Consent to thrombolysis in acute ischaemic stroke: from trial to practice

Ability of patients with acute ischemic stroke to recall given information on intravenous thrombolysis: Results of a prospective multicenter study

Introduction:

Intravenous thrombolysis (IVT) is an on label treatment for selected patients with acute ischemic stroke (AIS). As major bleeding or allergic shock may occur, the need to ensure patients’ informed consent for IVT is a matter of debate.

Patients and methods:

Prospective investigator-initiated multi-center observational study to assess the ability of AIS patients to recall information, provided by a physician during a standardized educational talk (SET) on IVT use. The recall of 20 pre-defined items was assessed in AIS after 60–90 min ( n = 93) or 23–25 h ( n = 40) after SET. About 40 patients with subacute stroke, 40 non-stroke patients, and 23 relatives of AIS patients served as controls, and were surveyed 60–90 min after SET.

Results:

Within 60–90 min after SET, AIS patients (median age 70 years, 31% female, median NIHSS score on admission 3 points) who were considered capable to provide informed consent recalled 55% (IQR 40%–66.7%) of the provided SET items. In multivariable linear regression analysis recapitulation by AIS patients was associated with their educational level (β = 6.497, p < 0.001), self-reported excitement level (β = 1.879, p = 0.011) and NIHSS score on admission (β = −1.186, p = 0.001). Patients with subacute stroke (70 years, 40% female, median NIHSS = 2) recalled 70% (IQR 55.7%–83.6%), non-stroke patients (75 years, 40% female) 70% (IQR 60%–78.7%), and AIS relatives (58 years, 83% female) 70% (IQR 60%–85%). Compared to subacute stroke patients, AIS patients less often recalled the frequency of IVT-related bleeding (21% vs 43%), allergic shock (15% vs 39%), and bleeding-related morbidity and mortality (44% vs 78%). AIS patients recalled 50% (IQR 42.3%–67.5%) of the provided items 23–25 h after SET.

Conclusion:

AIS patients eligible for IVT remember about half of all SET-items after 60–90 min or 23–25 h, respectively. The fact that the recapitulation of IVT-associated risks is particularly poor should be given special consideration.

Brief Consent Methods Enable Rapid Enrollment in Acute Stroke Trial: Results From the TICH-2 Randomized Controlled Trial

BACKGROUND

Seeking consent rapidly in acute stroke trials is crucial as interventions are time sensitive. We explored the association between consent pathways and time to enrollment in the TICH-2 (Tranexamic Acid in Intracerebral Haemorrhage-2) randomized controlled trial.

METHODS

Consent was provided by patients or by a relative or an independent doctor in incapacitated patients, using a 1-stage (full written consent) or 2-stage (initial brief consent followed by full written consent post-randomization) approach. The computed tomography-to-randomization time according to consent pathways was compared using the Kruskal-Wallis test. Multivariable logistic regression was performed to identify variables associated with onset-to-randomization time of ≤3 hours.

RESULTS

Of 2325 patients, 817 (35%) gave self-consent using 1-stage (557; 68%) or 2-stage consent (260; 32%). For 1507 (65%), consent was provided by a relative (1 stage, 996 [66%]; 2 stage, 323 [21%]) or a doctor (all 2-stage, 188 [12%]). One patient did not record prerandomization consent, with written consent obtained subsequently. The median (interquartile range) computed tomography-to-randomization time was 55 (38-93) minutes for doctor consent, 55 (37-95) minutes for 2-stage patient, 69 (43-110) minutes for 2-stage relative, 75 (48-124) minutes for 1-stage patient, and 90 (56-155) minutes for 1-stage relative consents (P<0.001). Two-stage consent was associated with onset-to-randomization time of ≤3 hours compared with 1-stage consent (adjusted odds ratio, 1.9 [95% CI, 1.5-2.4]). Doctor consent increased the odds (adjusted odds ratio, 2.3 [1.5-3.5]) while relative consent reduced the odds of randomization ≤3 hours (adjusted odds ratio, 0.10 [0.03-0.34]) compared with patient consent. Only 2 of 771 patients (0.3%) in the 2-stage pathways withdrew consent when full consent was sought later. Two-stage consent process did not result in higher withdrawal rates or loss to follow-up.

