Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
1.
Circulation ; 140(5): 379-389, 2019 07 30.
Article in English | MEDLINE | ID: mdl-31177811

ABSTRACT

BACKGROUND: Noninferiority trials are increasingly being performed. However, little is known about their methodological quality. We sought to characterize noninferiority cardiovascular trials published in the highest-impact journals, features that may bias results toward noninferiority, features related to reporting of noninferiority trials, and the time trends. METHODS: We identified cardiovascular noninferiority trials published in JAMA, Lancet, or New England Journal of Medicine from 1990 to 2016. Two independent reviewers extracted the data. Data elements included the noninferiority margin and the success of studies in achieving noninferiority. The proportion of trials showing major or minor features that may have affected the noninferiority inference was determined. Major factors included the lack of presenting the results in both intention-to-treat and per-protocol/as-treated cohorts, α>0.05, the new intervention not being compared with the best alternative, not justifying the noninferiority margin, and exclusion or loss of ≥10% of the cohort. Minor factors included suboptimal blinding, allocation concealment, and others. RESULTS: From 2544 screened studies, we identified 111 noninferiority cardiovascular trials. Noninferiority margins varied widely: risk differences of 0.4% to 25%, hazard ratios of 1.05 to 2.85, odds ratios of 1.1 to 2.0, and relative risks of 1.1 to 1.8. Eighty-six trials claimed noninferiority, of which 20 showed superiority, whereas 23 (21.1%) did not show noninferiority, of which 8 also demonstrated inferiority. Only 7 (6.3%) trials were considered low risk for all the major and minor biasing factors. Among common major factors for bias, 41 (37%) did not confirm the findings in both intention-to-treat and per-protocol/as-treated cohorts and 4 (3.6%) reported discrepant results between intention-to-treat and per-protocol analyses. Forty-three (38.7%) did not justify the noninferiority margin. Overall, 27 (24.3%) underenrolled or had >10% exclusions. Sixty trials (54.0%) were open label. Allocation concealment was not maintained or unclear in 11 (9.9%). Publication of noninferiority trials increased over time (P<0.001). Fifty-two (46.8%) were published after 2010 and had a lower risk of methodological or reporting limitations for major (P=0.03) and minor factors (P=0.002). CONCLUSIONS: Noninferiority trials in highest-impact journals commonly conclude noninferiority of the tested intervention, but vary markedly in the selected noninferiority margin, and frequently have limitations that may impact the inference related to noninferiority.


Subject(s)
Cardiovascular Diseases/therapy , Equivalence Trials as Topic , Journal Impact Factor , Periodicals as Topic/trends , Cardiovascular Diseases/epidemiology , Humans , Periodicals as Topic/standards
2.
J Law Med Ethics ; 46(2): 241-251, 2018 06.
Article in English | MEDLINE | ID: mdl-30146983

ABSTRACT

Physicians who care for critically ill people with opioid use disorder frequently face medical, legal, and ethical questions related to the provision of life-saving medical care. We examine a complex medical case that illustrates these challenges in a person with relapsing injection drug use. We focus on a specific question: Is futility an appropriate and useful standard by which to determine provision of life-saving care to such individuals? If so, how should such determinations be made? If not, what alternative decisionmaking framework exists? We determine that although futility has been historically utilized as a justification for withholding care in certain settings, it is not a useful standard to apply in cases involving people who use injection drugs for non-medical purposes. Instead, we are welladvised to explore each patient's situation in a holistic approach that includes the patient, family members, and care providers in the decision-making process. The scope of the problem illustrated demonstrates the urgent need to definitively improve outcomes in people who use injection drugs. Increasing access to high quality medication-assisted treatment and psychiatric care for individuals with opioid use disorder will help our patients achieve a sustained remission and allow us to reach this goal.


