Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
1.
Res Sq ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38947064

RESUMO

Background Cardiac arrest is a common and devastating emergency of both the heart and brain. More than 380,000 patients suffer out-of-hospital cardiac arrest annually in the United States. Induced cooling of comatose patients markedly improved neurological and functional outcomes in pivotal randomized clinical trials, but the optimal duration of therapeutic hypothermia has not yet been established. Methods This study is a multi-center randomized, response-adaptive, duration (dose) finding, comparative effectiveness clinical trial with blinded outcome assessment. We investigate two populations of adult comatose survivors of cardiac arrest to ascertain the shortest duration of cooling that provides the maximum treatment effect. The design is based on a statistical model of response as defined by the primary endpoint, a weighted 90-day mRS (modified Rankin Scale, a measure of neurologic disability), across the treatment arms. Subjects will initially be equally randomized between 12, 24, and 48 hours of therapeutic cooling. After the first 200 subjects have been randomized, additional treatment arms between 12 and 48 hours will be opened and patients will be allocated, within each initial cardiac rhythm type (shockable or non-shockable), by response adaptive randomization. As the trial continues, shorter and longer duration arms may be opened. A maximum sample size of 1800 subjects is proposed. Secondary objectives are to characterize: the overall safety and adverse events associated with duration of cooling, the effect on neuropsychological outcomes, and the effect on patient reported quality of life measures. Discussion In-vitro and in-vivo studies have shown the neuroprotective effects of therapeutic hypothermia for cardiac arrest. We hypothesize that longer durations of cooling may improve either the proportion of patients that attain a good neurological recovery or may result in better recovery among the proportion already categorized as having a good outcome. If the treatment effect of cooling is increasing across duration, for at least some set of durations, then this provides evidence of the efficacy of cooling itself versus normothermia, even in the absence of a normothermia control arm, confirming previous RCTs for OHCA survivors of shockable rhythms and provides the first prospective controlled evidence of efficacy in those without initial shockable rhythms. Trial registration ClinicalTrials.gov (NCT04217551, 2019-12-30).

2.
Stat Med ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885949

RESUMO

Emergency medical diseases (EMDs) are the leading cause of death worldwide. A time-to-death analysis is needed to accurately identify the risks and describe the pattern of an EMD because the mortality rate can peak early and then decline. Dose-ranging Phase II clinical trials are essential for developing new therapies for EMDs. However, most dose-finding trials do not analyze mortality as a time-to-event endpoint. We propose three Bayesian dose-response time-to-event models for a secondary mortality analysis of a clinical trial: a two-group (active treatment vs control) model, a three-parameter sigmoid EMAX model, and a hierarchical EMAX model. The study also incorporates one specific active treatment as an active comparator in constructing three new models. We evaluated the performance of these six models and a very popular independent model using simulated data motivated by a randomized Phase II clinical trial focused on identifying the most effective hyperbaric oxygen dose to achieve favorable functional outcomes in patients with severe traumatic brain injury. The results show that the three-group, EMAX, and EMAX model with an active comparator produce the smallest averaged mean squared errors and smallest mean absolute biases. We provide a new approach for time-to-event analysis in early-phase dose-ranging clinical trials for EMDs. The EMAX model with an active comparator can provide valuable insights into the mortality analysis of new EMDs or other conditions that have changing risks over time. The restricted mean survival time, a function of the model's hazards, is recommended for displaying treatment effects for EMD research.

4.
Stat Med ; 42(25): 4582-4601, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37599009

RESUMO

The Glasgow outcome scale-extended (GOS-E), an ordinal scale measure, is often selected as the endpoint for clinical trials of traumatic brain injury (TBI). Traditionally, GOS-E is analyzed as a fixed dichotomy with favorable outcome defined as GOS-E ≥ 5 and unfavorable outcome as GOS-E < 5. More recent studies have defined favorable vs unfavorable outcome utilizing a sliding dichotomy of the GOS-E that defines a favorable outcome as better than a subject's predicted prognosis at baseline. Both dichotomous approaches result in loss of statistical and clinical information. To improve on power, Yeatts et al proposed a sliding scoring of the GOS-E as the distance from the cutoff for favorable/unfavorable outcomes, and therefore used more information found in the original GOS-E to estimate the probability of favorable outcome. We used data from a published TBI trial to explore the ramifications to trial operating characteristics by analyzing the sliding scoring of the GOS-E as either dichotomous, continuous, or ordinal. We illustrated a connection between the ordinal data and time-to-event (TTE) data to allow use of Bayesian software that utilizes TTE-based modeling. The simulation results showed that the continuous method with continuity correction offers higher power and lower mean squared error for estimating the probability of favorable outcome compared to the dichotomous method, and similar power but higher precision compared to the ordinal method. Therefore, we recommended that future severe TBI clinical trials consider analyzing the sliding scoring of the GOS-E endpoint as continuous with continuity correction.