CONCLUSIONS

The use of initial brief consent was associated with shorter times to enrollment, while maintaining good participant retention. Seeking written consent from relatives was associated with significant delays.

REGISTRATION

URL: https://www.isrctn.com; Unique identifier: ISRCTN93732214.

Legal medicine implications in fibrinolytic therapy of acute ischemic stroke

Background

Before the advent of fibrinolytic therapy as a gold standard method of care for cases of acute ischemic stroke in Romania, issues regarding legal medicine aspects involved in this area of medical expertise were already presented and, in the majority of cases, the doctors seem to be unprepared for these situations.

Main text

The present research illustrates some of the cases in which these aspects were involved, that adressed a clinical center having 6 years of professional experience in the application of fibrinolytic treatment for stroke. The following cases report either situations in which the afore mentioned therapy was not rightfully administrated or legal aspects regarding the obtainment of informed consent.

Conclusion

Obtaining informed consent is a mandatory procedure, which takes time, to the detriment of application of fibrinolytic treatment.

Choices Regarding Thrombolysis Are Modified by the Way to Transfer the Messages

Although thrombolysis is the most effective medical treatment for acute ischemic stroke, many stroke patients eligible for thrombolysis miss this treatment as a result of delay or refusal by the patients and/or their proxies. To explore the influences of prognostic information for different intervals from stroke onset to the start of thrombolytic treatment (OTT) and other factors on the preferences of patients/proxies regarding thrombolytic therapy, a cross-sectional, discrete-choice experiment was performed between August 2013 and September 2014. A total of 613 Chinese inpatients or their immediate family members were consecutively recruited at the Department of Neurology. After random assignment to a negative-framing group or a positive-framing group, the subjects completed a series of surveys, including nine items about thrombolysis. Latent class analysis (LCA) was used to examine participants’ preference paradigms for thrombolysis and to categorize the participants into different subgroups. Subsequently, regression analyses were conducted to explore predictors of categorization of the participants into each subgroup and to construct a thrombolytic decision-making model. LCA revealed an optimal 3-subgroup model including a consent to thrombolysis subgroup and objection to thrombolysis subgroups 1 and 2. Multiple regression analysis demonstrated that compared with assignment to the consent to thrombolysis subgroup, assignment to objection to thrombolysis subgroup 1 or 2 could be predicted by different factors. χ² tests indicated effects of framing and other factors on participants’ choices regarding thrombolysis. Choices regarding thrombolysis were modified by not only prognostic information for different OTT intervals but also message framing, presentation format, and sociodemographic characteristics. To facilitate consent to thrombolysis, physicians should convey prognostic information to patients/proxies on the basis of patient OTT interval and should order the presentation of therapies according to the classification of patients/proxies. Individualized decision-making (IDM) might be an optimal strategy to increase the selection of thrombolysis, which providing important reference points for IDM in other clinical domains.

Profiling neuron-autonomous lncRNA changes upon ischemia/reperfusion injury

Extensive changes of neuronal transcriptome occur post ischemic stroke and during the following reperfusion. Although numerous studies focused on transcriptome changes of mRNAs associated with ischemic stroke, little is known about whether and how long non-coding RNAs (lncRNAs), which play critical roles in cellular homeostasis, are involved in this process. In this study, we performed high throughput screening to analyze expression changes of lncRNAs in primarily cultured hippocampal neurons under an oxygen-glucose deprivation/reperfusion (OGD/R) condition at 0 h, 6 h, 12 h, and 18 h, respectively. Knock down of one validated lncRNAs (Tnxa-ps1) promoted neuronal survival by inhibiting apoptosis. Coding non-coding co-expression network analysis revealed that the expression of Tnxa-ps1 was highly correlated with changes of a particular group of genes, many of which are associated with neural protection. Finally, we showed that down-regulation of Tnxa-ps1 reversed the expression changes of four mRNAs post OGD/R, revealing a regulatory effect between Tnxa-ps1 and selected genes. Together, our data revealed possible participation of lncRNAs in the pathophysiology of OGD/R and thereby provided new insights into the studies of potential therapeutic targets for ischemic stroke.