Subject(s)
Critical Care/ethics , Medical Futility/ethics , Medical Futility/legislation & jurisprudence , Opioid-Related Disorders/therapy , Standard of Care/ethics , Adult , Aged , Clinical Decision-Making/ethics , Critical Care/classification , Critical Illness , Female , Humans , Male , Physicians/ethics , Physicians/legislation & jurisprudence , Treatment Adherence and Compliance/psychology , Treatment Outcome , Withholding Treatment/ethics , Withholding Treatment/legislation & jurisprudence
3.
J Am Heart Assoc ; 6(3)2017 Mar 21.
Article in English | MEDLINE | ID: mdl-28325713

ABSTRACT

BACKGROUND: Surrogate endpoint trials test strategies more efficiently but are accompanied by uncertainty about the relationship between changes in surrogate markers and clinical outcomes. METHODS AND RESULTS: We identified cardiovascular trials with primary surrogate endpoints published in the New England Journal of Medicine, Lancet, and JAMA: Journal of the American Medical Association from 1990 to 2011 and determined the trends in publication of surrogate endpoint trials and the success of the trials in meeting their primary endpoints. We tracked for publication of clinical outcome trials on the interventions tested in surrogate trials. We screened 3016 articles and identified 220 surrogate endpoint trials. From the total of 220 surrogate trials, 157 (71.4%) were positive for their primary endpoint. Only 59 (26.8%) surrogate trials had a subsequent clinical outcomes trial. Among these 59 trials, 24 outcomes trial results validated the positive surrogates, whereas 20 subsequent outcome trials were negative following positive results on a surrogate. We identified only 3 examples in which the surrogate trial was negative but a subsequent outcomes trial was conducted and showed benefit. Findings were consistent in a sample cohort of 383 screened articles inclusive of 37 surrogate endpoint trials from 6 other high-impact journals. CONCLUSIONS: Although cardiovascular surrogate outcomes trials frequently show superiority of the tested intervention, they are infrequently followed by a prominent outcomes trial. When there was a high-profile clinical outcomes study, nearly half of the positive surrogate trials were not validated. Cardiovascular surrogate outcome trials may be more appropriate for excluding benefit from the patient perspective than for identifying it.


Subject(s)
Cardiovascular Diseases/therapy , Clinical Trials as Topic , Endpoint Determination/methods , Biomarkers , Humans
4.
Am J Cardiol ; 116(1): 1-7, 2015 Jul 01.
Article in English | MEDLINE | ID: mdl-25937348

ABSTRACT

Excess dosing of anticoagulant agents has been linked to increased risk of bleeding after percutaneous coronary intervention (PCI) for women compared with men, but these studies have largely included older patients. We sought to determine the prevalence and gender-based differences of excess dosing of anticoagulants including glycoprotein IIb/IIIa inhibitors, bivalirudin, and unfractionated heparin in young patients with acute myocardial infarction who underwent PCI and to examine its association with bleeding. Of 2,076 patients enrolled in the Variation in Recovery: Role of Gender on Outcomes of Young Acute Myocardial Infarction Patients study who underwent PCI, we abstracted doses of unfractionated heparin, bivalirudin, and glycoprotein IIb/IIIa inhibitors administered during PCI from the medical records. At least 47.2% received at least 1 excess dose of an anticoagulant, which did not differ by gender. We used logistic regression to determine the predictors of excess dosing and the association of excess dosing with bleeding. In multivariable analysis, only lower body weight and younger age were significant predictors of excess dosing. Bleeding was higher in young women who received excess dosing versus those who did not (9.3% vs 6.0%, p = 0.03) but was comparable among men (5.2% vs 5.9%, p = 0.69) in univariate analysis. In multivariable analysis, there was a trend to an association between excess dosing and bleeding (odds ratio 1.33, 95% confidence interval 0.92 to 1.91) although not statistically significant. In conclusion, approximately half of the patients received excess dosing of anticoagulant drugs during PCI, which did not vary based on gender. There was a trend toward an association between excess dosing and increased bleeding, although not statistically significant.


Subject(s)
Anticoagulants/administration & dosage , Anticoagulants/adverse effects , Hemorrhage/chemically induced , Myocardial Infarction/therapy , Percutaneous Coronary Intervention , Platelet Glycoprotein GPIIb-IIIa Complex , Adult , Age Distribution , Angioplasty, Balloon, Coronary/methods , Antithrombins/administration & dosage , Antithrombins/adverse effects , Body Mass Index , Cohort Studies , Female , Hemorrhage/epidemiology , Hemorrhage/prevention & control , Heparin/administration & dosage , Heparin/adverse effects , Hirudins/administration & dosage , Hirudins/adverse effects , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Peptide Fragments/administration & dosage , Peptide Fragments/adverse effects , Platelet Glycoprotein GPIIb-IIIa Complex/antagonists & inhibitors , Prevalence , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Risk Assessment , Risk Factors , Sex Distribution , Treatment Outcome , United States/epidemiology
5.
Int J Anal Chem ; 2012: 690356, 2012.
Article in English | MEDLINE | ID: mdl-22966229