Assuntos
Lesões Encefálicas Traumáticas , Humanos , Teorema de Bayes , Lesões Encefálicas Traumáticas/terapia , Escala de Resultado de Glasgow , Probabilidade , Prognóstico , Ensaios Clínicos como Assunto
5.
Res Methods Med Health Sci ; 4(1): 34-48, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37009524

RESUMO

Studies that investigate the performance of prognostic and predictive biomarkers are commonplace in medicine. Evaluating the performance of biomarkers is challenging in traumatic brain injury (TBI) and other conditions when both the time factor (i.e. time from injury to biomarker measurement) and different levels or doses of treatments are in play. Such factors need to be accounted for when assessing the biomarker's performance in relation to a clinical outcome. The Hyperbaric Oxygen in Brain Injury Treatment (HOBIT) trial, a phase II randomized control clinical trial seeks to determine the dose of hyperbaric oxygen therapy (HBOT) for treating severe TBI that has the highest likelihood of demonstrating efficacy in a phase III trial. Hyperbaric Oxygen in Brain Injury Treatment will study up to 200 participants with severe TBI. This paper discusses the statistical approaches to assess the prognostic and predictive performance of the biomarkers studied in this trial, where prognosis refers to the association between a biomarker and the clinical outcome while the predictiveness refers to the ability of the biomarker to identify patient subgroups that benefit from therapy. Analyses based on initial biomarker levels accounting for different levels of HBOT and other baseline clinical characteristics, and analyses of longitudinal changes in biomarker levels are discussed from a statistical point of view. Methods for combining biomarkers that are of complementary nature are also considered and the relevant algorithms are illustrated in detail along with an extensive simulation study that assesses the performance of the statistical methods. Even though the discussed approaches are motivated by the HOBIT trial, their applications are broader. They can be applied in studies assessing the predictiveness and prognostic ability of biomarkers in relation to a well-defined therapeutic intervention and clinical outcome.

6.
JCI Insight ; 8(8)2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-36862515

RESUMO

Multiple randomized, controlled clinical trials have yielded discordant results regarding the efficacy of convalescent plasma in outpatients, with some showing an approximately 2-fold reduction in risk and others showing no effect. We quantified binding and neutralizing antibody levels in 492 of the 511 participants from the Clinical Trial of COVID-19 Convalescent Plasma in Outpatients (C3PO) of a single unit of COVID-19 convalescent plasma (CCP) versus saline infusion. In a subset of 70 participants, peripheral blood mononuclear cells were obtained to define the evolution of B and T cell responses through day 30. Binding and neutralizing antibody responses were approximately 2-fold higher 1 hour after infusion in recipients of CCP compared with saline plus multivitamin, but levels achieved by the native immune system by day 15 were almost 10-fold higher than those seen immediately after CCP administration. Infusion of CCP did not block generation of the host antibody response or skew B or T cell phenotype or maturation. Activated CD4+ and CD8+ T cells were associated with more severe disease outcome. These data show that CCP leads to a measurable boost in anti-SARS-CoV-2 antibodies but that the boost is modest and may not be sufficient to alter disease course.


Assuntos
COVID-19 , Leucócitos Mononucleares , Humanos , COVID-19/terapia , Soroterapia para COVID-19 , Anticorpos Neutralizantes , Imunidade Adaptativa
7.
Clin Trials ; 19(6): 636-646, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35786002

RESUMO

BACKGROUND/AIMS: Fibrinolytic therapy with tenecteplase has been proposed for patients with pulmonary embolism but the optimal dose is unknown. Higher-than-necessary dosing is likely to cause excess bleeding. We designed an adaptive clinical trial to identify the minimum and assumed safest dose of tenecteplase that maintains efficacy. METHODS: We propose a Bayesian adaptive, placebo-controlled, group-sequential dose-finding trial using response-adaptive randomization to preferentially allocate subjects to the most promising doses, dual analyses strategies (continuous and dichotomized) using a gatekeeping approach to maximize clinical impact, and interim stopping rules to efficiently address competing trial objectives. The operating characteristics of the proposed design were evaluated using Monte Carlo simulation across multiple hypothetical efficacy scenarios. RESULTS: Simulation demonstrated response-adaptive randomization can preferentially allocate subjects to doses which appear to be performing well based on interim data. Interim decision-making, including the interim evaluation of both analysis strategies with gatekeeping, allows the trial to continue enrollment when success with the dichotomized analysis strategy appears sufficiently likely and to stop enrollment and declare superiority based on the continuous analysis strategy when there is little chance of ultimately declaring superiority with the dichotomized analysis. CONCLUSION: The proposed design allows evaluation of a greater number of dose levels than would be possible with a non-adaptive design and avoids the need to choose either the continuous or the dichotomized analysis strategy for the primary endpoint.


Assuntos
Embolia Pulmonar , Projetos de Pesquisa , Humanos , Doença Aguda , Teorema de Bayes , Ensaios Clínicos como Assunto , Relação Dose-Resposta a Droga , Embolia Pulmonar/tratamento farmacológico , Tenecteplase/uso terapêutico
8.
JAMA Netw Open ; 5(5): e2211616, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35544137