Neuron-autonomous transcriptome changes upon ischemia/reperfusion injury

Ischemic stroke and the following reperfusion, an acute therapeutic intervention, can cause irreversible brain damages. However, the underlying pathological mechanisms are still under investigation. To obtain a comprehensive, real-time view of the cell-autonomous mechanisms involved in ischemic stroke and reperfusion, we applied the next-generation sequencing (NGS) technology to characterize the temporal changes in gene expression profiles using primarily cultured hippocampal neurons under an oxygen-glucose deprivation/reperfusion (OGD/R) condition. We first identified the differentially expressed genes (DEGs) between normal cultured neurons, neurons with OGD, and neurons with OGD followed by reperfusion for 6 h, 12 h, and 18 h, respectively. We then performed bioinformatics analyses, including gene ontological (GO) and pathway analysis and co-expression network analysis to screen for novel key pathways and genes involved in the pathology of OGD/R. After we confirmed the changes of selected key genes in hippocampal cultures with OGD/R, we further validated their expression changes in an in vivo ischemic stroke model (MCAO). Finally, we demonstrated that prevention of the up-regulation of a key gene (Itga5) associated with OGD/R promoted hippocampal neuronal survival. Our research thereby provided novel insights into the molecular mechanisms in ischemic stroke pathophysiology and potential targets for therapeutic intervention after ischemic stroke.

Efficacy and Safety Evaluation on Arterial Thrombolysis in Treating Acute Cerebral Infarction

The objective of this study was to evaluate the efficacy and safety of intra-arterial thrombolysis in treating acute cerebral infarction and further discuss the indications of acute cerebral infarction treatment, in order to enhance the therapeutic effects of arterial thrombolysis. The data of 164 patients with acute cerebral infarction who accepted intra-arterial thrombolysis treatment by using rt-PA or reteplase between 2009 and 2014 at the Department of Neurology of our hospital, were collected, including patients' medical history, characteristics of the onset procedure, intervals between onset and intra-arterial thrombolysis, bleeding or death, and the changing process of patient's main neurologic function after the treatment. The neurological functions including muscle strength, speech, and level of consciousness were chosen for evaluation. Through a review of cerebral angiography, we collected the digital subtraction angiography (DSA) morphological changes of blood vessels before and after arterial thrombolysis to evaluate whether those blood vessels had been reperfused. Thereafter, we analyzed and statistically processed above-mentioned data. The mean time of arterial thrombolysis was 5.7 h. DSA results were as follows: 22 patients had complete internal carotid artery (ICA) occlusion; 49 patients middle cerebral artery's (MCA's) Ml or M2 segment occlusion; 6 patients anterior cerebral artery (ACA) occlusion; 58 patients reperfusion after thrombolysis, and the recanalization rate was 76 %. Based on vertebral-basilar artery (VBA) system, 18 patients had complete occlusion, 11 patients had reperfusion after thrombolysis, and the recanalization rate was 61 %. A total of 63 patients had severe stenosis, and they had significantly improved after thrombolysis. The clinical symptoms of patients were improved: 79 out of 164 patients with paralysis had partially recovered their limb muscle strength after operation, while 33 patients had completely recovered, and there was no recovery at all of the muscle strength in 4 patients after operation. In total, 59 out of 63 patients with aphasia had improved their language function, while 19 patients with disturbance of consciousness turned for the better after arterial thrombolysis. Only one patient experienced the cerebral hemorrhage, and 14 cases had gingival bleeding, oral mucosa bleeding, and urethrorrhagia. The overall effective rates of intra-arterial thrombolysis in treating the acute cerebral infarction by reteplase had no significant differences compared to those by rt-PA, and there were no hemorrhagic complications. It is safe and effective if the arterial thrombolysis using reteplase is performed within a few hours after acute cerebral infarction onset because reteplase has a higher clinical efficacy and lower hemorrhagic transformation, which suggests that it may become a new feasible option for clinical arterial thrombolysis.

Advance preferences regarding thrombolysis in patients at risk for stroke: a cross-sectional study

BACKGROUND

It is difficult to obtain informed consent for thrombolysis in stroke patients given the emergency setting, the need for a speedy decision and the effects of neurological deficits.

