Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Mais filtros

País/Região como assunto
Intervalo de ano de publicação
1.
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
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.

3.
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
4.
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
5.
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
6.
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
7.
N Engl J Med ; 379(3): 215-225, 2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-29766750

RESUMO

BACKGROUND: Combination antiplatelet therapy with clopidogrel and aspirin may reduce the rate of recurrent stroke during the first 3 months after a minor ischemic stroke or transient ischemic attack (TIA). A trial of combination antiplatelet therapy in a Chinese population has shown a reduction in the risk of recurrent stroke. We tested this combination in an international population. METHODS: In a randomized trial, we assigned patients with minor ischemic stroke or high-risk TIA to receive either clopidogrel at a loading dose of 600 mg on day 1, followed by 75 mg per day, plus aspirin (at a dose of 50 to 325 mg per day) or the same range of doses of aspirin alone. The dose of aspirin in each group was selected by the site investigator. The primary efficacy outcome in a time-to-event analysis was the risk of a composite of major ischemic events, which was defined as ischemic stroke, myocardial infarction, or death from an ischemic vascular event, at 90 days. RESULTS: A total of 4881 patients were enrolled at 269 international sites. The trial was halted after 84% of the anticipated number of patients had been enrolled because the data and safety monitoring board had determined that the combination of clopidogrel and aspirin was associated with both a lower risk of major ischemic events and a higher risk of major hemorrhage than aspirin alone at 90 days. Major ischemic events occurred in 121 of 2432 patients (5.0%) receiving clopidogrel plus aspirin and in 160 of 2449 patients (6.5%) receiving aspirin plus placebo (hazard ratio, 0.75; 95% confidence interval [CI], 0.59 to 0.95; P=0.02), with most events occurring during the first week after the initial event. Major hemorrhage occurred in 23 patients (0.9%) receiving clopidogrel plus aspirin and in 10 patients (0.4%) receiving aspirin plus placebo (hazard ratio, 2.32; 95% CI, 1.10 to 4.87; P=0.02). CONCLUSIONS: In patients with minor ischemic stroke or high-risk TIA, those who received a combination of clopidogrel and aspirin had a lower risk of major ischemic events but a higher risk of major hemorrhage at 90 days than those who received aspirin alone. (Funded by the National Institute of Neurological Disorders and Stroke; POINT ClinicalTrials.gov number, NCT00991029 .).


Assuntos
Aspirina/administração & dosagem , Ataque Isquêmico Transitório/tratamento farmacológico , Inibidores da Agregação Plaquetária/administração & dosagem , Prevenção Secundária , Acidente Vascular Cerebral/tratamento farmacológico , Ticlopidina/análogos & derivados , Idoso , Aspirina/efeitos adversos , Isquemia Encefálica/prevenção & controle , Clopidogrel , Método Duplo-Cego , Quimioterapia Combinada/efeitos adversos , Feminino , Hemorragia/induzido quimicamente , Humanos , Isquemia/mortalidade , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/prevenção & controle , Inibidores da Agregação Plaquetária/efeitos adversos , Risco , Acidente Vascular Cerebral/prevenção & controle , Ticlopidina/administração & dosagem , Ticlopidina/efeitos adversos
8.
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
9.
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
10.
Stroke ; 50(7): 1669-1675, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31138085

RESUMO

Background and Purpose- Effective stroke prevention depends on accurate stroke risk prediction. We determined the discriminative ability of NfL (neurofilament light chain) levels for distinguishing between adults with diabetes mellitus who develop incident stroke and those who remain stroke free during a 7-year follow-up period. Methods- We performed a case-control study of participants selected from the previously completed ACCORD trial (Action to Control Cardiovascular Risk in Diabetes). Cases were all ACCORD subjects who were stroke free at enrollment and developed incident stroke during follow-up (n=113). Control subjects (n=250) were randomly selected ACCORD subjects who had no stroke events either before or after randomization. NfL was measured in baseline samples using Single Molecule Array technology (Quanterix). Results- Baseline NfL levels were higher in stroke subjects, compared to controls, after adjusting for age, race, blood pressure, weight, and the Framingham Stroke Risk Score. Relative to the subjects in the lowest quintile of NfL levels, the hazard ratios of incident stroke for subjects in the second to fifth quintiles were 3.91 (1.45-10.53), 4.05 (1.52-10.79), 5.63 (2.16-14.66), and 9.75 (3.84-27.71), respectively, after adjusting for race and Framingham Stroke Risk Score. Incorporating NfL levels into a predictive score that already included race and Framingham Stroke Risk Score increased the score's C statistic from 0.71 (95% CI, 0.66-0.77) to 0.78 (95% CI, 0.73-0.83), P<0.001. Older age, nonwhite race, higher systolic blood pressure, glomerular filtration rate <60, and higher hemoglobin A1C were independent predictors of serum NfL in this cohort but diastolic blood pressure, durations of hypertension or diabetes mellitus, and lipid levels were not. In total, cardiovascular disease risk factors explained 19.2% of the variability in baseline NfL levels. Conclusions- Serum NfL levels predict incident stroke and add considerably to the discriminatory power of the Framingham Stroke Risk Score in a cohort of middle-aged and older adults with diabetes mellitus.