RESUMO

Importance: Bayesian adaptive trial design has the potential to create more efficient clinical trials. However, a barrier to the uptake of bayesian adaptive designs for confirmatory trials is limited experience with how they may perform compared with a frequentist design. Objective: To compare the performance of a bayesian and a frequentist adaptive clinical trial design. Design, Setting, and Participants: This prospective cohort study compared 2 trial designs for a completed multicenter acute stroke trial conducted within a National Institutes of Health neurologic emergencies clinical trials network, with individual patient-level data, including the timing and order of enrollments and outcome ascertainment, from 1151 patients with acute stroke and hyperglycemia randomized to receive intensive or standard insulin therapy. The implemented frequentist design had group sequential boundaries for efficacy and futility interim analyses at 90 days after randomization for 500, 700, 900, and 1100 patients. The bayesian alternative used predictive probability of trial success to govern early termination for efficacy and futility with a first interim analysis at 500 randomized patients and subsequent interims after every 100 randomizations. Main Outcomes and Measures: The main outcome was the sample size at end of study, which was defined as the sample size at which each of the studies stopped accrual of patients. Results: Data were collected from 1151 patients. As conducted, the frequentist design passed the futility boundary after 936 participants were randomized. Using the same sequence and timing of randomization and outcome data, the bayesian alternative crossed the futility boundary approximately 3 months earlier after 800 participants were randomized. Conclusions and Relevance: Both trial designs stopped for futility before reaching the planned maximum sample size. In both cases, the clinical community and patients would benefit from learning the answer to the trial's primary question earlier. The common feature across the 2 designs was frequent interim analyses to stop early for efficacy or for futility. Differences between how these analyses were implemented between the 2 trials resulted in the differences in early stopping.


Assuntos
Hiperglicemia , Acidente Vascular Cerebral , Teorema de Bayes , Humanos , Hiperglicemia/tratamento farmacológico , Insulina/uso terapêutico , Insulina Regular Humana , Estudos Prospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Estados Unidos
9.
BMJ Open ; 12(3): e060188, 2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35273066

RESUMO

INTRODUCTION: Management of traumatic brain injury (TBI) includes invasive monitoring to prevent secondary brain injuries. Intracranial pressure (ICP) monitor is the main measurement used to that intent but cerebral hypoxia can occur despite normal ICP. This study will assess whether the addition of a brain tissue oxygenation (PbtO2) monitor prevents more secondary injuries that will translate into improved functional outcome. METHODS AND ANALYSIS: Multicentre, randomised, blinded-endpoint comparative effectiveness study enrolling 1094 patients with severe TBI monitored with both ICP and PbtO2. Patients will be randomised to medical management guided by ICP alone (treating team blinded to PbtO2 values) or both ICP and PbtO2. Management is protocolised according to international guidelines in a tiered approach fashion to maintain ICP <22 mm Hg and PbtO2 >20 mm Hg. ICP and PbtO2 will be continuously recorded for a minimum of 5 days. The primary outcome measure is the Glasgow Outcome Scale-Extended performed at 180 (±30) days by a blinded central examiner. Favourable outcome is defined according to a sliding dichotomy where the definition of favourable outcome varies according to baseline severity. Severity will be defined according to the probability of poor outcome predicted by the IMPACT core model. A large battery of secondary outcomes including granular neuropsychological and quality of life measures will be performed. ETHICS AND DISSEMINATION: This has been approved by Advarra Ethics Committee (Pro00030585). Results will be presented at scientific meetings and published in peer-reviewed publications. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT03754114).


Assuntos
Lesões Encefálicas Traumáticas , Pressão Intracraniana , Encéfalo , Lesões Encefálicas Traumáticas/terapia , Humanos , Oxigênio , Qualidade de Vida
10.
N Engl J Med ; 385(21): 1951-1960, 2021 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-34407339

RESUMO

BACKGROUND: Early administration of convalescent plasma obtained from blood donors who have recovered from coronavirus disease 2019 (Covid-19) may prevent disease progression in acutely ill, high-risk patients with Covid-19. METHODS: In this randomized, multicenter, single-blind trial, we assigned patients who were being treated in an emergency department for Covid-19 symptoms to receive either one unit of convalescent plasma with a high titer of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or placebo. All the patients were either 50 years of age or older or had one or more risk factors for disease progression. In addition, all the patients presented to the emergency department within 7 days after symptom onset and were in stable condition for outpatient management. The primary outcome was disease progression within 15 days after randomization, which was a composite of hospital admission for any reason, seeking emergency or urgent care, or death without hospitalization. Secondary outcomes included the worst severity of illness on an 8-category ordinal scale, hospital-free days within 30 days after randomization, and death from any cause. RESULTS: A total of 511 patients were enrolled in the trial (257 in the convalescent-plasma group and 254 in the placebo group). The median age of the patients was 54 years; the median symptom duration was 4 days. In the donor plasma samples, the median titer of SARS-CoV-2 neutralizing antibodies was 1:641. Disease progression occurred in 77 patients (30.0%) in the convalescent-plasma group and in 81 patients (31.9%) in the placebo group (risk difference, 1.9 percentage points; 95% credible interval, -6.0 to 9.8; posterior probability of superiority of convalescent plasma, 0.68). Five patients in the plasma group and 1 patient in the placebo group died. Outcomes regarding worst illness severity and hospital-free days were similar in the two groups. CONCLUSIONS: The administration of Covid-19 convalescent plasma to high-risk outpatients within 1 week after the onset of symptoms of Covid-19 did not prevent disease progression. (SIREN-C3PO ClinicalTrials.gov number, NCT04355767.).