AIM

To determine the advance preferences for thrombolysis of patients at risk for stroke following discussion of the potential risks and benefits.

DESIGN

Cross-sectional survey.

METHODS

Data on benefits and risks of thrombolysis within 3 h and between 3 and 4.5 h after stroke were presented orally, in writing and pictorially to patients attending geriatric and stroke services in a teaching hospital with specified stroke risk factors and preferences for thrombolysis were recorded.

RESULTS

Of the 121 participants, 108 (89.3%; 95% confidence interval [CI] 82.4-93.7) would opt for thrombolysis within the 3-h period and 100 (82.6%; 95% CI 74.9-88.4) within the 3- to 4.5-h period after acute stroke (P = 0.04, McNemar's test for correlated proportions). Previous stroke or transient ischaemic attack was more common among those who agreed to thrombolysis (54.1% vs. 30.4%, P = 0.04) and those who opted for thrombolysis were significantly more likely to agree to have their preferences recorded and used in the event of a stroke than those who refused thrombolysis (88.8% vs. 30.4%, P = 0.002).

CONCLUSION

Advance discussion of the potential risks and benefits of thrombolysis in at-risk patients may improve decision making if thrombolysis is being considered and the patient can no longer make a decision.

Understanding clinicians' decisions to offer intravenous thrombolytic treatment to patients with acute ischaemic stroke: a protocol for a discrete choice experiment

BACKGROUND

Intravenous thrombolysis is an effective emergency treatment for acute ischaemic stroke for patients meeting specific criteria. Approximately 12% of eligible patients in England, Wales and Northern Ireland received thrombolysis in the first quarter of 2013, yet as many as 15% are eligible to receive treatment. Suboptimal use of thrombolysis may have been largely attributable to structural factors; however, with the widespread implementation of 24/7 hyper acute stroke services, continuing variation is likely to reflect differences in clinical decision-making, in particular the influence of ambiguous areas within the guidelines, licensing criteria and research evidence. Clinicians' perceptions about thrombolysis may now exert a greater influence on treatment rates than structural/service factors. This research seeks to elucidate factors influencing thrombolysis decision-making by using patient vignettes to identify (1) patient-related and clinician-related factors that may help to explain variation in treatment and (2) associated trade-offs in decision-making based on the interplay of critical factors.

METHODS/ANALYSIS

A discrete choice experiment (DCE) will be conducted to better understand how clinicians make decisions about whether or not to offer thrombolysis to patients with acute ischaemic stroke. To inform the design, exploratory work will be undertaken to ensure that (1) all potentially influential factors are considered for inclusion; and (2) to gain insights into the 'grey areas' of patient factors. A fractional factorial design will be used to combine levels of patient factors in vignettes, which will be presented to clinicians to allow estimation of the variable effects on decisions to offer thrombolysis.

ETHICS AND DISSEMINATION

Ethical approval for this study was obtained from the Newcastle University Research Ethics Committee. The results will be disseminated in peer review publications and at national conferences. Findings will be translated into continuing professional development activities and will support implementation of a computerised decision aid for thrombolysis (COMPASS) in acute stroke care.

Ethical considerations in consenting critically ill patients for bedside clinical care and research

Care of critically ill patients, as in any other field, demands the exercise of ethical principles related to respect of patient's autonomy, beneficence, nonmaleficence, and distributive justice. Professional duty and the common law require doctors to obtain consent before giving treatment or for requesting participation in clinical research. A procedure or research study must be adequately explained, and the patient must have the capacity to consent. If a patient does not have decision-making capacity, treatment must be given using alternative forms of consent or using principles of implied consent in emergency or life-threatening situations. In the case of clinical research, informed consent must always be sought. Exemptions to this rule are morally justified in circumstances related to research in life-threatening conditions or life-saving interventions in which the investigator departs from sound principles of equipoise. This usually implies the imposition of safeguards such as consultation with the community in which the study were to take place, oversight in patient screening and recruitment process by institutional review boards, special study designs, retrospective and prospective consent processes, and independent safety monitoring.

A review of decision support, risk communication and patient information tools for thrombolytic treatment in acute stroke: lessons for tool developers

BACKGROUND

Tools to support clinical or patient decision-making in the treatment/management of a health condition are used in a range of clinical settings for numerous preference-sensitive healthcare decisions. Their impact in clinical practice is largely dependent on their quality across a range of domains. We critically analysed currently available tools to support decision making or patient understanding in the treatment of acute ischaemic stroke with intravenous thrombolysis, as an exemplar to provide clinicians/researchers with practical guidance on development, evaluation and implementation of such tools for other preference-sensitive treatment options/decisions in different clinical contexts.

METHODS

Tools were identified from bibliographic databases, Internet searches and a survey of UK and North American stroke networks. Two reviewers critically analysed tools to establish: information on benefits/risks of thrombolysis included in tools, and the methods used to convey probabilistic information (verbal descriptors, numerical and graphical); adherence to guidance on presenting outcome probabilities (IPDASi probabilities items) and information content (Picker Institute Checklist); readability (Fog Index); and the extent that tools had comprehensive development processes.

RESULTS

Nine tools of 26 identified included information on a full range of benefits/risks of thrombolysis. Verbal descriptors, frequencies and percentages were used to convey probabilistic information in 20, 19 and 18 tools respectively, whilst nine used graphical methods. Shortcomings in presentation of outcome probabilities (e.g. omitting outcomes without treatment) were identified. Patient information tools had an aggregate median Fog index score of 10. None of the tools had comprehensive development processes.

CONCLUSIONS

Tools to support decision making or patient understanding in the treatment of acute stroke with thrombolysis have been sub-optimally developed. Development of tools should utilise mixed methods and strategies to meaningfully involve clinicians, patients and their relatives in an iterative design process; include evidence-based methods to augment interpretability of textual and probabilistic information (e.g. graphical displays showing natural frequencies) on the full range of outcome states associated with available options; and address patients with different levels of health literacy. Implementation of tools will be enhanced when mechanisms are in place to periodically assess the relevance of tools and where necessary, update the mode of delivery, form and information content.

Endovascular treatment for acute ischemic stroke

BACKGROUND

In patients with ischemic stroke, endovascular treatment results in a higher rate of recanalization of the affected cerebral artery than systemic intravenous thrombolytic therapy. However, comparison of the clinical efficacy of the two approaches is needed.

METHODS

We randomly assigned 362 patients with acute ischemic stroke, within 4.5 hours after onset, to endovascular therapy (intraarterial thrombolysis with recombinant tissue plasminogen activator [t-PA], mechanical clot disruption or retrieval, or a combination of these approaches) or intravenous t-PA. Treatments were to be given as soon as possible after randomization. The primary outcome was survival free of disability (defined as a modified Rankin score of 0 or 1 on a scale of 0 to 6, with 0 indicating no symptoms, 1 no clinically significant disability despite symptoms, and 6 death) at 3 months.

RESULTS

A total of 181 patients were assigned to receive endovascular therapy, and 181 intravenous t-PA. The median time from stroke onset to the start of treatment was 3.75 hours for endovascular therapy and 2.75 hours for intravenous t-PA (P<0.001). At 3 months, 55 patients in the endovascular-therapy group (30.4%) and 63 in the intravenous t-PA group (34.8%) were alive without disability (odds ratio adjusted for age, sex, stroke severity, and atrial fibrillation status at baseline, 0.71; 95% confidence interval, 0.44 to 1.14; P=0.16). Fatal or nonfatal symptomatic intracranial hemorrhage within 7 days occurred in 6% of the patients in each group, and there were no significant differences between groups in the rates of other serious adverse events or the case fatality rate.

CONCLUSIONS

The results of this trial in patients with acute ischemic stroke indicate that endovascular therapy is not superior to standard treatment with intravenous t-PA. (Funded by the Italian Medicines Agency, ClinicalTrials.gov number, NCT00640367.).

