinical study. Neuroprotection by agents that block glutamate release in vitro may be due to sodium channel blockade in vivo, but some agents (619C89) exhibit neurological effects similar to NMDA antagonists in stroke. The therapeutic index is unknown for different drugs but may be determined by cardiovascular effects, especially hypotension, which may be detrimental after stroke. CONCLUSIONS Excitatory amino acid antagonists are in advanced development in the treatment of stroke and traumatic brain injury. A similar pattern of side effects is apparent with the majority of agents. However, cardiovascular effects may ultimately define therapeutic index for each drug.

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.