Assuntos
COVID-19/terapia , Progressão da Doença , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , COVID-19/complicações , COVID-19/imunologia , COVID-19/mortalidade , Serviço Hospitalar de Emergência , Feminino , Hospitalização , Humanos , Imunização Passiva , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Método Simples-Cego , Falha de Tratamento , Adulto Jovem , Soroterapia para COVID-19
11.
Res Pract Thromb Haemost ; 5(5): e12563, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34278192

RESUMO

OBJECTIVE: Alterations in coagulation could mediate functional outcome in patients with hyperglycemia after acute ischemic stroke (AIS). We prospectively studied the effects of intensive versus standard glucose control on coagulation markers and their relationships to functional outcomes in patients with AIS. APPROACH: The Insights on Selected Procoagulation Markers and Outcomes in Stroke Trial measured the coagulation biomarkers whole blood tissue factor procoagulant activity (TFPCA); plasma factors VII (FVII), VIIa (FVIIa), and VIII (FVIII); thrombin-antithrombin (TAT) complex; D-dimer; tissue factor pathway inhibitor, and plasminogen activator inhibitor-1 (PAI-1) antigen in patients enrolled in the Stroke Hyperglycemia Insulin Network Effort trial of intensive versus standard glucose control on functional outcome at 3 months after AIS. Changes in biomarkers over time (from baseline ≈12 hours after stroke onset) to 48 hours, and changes in biomarkers between treatment groups, functional outcomes, and their interaction were analyzed by two-way analysis of variance. RESULTS: A total of 125 patients were included (57 in the intensive treatment group and 68 in the standard treatment group). The overall mean age was 66 years; 42% were women. Changes from baseline to 48 hours in coagulation markers were significantly different between treatment groups for TFPCA (P = 0.02) and PAI-1 (P = .04) and FVIIa (P = .04). Increases in FVIIa and decreases in FVIII were associated with favorable functional outcomes (P = .04 and .04, respectively). In the intensive treatment group, reductions in TFPCA and FVIII and increases in FVIIa were greater in patients with favorable than unfavorable outcomes (P = .02, 0.002, 0.03, respectively). In the standard treatment group, changes in FVII were different by functional outcome (P = .006). CONCLUSIONS: Intensive glucose control induced greater alterations in coagulation biomarkers than standard treatment, and these were associated with a favorable functional outcome at 3 months after AIS.

12.
J Neurotrauma ; 38(14): 1953-1960, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33319651

RESUMO

Early treatment of moderate/severe traumatic brain injury (TBI) with progesterone does not improve clinical outcomes. This is in contrast with findings from pre-clinical studies of progesterone in TBI. To understand the reasons for the negative clinical trial, we investigated whether progesterone treatment has the desired biological effect of decreasing brain cell death. We quantified brain cell death using serum levels of biomarkers of glial and neuronal cell death (glial fibrillary acidic protein [GFAP], ubiquitin carboxy-terminal hydrolase-L1 [UCH-L1], S100 calcium-binding protein B [S100B], and Alpha II Spectrin Breakdown Product 150 [SBDP]) in the Biomarkers of Injury and Outcome-Progesterone for Traumatic Brain Injury, Experimental Clinical Treatment (BIO-ProTECT) study. Serum levels of GFAP, UCHL1, S100B, and SBDP were measured at baseline (≤4 h post-injury and before administration of study drug) and at 24 and 48 h post-injury. Serum progesterone levels were measured at 24 and 48 h post-injury. The primary outcome of ProTECT was based on the Glasgow Outcome Scale-Extended assessed at 6 months post-randomization. We found that at baseline, there were no differences in biomarker levels between subjects randomized to progesterone treatment and those randomized to placebo (p > 0.10). Similarly, at 24 and 48 h post-injury, there were no differences in biomarker levels in the progesterone versus placebo groups (p > 0.15). There was no statistically significant correlation between serum progesterone concentrations and biomarker values obtained at 24 and 48 h. When examined as a continuous variable, baseline biomarker levels did not modify the association between progesterone treatment and neurological outcome (p of interaction term >0.39 for all biomarkers). We conclude that progesterone treatment does not decrease levels of biomarkers of glial and neuronal cell death during the first 48 h post-injury.


Assuntos
Lesões Encefálicas Traumáticas/sangue , Lesões Encefálicas Traumáticas/tratamento farmacológico , Proteína Glial Fibrilar Ácida/sangue , Progesterona/uso terapêutico , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Espectrina/metabolismo , Ubiquitina Tiolesterase/sangue , Adulto , Biomarcadores/sangue , Lesões Encefálicas Traumáticas/patologia , Morte Celular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neuroglia/patologia , Neurônios/patologia , Progestinas/uso terapêutico , Adulto Jovem
13.
JAMA Neurol ; 77(11): 1355-1365, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32897310

RESUMO

Importance: The safety and efficacy of intensive systolic blood pressure reduction in patients with intracerebral hemorrhage who present with systolic blood pressure greater than 220 mm Hg appears to be unknown. Objective: To evaluate the differential outcomes of intensive (goal, 110-139 mm Hg) vs standard (goal, 140-179 mm Hg) systolic blood pressure reduction in patients with intracerebral hemorrhage and initial systolic blood pressure of 220 mm Hg or more vs less than 220 mm Hg. Design, Setting, and Participants: This post hoc analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage-II trial was performed in November 2019 on data from the multicenter randomized clinical trial, which was conducted between May 2011 to September 2015. Patients with intracerebral hemorrhage and initial systolic blood pressure of 180 mm Hg or more, randomized within 4.5 hours after symptom onset, were included. Interventions: Intravenous nicardipine infusion titrated to goals. Main Outcomes and Measures: Neurological deterioration and hematoma expansion within 24 hours and death or severe disability at 90 days, plus kidney adverse events and serious adverse events until day 7 or hospital discharge. Results: A total of 8532 patients were screened, and 999 individuals (mean [SD] age, 62.0 [13.1] years; 620 men [62.0%]) underwent randomization and had an initial SBP value. Among 228 participants with initial systolic blood pressures of 220 mm Hg or more, the rate of neurological deterioration within 24 hours was higher in those who underwent intensive (vs standard) systolic blood pressure reduction (15.5% vs 6.8%; relative risk, 2.28 [95% CI, 1.03-5.07]; P = .04). The rate of death and severe disability (39.0% vs 38.4%; relative risk, 1.02 [95% CI, 0.73-1.78]; P = .92) was not significantly different between the 2 groups. There was a significantly higher rate of kidney adverse events in participants randomized to intensive systolic blood pressure reduction (13.6% vs 4.2%; relative risk, 3.22 [95% CI, 1.21-8.56]; P = .01), but no difference was observed in the rate of kidney serious adverse events. Conclusions and Relevance: The higher rate of neurological deterioration within 24 hours associated with intensive treatment in patients with intracerebral hemorrhage and initial systolic blood pressure of 220 mm Hg or more, without any benefit in reducing hematoma expansion at 24 hours or death or severe disability at 90 days, warrants caution against generalization of recommendations for intensive systolic blood pressure reduction.


Assuntos
Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hemorragia Cerebral/tratamento farmacológico , Hipertensão/tratamento farmacológico , Estudos Multicêntricos como Assunto/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Idoso , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/fisiologia , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/mortalidade , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/mortalidade , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/etiologia , Doenças do Sistema Nervoso/mortalidade , Resultado do Tratamento
14.
J Neurotrauma ; 37(24): 2674-2679, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-32664792

RESUMO

The Glasgow Outcome Scale-Extended (GOS-E), an ordinal scale measuring global outcome, is used commonly as the primary outcome measure in clinical trials of traumatic brain injury. Analysis is often based on a dichotomization and thus has inherent statistical limitations, including loss of information related to the collapse of adjacent categories. A fixed dichotomization defines favorable outcome consistently for all subjects, whereas a sliding dichotomy tailors the definition of favorable outcome according to baseline prognosis/severity. Literature indicates that the sliding dichotomy is more statistically efficient than the fixed dichotomy; however, the sliding dichotomy still collapses categories and therefore discards information. We propose an alternative, a sliding scoring system for the GOS-E, intended to address the limitations of the sliding dichotomy. The score is assigned based on the number of levels between the achieved score and the favorable cut-point. The proposed scoring system reflects the magnitude of change, where change is defined according to each subject's baseline prognosis. Because the score is approximately continuous, statistical methods can rely on the normal distribution, both for analysis and study design. Two examples show the corresponding potential for improved power. A sliding score approach allows for quantification of the magnitude of change while still accounting for prognosis. Scientific advantages include increased power and an intuitive interpretation.


Assuntos
Lesões Encefálicas Traumáticas , Escala de Resultado de Glasgow , Avaliação de Resultados em Cuidados de Saúde , Ensaios Clínicos como Assunto , Humanos
15.
Stroke ; 51(7): 2058-2065, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32568642

RESUMO

BACKGROUND AND PURPOSE: Clopidogrel is an antiplatelet drug that is metabolized to its active form by the CYP2C19 enzyme. The CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events) found a significant interaction between loss-of-function allele status for the CYP2C19 gene and the effect of dual antiplatelet therapy with aspirin and clopidogrel on the rate of early recurrent stroke following acute transient ischemic attack/minor stroke. The POINT (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke Trial), similar in design to CHANCE but performed largely in North America and Europe, demonstrated a reduction in early recurrent stroke with dual antiplatelet therapy compared with aspirin alone. This substudy was done to evaluate a potential interaction between loss-of-function CYP2C19 alleles and outcome by treatment group in POINT. METHODS: Of the 269 sites in 10 countries that enrolled patients in POINT, 134 sites participated in this substudy. DNA samples were genotyped for CYP2C19 *2, *3, and *17 alleles and classified as being carriers or noncarriers of loss-of-function alleles. Major ischemia consisted of ischemic stroke, myocardial infarction, or ischemic vascular death. RESULTS: Nine hundred thirty-two patients provided analyzable DNA. The rates of major ischemia were 6.7% for the aspirin group versus 2.3% for the dual antiplatelet therapy group (hazard ratio, 0.33 [95% CI, 0.09-1.21]; P=0.09) among carriers of loss-of-function allele. The rates of major ischemia were 5.6% for the aspirin group versus 3.7% for the dual antiplatelet therapy group (hazard ratio, 0.65 [95% CI, 0.32-1.34]; P=0.25) among noncarriers. There was no significant interaction by genotype for major ischemia (P=0.36) or stroke (P=0.33). CONCLUSIONS: This substudy of POINT found no significant interaction with CYP2C19 loss-of-function carrier status and outcome by treatment group. Failure to confirm the findings from the CHANCE trial may be because the loss-of-function alleles tested are not clinically important in this context or because the 2 trials had differences in racial/ethnic composition. Additionally, differences between the 2 trials might be due to chance as our statistical power was limited to 50%. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00991029.


Assuntos
Clopidogrel/uso terapêutico , Citocromo P-450 CYP2C19/efeitos dos fármacos , Ataque Isquêmico Transitório/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Idoso , Alelos , Infarto Cerebral/tratamento farmacológico , Citocromo P-450 CYP2C19/genética , Feminino , Genótipo , Humanos , Ataque Isquêmico Transitório/genética , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/uso terapêutico , Resultado do Tratamento
16.
Lancet ; 395(10231): 1217-1224, 2020 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-32203691

RESUMO

BACKGROUND: Benzodiazepine-refractory, or established, status epilepticus is thought to be of similar pathophysiology in children and adults, but differences in underlying aetiology and pharmacodynamics might differentially affect response to therapy. In the Established Status Epilepticus Treatment Trial (ESETT) we compared the efficacy and safety of levetiracetam, fosphenytoin, and valproate in established status epilepticus, and here we describe our results after extending enrolment in children to compare outcomes in three age groups. METHODS: In this multicentre, double-blind, response-adaptive, randomised controlled trial, we recruited patients from 58 hospital emergency departments across the USA. Patients were eligible for inclusion if they were aged 2 years or older, had been treated for a generalised convulsive seizure of longer than 5 min duration with adequate doses of benzodiazepines, and continued to have persistent or recurrent convulsions in the emergency department for at least 5 min and no more than 30 min after the last dose of benzodiazepine. Patients were randomly assigned in a response-adaptive manner, using Bayesian methods and stratified by age group (<18 years, 18-65 years, and >65 years), to levetiracetam, fosphenytoin, or valproate. All patients, investigators, study staff, and pharmacists were masked to treatment allocation. The primary outcome was absence of clinically apparent seizures with improved consciousness and without additional antiseizure medication at 1 h from start of drug infusion. The primary safety outcome was life-threatening hypotension or cardiac arrhythmia. The efficacy and safety outcomes were analysed by intention to treat. This study is registered in ClinicalTrials.gov, NCT01960075. FINDINGS: Between Nov 3, 2015, and Dec 29, 2018, we enrolled 478 patients and 462 unique patients were included: 225 children (aged <18 years), 186 adults (18-65 years), and 51 older adults (>65 years). 175 (38%) patients were randomly assigned to levetiracetam, 142 (31%) to fosphenyltoin, and 145 (31%) were to valproate. Baseline characteristics were balanced across treatments within age groups. The primary efficacy outcome was met in those treated with levetiracetam for 52% (95% credible interval 41-62) of children, 44% (33-55) of adults, and 37% (19-59) of older adults; with fosphenytoin in 49% (38-61) of children, 46% (34-59) of adults, and 35% (17-59) of older adults; and with valproate in 52% (41-63) of children, 46% (34-58) of adults, and 47% (25-70) of older adults. No differences were detected in efficacy or primary safety outcome by drug within each age group. With the exception of endotracheal intubation in children, secondary safety outcomes did not significantly differ by drug within each age group. INTERPRETATION: Children, adults, and older adults with established status epilepticus respond similarly to levetiracetam, fosphenytoin, and valproate, with treatment success in approximately half of patients. Any of the three drugs can be considered as a potential first-choice, second-line drug for benzodiazepine-refractory status epilepticus. FUNDING: National Institute of Neurological Disorders and Stroke, National Institutes of Health.


Assuntos
Anticonvulsivantes/administração & dosagem , Levetiracetam/administração & dosagem , Fenitoína/análogos & derivados , Estado Epiléptico/tratamento farmacológico , Ácido Valproico/administração & dosagem , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anticonvulsivantes/efeitos adversos , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Lactente , Levetiracetam/efeitos adversos , Masculino , Pessoa de Meia-Idade , Fenitoína/administração & dosagem , Fenitoína/efeitos adversos , Ácido Valproico/efeitos adversos , Adulto Jovem
17.
N Engl J Med ; 381(22): 2103-2113, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31774955

RESUMO

BACKGROUND: The choice of drugs for patients with status epilepticus that is refractory to treatment with benzodiazepines has not been thoroughly studied. METHODS: In a randomized, blinded, adaptive trial, we compared the efficacy and safety of three intravenous anticonvulsive agents - levetiracetam, fosphenytoin, and valproate - in children and adults with convulsive status epilepticus that was unresponsive to treatment with benzodiazepines. The primary outcome was absence of clinically evident seizures and improvement in the level of consciousness by 60 minutes after the start of drug infusion, without additional anticonvulsant medication. The posterior probabilities that each drug was the most or least effective were calculated. Safety outcomes included life-threatening hypotension or cardiac arrhythmia, endotracheal intubation, seizure recurrence, and death. RESULTS: A total of 384 patients were enrolled and randomly assigned to receive levetiracetam (145 patients), fosphenytoin (118), or valproate (121). Reenrollment of patients with a second episode of status epilepticus accounted for 16 additional instances of randomization. In accordance with a prespecified stopping rule for futility of finding one drug to be superior or inferior, a planned interim analysis led to the trial being stopped. Of the enrolled patients, 10% were determined to have had psychogenic seizures. The primary outcome of cessation of status epilepticus and improvement in the level of consciousness at 60 minutes occurred in 68 patients assigned to levetiracetam (47%; 95% credible interval, 39 to 55), 53 patients assigned to fosphenytoin (45%; 95% credible interval, 36 to 54), and 56 patients assigned to valproate (46%; 95% credible interval, 38 to 55). The posterior probability that each drug was the most effective was 0.41, 0.24, and 0.35, respectively. Numerically more episodes of hypotension and intubation occurred in the fosphenytoin group and more deaths occurred in the levetiracetam group than in the other groups, but these differences were not significant. CONCLUSIONS: In the context of benzodiazepine-refractory convulsive status epilepticus, the anticonvulsant drugs levetiracetam, fosphenytoin, and valproate each led to seizure cessation and improved alertness by 60 minutes in approximately half the patients, and the three drugs were associated with similar incidences of adverse events. (Funded by the National Institute of Neurological Disorders and Stroke; ESETT ClinicalTrials.gov number, NCT01960075.).


Assuntos
Anticonvulsivantes/uso terapêutico , Levetiracetam/uso terapêutico , Fenitoína/análogos & derivados , Estado Epiléptico/tratamento farmacológico , Ácido Valproico/uso terapêutico , Adolescente , Adulto , Anticonvulsivantes/efeitos adversos , Benzodiazepinas/uso terapêutico , Criança , Pré-Escolar , Método Duplo-Cego , Resistência a Medicamentos , Feminino , Humanos , Hipotensão/induzido quimicamente , Infusões Intravenosas , Injeções Intramusculares , Levetiracetam/efeitos adversos , Masculino , Pessoa de Meia-Idade , Fenitoína/efeitos adversos , Fenitoína/uso terapêutico , Ácido Valproico/efeitos adversos , Adulto Jovem
18.
JAMA Netw Open ; 2(9): e1910769, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31490536

RESUMO

Importance: Debate continues about the value of event adjudication in clinical trials and whether independent centralized assessments improve reliability and validity of study results in masked randomized trials compared with local, investigator-assessed end points. Objective: To assess the results of the adjudicated end point process in the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial by comparing end points assessed by local site investigators with centrally adjudicated end points. Design, Setting, and Participants: This is an ad hoc secondary analysis of a randomized, double-blind clinical trial comparing safety and effectiveness of clopidogrel bisulphate plus aspirin vs placebo plus aspirin. Patients received either 600 mg of clopidogrel bisulphate on day 1, then 75 mg per day through day 90 plus 50 to 325 mg of aspirin per day, or the same range of dosages of placebo plus aspirin. Investigators reported all potential end points; independent masked adjudicators were randomly assigned to review using definitions specified in the study protocol. This was a multicenter study; 269 international sites in 10 countries enrolled from May 28, 2010, to December 19, 2017. The study enrolled 4881 patients 18 years or older with transient ischemic attack or minor acute ischemic stroke within 12 hours of symptom onset and followed for 90 days from randomization; last follow-up was completed in March 2018. Main Outcomes and Measures: Independent adjudicators external to the study and masked to study treatment assignment adjudicated 467 primary and secondary effectiveness outcomes and major and minor bleeding events, including the primary composite end point, which was the risk of a composite of major ischemic events at 90 days, defined as ischemic stroke, myocardial infarction, or death from an ischemic vascular event. The primary safety end point was major hemorrhage. All components of the primary and safety outcomes were adjudicated. Results: In this secondary analysis of an international randomized clinical trial, a total of 269 sites worldwide randomized 4881 patients (median age, 65.0 years; interquartile range, 55-74 years); 55.0% were male. The primary results have been published previously. The hazard ratios for clopidogrel plus aspirin vs placebo plus aspirin for the primary composite end point were 0.75 (95% CI, 0.59-0.95) for adjudicator-assessed events and 0.76 (95% CI, 0.60-0.95) for investigator-assessed events. Agreement between adjudicator and investigator assessments was 90.7%. The hazard ratios for clopidogrel plus aspirin vs placebo plus aspirin for the primary safety end point were 2.32 (95% CI, 1.10-4.87) for adjudicator-assessed events and 2.58 (95% CI, 1.19-5.58) for investigator-assessed events, with an agreement rate of 77.5%. Conclusions and Relevance: Independent end point adjudication did not substantially alter estimates of the primary treatment effectiveness in the POINT trial. Trial Registration: ClinicalTrials.gov identifier: NCT00991029.