Situationally-sensitive knowledge translation and relational decision making in hyperacute stroke: a qualitative study

Stroke is a leading cause of disability. Early treatment of acute ischaemic stroke with rtPA reduces the risk of longer term dependency but carries an increased risk of causing immediate bleeding complications. To understand the challenges of knowledge translation and decision making about treatment with rtPA in hyperacute stroke and hence to inform development of appropriate decision support we interviewed patients, their family and health professionals. The emergency setting and the symptomatic effects of hyper-acute stroke shaped the form, content and manner of knowledge translation to support decision making. Decision making about rtPA in hyperacute stroke presented three conundrums for patients, family and clinicians. 1) How to allow time for reflection in a severely time-limited setting. 2) How to facilitate knowledge translation regarding important treatment risks and benefits when patient and family capacity is blunted by the effects and shock of stroke. 3) How to ensure patient and family views are taken into account when the situation produces reliance on the expertise of clinicians. Strategies adopted to meet these conundrums were fourfold: face to face communication; shaping decisions; incremental provision of information; and communication tailored to the individual patient. Relational forms of interaction were understood to engender trust and allay anxiety. Shaping decisions with patients was understood as an expression of confidence by clinicians that helped alleviate anxiety and offered hope and reassurance to patients and their family experiencing the shock of the stroke event. Neutral presentations of information and treatment options promoted uncertainty and contributed to anxiety. ‘Drip feeding’ information created moments for reflection: clinicians literally made time. Tailoring information to the particular patient and family situation allowed clinicians to account for social and emotional contexts. The principal responses to the challenges of decision making about rtPA in hyperacute stroke were relational decision support and situationally-sensitive knowledge translation.

Evidence from the scene: paramedic perspectives on involvement in out-of-hospital research

STUDY OBJECTIVE

In the context of calls to develop better systems for out-of-hospital clinical research, we seek to understand paramedics' perceptions of involvement in research and the barriers and facilitators to that involvement.

METHODS

This was a qualitative study using semistructured focus groups with 58 United Kingdom paramedics and interviews with 30 US firefighter-paramedics. The study focused on out-of-hospital research (trials of out-of-hospital treatment for stroke), whereby paramedics identified potential study subjects or obtained consent and administered study treatment in the field. Data were analyzed with a thematic and discourse approach.

RESULTS

Three key themes emerged as significant facilitators and barriers to paramedic involvement in research: patient benefit, professional identity and responsibility, and time. Paramedics showed willingness and capacity to engage in research but also some reticence because of the perceived sacrifice of autonomy and challenge to their identity. Paramedics work in a time-sensitive environment and were concerned that research would increase time taken in the field.

CONCLUSION

Awareness of these perspectives will help with development of out-of-hospital research protocols and potentially facilitate greater participation.

Eligibility and rate of treatment for recombinant tissue plasminogen activator in acute ischemic stroke using different criteria

OBJECTIVES

The rate of recombinant tissue plasminogen activator (rtPA) use for stroke is low among the Chinese-Taiwanese. The study objective was to determine if less restrictive exclusion criteria for rtPA would increase eligibility and the rate of treatment.

METHODS

This retrospective before-and-after study was conducted from 2006 to 2009. The authors compared stroke patients treated under the old rtPA exclusion criteria (January 2006 to December 2008) with those treated with less restrictive rtPA exclusion criteria (January to December 2009). Rates of eligibility and treatment and reasons for exclusion from rtPA between the two phases were assessed.

RESULTS

Of 461 eligible patients during the study period, 333 were evaluated by the old criteria and 128 were evaluated by the less restrictive criteria. Minor or improving stroke was the primary exclusion reason in both groups (194/333, 58% vs. 70/128, 55%). Eligibility for rtPA was increased in the less restrictive criteria (35/127, 27%, 95% confidence interval [CI] = 20% to 36%) compared to the old criteria (40/333, 12%, 95% CI = 8.7% to 16%; p = 0.0001). Fewer patients were excluded due to old age in the less restrictive criteria (0/128, 0%) compared to the old criteria (37/333, 11%; p = 0.0001). The rate of consent refusal increased in the less restrictive criteria (27/128, 21%, 95% CI = 14% to 29%) compared to the old criteria (23/333, 6.9%, 95% CI = 4.4% to 10%; p < 0.0001). Rate of rtPA treatment was unchanged between the less restrictive criteria (8/128, 6.3%, 95% CI = 2.7% to 12%) and the old criteria (17/333, 5.1%, 95% CI = 3% to 8%; p = 0.63).

