Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Effectiveness of intermittent pneumatic compression in reduction of risk of deep vein thrombosis in patients who have had a stroke (CLOTS 3): a multicentre randomised controlled trial

BACKGROUND

Venous thromboembolism is a common, potentially avoidable cause of death and morbidity in patients in hospital, including those with stroke. In surgical patients, intermittent pneumatic compression (IPC) reduces the risk of deep vein thrombosis (DVT), but no reliable evidence exists about its effectiveness in patients who have had a stroke. We assessed the effectiveness of IPC to reduce the risk of DVT in patients who have had a stroke.

METHODS

The CLOTS 3 trial is a multicentre parallel group randomised trial assessing IPC in immobile patients (ie, who cannot walk to the toilet without the help of another person) with acute stroke. We enrolled patients from day 0 to day 3 of admission and allocated them via a central randomisation system (ratio 1:1) to receive either IPC or no IPC. A technician who was masked to treatment allocation did a compression duplex ultrasound (CDU) of both legs at 7-10 days and, wherever practical, at 25-30 days after enrolment. Caregivers and patients were not masked to treatment assignment. Patients were followed up for 6 months to determine survival and later symptomatic venous thromboembolism. The primary outcome was a DVT in the proximal veins detected on a screening CDU or any symptomatic DVT in the proximal veins, confirmed on imaging, within 30 days of randomisation. Patients were analysed according to their treatment allocation.

TRIAL REGISTRATION

ISRCTN93529999.

FINDINGS

Between Dec 8, 2008, and Sept 6, 2012, 2876 patients were enrolled in 94 centres in the UK. The included patients were broadly representative of immobile stroke patients admitted to hospital and had a median age of 76 years (IQR 67-84). The primary outcome occurred in 122 (8·5%) of 1438 patients allocated IPC and 174 (12·1%) of 1438 patients allocated no IPC; an absolute reduction in risk of 3·6% (95% CI 1·4-5·8). Excluding the 323 patients who died before any primary outcome and 41 without any screening CDU, the adjusted OR for the comparison of 122 of 1267 patients vs 174 of 1245 patients was 0·65 (95% CI 0·51-0·84; p=0·001). Deaths in the treatment period occurred in 156 (11%) patients allocated IPC and 189 (13%) patients allocated no IPC died within the 30 days of treatment period (p=0·057); skin breaks on the legs were reported in 44 (3%) patients allocated IPC and in 20 (1%) patients allocated no IPC (p=0·002); falls with injury were reported in 33 (2%) patients in the IPC group and in 24 (2%) patients in the no-IPC group (p=0·221).

INTERPRETATION

IPC is an effective method of reducing the risk of DVT and possibly improving survival in a wide variety of patients who are immobile after stroke.

FUNDING

National Institute of Health Research (NIHR) Health Technology Assessment (HTA) programme, UK; Chief Scientist Office of Scottish Government; Covidien (MA, USA).

CRASH-2 (Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage) intracranial bleeding study: the effect of tranexamic acid in traumatic brain injury--a nested randomised, placebo-controlled trial

BACKGROUND

Tranexamic acid (TXA) has been shown to reduce blood loss in surgical patients and the risk of death in patients with traumatic bleeding, with no apparent increase in vascular occlusive events. These findings raise the possibility that it might also be effective in traumatic brain injury (TBI).

OBJECTIVE

The Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage Intracranial Bleeding Study (CRASH-2 IBS) was conducted to quantify the effect of an early short course of TXA on intracranial haemorrhage and new focal cerebral ischaemic lesions in patients with TBI.

DESIGN

CRASH-2 IBS was a prospective randomised controlled trial nested within the CRASH-2 trial. Randomisation was balanced by centre, with an allocation sequence based on a block size of eight. We used a local pack system that selected the lowest numbered treatment pack from a box containing eight numbered packs. Apart from the pack number, the treatment packs were identical. The pack number was recorded on the entry form, which was sent to the international trial co-ordinating centre in London, UK. Once the treatment pack number was recorded, the patient was included in the trial whether or not the treatment pack was opened or the allocated treatment started. All site investigators and trial co-ordinating centre staff were masked to treatment allocation.

SETTING

Ten hospitals: (India) Aditya Neuroscience Centre, Sanjivani Hospital, CARE Hospital, Christian Medical College, Medical Trust Hospital, Jeevan Jyoti Hospital and (Colombia) Hospital Universitario San Vicente de Paul, Hospital Pablo Tobón Uribe, Hospital Universitario San José de Popayán and Fundación Valle del Lili.

PARTICIPANTS

The trial was conducted in a subset of 270 CRASH-2 trial participants. Patients eligible for inclusion in the CRASH-2 IBS fulfilled the inclusion criteria for the CRASH-2 trial, and also had TBI [Glasgow Coma Scale score of ≤ 14 and a brain computerised tomography (CT) scan compatible with TBI]. Pregnant women and patients for whom a second brain CT scan was not possible were excluded.

INTERVENTIONS

Participants were randomly allocated to receive either a loading dose of 1 g of TXA infused over 10 minutes followed by an intravenous infusion of 1 g over 8 hours or matching placebo.

MAIN OUTCOME MEASURE

The primary outcome was the increase in size of intracranial haemorrhage growth between a CT scan at hospital admission and a second scan 24-48 hours later.

RESULTS

One hundred and thirty-three patients were allocated to TXA and 137 to placebo, of whom information on the primary (imaging) outcome was available for 123 (92%) and 126 (92%) respectively. The analysis suggested that TXA was likely to be associated with a reduction in haemorrhage growth [adjusted difference -3.8 ml, 95% credibility interval (CrI) -11.5 ml to 3.9 ml], fewer focal ischaemic lesions [adjusted odds ratio (OR) 0.54, 95% CrI 0.20 to 1.46] and fewer deaths (adjusted OR 0.49, 95% CrI 0.22 to 1.06).

CONCLUSIONS

This was the first randomised controlled study to evaluate the effect of TXA in TBI patients and it found that neither moderate benefits nor moderate harmful effects can be excluded. However, although uncertainty remains, our analyses suggest that TXA administration might improve outcome in TBI patients and provide grounds for evaluating this hypothesis in future research.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN86750102.

SOURCE OF FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 13. See the HTA programme website for further project information.

The timing, extent, progression and regression of deep vein thrombosis in immobile stroke patients: observational data from the CLOTS multicenter randomized trials

BACKGROUND

Deep vein thrombosis (DVT) is an important complication of stroke, but the evidence to support commonly used prophylactic strategies is conflicting.