Assuntos
Complicações do Diabetes/sangue , Complicações do Diabetes/epidemiologia , Proteínas de Neurofilamentos/sangue , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/epidemiologia , Adulto , Fatores Etários , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Etnicidade , Feminino , Taxa de Filtração Glomerular , Hemoglobinas Glicadas/análise , Humanos , Hipertensão/epidemiologia , Incidência , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores Socioeconômicos
11.
Stroke ; 50(7): e187-e210, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31104615

RESUMO

In 2005, the American Stroke Association published recommendations for the establishment of stroke systems of care and in 2013 expanded on them with a statement on interactions within stroke systems of care. The aim of this policy statement is to provide a comprehensive review of the scientific evidence evaluating stroke systems of care to date and to update the American Stroke Association recommendations on the basis of improvements in stroke systems of care. Over the past decade, stroke systems of care have seen vast improvements in endovascular therapy, neurocritical care, and stroke center certification, in addition to the advent of innovations, such as telestroke and mobile stroke units, in the context of significant changes in the organization of healthcare policy in the United States. This statement provides an update to prior publications to help guide policymakers and public healthcare agencies in continually updating their stroke systems of care in light of these changes. This statement and its recommendations span primordial and primary prevention, acute stroke recognition and activation of emergency medical services, triage to appropriate facilities, designation of and treatment at stroke centers, secondary prevention at hospital discharge, and rehabilitation and recovery.


Assuntos
Certificação , Serviços Médicos de Emergência , Política Organizacional , Acidente Vascular Cerebral , Serviços Médicos de Emergência/métodos , Serviços Médicos de Emergência/organização & administração , Serviços Médicos de Emergência/normas , Humanos , Guias de Prática Clínica como Assunto , Sociedades Médicas , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Estados Unidos
12.
N Engl J Med ; 375(11): 1033-43, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27276234

RESUMO

BACKGROUND: Limited data are available to guide the choice of a target for the systolic blood-pressure level when treating acute hypertensive response in patients with intracerebral hemorrhage. METHODS: We randomly assigned eligible participants with intracerebral hemorrhage (volume, <60 cm(3)) and a Glasgow Coma Scale (GCS) score of 5 or more (on a scale from 3 to 15, with lower scores indicating worse condition) to a systolic blood-pressure target of 110 to 139 mm Hg (intensive treatment) or a target of 140 to 179 mm Hg (standard treatment) in order to test the superiority of intensive reduction of systolic blood pressure to standard reduction; intravenous nicardipine to lower blood pressure was administered within 4.5 hours after symptom onset. The primary outcome was death or disability (modified Rankin scale score of 4 to 6, on a scale ranging from 0 [no symptoms] to 6 [death]) at 3 months after randomization, as ascertained by an investigator who was unaware of the treatment assignments. RESULTS: Among 1000 participants with a mean (±SD) systolic blood pressure of 200.6±27.0 mm Hg at baseline, 500 were assigned to intensive treatment and 500 to standard treatment. The mean age of the patients was 61.9 years, and 56.2% were Asian. Enrollment was stopped because of futility after a prespecified interim analysis. The primary outcome of death or disability was observed in 38.7% of the participants (186 of 481) in the intensive-treatment group and in 37.7% (181 of 480) in the standard-treatment group (relative risk, 1.04; 95% confidence interval, 0.85 to 1.27; analysis was adjusted for age, initial GCS score, and presence or absence of intraventricular hemorrhage). Serious adverse events occurring within 72 hours after randomization that were considered by the site investigator to be related to treatment were reported in 1.6% of the patients in the intensive-treatment group and in 1.2% of those in the standard-treatment group. The rate of renal adverse events within 7 days after randomization was significantly higher in the intensive-treatment group than in the standard-treatment group (9.0% vs. 4.0%, P=0.002). CONCLUSIONS: The treatment of participants with intracerebral hemorrhage to achieve a target systolic blood pressure of 110 to 139 mm Hg did not result in a lower rate of death or disability than standard reduction to a target of 140 to 179 mm Hg. (Funded by the National Institute of Neurological Disorders and Stroke and the National Cerebral and Cardiovascular Center; ATACH-2 ClinicalTrials.gov number, NCT01176565 .).