Assuntos
Aspirina/uso terapêutico , Clopidogrel/uso terapêutico , Ataque Isquêmico Transitório/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Idoso , Aspirina/farmacologia , Clopidogrel/farmacologia , Método Duplo-Cego , Quimioterapia Combinada , Determinação de Ponto Final , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/farmacologia , Projetos de Pesquisa , Prevenção Secundária , Resultado do Tratamento
19.
JAMA ; 322(4): 326-335, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31334795

RESUMO

Importance: Hyperglycemia during acute ischemic stroke is common and is associated with worse outcomes. The efficacy of intensive treatment of hyperglycemia in this setting remains unknown. Objectives: To determine the efficacy of intensive treatment of hyperglycemia during acute ischemic stroke. Design, Setting, and Participants: The Stroke Hyperglycemia Insulin Network Effort (SHINE) randomized clinical trial included adult patients with hyperglycemia (glucose concentration of >110 mg/dL if had diabetes or ≥150 mg/dL if did not have diabetes) and acute ischemic stroke who were enrolled within 12 hours from stroke onset at 63 US sites between April 2012 and August 2018; follow-up ended in November 2018. The trial included 1151 patients who met eligibility criteria. Interventions: Patients were randomized to receive continuous intravenous insulin using a computerized decision support tool (target blood glucose concentration of 80-130 mg/dL [4.4-7.2 mmol/L]; intensive treatment group: n = 581) or insulin on a sliding scale that was administered subcutaneously (target blood glucose concentration of 80-179 mg/dL [4.4-9.9 mmol/L]; standard treatment group: n = 570) for up to 72 hours. Main Outcomes and Measures: The primary efficacy outcome was the proportion of patients with a favorable outcome based on the 90-day modified Rankin Scale score (a global stroke disability scale ranging from 0 [no symptoms or completely recovered] to 6 [death]) that was adjusted for baseline stroke severity. Results: Among 1151 patients who were randomized (mean age, 66 years [SD, 13.1 years]; 529 [46%] women, 920 [80%] with diabetes), 1118 (97%) completed the trial. Enrollment was stopped for futility based on prespecified interim analysis criteria. During treatment, the mean blood glucose level was 118 mg/dL (6.6 mmol/L) in the intensive treatment group and 179 mg/dL (9.9 mmol/L) in the standard treatment group. A favorable outcome occurred in 119 of 581 patients (20.5%) in the intensive treatment group and in 123 of 570 patients (21.6%) in the standard treatment group (adjusted relative risk, 0.97 [95% CI, 0.87 to 1.08], P = .55; unadjusted risk difference, -0.83% [95% CI, -5.72% to 4.06%]). Treatment was stopped early for hypoglycemia or other adverse events in 65 of 581 patients (11.2%) in the intensive treatment group and in 18 of 570 patients (3.2%) in the standard treatment group. Severe hypoglycemia occurred only among patients in the intensive treatment group (15/581 [2.6%]; risk difference, 2.58% [95% CI, 1.29% to 3.87%]). Conclusions and Relevance: Among patients with acute ischemic stroke and hyperglycemia, treatment with intensive vs standard glucose control for up to 72 hours did not result in a significant difference in favorable functional outcome at 90 days. These findings do not support using intensive glucose control in this setting. Trial Registration: ClinicalTrials.gov Identifier: NCT01369069.


Assuntos
Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Acidente Vascular Cerebral/complicações , Idoso , Isquemia Encefálica/complicações , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Hiperglicemia/complicações , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Infusões Intravenosas , Injeções Subcutâneas , Insulina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento
20.
Circulation ; 140(8): 658-664, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31238700

RESUMO

BACKGROUND: In patients with acute minor ischemic stroke or high-risk transient ischemic attack enrolled in the POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke [POINT] Trial), the combination of clopidogrel and aspirin for 90 days reduced major ischemic events but increased major hemorrhage in comparison to aspirin alone. METHODS: In a secondary analysis of POINT (N=4881), we assessed the time course for benefit and risk from the combination of clopidogrel and aspirin. The primary efficacy outcome was a composite of ischemic stroke, myocardial infarction, or ischemic vascular death. The primary safety outcome was major hemorrhage. Risks and benefits were estimated for delayed times of treatment initiation using left-truncated models. RESULTS: Through 90 days, the rate of major ischemic events was initially high then decreased markedly, whereas the rate of major hemorrhage remained low but relatively constant throughout. With the use of a model-based approach, the optimal change point for major ischemic events was 21 days (0-21 days hazard ratio 0.65 for clopidogrel-aspirin versus aspirin; 95% CI, 0.50-0.85; P=0.0015, in comparison to 22-90 days hazard ratio, 1.38; 95% CI, 0.81-2.35; P=0.24). Models showed benefits of clopidogrel-aspirin for treatment delayed as long as 3 days after symptom onset. CONCLUSIONS: The benefit of clopidogrel-aspirin occurs predominantly within the first 21 days, and outweighs the low, but ongoing risk of major hemorrhage. When considered with the results of the CHANCE trial (Clopidogrel in High-Risk Patients With Non-disabling Cerebrovascular Events), a similar trial treating with clopidogrel-aspirin for 21 days and showing no increase in major hemorrhage, these results suggest that limiting clopidogrel-aspirin use to 21 days may maximize benefit and reduce risk after high-risk transient ischemic attack or minor ischemic stroke. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00991029.


Assuntos
Aspirina/uso terapêutico , Clopidogrel/uso terapêutico , Quimioterapia Combinada/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Hemorragia/prevenção & controle , Isquemia/tratamento farmacológico , Ataque Isquêmico Transitório/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Fatores de Tempo , Doença Aguda , Aspirina/efeitos adversos , Protocolos Clínicos , Clopidogrel/efeitos adversos , Hemorragia/etiologia , Humanos , Inibidores da Agregação Plaquetária/efeitos adversos , Modelos de Riscos Proporcionais , Risco , Medição de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...