OBJECTIVES

To describe the incidence, extent, associated clinical features and evolution of DVT after stroke.

PATIENTS/METHODS

The CLOTS trials 1 and 2 together randomized 5632 immobile stroke patients in 135 hospitals in nine countries. We screened patients for asymptomatic DVT with compression duplex ultrasound (CDU) at about 7-10 days and again at about 25-30 days after enrollment.

RESULTS

Six hundred and forty-one (11.4%) of 5632 patients had DVT detected on the first CDU scan at a median of 8 days (interquartile range [IQR] 7-10 days) after enrollment, and an additional 176 (3.1%) had a DVT on the second CDU scan at a median of 28 days (IQR 26-30 days). Of the 817 with DVTs, 289 (35%) were symptomatic and 39 (5%) had pulmonary embolism (PE) confirmed by imaging. Six hundred and seventy-six (83%) were unilateral, 141 (17%) were bilateral, 322 (39%) were limited to calf veins, 172 (21%) were popliteal, and 323 (40%) were femoral. Among the 542 patients with DVT and a weak leg, the DVT affected the weaker leg in 396 (73%), the stronger leg in 59 (11%), and was bilateral in 87 (16%). Among the 318 patients with a DVT detected on the first CDU scan who had a second scan, the DVT regressed in 148 (47%), stayed the same in 140 (44%), and progressed in only 30 (9%).

CONCLUSIONS

Although most DVTs develop within the first week, some develop later, and some early DVTs progress. Any prophylaxis needs to be started early but ideally continued for at least 4 weeks.

Magnetic resonance perfusion diffusion mismatch and thrombolysis in acute ischaemic stroke: a systematic review of the evidence to date

BACKGROUND

The mismatch between perfusion and diffusion lesions on magnetic resonance perfusion-weighted imaging (PWI)/diffusion-weighted imaging (DWI) may help identify patients for thrombolysis. Evidence underlying this hypothesis was assessed.

METHODS

All papers describing magnetic resonance PWI/DWI findings in patients with acute ischaemic stroke, and their functional and/or radiological outcome at 1 month, with or without thrombolysis were systematically reviewed.

RESULTS

11 papers fulfilled the inclusion criteria. Among these, there were 5 different mismatch definitions and at least 7 different PWI methods. Only 3 papers including 61 patients with and 18 without mismatch provided data on mismatch, outcome and influence of thrombolysis. Mismatch (v no mismatch) without thrombolysis was associated with a non-significant twofold increase in the odds of infarct expansion (odds ratio (OR) 2.2, 95% confidence interval (CI) 0.34 to 14.1), which did not change with thrombolysis (OR 2.0, 95% CI 0.37 to 10.9). Half of the patients without mismatch also had infarct growth (with or without thrombolysis). No data were available on functional outcome.

CONCLUSIONS

Standardised definitions of mismatch and perfusion are needed. Infarct growth may occur even in the absence of mismatch. Currently, data available on mismatch are too limited to guide thrombolysis in routine practice. More data are needed from studies including patients with and without mismatch, and randomised treatment allocation, to determine the role of mismatch.

Low-molecular-weight heparins or heparinoids versus standard unfractionated heparin for acute ischaemic stroke

BACKGROUND

Low-molecular-weight heparins and heparinoids are anticoagulants that may be associated with lower risks of haemorrhage and more powerful antithrombotic (anti-clotting) effects than standard unfractionated heparin.

OBJECTIVES

The objective of this review was to compare the effects of low-molecular-weight heparins or heparinoids with those of unfractionated heparin in people with acute, confirmed or presumed, ischaemic stroke (sudden blockage of an artery carrying blood to the brain).

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched November 2003). In addition we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2003), MEDLINE (1966 to October 2003) and EMBASE (1980 to October 2003). For previous versions of this review we searched MedStrategy (1995) and also contacted pharmaceutical companies.

SELECTION CRITERIA

Randomised trials comparing heparinoids or low-molecular-weight heparins with standard unfractionated heparin in people with acute ischaemic stroke. Only trials where treatment was started within 14 days of stroke onset were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Six trials involving 740 people were included. Four trials compared a heparinoid (danaparoid), one trial compared a low-molecular-weight heparin (enoxaparin), and one trial compared an unspecified low-molecular-weight heparin with standard unfractionated heparin. Allocation a to low-molecular-weight heparin or heparinoid was associated with a significant reduction in the odds of deep vein thrombosis (Peto odds ratio 0.52, 95% confidence interval 0.56 to 0.79). However, the number of more major events (pulmonary embolism, death, intra-cranial or extra-cranial haemorrhage) was too small to provide a reliable estimate of more important benefits and risks. No information was reported for recurrent stroke or functional outcome.

AUTHORS' CONCLUSIONS

Treatment with a low-molecular-weight heparin or heparinoid after acute ischaemic stroke appears to decrease the occurrence of deep vein thrombosis compared to standard unfractionated heparin, but there are too few data to provide reliable information on their effects on other important outcomes, including death and intracranial haemorrhage.

Physical methods for preventing deep vein thrombosis in stroke

BACKGROUND

Deep vein thrombosis (DVT) and resulting pulmonary embolism (PE) are uncommon but important complications of stroke. There is good evidence that anticoagulants can reduce the risk of DVT and PE after stroke, but this benefit is offset by a small but definite risk of serious haemorrhages. Physical methods to prevent DVT and PE (such as compression stockings applied to the legs) are not associated with any bleeding risk and are effective in some categories of medical and surgical patients. We sought to assess their effects in stroke patients.

OBJECTIVES

To assess the effectiveness and safety of physical methods of preventing the onset of deep vein thrombosis and fatal or non fatal pulmonary embolism in patients with recent stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched June 2003). In addition we searched the following electronic bibliographic databases: Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), MEDLINE (1966 to June 2003), EMBASE (1980 to June 2003) and CINAHL (1982 to June 2003). The reference lists of all relevant papers were screened for additional trials.

SELECTION CRITERIA

Unconfounded randomised controlled trials comparing physical methods for the prevention of DVT with control, in which prophylaxis was started within seven days of the onset of stroke.

DATA COLLECTION AND ANALYSIS

Two reviewers independently searched for relevant trials and three others independently checked the results.