Assuntos
Anti-Hipertensivos/administração & dosagem , Hemorragia Cerebral/complicações , Hipertensão/tratamento farmacológico , Nicardipino/administração & dosagem , Idoso , Anti-Hipertensivos/efeitos adversos , Hemorragia Cerebral/mortalidade , Hemorragia Cerebral/fisiopatologia , Feminino , Escala de Coma de Glasgow , Humanos , Hipertensão/etiologia , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nicardipino/efeitos adversos , Falha de Tratamento , Resultado do Tratamento
13.
Stat Med ; 38(17): 3123-3138, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31070807

RESUMO

A primary goal of a phase II dose-ranging trial is to identify a correct dose before moving forward to a phase III confirmatory trial. A correct dose is one that is actually better than control. A popular model in phase II is an independent model that puts no structure on the dose-response relationship. Unfortunately, the independent model does not efficiently use information from related doses. One very successful alternate model improves power using a pre-specified dose-response structure. Past research indicates that EMAX models are broadly successful and therefore attractive for designing dose-response trials. However, there may be instances of slight risk of nonmonotone trends that need to be addressed when planning a clinical trial design. We propose to add hierarchical parameters to the EMAX model. The added layer allows information about the treatment effect in one dose to be "borrowed" when estimating the treatment effect in another dose. This is referred to as the hierarchical EMAX model. Our paper compares three different models (independent, EMAX, and hierarchical EMAX) and two different design strategies. The first design considered is Bayesian with a fixed trial design, and it has a fixed schedule for randomization. The second design is Bayesian but adaptive, and it uses response adaptive randomization. In this article, a randomized trial of patients with severe traumatic brain injury is provided as a motivating example.


Assuntos
Ensaios Clínicos Fase II como Assunto , Relação Dose-Resposta a Droga , Oxigenoterapia Hiperbárica , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Teorema de Bayes , Humanos , Estudos Multicêntricos como Assunto , Estudos Prospectivos
14.
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
15.
Stroke ; 49(6): 1412-1418, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29789395

RESUMO

BACKGROUND AND PURPOSE: We compared the rates of death or disability, defined by modified Rankin Scale score of 4 to 6, at 3 months in patients with intracerebral hemorrhage according to post-treatment systolic blood pressure (SBP)-attained status. METHODS: We divided 1000 subjects with SBP ≥180 mm Hg who were randomized within 4.5 hours of symptom onset as follows: SBP <140 mm Hg achieved or not achieved within 2 hours; subjects in whom SBP <140 mm Hg was achieved within 2 hours were further divided: SBP <140 mm Hg for 21 to 22 hours (reduced and maintained) or SBP was ≥140 mm Hg for at least 2 hours during the period between 2 and 24 hours (reduced but not maintained). RESULTS: Compared with subjects without reduction of SBP <140 mm Hg within 2 hours, subjects with reduction and maintenance of SBP <140 mm Hg within 2 hours had a similar rate of death or disability (relative risk of 0.98; 95% confidence interval, 0.74-1.29). The rates of neurological deterioration within 24 hours were significantly higher in reduced and maintained group (10.4%; relative risk, 1.98; 95% confidence interval, 1.08-3.62) and in reduced but not maintained group (11.5%; relative risk, 2.08; 95% confidence interval, 1.15-3.75) compared with reference group. The rates of cardiac-related adverse events within 7 days were higher among subjects with reduction and maintenance of SBP <140 mmHg compared to subjects without reduction (11.2% versus 6.4%). CONCLUSIONS: No decline in death or disability but higher rates of neurological deterioration and cardiac-related adverse events were observed among intracerebral hemorrhage subjects with reduction with and without maintenance of intensive SBP goals. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01176565.