ABSTRACT

Trimethylsilanol (TMSOH) can cause damage to surfaces of scanner lenses in the semiconductor industry, and there is a critical need to measure and control airborne TMSOH concentrations. This study develops a thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) method for measuring trace-level TMSOH in occupational indoor air. Laboratory method optimization obtained best performance when using dual-bed tube configuration (100 mg of Tenax TA followed by 100 mg of Carboxen 569), n-decane as a solvent, and a TD temperature of 300°C. The optimized method demonstrated high recovery (87%), satisfactory precision (<15% for spiked amounts exceeding 1 ng), good linearity (R(2) = 0.9999), a wide dynamic mass range (up to 500 ng), low method detection limit (2.8 ng m(-3) for a 20-L sample), and negligible losses for 3-4-day storage. The field study showed performance comparable to that in laboratory and yielded first measurements of TMSOH, ranging from 1.02 to 27.30 µg/m(3), in the semiconductor industry. We suggested future development of real-time monitoring techniques for TMSOH and other siloxanes for better maintenance and control of scanner lens in semiconductor wafer manufacturing.

6.
Am J Physiol Heart Circ Physiol ; 292(2): H1095-104, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17056665

ABSTRACT

The in vivo cardiac differentiation and functional effects of unmodified adult bone marrow mesenchymal stem cells (MSCs) after myocardial infarction (MI) is controversial. We postulated that ex vivo pretreatment of autologous MSCs using cardiomyogenic growth factors will lead to cardiomyogenic specification and will result in superior biological and functional effects on cardiac regeneration of chronically infarcted myocardium. We used a chronic dog MI model generated by ligation of the coronary artery (n = 30). Autologous dog bone marrow MSCs were isolated, culture expanded, and specified into a cardiac lineage by adding growth factors, including basic FGF, IGF-1, and bone morphogenetic protein-2. Dogs underwent cell injection >8 wk after the infarction and were randomized into two groups. Group A dogs (n = 20) received MSCs specified with growth factors (147 +/- 96 x 10(6)), and group B (n = 10) received unmodified MSCs (168 +/- 24 x 10(6)). After the growth factor treatment, MSCs stained positive for the early muscle and cardiac markers desmin, antimyocyte enhancer factor-2, and Nkx2-5. In group A dogs, prespecified MSCs colocalized with troponin I and cardiac myosin. At 12 wk, group A dogs showed a significantly larger increase in regional wall thickening of the infarcted territory (from 22 +/- 8 to 32 +/- 6% in group A; P < 0.05 vs. baseline and group B, and from 19 +/- 7 to 21 +/- 7% in group B, respectively) and a decrease in the wall motion score index (from 1.60 +/- 0.05 to 1.35 +/- 0.03 in group A; P < 0.05 vs. baseline and group B, and from 1.58 +/- 0.07 vs. 1.56 +/- 0.08 in group B, respectively). The biological ex vivo cardiomyogenic specification of adult MSCs before their transplantation is feasible and appears to improve their in vivo cardiac differentiation as well as the functional recovery in a dog model of the chronically infarcted myocardium.


Subject(s)
Adult Stem Cells/drug effects , Bone Marrow Cells/drug effects , Intercellular Signaling Peptides and Proteins/pharmacology , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Myocardial Infarction/surgery , Animals , Bone Morphogenetic Proteins/pharmacology , Cell Differentiation/drug effects , Cell Lineage/drug effects , Cells, Cultured , Chronic Disease , Disease Models, Animal , Dogs , Fibroblast Growth Factors/pharmacology , Heart Ventricles/pathology , Insulin-Like Growth Factor I/pharmacology , Mesenchymal Stem Cells/drug effects , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Random Allocation , Recovery of Function , Time Factors , Transplantation, Autologous , Ventricular Function, Left
SELECTION OF CITATIONS
SEARCH DETAIL
...