MAIN RESULTS

We identified two small trials which included 123 patients. In one trial of 97 patients, compression stockings were associated with a non significant trend towards a reduction in DVT detected by Doppler ultrasound. In one trial of 26 patients, an intermittent pneumatic compression device was not associated with a significant reduction in DVT detected by 125-I-fibrinogen scanning. Overall, physical methods were not associated with a significant reduction in DVT during the treatment period in survivors (Odds ratio (OR) 0.54, 95% Confidence Interval (CI) 0.18 to 1.57) or death (OR 1.54, 95% CI 0.5 to 4.77).

REVIEWERS' CONCLUSIONS

There is insufficient evidence from randomised trials to support the routine use of physical methods for preventing DVT in acute stroke.

In-hospital care pathways for stroke

BACKGROUND

Stroke care pathways have the potential to promote organised and efficient patient care that is based on best evidence and guidelines, but evidence to support their use is unclear.

OBJECTIVES

We aimed to assess the effects of care pathways, compared with standard medical care, among patients with acute stroke who had been admitted to hospital.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched in June 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), MEDLINE (1975 to June 2003), EMBASE (1980 to June 2003), CINAHL (1982 to June 2003), ISI Proceedings: Science & Technology (1990 to November 2003), and HealthSTAR (1994 to May 2001). We also handsearched the Journal of Integrated Care Pathways (2001 to 2003), formerly Journal of Managed Care (1997 to 1998) and Journal of Integrated Care (1998 to 2001). Reference lists of articles were searched.

SELECTION CRITERIA

We considered randomised controlled trials and non-randomised studies that compared care pathway care with standard medical care.

DATA COLLECTION AND ANALYSIS

One reviewer selected studies for inclusion and the other independently checked the decisions. Two reviewers independently assessed the methodological quality of the studies. One reviewer extracted the data and the other checked the extracted data.

MAIN RESULTS

Three randomised controlled trials (340 patients) and 12 non-randomised studies (4081 patients) were included. There was significant statistical heterogeneity in the analysis of many of the outcomes. We found no significant difference between care pathway and control groups in terms of death or discharge destination. Patients managed with a care pathway were: (a) more dependent at discharge (P = 0.04); (b) less likely to suffer a urinary tract infection (Odds Ratio (OR) 0.51, 95% Confidence Interval (CI) 0.34 to 0.79); (c) less likely to be readmitted (OR 0.11, 95% CI 0.03 to 0.39); and (d) more likely to have neuroimaging (OR 2.42, 95% CI 1.12 to 5.25). Evidence from randomised trials suggested that patient satisfaction and quality of life were significantly lower in the care pathway group (P = 0.02 and P < 0.005 respectively).

REVIEWERS' CONCLUSIONS

Use of stroke care pathways may be associated with positive and negative effects. Since most of the results have been derived from non-randomised studies, they are likely to be influenced by potential biases and confounding factors. There is currently insufficient supporting evidence to justify the routine implementation of care pathways for acute stroke management or stroke rehabilitation.

In-hospital care pathways for stroke

BACKGROUND

Stroke care pathways have the potential to promote organised and efficient patient care that is based on best evidence and guidelines, but evidence to support their use is unclear.

OBJECTIVES

We aimed to assess the effects of care pathways, compared with standard medical care, among patients with acute stroke who had been admitted to hospital.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched in June 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), MEDLINE (1975 to June 2003), EMBASE (1980 to June 2003), CINAHL (1982 to June 2003), ISI Proceedings: Science & Technology (1990 to November 2003), and HealthSTAR (1994 to May 2001). We also handsearched the Journal of Integrated Care Pathways (2001 to 2003), formerly Journal of Managed Care (1997 to 1998) and Journal of Integrated Care (1998 to 2001). Reference lists of articles were searched.

SELECTION CRITERIA

We considered randomised controlled trials and non-randomised studies that compared care pathway care with standard medical care.

DATA COLLECTION AND ANALYSIS

One reviewer selected studies for inclusion and the other independently checked the decisions. Two reviewers independently assessed the methodological quality of the studies. One reviewer extracted the data and the other checked the extracted data.

MAIN RESULTS

Three randomised controlled trials (340 patients) and 12 non-randomised studies (4081 patients) were included. There was significant statistical heterogeneity in the analysis of many of the outcomes. We found no significant difference between care pathway and control groups in terms of death or discharge destination. Patients managed with a care pathway were: (a) more dependent at discharge (P = 0.04); (b) less likely to suffer a urinary tract infection (Odds Ratio (OR) 0.51, 95% Confidence Interval (CI) 0.34 to 0.79); (c) less likely to be readmitted (OR 0.11, 95% CI 0.03 to 0.39); and (d) more likely to have neuroimaging (OR 2.42, 95% CI 1.12 to 5.25). Evidence from randomised trials suggested that patient satisfaction and quality of life were significantly lower in the care pathway group (P = 0.02 and P < 0.005 respectively).

REVIEWERS' CONCLUSIONS

Use of stroke care pathways may be associated with positive and negative effects. Since most of the results have been derived from non-randomised studies, they are likely to be influenced by potential biases and confounding factors. There is currently insufficient supporting evidence to justify the routine implementation of care pathways for acute stroke management or stroke rehabilitation.

Improving the efficiency of delivery of thrombolysis for acute stroke: a systematic review

BACKGROUND

Thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) is licensed for use within 3 h of acute ischaemic stroke. The less the delay to treatment, the more likely it is to be effective.

AIMS

To assess the effectiveness of interventions designed to overcome barriers to rapid administration of thrombolytic therapy.

DESIGN

Systematic review of previous clinical studies.

METHODS

We searched for studies that evaluated the effect of an intervention to reduce delays to administration of rt-PA. We searched MEDLINE, EMBASE, the trials register of the Cochrane Stroke Group, and the Cochrane Controlled Trials Register. We sought randomized and non-randomized controlled trials, before-and-after studies, interrupted time series, and observational studies.

RESULTS

We identified 10 non-randomized studies that evaluated interventions that could speed up admission to hospital and administration of rt-PA. The types of interventions included: (a) education programmes for the public to improve their knowledge about symptoms of acute stroke; (b) training programmes for paramedical staff to improve their accuracy of stroke diagnosis and hasten transport of the patient to hospital; (c) helicopter transfer of patients to hospital; (d) training programmes in acute stroke therapy for emergency department staff; and (e) re-organization of in-hospital systems to streamline acute stroke care. Several programmes were multifaceted interventions.