CONCLUSIONS

Increasing eligibility for rtPA does not increase the rate of treatment, possibly due to the high symptomatic intracerebral hemorrhage rate among Chinese-Taiwanese, which is a major concern among emergency physicians (EPs), neurologists, and patients. Dealing with perceived safety issues of rtPA is crucial before the rate of treatment can be increased.

Consent issues in neurology

The requirement that doctors obtain valid consent from patients before providing medical treatment has long been ingrained in both legal doctrine and medical ethics. We summarize the foundations of the informed consent doctrine and discuss the recent evolution in thinking about consent and medical decision making. We show how consent has evolved from physicians merely providing patients information to shared decision making between patients and physicians. We then address three specific examples of situations common in neurological practice that pose challenges in obtaining valid consent: the administration of intravenous tPA following ischemic stroke, consideration of carotid endarterectomy for carotid artery stenosis, and implementation of do-not-resuscitate orders.

Third international stroke trial (IST-3) of thrombolysis for acute ischaemic stroke

BACKGROUND

Intravenous recombinant tissue plasminogen activator (rt-PA) is approved for use in selected patients with ischaemic stroke within 3 hours of symptom onset. IST-3 seeks to determine whether a wider range of patients may benefit.

DESIGN

International, multi-centre, prospective, randomized, open, blinded endpoint (PROBE) trial of intravenous rt-PA in acute ischaemic stroke. Suitable patients must be assessed and able to start treatment within 6 hours of developing symptoms, and brain imaging must have excluded intracerebral haemorrhage. With 1000 patients, the trial can detect a 7% absolute difference in the primary outcome. With 3500 patients, it can detect a 4.0% absolute benefit & with 6000, (mostly treated between 3 & 6 hours), it can detect a 3% benefit. TRIAL PROCEDURES: Patients are entered into the trial by telephoning a fast, secure computerised central randomisation system or via a secure web interface. Repeat brain imaging must be performed at 24-48 hours. The scans are reviewed 'blind' by expert readers. The primary measure of outcome is the proportion of patients alive and independent (Modified Rankin 0-2) at six months (assessed via a postal questionnaire mailed directly to the patient). Secondary outcomes include: events within 7 days (death, recurrent stroke, symptomatic intracranial haemorrhage), outcome at six months (death, functional status, EuroQol).

TRIAL REGISTRATION

ISRCTN25765518.

Impact of Stroke Syndrome and Stroke Severity on the Process of Consent in the Third International Stroke Trial

BACKGROUND

Obtaining informed consent for a patient's participation in a randomized trial of treatment for use in a medical emergency may be achieved in a variety of ways. We sought to assess the process of consent and to evaluate the influence of the patient's neurological deficit on the method used to obtain consent in the first 300 patients recruited into the Third International Stroke Trial (IST-3).

METHODS

IST-3 is the first large-scale randomized controlled trial of intravenous thrombolysis in acute ischaemic stroke. The clinician could use one of four procedures to recruit the patient: written consent, witnessed consent, assent, or a waiver of consent. The patient's neurological deficits were recorded at baseline. We analysed the relationship between the neurological deficits at baseline and the consent procedure.

RESULTS

The method of consent used was written consent in 71 subjects (24%), witnessed verbal consent in 30 subjects (10%), assent by a relative in 197 subjects (66%), and waiver of consent in 2 subjects (1%). Patients with severe neurological deficits (as measured either by their stroke syndrome or their lower predicted probability of being alive and independent at 6 months) were more likely to be recruited by assent. Patients able to give written consent had less severe strokes.

CONCLUSIONS

Patients with non-lacunar hemispheric stroke syndromes or with a more severe neurological deficit were less likely to give written consent. Excluding such patients from acute stroke treatment trials would eliminate many otherwise eligible subjects, who have a poor predicted outcome without treatment and yet might benefit from acute treatments such as thrombolysis. Flexible consent procedures developed for IST-3 have made it feasible to recruit the target population.