Assuntos
Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Nicardipino/uso terapêutico , Idoso , Determinação da Pressão Arterial/métodos , Hemorragia Cerebral/tratamento farmacológico , Ensaios Clínicos como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
16.
N Engl J Med ; 371(26): 2457-66, 2014 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-25493974

RESUMO

BACKGROUND: Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Progesterone has been shown to improve neurologic outcome in multiple experimental models and two early-phase trials involving patients with TBI. METHODS: We conducted a double-blind, multicenter clinical trial in which patients with severe, moderate-to-severe, or moderate acute TBI (Glasgow Coma Scale score of 4 to 12, on a scale from 3 to 15, with lower scores indicating a lower level of consciousness) were randomly assigned to intravenous progesterone or placebo, with the study treatment initiated within 4 hours after injury and administered for a total of 96 hours. Efficacy was defined as an increase of 10 percentage points in the proportion of patients with a favorable outcome, as determined with the use of the stratified dichotomy of the Extended Glasgow Outcome Scale score at 6 months after injury. Secondary outcomes included mortality and the Disability Rating Scale score. RESULTS: A total of 882 of the planned sample of 1140 patients underwent randomization before the trial was stopped for futility with respect to the primary outcome. The study groups were similar with regard to baseline characteristics; the median age of the patients was 35 years, 73.7% were men, 15.2% were black, and the mean Injury Severity Score was 24.4 (on a scale from 0 to 75, with higher scores indicating greater severity). The most frequent mechanism of injury was a motor vehicle accident. There was no significant difference between the progesterone group and the placebo group in the proportion of patients with a favorable outcome (relative benefit of progesterone, 0.95; 95% confidence interval [CI], 0.85 to 1.06; P=0.35). Phlebitis or thrombophlebitis was more frequent in the progesterone group than in the placebo group (relative risk, 3.03; CI, 1.96 to 4.66). There were no significant differences in the other prespecified safety outcomes. CONCLUSIONS: This clinical trial did not show a benefit of progesterone over placebo in the improvement of outcomes in patients with acute TBI. (Funded by the National Institute of Neurological Disorders and Stroke and others; PROTECT III ClinicalTrials.gov number, NCT00822900.).


Assuntos
Lesões Encefálicas/tratamento farmacológico , Progesterona/administração & dosagem , Acidentes de Trânsito , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Esquema de Medicação , Feminino , Escala de Resultado de Glasgow , Humanos , Infusões Intravenosas , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Flebite/induzido quimicamente , Progesterona/efeitos adversos , Falha de Tratamento , Adulto Jovem
17.
Clin Trials ; 14(3): 246-254, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28135827

RESUMO

BACKGROUND: Adaptive clinical trials use accumulating data from enrolled subjects to alter trial conduct in pre-specified ways based on quantitative decision rules. In this research, we sought to characterize the perspectives of key stakeholders during the development process of confirmatory-phase adaptive clinical trials within an emergency clinical trials network and to build a model to guide future development of adaptive clinical trials. METHODS: We used an ethnographic, qualitative approach to evaluate key stakeholders' views about the adaptive clinical trial development process. Stakeholders participated in a series of multidisciplinary meetings during the development of five adaptive clinical trials and completed a Strengths-Weaknesses-Opportunities-Threats questionnaire. In the analysis, we elucidated overarching themes across the stakeholders' responses to develop a conceptual model. RESULTS: Four major overarching themes emerged during the analysis of stakeholders' responses to questioning: the perceived statistical complexity of adaptive clinical trials and the roles of collaboration, communication, and time during the development process. Frequent and open communication and collaboration were viewed by stakeholders as critical during the development process, as were the careful management of time and logistical issues related to the complexity of planning adaptive clinical trials. CONCLUSION: The Adaptive Design Development Model illustrates how statistical complexity, time, communication, and collaboration are moderating factors in the adaptive design development process. The intensity and iterative nature of this process underscores the need for funding mechanisms for the development of novel trial proposals in academic settings.


Assuntos
Ensaios Clínicos Adaptados como Assunto/métodos , Pesquisa Biomédica/métodos , Projetos de Pesquisa , Comunicação , Comportamento Cooperativo , Humanos , Modelos Estatísticos , Pesquisa Qualitativa , Inquéritos e Questionários
18.
Pharm Stat ; 15(5): 396-404, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27306921