DISCUSSION

We identified important areas that could be targets for interventions to improve the efficiency of delivering thrombolysis for acute stroke. Multifaceted programmes might be more likely to be successful in reducing delays to therapy.

Anticoagulants for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blood clots blocking an artery in the brain. Clot prevention with anticoagulant therapy could have a significant impact on patient survival, disability and stroke recurrence.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulant therapy versus control in the early treatment of patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched 30 October 2003). For previous updates of this review, we searched the register of the Antithrombotic Trialists' (ATT) Collaboration, consulted MedStrategy (1995), and contacted relevant drug companies.

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in patients with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Twenty-two trials involving 23,547 patients were included. The quality of the trials varied considerably. The anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Based on nine trials (22,570 patients) there was no evidence that anticoagulant therapy reduced the odds of death from all causes (odds ratio (OR) = 1.05, 95% confidence interval (CI) 0.98 to 1.12) at the end of follow-up. Similarly, based on six trials (21,966 patients), there was no evidence that anticoagulants reduced the odds of being dead or dependent at the end of follow-up (OR = 0.99; 95% CI 0.93 to 1.04). Although anticoagulant therapy was associated with about 9 fewer recurrent ischaemic strokes per 1000 patients treated (OR = 0.76; 95% CI 0.65 to 0.88), it was also associated with a similar sized 9 per 1000 increase in symptomatic intracranial haemorrhages (OR = 2.52; 95% CI 1.92 to 3.30). Similarly, anticoagulants avoided about 4 pulmonary emboli per 1000 (OR = 0.60, 95% CI 0.44 to 0.81), but this benefit was offset by an extra 9 major extracranial haemorrhages per 1000 (OR = 2.99; 95% CI 2.24 to 3.99). Sensitivity analyses did not identify a particular type of anticoagulant regimen or patient characteristic associated with net benefit.

REVIEWERS' CONCLUSIONS

Immediate anticoagulant therapy in patients with acute ischaemic stroke is not associated with net short- or long-term benefit. The data from this review do not support the routine use of any type of anticoagulant in acute ischaemic stroke. People treated with anticoagulants had less chance of developing deep vein thrombosis (DVT) and pulmonary embolism (PE) following their stroke, but these sorts of blood clots are not very common, and may be prevented in other ways.

Antiplatelet therapy for acute ischaemic stroke

BACKGROUND

In patients with acute ischaemic stroke, platelets become activated. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and reduce the risk of early recurrent ischaemic stroke. This might reduce the risk of early death and improve long-term outcome in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage.

OBJECTIVES

The aim of this review is to assess the efficacy and safety of antiplatelet therapy in acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched August 2002), the Cochrane Controlled Trials Register (CCTR) (Cochrane Library Issue 1 2002), MEDLINE (June 1998-October 2001), and EMBASE (June 1998-February 2002). In 1998, for previous versions of this review, we searched the register of the Antiplatelet Trialists Collaboration, MedStrategy and contacted relevant drug companies.

SELECTION CRITERIA

Randomised trials comparing antiplatelet therapy (started within 14 days of the stroke) with control in patients with definite or presumed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied the inclusion criteria and assessed trial quality, and for the included trials, extracted and cross-checked the data.

MAIN RESULTS

Nine trials involving 41,399 patients were included. Two trials testing aspirin 160 to 300 mg once daily started within 48 hours of onset contributed 98% of the data. The maximum follow-up was six months. With treatment, there was a significant decrease in death or dependency at the end of follow-up (OR = 0.94; 95% CI 0.91 to 0.98). In absolute terms, 13 more patients were alive and independent at the end of follow-up for every 1000 patients treated. Furthermore, treatment increased the odds of making a complete recovery from the stroke (OR = 1.06; 95% CI 1.01 to 1.11). In absolute terms, 10 more patients made a complete recovery for every 1000 patients treated. Antiplatelet therapy was associated with a small but definite excess of 2 symptomatic intracranial haemorrhages for every 1000 patients treated, but this was more than offset by a reduction of 7 recurrent ischaemic strokes and about one pulmonary embolus for every 1000 patients treated.

REVIEWER'S CONCLUSIONS

Antiplatelet therapy with aspirin 160 to 300 mg daily, given orally (or per rectum in patients who cannot swallow), and started within 48 hours of onset of presumed ischaemic stroke reduces the risk of early recurrent ischaemic stroke without a major risk of early haemorrhagic complications and improves long-term outcome.

Anticoagulants for preventing recurrence following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack

BACKGROUND

After a first ischaemic stroke, further vascular events due to thromboembolism (especially myocardial infarction and recurrent stroke) are common and often fatal. Anticoagulants could potentially reduce the risk of such events, but any benefits could be offset by an increased risk of fatal or disabling haemorrhages.

OBJECTIVES

The objective of this review was to assess the effect of prolonged anticoagulant therapy (compared with placebo or open control) following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register. We contacted companies marketing anticoagulant agents. The most recent search for this review was carried out in August 2002.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing at least one month of anticoagulant therapy with control in people with previous presumed non-cardioembolic ischaemic stroke or transient ischaemic attack.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Eleven trials involving 2487 patients were included. The quality of the 9 trials which predated routine computerised tomography scanning and the use of the International Normalised Ratio to monitor anticoagulation was poor. There was no evidence of an effect of anticoagulant therapy on either the odds of death or dependency (two trials, odds ratio 0.83, 95% confidence interval [CI] 0.52 to 1.34) or of 'non-fatal stroke, myocardial infarction, or vascular death' (four trials, odds ratio 0.96, 95% CI 0.68-1.37). Death from any cause (odds ratio 0.95, 95% CI 0.73 to 1.24) and death from vascular causes (odds ratio 0.86, 95% CI 0.66 to 1.13) were not significantly different between treatment and control. The inclusion of two recent completed trials did not alter these conclusions. There was no evidence of an effect of anticoagulant therapy on the risk of recurrent ischaemic stroke (odds ratio 0.85, 95% CI 0.66 to 1.09). However, anticoagulants increased fatal intracranial haemorrhage (odds ratio 2.54, 95% CI 1.19 to 5.45), and major extracranial haemorrhage (odds ratio 3.43, 95% CI 1.94 to 6.08). This is equivalent to anticoagulant therapy causing about 11 additional fatal intracranial haemorrhages and 25 additional major extracranial haemorrhages per year for every 1000 patients given anticoagulant therapy.

REVIEWER'S CONCLUSIONS

Compared with control, there was no evidence of benefit from long-term anticoagulant therapy in people with presumed non-cardioembolic ischaemic stroke or transient ischaemic attack, but there was a significant bleeding risk.

The MRC CRASH Trial: study design, baseline data, and outcome in 1000 randomised patients in the pilot phase

OBJECTIVES

To test the design and feasibility of a large scale multicentre randomised controlled trial evaluating the efficacy and safety of a high dose corticosteroid infusion after head injury. To assess whether large numbers of patients could be enrolled and treated within eight hours from injury and then followed up at six months.

METHODS

Randomised placebo controlled multicentre trial of a 48 hour corticosteroid infusion after significant head injury. All head injured adults who were observed while in hospital to have GCS of 14 or less (out of a maximum score of 15), and who were within eight hours of the injury, were eligible for trial entry. Analysis of baseline and outcome data (for both treatment groups combined) for 1000 patients enrolled in the pilot phase of the MRC CRASH Trial.

RESULTS

Fifty two hospitals in 14 countries participated in the pilot phase, recruiting an average of one patient per hospital per month. Of the 1000 randomised patients, 330 (33%) had mild head injury, 289 (29%) had moderate head injury, and 381 (38%) had severe head injury. Seven hundred and nine (71%) patients were randomised within three hours of injury. Outcome at two weeks from injury was known for 991 (99%) patients, of whom 170 (17%) patients died. At the time of writing, six month follow up for the first 500 patients was nearly complete. Vital status was known for 465 (93%) of the 500 patients, of whom 97 (21%) had died. Functional status based on the Glasgow Outcome Scale was known for 438 (88%) of the 500 patients: 21% were dead, 17% were severely disabled, 22% were moderately disabled, and 34% had made a good recovery.

CONCLUSIONS

The trial procedures proved practicable and a wide variety of patients were recruited in the emergency department within eight hours of injury. Using simple outcome measures, large numbers of patients can be successfully followed up.

Lubeluzole for acute ischaemic stroke

BACKGROUND

Experimental studies have shown that ischaemic insults cause excess release of excitatory amino acid (EAA) neurotransmitters, particularly glutamate. Glutamate re-uptake is impaired under ischaemic conditions. In preclinical models of stroke, antagonists of excitatory amino acids or of glutamate release protect against ischaemic injury, even when administered after the ischaemic insult. Lubeluzole is a benzothiazole derivative that has shown neuroprotective properties in different experimental models inhibiting glutamate release, nitric oxide (NO) synthesis and blocking voltage-gated Na+ and Ca2+ ion channels.

OBJECTIVES

The objective of this review is to assess the effectiveness and safety of lubeluzole given in the acute phase of acute ischaemic stroke.

SEARCH STRATEGY

The Cochrane Stroke Group trials register was searched. Additional searches of Cochrane Controlled Trials Register (CENTRAL/CCTR), Medline, Embase, Pascal BioMed (1996-2001) and Current Contents CCSearch reg 7 Editions (1996-2001) were made to supplement the Stroke Group general strategy. We contacted Janssen Research Foundation to identify further studies.

SELECTION CRITERIA

All randomised unconfounded trials comparing intravenous lubeluzole with placebo or open control in patients with a clinical syndrome definitely considered as an acute stroke in whom CT scanning showed an infarct or was normal.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Five trials involving a total of 3,510 patients were included. The quality of the trials did not vary considerably. Sensitivity/subgroups analysis was not completely performed because of lack of data. Lubeluzole given at the doses of 5, 10 and 20 mg/day for 5 days was tested against a placebo-control group. There was no evidence that Lubeluzole given at any dose either reduced the odds of death from all causes (OR=0.93, 95% CI 0.79-1.09) or reduced the odds of being dead or dependent at the end of follow-up (OR=1.04, 95% CI 0.91-1.19). On the other hand, given at any dose, Lubeluzole was associated with a significant excess of heart-conduction disorders (Q-T prolonged > 450 msec) at the end of follow-up (OR=1.43, 95% CI 1.09-1.87).

REVIEWER'S CONCLUSIONS

Lubeluzole, given in the acute phase of ischaemic stroke, is not associated with a significant reduction of death or dependency at the end of scheduled follow-up period but seems to be associated with a significant increase of heart-conduction disorders (Q-T prolonged >450 msec).

In-hospital care pathways for stroke

BACKGROUND

Care within a stroke unit reduces death or dependency after stroke. However, studies have found significant variations in clinical practice, access to stroke unit care, organisation of patient care, and clinical outcome. Stroke care pathways have been introduced as a method to promote organised and efficient patient care that is based on best evidence and guidelines.

OBJECTIVES

We aimed to assess the effects of care pathways, as compared to standard medical care, among patients with acute stroke who had been admitted to hospital.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Specialised Trials Register (last searched in May 2001), the Cochrane Controlled Trials Register (Issue 4, 2000), MEDLINE (1975-2000), EMBASE (1980-2000), CINAHL (1982-2000), the Index to Scientific and Technical Proceedings (ISTP, May 2001), and HealthSTAR (May 2001). We also handsearched the Journal of Managed Care (1997 to 1998), which was later renamed the Journal of Integrated Care (1998 to 2001). Reference lists of articles were searched.

SELECTION CRITERIA

We considered randomised controlled trials and non-randomised studies (quasi-randomised trials, comparative studies, controlled and uncontrolled before and after studies, and interrupted time series) that compared care pathway care with standard medical care.

DATA COLLECTION AND ANALYSIS

One reviewer selected studies for inclusion and the other independently checked the decisions. Two reviewers independently assessed the methodological quality of the studies. One reviewer extracted the data and the other checked the extracted data. Data from randomised and non-randomised studies were analysed separately. We found significant statistical heterogeneity in the analysis of two outcomes (computed tomography brain scanning and duration of stay).

MAIN RESULTS

There were three randomised controlled trials (total of 340 patients) and seven non-randomised studies (total of 1673 patients) that compared care pathway care with standard medical care. We found no difference between care pathway and control groups in terms of death, dependency, or discharge destination. Evidence from mainly non-randomised studies suggests that patients managed using a care pathway may be: a) less likely to suffer a urinary tract infection (OR 0.38, CI 0.18 to 0.79), b) less likely to be readmitted (OR 0.11, CI 0.03 to 0.39), and c) more likely to have a computed tomography brain scan (OR 3.66, CI 1.45 to 9.27) or carotid duplex study (OR 2.45, CI 1.3 to 4.61). Evidence from randomised trials suggests that patient satisfaction and quality of life may be significantly lower in the care pathway group (P=0.02 and P<0.005 respectively).

REVIEWER'S CONCLUSIONS

The use of care pathways to manage stroke patients in hospital may be associated with both positive and negative effects on the process of care and clinical outcomes. Since most of the results have been derived from non-randomised studies, they are likely to be influenced by potential biases and confounding factors. There is currently insufficient supporting evidence to justify routine implementation of care pathways for acute stroke management or stroke rehabilitation.

Anticoagulants versus antiplatelet agents for acute ischaemic stroke

BACKGROUND

Antiplatelet agents produce a small, but worthwhile benefit in long-term functional outcome and survival, and have become standard treatment for acute ischaemic stroke. Anticoagulants are often used as an alternative treatment, despite evidence that they are ineffective in producing long-term benefits. We wanted to review trials which have directly compared anticoagulants and antiplatelet agents, to assess whether any anticoagulant regimen offers net advantages over antiplatelet agents, overall or in some particular category of patients (e.g. patients with atrial fibrillation).

OBJECTIVES

a) To assess the effectiveness of anticoagulants compared with antiplatelet agents in acute ischaemic stroke b) To assess whether the addition of anticoagulants to antiplatelet agents offers any net advantage over antiplatelet agents alone.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register, the Cochrane Controlled Trials Register (Central/CCTR), the trials register held by the Antithrombotic Therapy Trialists' Collaboration, MEDLINE (1966-2000), and EMBASE (1980-2000). All searches were performed during April and May 2001.

SELECTION CRITERIA

Truly unconfounded, randomised-controlled trials comparing anticoagulants with antiplatelet agents, or anticoagulants and antiplatelet agents with antiplatelet agents alone, given within 14 days of onset of presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Both reviewers independently selected trials for inclusion in the review, assessed trial quality and extracted data.

MAIN RESULTS

A total of 16,558 patients from four trials contributed to the analyses. The methodological quality was high in all four trials. The anticoagulants tested were unfractionated heparin (UFH) and low molecular-weight heparin. Aspirin was used as control in all trials. Overall, there was no evidence that anticoagulants were superior to aspirin in reducing 'death or dependency' at long-term follow-up (odds ratio [OR] 1.07, 95% confidence interval [95% CI] 0.98-1.15). Compared with aspirin, anticoagulants were associated with a small but significant increase in the number of deaths at the end of follow-up (OR 1.10, 95% CI 1.01-1.29), equivalent to 20 more deaths (95% CI 0-30) per 1000 patients treated; a significant increased risk of symptomatic intracranial haemorrhage (OR 2.35, 95% CI 1.49-3.46); and a non-significant increased risk of 'any recurrent stroke' during treatment (OR 1.20, 95% CI 0.99-1.46). These neutral or adverse effects outweighed a small, but significant effect on symptomatic deep vein thrombosis (OR 1.20, 95% CI 0.07-0.58), equivalent to 10 fewer (95% CI 0-30) DVTs by 14 days per 1000 patients treated with anticoagulants instead of aspirin. Subgroup analysis could not identify any type, dose, or route of administration of anticoagulants associated with net benefit, or any benefit in patients with atrial fibrillation. Overall, the combination of UFH and aspirin did not appear to be associated with a net advantage over aspirin alone. A subgroup analysis showed that, compared with aspirin, the combination of low-dose UFH and aspirin was associated with a marginally significant reduced risk of 'any recurrent stroke' (OR 0.75, 95% CI 0.56-1.03) and a marginally significant reduced risk of death at 14 days (OR 0.84, 95% CI 0.69-1.01), and with no clear adverse effect on death at end of follow-up (OR 0.98, 95% CI 0.85-1.12).

REVIEWER'S CONCLUSIONS

Anticoagulants offered no net advantages over antiplatelet agents in acute ischaemic stroke. The combination of low-dose UFH and aspirin appeared in a subgroup analysis to be associated with net benefits compared with aspirin alone, and this merits further research.

Physical methods for preventing deep vein thrombosis in stroke

BACKGROUND

Deep vein thrombosis (DVT) and resulting pulmonary embolism (PE) are uncommon but important complications of stroke. There is good evidence that anticoagulants can reduce the risk of DVT and PE after stroke, but this benefit is offset by a small but definite risk of serious haemorrhages. Physical methods to prevent DVT and PE (such as compression stockings applied to the legs) are not associated with any bleeding risk and are effective in some categories of medical and surgical patients. We sought to assess their effects in stroke patients.

OBJECTIVES

To assess the effectiveness and safety of physical methods of preventing the onset of deep vein thrombosis and fatal or non fatal pulmonary embolism in patients with recent stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched October 2001). In addition we searched the following electronic bibliographic databases: Cochrane Controlled Trials Register (1999, Issue 3), MEDLINE (1966- Jan 2001), EMBASE (1980- Jan 2001) and CINAHL (1982-May 1999). The reference lists of all relevant papers were screened for additional trials.

SELECTION CRITERIA

All completed randomised unconfounded trials or controlled clinical trials comparing physical methods in patients allocated to receive physical methods, applied within one week of onset of stroke, with patients allocated to no physical methods.

DATA COLLECTION AND ANALYSIS

Two reviewers independently searched for relevant trials and three others independently checked the results.

MAIN RESULTS

We identified two small trials which included 123 patients. In one trial of 97 patients, compression stockings were associated with a non significant trend towards a reduction in DVT detected by Doppler ultrasound. In one trial of 26 patients, an intermittent pneumatic compression device was not associated with a significant reduction in DVT detected by 125-I-fibrinogen scanning. Overall, physical methods were not associated with a significant reduction in DVT (Odds ratio 0.59, 95%.CI 0.24-1.48) or death (Odds ratio 5.06, 95% CI 0.96-26.78).

REVIEWER'S CONCLUSIONS

There is insufficient evidence from randomised trials to support the routine use of physical methods for preventing DVT in acute stroke.

Are the modified "simple questions" a valid and reliable measure of health related quality of life after stroke? United Kingdom Collaborators in the International Stroke Trial

OBJECTIVES

Two "simple questions" were developed as a minimalist measurement tool to assess outcome in large trials and epidemiological studies after stroke. A previous study of their validity had disclosed ambiguities in their wording. In this study, the clarity, validity, and reliability of a modified version of these simple questions were examined. The relation between patients' responses to these questions and two widely used generic measures of health related quality of life were also studied.

METHODS

A hospital based stroke register cohort of 152 patients, who were all visited at home by a study nurse, was used to study validity. A cohort of 1753 patients derived from the International Stroke Trial was used to study the relation with measures of quality of life. The sensitivity, specificity, and accuracy with which responses to each question predicted the patients' outcome measured using standard instruments was assessed. The distribution of scores for the EuroQol and SF-36 was examined for patients classified as dependent, independent, and fully recovered by the combined use of the modified simple questions.

RESULTS

The modified "dependency" question had excellent sensitivity (>85%), specificity (>79%), and accuracy (>82%) for identifying dependency after stroke. The "problems" question had good sensitivity (65-88%) and moderate specificity (36-72%) for the detection of problems in a broad range of domains. The combined use of the modified dependency and problems questions provided a valid, simple, and reliable overall indicator of health related quality of life after stroke.

CONCLUSIONS

The modified simple questions have excellent face validity and good measurement properties for the assessment of outcome after stroke. They are particularly well suited for large epidemiological studies and randomised trials.

Indications for early aspirin use in acute ischemic stroke : A combined analysis of 40 000 randomized patients from the chinese acute stroke trial and the international stroke trial. On behalf of the CAST and IST collaborative groups

BACKGROUND AND PURPOSE

Long-term daily aspirin is of benefit in the years after ischemic stroke, and 2 large randomized trials (the Chinese Acute Stroke Trial [CAST] and the International Stroke Trial [IST]), with 20 000 patients in each, have shown that starting daily aspirin promptly in patients with suspected acute ischemic stroke also reduces the immediate risk of further stroke or death in hospital and the overall risk of death or dependency. However, some uncertainty remains about the effects of early aspirin in particular categories of patient with acute stroke.

METHODS

To assess the balance of benefits and risks of aspirin in particular categories of patient with acute stroke (eg, the elderly, those without a CT scan, or those with atrial fibrillation), a prospectively planned meta-analysis is presented of the data from 40 000 individual patients from both trials on events that occurred in the hospital during the scheduled treatment period (4 weeks in CAST, 2 weeks in IST), with 10 characteristics used to define 28 subgroups. This represents 99% of the worldwide evidence from randomized trials.

RESULTS

There was a highly significant reduction of 7 per 1000 (SD 1) in recurrent ischemic stroke (320 [1.6%] aspirin versus 457 [2. 3%] control, 2P<0.000001) and a less clearly significant reduction of 4 (SD 2) per 1000 in death without further stroke (5.0% versus 5. 4%, 2P=0.05). Against these benefits, there was an increase of 2 (SD 1) per 1000 in hemorrhagic stroke or hemorrhagic transformation of the original infarct (1.0% versus 0.8%, 2P=0.07) and no apparent effect on further stroke of unknown cause (0.9% versus 0.9%). In total, therefore, there was a net decrease of 9 (SD 3) per 1000 in the overall risk of further stroke or death in hospital (8.2% versus 9.1%, 2P=0.001). For the reduction of one third in recurrent ischemic stroke, subgroup-specific analyses found no significant heterogeneity of the proportional benefit of aspirin (chi(2)(18)=20. 9, NS), even though the overall treatment effect (chi(2)(1)=24.8, 2P<0.000001) was sufficiently large for such subgroup analyses to be statistically informative. The absolute risk among control patients was similar in all 28 subgroups, so the absolute reduction of approximately 7 per 1000 in recurrent ischemic stroke does not differ substantially with respect to age, sex, level of consciousness, atrial fibrillation, CT findings, blood pressure, stroke subtype, or concomitant heparin use. There was no good evidence that the apparent decrease of approximately 4 per 1000 in death without further stroke was reversed in any subgroup or that in any subgroup the increase in hemorrhagic stroke was much larger than the overall average of approximately 2 per 1000. Finally, there was no significant heterogeneity between the reductions in the composite outcome of any further stroke or death (chi(2)(18)=16.5, NS). Among the 9000 patients (22%) randomized without a prior CT scan, aspirin appeared to be of net benefit with no unusual excess of hemorrhagic stroke; moreover, even among the 800 (2%) who had inadvertently been randomized after a hemorrhagic stroke, there was no evidence of net hazard (further stroke or death, 63 aspirin versus 67 control).

CONCLUSIONS

Early aspirin is of benefit for a wide range of patients, and its prompt use should be routinely considered for all patients with suspected acute ischemic stroke, mainly to reduce the risk of early recurrence.

Low-molecular-weight heparins or heparinoids versus standard unfractionated heparin for acute ischaemic stroke

BACKGROUND

Low molecular weight heparins and heparinoids may be associated with lower risks of haemorrhage and more powerful antithrombotic effects than standard unfractionated heparin.

OBJECTIVES

The objective of this review was to compare the effects of low molecular weight heparins or heparinoids with those of unfractionated heparin in people with acute confirmed or presumed ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register and MedStrategy (1995). We also contacted pharmaceutical companies. Date of most recent search: April 1999.

SELECTION CRITERIA

Randomised trials comparing heparinoids or low molecular weight heparins with standard unfractionated heparin in people with acute ischaemic stroke. Only trials where treatment was started within 14 days of stroke onset were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Five trials involving 705 people were included. Four trials compared a heparinoid (danaparoid), and one compared a low molecular weight heparin (enoxaparin), with standard unfractionated heparin. Overall, 55/414 (13%) of the patients allocated danaparoid or enoxaparin had deep vein thrombosis compared with 65/291 (22%) of those allocated unfractionated heparin. This reduction was significant (odds ratio 0.52, 95% confidence interval 0.56 - 0.79). However, the number of more major events (pulmonary embolism, death, intra-cranial or extra-cranial haemorrhage) was too small to provide a reliable estimate of more important benefits and risks. No information was reported for recurrent stroke or functional outcome in survivors.

REVIEWER'S CONCLUSIONS

Low molecular weight heparin or heparinoid appear to decrease the occurrence of deep vein thrombosis compared to standard unfractionated heparin, but there are too few data to provide reliable information on their effect on other important outcomes, including death and intracranial haemorrhage.

Anticoagulants for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blood clots blocking an artery in the brain. Clot prevention with anticoagulant therapy could have a significant impact on patient survival, disability and recurrence of stroke.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulant therapy in the early treatment of patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (most recent search: March 1999) and consulted MedStrategy (1995). We also contacted drug companies.

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in patients with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Twenty-one trials involving 23,427 patients were included. The quality of the trials varied considerably. The anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Based on eight trials (22,450 patients) there was no evidence that anticoagulant therapy reduced the odds of death from all causes (odds ratio 1.05, 95% confidence intervals 0.98-1.12). Similarly, based on five trials (21, 846 patients), there was no evidence that anticoagulants reduced the odds of being dead or dependent at the end of follow-up (odds ratio 0.99, 95% confidence intervals 0.94-1.05). Although anticoagulant therapy was associated with about 9 fewer recurrent ischaemic strokes per 1000 patients treated, it was also associated with a similar sized 9 per 1000 increase in symptomatic intracranial haemorrhages. Similarly, anticoagulants avoided about 4 pulmonary emboli per 1000, but this benefit was offset by an extra 9 major extracranial haemorrhages per 1000. Sensitivity analyses did not identify a particular type of anticoagulant regimen or patient characteristic associated with net benefit.

REVIEWER'S CONCLUSIONS

Immediate anticoagulant therapy in patients with acute ischaemic stroke is not associated with net short- or long-term benefit. The data from this review do not support the routine use of any type of anticoagulant in acute ischaemic stroke.

[International Stroke Trial Switzerland: some epidemiologic data]

Randomised trials provide the best evidence on the effects of treatment on a particular disease. They can also provide valuable data on outcome. In the present article, data from 1631 Swiss patients randomised in the International Stroke Trial (IST) are presented. Baseline characteristics and outcome in the Swiss patients were compared with the 17,804 patients randomised in other countries. On average, compared with other countries, Swiss patients were: 2.5 years older (CI: 1.9-3.1; p < 0.001); more likely to have presented with total anterior circulation infarcts (28 vs 23%); less likely to have lacunar strokes (16 vs 25%; p < 0.00001); more likely to be randomised and treated early (within 3 hours, 7 vs 4%, and within 6 hours, 25 vs 15%; p < 0.00001). However, Swiss patients were more likely to be dead or dependent 6 months after the stroke (66.9 vs 62.2%; p < 0.00001). The difference in death or dependency was almost entirely explained by the difference in age and baseline severity of strokes. These data highlight the difficulties inherent in between-country comparisons of outcome after stroke. They also emphasise the need for international multicentre trials to use methods of randomisation (either stratification or minimisation), as IST did, to ensure balance of prognostic factors within each participating country; to do otherwise might confound the assessment of the effect of treatment.

Families of trials: the answers to all our questions?

Many of the important clinical decisions we make on a daily basis in stroke medicine are not supported by adequate evidence. This leads to variations in practice. If practice influences outcome, this must be regarded as unacceptable since it implies that many patients are receiving sub-optimal treatment. Where the advantages of certain treatment policies over others are only moderate, large randomised clinical trials provide the most reliable evidence of effectiveness. However, only a tiny proportion of patients with stroke are randomised in trials. Instead, the majority are exposed to treatments allocated haphazardly, rather than randomly, which serves only to delay the emergence of evidence concerning the relative merits of alternative treatment approaches. We suggest that we might increase the proportion of patients who contribute to advancing our knowledge by developing 'families' of trials. A 'family' would comprise a series of randomised trials into which patients with stroke may be enrolled either simultaneously or sequentially into one or more of the trials which would share common systems for randomisation and follow-up. Such a system would facilitate large, simple, randomised trials, reduce research costs, increase the generalisability of trial results and allow clinicians and patients to contribute to advancing our knowledge whenever they are uncertain about the best treatment. In this article, we discuss the advantages of this approach, some of the problems and their potential solutions.

Reports of randomized trials in acute stroke, 1955 to 1995. What proportions were commercially sponsored?

BACKGROUND AND PURPOSE

Research in acute stroke has expanded rapidly. Many potentially important interventions lack commercial potential (eg, admission to a stroke unit). We therefore wished to examine the frequency of reports of randomized trials of interventions for acute stroke over the past 40 years, the source of support for such trials, the reporting of the commercial involvement, and whether the proportion of commercially supported trials had changed.

METHODS

Eligible trials were identified from the Cochrane Stroke Group's specialized register of controlled clinical trials. We included all randomized trials in patients with acute stroke which published a full text report, in English, between 1955 and 1995. Two reviewers independently extracted data on the involvement of the pharmaceutical industry in all eligible trials.

RESULTS

There was a substantial increase in the number of acute stroke trials published per year between 1955 and 1995. The description of pharmaceutical industry involvement in each trial report was poor. Only a minority of supported trials made explicit statements about the role of the sponsoring company. The proportion of trials apparently supported by the pharmaceutical industry has increased substantially.

CONCLUSIONS

The increasingly important role of the pharmaceutical industry in evaluating new treatments gives substantial scope for bias and may not be in the interests of public health. Poor reporting of the sponsor's involvement suggests that modifications to the guidelines for the reporting of randomized controlled trials to include more details of the sponsor's involvement in the design, conduct, management, analysis, and reporting of the trial are justified.

How do scores on the EuroQol relate to scores on the SF-36 after stroke?

BACKGROUND AND PURPOSE

The EuroQol and Medical Outcome Survey 36-item short-form health survey (SF-36) questionnaires have both been validated for the assessment of health-related quality of life after stroke. However, the relationship between these instruments has not been studied after stroke. We therefore sought to compare the responses of a group of stroke patients to both instruments.

METHODS

A total of 2253 patients with stroke entered by United Kingdom hospitals in the International Stroke Trial were randomized to follow-up with either the EuroQol or SF-36 instruments. We randomly selected one third of patients who had responded to the EuroQol for follow-up, again using the SF-36, and two thirds of patients who had responded to the SF-36 for follow-up, again using the EuroQol. We assessed the patients' mean score for each domain of the SF-36 categorized by their response to the corresponding EuroQol domain and the correlation between the domains of the 2 instruments.

RESULTS

The domains for both instruments, which assessed physical functioning, social functioning, bodily pain, and overall health-related quality of life, correlated closely. The mental health domain of the SF-36 correlated only poorly with the psychological functioning domain of the EuroQol.

CONCLUSIONS

Both the EuroQol and SF-36 measure broadly similar domains of health. The weak relationship between the assessments of mental health may reflect a difference in content or more fundamental problems with the validity or reliability of the items in one of the instruments with respect to this domain. This study has provided the first empirical qualitative evidence by which the data on the SF-36 after stroke may be interpreted.