RESUMO

The goals of phase II clinical trials are to gain important information about the performance of novel treatments and decide whether to conduct a larger phase III trial. This can be complicated in cases when the phase II trial objective is to identify a novel treatment having several factors. Such multifactor treatment scenarios can be explored using fixed sample size trials. However, the alternative design could be response adaptive randomization with interim analyses and additionally, longitudinal modeling whereby more data could be used in the estimation process. This combined approach allows a quicker and more responsive adaptation to early estimates of later endpoints. Such alternative clinical trial designs are potentially more powerful, faster, and smaller than fixed randomized designs. Such designs are particularly challenging, however, because phase II trials tend to be smaller than subsequent confirmatory phase III trials. The phase II trial may need to explore a large number of treatment variations to ensure that the efficacy of optimal clinical conditions is not overlooked. Adaptive trial designs need to be carefully evaluated to understand how they will perform and to take full advantage of their potential benefits. This manuscript discusses a Bayesian response adaptive randomization design with a longitudinal model that uses a multifactor approach for predicting phase III study success via the phase II data. The approach is based on an actual clinical trial design for the hyperbaric oxygen brain injury treatment trial. Specific details of the thought process and the models informing the trial design are provided. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Lesões Encefálicas/terapia , Ensaios Clínicos Fase II como Assunto/estatística & dados numéricos , Oxigenoterapia Hiperbárica/estatística & dados numéricos , Modelos Estatísticos , Causalidade , Ensaios Clínicos Fase II como Assunto/métodos , Humanos , Estudos Longitudinais , Distribuição Aleatória
19.
N Engl J Med ; 366(7): 591-600, 2012 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-22335736

RESUMO

BACKGROUND: Early termination of prolonged seizures with intravenous administration of benzodiazepines improves outcomes. For faster and more reliable administration, paramedics increasingly use an intramuscular route. METHODS: This double-blind, randomized, noninferiority trial compared the efficacy of intramuscular midazolam with that of intravenous lorazepam for children and adults in status epilepticus treated by paramedics. Subjects whose convulsions had persisted for more than 5 minutes and who were still convulsing after paramedics arrived were given the study medication by either intramuscular autoinjector or intravenous infusion. The primary outcome was absence of seizures at the time of arrival in the emergency department without the need for rescue therapy. Secondary outcomes included endotracheal intubation, recurrent seizures, and timing of treatment relative to the cessation of convulsive seizures. This trial tested the hypothesis that intramuscular midazolam was noninferior to intravenous lorazepam by a margin of 10 percentage points. RESULTS: At the time of arrival in the emergency department, seizures were absent without rescue therapy in 329 of 448 subjects (73.4%) in the intramuscular-midazolam group and in 282 of 445 (63.4%) in the intravenous-lorazepam group (absolute difference, 10 percentage points; 95% confidence interval, 4.0 to 16.1; P<0.001 for both noninferiority and superiority). The two treatment groups were similar with respect to need for endotracheal intubation (14.1% of subjects with intramuscular midazolam and 14.4% with intravenous lorazepam) and recurrence of seizures (11.4% and 10.6%, respectively). Among subjects whose seizures ceased before arrival in the emergency department, the median times to active treatment were 1.2 minutes in the intramuscular-midazolam group and 4.8 minutes in the intravenous-lorazepam group, with corresponding median times from active treatment to cessation of convulsions of 3.3 minutes and 1.6 minutes. Adverse-event rates were similar in the two groups. CONCLUSIONS: For subjects in status epilepticus, intramuscular midazolam is at least as safe and effective as intravenous lorazepam for prehospital seizure cessation. (Funded by the National Institute of Neurological Disorders and Stroke and others; ClinicalTrials.gov number, ClinicalTrials.gov NCT00809146.).


Assuntos
Anticonvulsivantes/administração & dosagem , Serviços Médicos de Emergência , Infusões Intravenosas , Injeções Intramusculares , Lorazepam/administração & dosagem , Midazolam/administração & dosagem , Estado Epiléptico/tratamento farmacológico , Adolescente , Adulto , Anticonvulsivantes/efeitos adversos , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Hipnóticos e Sedativos/administração & dosagem , Lactente , Lorazepam/efeitos adversos , Masculino , Midazolam/efeitos adversos , Pessoa de Meia-Idade , Recidiva , Fatores de Tempo , Resultado do Tratamento
20.
Crit Care ; 19: 186, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25896893

RESUMO

Neuroprotective strategies that limit secondary tissue loss and/or improve functional outcomes have been identified in multiple animal models of ischemic, hemorrhagic, traumatic and nontraumatic cerebral lesions. However, use of these potential interventions in human randomized controlled studies has generally given disappointing results. In this paper, we summarize the current status in terms of neuroprotective strategies, both in the immediate and later stages of acute brain injury in adults. We also review potential new strategies and highlight areas for future research.


Assuntos
Lesões Encefálicas/terapia , Isquemia Encefálica/prevenção & controle , Neuroproteção , Fármacos Neuroprotetores/uso terapêutico , Acidente Vascular Cerebral/terapia , Lesões Encefálicas/patologia , Isquemia Encefálica/patologia , Humanos , Acidente Vascular Cerebral/mortalidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA