pH-responsive i-motif-conjugated nanoparticles for MRI analysis.

Gadolinium (Gd)-based contrast agents (CAs) are widely used to enhance anatomical details in magnetic resonance imaging (MRI). Significant research has expanded the field of CAs into bioresponsive CAs by modulating the signal to image and monitor biochemical processes, such as pH. In this work, we introduce the modular, dynamic actuation mechanism of DNA-based nanostructures as a new way to modulate the MRI signal based on the rotational correlation time, τR. We combined a pH-responsive oligonucleotide (i-motif) and a clinical standard CA (Gd-DOTA) to develop a pH-responsive MRI CA. The i-motif folds into a quadruplex under acidic conditions and was incorporated onto gold nanoparticles (iM-GNP) to achieve increased relaxivity, r1, compared to the unbound i-motif. In vitro, iM-GNP resulted in a significant increase in r1 over a decreasing pH range (7.5-4.5) with a calculated pKa = 5.88 ± 0.01 and a 16.7% change per 0.1 pH unit. In comparison, a control CA with a non-responsive DNA strand (T33-GNP) did not show a significant change in r1 over the same pH range. The iM-GNP was further evaluated in 20% human serum and demonstrated a 28.14 ± 11.2% increase in signal from neutral pH to acidic pH. This approach paves a path for novel programmable, dynamic DNA-based complexes for τR-modulated bioresponsive MRI CAs.

Accuracy and interrater agreement of death event adjudications by physician trainees: validation of the ISTH definition of pulmonary embolism-related death in an autopsy cohort.

BACKGROUND: We previously determined good agreement and high specificity of the International Society on Thrombosis and Haemostasis (ISTH) definition of pulmonary embolism (PE)-related death among an expert central adjudication committee (CAC). CACs are often composed of experts in the corresponding research field. Involving physician trainees in CACs would allow investigators to divide the workload and foster trainees' research experience. OBJECTIVE: To evaluate the accuracy of the ISTH definition of PE-related death for PE- versus non-PE-related deaths as confirmed by autopsy and its interrater agreement among physician trainees. METHODS: This retrospective autopsy cohort included all patients with PE-related deaths between January 2010 and July 2019 as well as patients who died in 2018 from a cause other than PE at the New York-Presbyterian Hospital. Based on premortem clinical summaries, two physician trainees independently determined the cause of death using the ISTH definition of PE-related death. We calculated the sensitivity and specificity of the ISTH definition to identify autopsy-confirmed PE-related death and its interrater agreement. RESULTS: Overall, 126 death events were adjudicated (median age, 68 years; 60 [48%] women), of which 29 (23%) were due to PE, as confirmed by autopsy. Sensitivity and specificity of the ISTH definition for autopsy-confirmed PE-related death was 48% (95% CI, 29-67) and 100% (95% CI, 96-100), respectively. Interrater reliability for PE-related death was good (percentage agreement, 93%; 95% CI, 87-96, Cohen's Kappa, 0.67; 95% CI, 44-85). CONCLUSION: Our findings are consistent with our previous validation study. They further support the use of the ISTH definition of PE-related death and revealed high agreement between adjudicators with varied experience.

Nucleic acid nanostructures for in vivo applications: The influence of morphology on biological fate.

The development of programmable biomaterials for use in nanofabrication represents a major advance for the future of biomedicine and diagnostics. Recent advances in structural nanotechnology using nucleic acids have resulted in dramatic progress in our understanding of nucleic acid-based nanostructures (NANs) for use in biological applications. As the NANs become more architecturally and functionally diverse to accommodate introduction into living systems, there is a need to understand how critical design features can be controlled to impart desired performance in vivo. In this review, we survey the range of nucleic acid materials utilized as structural building blocks (DNA, RNA, and xenonucleic acids), the diversity of geometries for nanofabrication, and the strategies to functionalize these complexes. We include an assessment of the available and emerging characterization tools used to evaluate the physical, mechanical, physiochemical, and biological properties of NANs in vitro. Finally, the current understanding of the obstacles encountered along the in vivo journey is contextualized to demonstrate how morphological features of NANs influence their biological fates. We envision that this summary will aid researchers in the designing novel NAN morphologies, guide characterization efforts, and design of experiments and spark interdisciplinary collaborations to fuel advancements in programmable platforms for biological applications.

Development of an international standard set of outcome measures for patients with venous thromboembolism: an International Consortium for Health Outcomes Measurement consensus recommendation.

The International Consortium for Health Outcomes Measurement assembled an international working group of venous thromboembolism experts and patient representatives to develop a standardised minimum set of outcomes and outcome measurements for integration into clinical practice and potentially research to support clinical decision making and benchmarking of quality of care. 15 core outcomes important to patients and health-care professionals were selected and categorised into four domains: patient-reported outcomes, long term consequences of the disease, disease-specific complications, and treatment-related complications. The outcomes and outcome measures were designed to apply to all patients with venous thromboembolism aged 16 years or older. A measurement tool package was selected for inclusion in the core standard set, with a minimum number of items to be measured at predefined timepoints, which capture all core outcomes. Additional measures can be introduced to the user by a cascade opt-in system that allows for further assessment if required. This set of outcomes and measurement tools will facilitate the implementation of the use of patient-centred outcomes in daily practice.

Evaluation of patients' experience and related qualitative outcomes in venous thromboembolism: A scoping review.

BACKGROUND: Venous thromboembolism (VTE) is a prevalent disease with high morbidity and mortality. VTE has well-documented physical sequelae; however, the psychological and emotional impacts are seldom evaluated in randomized controlled trials. OBJECTIVE: We conducted a scoping review of published qualitative studies aiming to understand the physical, psychological, and emotional impact of VTE as reflected from patients' perspectives. This scoping review is part of a larger initiative to develop a core outcome set for VTE treatment studies. METHODS: A systematic literature search was conducted to identify qualitative studies assessing patient experience of VTE. Two authors independently screened titles and abstracts using Covidence systematic review software. Full-text reviews were conducted independently by 2 study team members. A modified method of "thematic synthesis" was used to collate themes upon reading and rereading of the publications. RESULTS: Our search strategy returned a total of 4944 citations; 28 were ultimately included in the analysis. The studies were conducted across 13 countries and representative of 436 participants including a spectrum of VTE subpopulations. There were seven major themes identified: Acute impacts: an unforeseen blow, Sustained psychological distress, Loss of self: life is changed, Challenges of thrombosis management, Balancing coping and control, Negative experience with the medical system, and VTE in the context of other conditions. CONCLUSIONS: The physical, psychological, and emotional impacts of VTE extend beyond objective outcomes typically evaluated in clinical trials. An improved understanding of the outcomes most important to patients will improve patient-centered care in VTE.

Identification of outcomes in clinical studies of interventions for venous thromboembolism in non-pregnant adults: A scoping review.

BACKGROUND: The development of a core outcome set (COS), defined as an agreed minimum set of outcome domains that should be measured and reported in all trials of a specific disease, aims to increase the relevance of study findings to stakeholder groups and improve standardization. OBJECTIVES: As the first step in developing a COS for venous thromboembolism (VTE) treatment studies, we aimed to generate an inclusive list of unique outcomes reported in previous VTE treatment studies and classify them into domains and core areas. METHODS: MEDLINE, Embase and CENTRAL were searched for prospective studies reporting on interventions for VTE in non-pregnant adults. Study selection and data extraction were performed in blocks based on publication date, starting with 2015-2020 and subsequent 1-year periods, until no new outcome was identified. Outcomes were classified into domains, which are groups of closely related outcomes, and domains into four core areas including death, pathophysiological manifestations/abnormalities, life impact, and resource use. RESULTS: Of 7100 records identified, 240 publications were included, representing 165 distinct studies. A total of 205 unique outcomes were identified that were grouped into 48 domains; 30 (13%) studies covered at least three core areas; death was included in 102 (43%), pathophysiological manifestations/abnormalities in 218 (91%), life impact in 41 (17%), and resource use in 25 (10%) studies. CONCLUSION: Most VTE treatment studies evaluated pathophysiological features of VTE, but few studies reported outcomes that measured life impact or resource use. The findings will inform next steps in the development of a COS for VTE treatment studies.

Characterization of DNA nanostructure stability by size exclusion chromatography.

DNA-based nanostructures (DNs) are advantageous for the design of functional materials for biology and medicine due to the nanoscale control provided by their predictable self-assembly. However, the use of DNs in vivo has been limited due to structural instability in biofluids. As the stability of a particular DN sets the scope of its potential biological applications, efficient methods to characterize stability are required. Here, we apply size exclusion chromatography (SEC) to study the stability of a tetrahedron DNA nanostructure (TDN) and demonstrate the analytical capabilities of our method in characterizing degradation by enzymes and a diluted human serum matrix. We show that SEC analysis can reliably assay TDN degradation by a nuclease through direct injection and peak integration. Furthermore, data analysis using a ratio chromatogram technique enables TDN peak deconvolution from the matrix of serum proteins. Using our method, we found that TDNs exhibit half-lives of 23.9 hours and 10.1 hours in 20% and 50% diluted human serum, respectively, which is consistent with reported stability studies in 10% fetal bovine serum. We anticipate that this method can be broadly applicable to characterize a variety of DNs and serve as an efficient technique toward analysis of the stability of new DN designs in complex biological matrixes.

ISTH definition of pulmonary embolism-related death and classification of the cause of death in venous thromboembolism studies: Validation in an autopsy cohort.

BACKGROUND: The International Society on Thrombosis and Haemostasis (ISTH)'s Scientific and Standardization Committee (SSC) recently proposed a definition of pulmonary embolism (PE)-related death. OBJECTIVES: To evaluate the accuracy and interrater reliability of the ISTH definition of PE-related death in an autopsy cohort. METHODS: We reviewed reports of 1064 consecutive adult autopsies that were performed at the NewYork-Presbyterian Hospital from January 2010 until July 2019. We included all patients with autopsy-confirmed PE-related death (cases) during that time frame, combined with patients who died in 2018 from a cause other than PE (controls). Based on clinical summaries, two adjudicators independently adjudicated the cause of death in each patient using the ISTH classification for the cause of death, blinded to the case/control status and ratio. The primary outcome was autopsy-confirmed PE-related death. We determined the sensitivity and specificity of the ISTH definition to identify autopsy-confirmed PE-related death, and its interrater reliability using the percentage agreement and Cohen's kappa. RESULTS: A total of 126 patients who underwent autopsy were included in the analysis (median age, 68 years [range, 21-94], 60 [48%] women), of which 29 (23%) had died from PE as confirmed by autopsy. The ISTH definition's sensitivity and specificity for autopsy-confirmed PE-related death were 45% (95% CI, 26-64) and 99% (95% CI, 94-100), respectively. Interrater reliability for PE-related death was substantial (percentage agreement, 94% [95% CI, 89-97]; kappa, 0.73 [95% CI, 0.55-0.97]). CONCLUSION: Adjudication of the cause of death using the ISTH definition resulted in very high specificity, moderate sensitivity, and good interrater reliability for PE-related death.

Development and implementation of common data elements for venous thromboembolism research: on behalf of SSC Subcommittee on official Communication from the SSC of the ISTH.

Clinical research in venous thromboembolism (VTE) is hindered by variability in the collection and reporting of data and outcomes. A consistent data language facilitates efficiencies, leads to higher quality data, and permits between-study comparisons and evidence synthesis. The International Society on Thrombosis and Haemostasis (ISTH) launched an international task force of more than 50 researchers to develop common data elements for clinical research in venous thromboembolism. The project was organized in seven working groups, each focusing on a topic area: General Core Data Elements; Anticoagulation and Other Therapies; Chronic VTE and Functional Outcomes; Diagnosis of VTE; Malignancy; Perioperative; and Predictors of VTE. The groups met via teleconference to collaboratively identify key data elements and develop definitions and data standards that were structured in a project-specific taxonomy. A Steering Committee met by teleconference and in-person to determine the overall scope of the project and resolve questions arising from the working groups. ISTH held an open public comment period to enable broader stakeholder involvement and feedback. The common data elements were then refined by the working groups to create a set of 512 unique data elements that are publicly available at http://isth.breakthrough.healthcare. The ISTH VTE Common Data Elements are intended to be a living project with ongoing curation, future expansion, and adaptation to meet the needs of the thrombosis and hemostasis research community.

Protocol for a scoping review of outcomes in clinical studies of interventions for venous thromboembolism in adults.

INTRODUCTION: Venous thromboembolism (VTE) is a common, potentially fatal yet treatable disease. Several advances in treatment of VTE have been made over the past decades, but definition and reporting of outcomes across those studies are inconsistent. Development of an international core outcome set for clinical studies of interventions for VTE addresses this lack of standardisation. The first step in the development of a core outcome set is to conduct a scoping review which aims to generate an inclusive list of unique outcomes that have been reported in previous studies. METHODS AND ANALYSIS: MEDLINE, Embase and the Cochrane Central Register of Controlled Trials will be searched with no language restriction for prospective studies reporting on interventions for treatment of VTE in patients who are adult and non-pregnant. Records will be sorted in reverse chronological order. Study screening and data extraction will be independently performed by two authors in blocks based on date of publication, starting with 2015 to 2020 and subsequent 1-year periods, until no new outcome measures are identified from the set of included studies. After homogenising spelling and combining outcomes with the same meaning, a list of unique outcomes will be determined. Those outcomes will be grouped into outcome domains. Qualitative analysis and descriptive statistics will be used to report results. ETHICS AND DISSEMINATION: Ethical approval is not required for this study. The results of this scoping review will be presented at scientific conferences, published in a peer-reviewed journal, and they will provide candidate outcome domains to be considered in subsequent steps in the development of a core outcome set for clinical studies of interventions for VTE. PROTOCOL REGISTRATION DETAILS: http://hdl.handle.net/10393/40459.

A toolkit for the collection of thrombosis-related data elements in COVID-19 clinical studies.

Thrombosis has emerged as an important complication of coronavirus disease 2019 (COVID-19), particularly among individuals with severe illness. However, the precise incidence of thrombotic events remains uncertain due to differences in study design, patient populations, outcome ascertainment, event definitions, and reporting. In an effort to overcome some of these challenges and promote standardized data collection and reporting in clinical studies, the American Society of Hematology Research Collaborative COVID-19 Non-Malignant Hematology Task Force, in collaboration with the International Society on Thrombosis and Haemostasis COVID-19 Task Force, developed sets of data elements in the following domains: venous thromboembolism, myocardial infarction, stroke/transient ischemic attack, peripheral arterial thrombosis, bleeding, laboratory investigations, and antithrombotic therapy. Data elements in each of these domains were developed with 3 levels of detail to facilitate their incorporation into studies evaluating a range of interventions and outcomes. Previously published data elements were included where possible. The use of standardized variables in a range of clinical studies can enhance the quality of data collection, create efficiency, enhance comparison of results across studies, and facilitate future pooling of data sets.

Definition of pulmonary embolism-related death and classification of the cause of death in venous thromboembolism studies: Communication from the SSC of the ISTH.

Pulmonary embolism (PE)-related death is often a component of the primary outcome in venous thromboembolism (VTE) clinical studies. Definitions for PE-related death vary widely, which may lead to biased risk estimates of clinical outcomes, thereby affecting both internal and external validity of study results. We here provide a standardized definition of PE-related death and propose guidance for classification and reporting of the cause of death for clinical studies in VTE. The proposal was developed in a four-step process, including a systematic review of definitions used for PE-related death in previous studies, two subsequent surveys with VTE experts, and meetings held within the Scientific and Standardization Committee (SSC) working group until consensus on the proposal was reached. The proposed classification comprises three categories: Category A: PE-related death, category B: undetermined cause of death, and category C: cause of death other than PE. Category A includes A1: autopsy-confirmed PE in the absence of another more likely cause of death; A2: objectively confirmed PE before death in the absence of another more likely cause of death; and A3: PE is not objectively confirmed, but is most likely the main cause of death. Category B includes B1: cause of death is undetermined, despite available information; and B2: insufficient clinical information available to determine the cause of death. The use of the proposed definition will hopefully improve the accuracy of study outcomes, between-study comparisons, meta-analyses, and validity of future clinical VTE studies.

Development of a standardized definition of pulmonary embolism-related death: A cross-sectional survey of international thrombosis experts.

INTRODUCTION: Pulmonary embolism (PE)-related death is often part of the primary outcome in venous thromboembolism (VTE) studies. The Scientific and Standardization Committee (SSC) of the International Society on Thrombosis and Haemostasis developed a definition for PE-related death and classification of the cause of death. The present survey evaluated a preliminary version of this definition and classification. METHODS: Sixty-nine VTE experts from nine countries were invited for a cross-sectional online survey on January 15, 2019, including multiple-choice and open-ended questions on a seven-subcategory classification of the cause of death. Descriptive statistics were used to describe the results; qualitative comments were summarized. RESULTS: Forty of 69 (58%) invitees completed the survey. All respondents agreed that guidance on classification of the cause of death in VTE studies is required. There was high agreement on the proposal (median overall score, 6; interquartile range, 6-7; scale from 1 [poor] to 7 [excellent]). All respondents approved the wording and content of the seven subcategories, except for one disagreeing vote for two subcategories (A3: "PE is not objectively confirmed, but is most likely the main cause of death" and C1: "Another cause of death is more likely than PE but has not been objectively confirmed"). Suggestions for improvement mainly concerned the extensiveness of the criteria and clinical situations described to define the cause of death. CONCLUSION: Acceptance of the proposal was excellent. Suggestions for improvement were incorporated in the SSC communication on the definition of PE-related death and classification of the cause of death in VTE studies.

The risk of cesarean delivery after labor induction among women with prior pregnancy complications: a subgroup analysis of the AFFIRM study.

BACKGROUND: To determine the risk of cesarean delivery after labor induction among patients with prior placenta-mediated pregnancy complications (pre-eclampsia, late pregnancy loss, placental abruption or intrauterine growth restriction). METHODS: The AFFIRM database includes patient level data from 9 randomized controlled trials that evaluated the role of LMWH versus no LMWH during pregnancy to prevent recurrent placenta-mediated pregnancy complications. The primary outcome of this sub-study was the proportion of women who had an unplanned cesarean delivery after induction of labor compared to after spontaneous labor. RESULTS: There were 512 patients from 7 randomized trials included in our sub-study. There was no difference in the risk of cesarean delivery between women with labor induction (21/148, 14.2%) and spontaneous labor (79/364, 21.7%) (odds ratio (OR) 0.60, 95% CI, 0.35-1.01; p = 0.052). Among 274 women who used LMWH prophylaxis during pregnancy, the risk of cesarean delivery was lower among those that underwent labor induction (9.8%) compared to spontaneous labor (22.4%) (OR 0.38, 95% CI, 0.17-0.84; p = 0.01). CONCLUSIONS: The risk of cesarean delivery is not increased after labor induction among a higher risk patient population with prior pregnancy complications. Our results suggest that women who receive LMWH during pregnancy might benefit from labor induction.

Pilot trials in thrombosis: Purpose and pitfalls.

Randomized controlled trials provide important evidence to guide clinical practice. These full-scale trials are expensive, time consuming and many are never successfully completed. Well conducted pilot studies help with full-scale trial design, assessment and optimization of feasibility, and can avoid the waste of resources associated with starting a full-scale trial that will not succeed. They also provide an opportunity for capacity growth and mentorship of new investigators. It is important to appreciate that the usual goal of a pilot trial is assessment of feasibility and refinement of trial design rather than to gain preliminary evidence of efficacy. Indeed, using event rates from a pilot trial to calculate sample sizes can be misleading in therapeutic trials. Misconceptions exist that pilot trials are just "small trials," are easy to perform, and are not worthy of publication. While, in the past, many pilot trials were poorly conducted and not followed by a full-scale trial, by following the recommendations in the "CONSORT 2010 statement: extension to randomized pilot and feasibility trials," high-quality pilot trials can be performed and reported that will greatly improve the chances of successfully completing a practice-changing trial. We propose that pilot trials are a valuable investment and describe the TRIM-Line pilot trial (NCT03506815), a pilot study assessing the feasibility of a randomized controlled trial investigating primary thromboprophylaxis with rivaroxaban in patients with malignancy and central venous catheters, as an illustrative example of how a pilot trial in the area of thrombosis should be designed.

"HERDOO2" clinical decision rule to guide duration of anticoagulation in women with unprovoked venous thromboembolism. Can I use any d-Dimer?

BACKGROUND: The "HERDOO2 rule" is a prospectively validated clinical decision rule used to identify low-risk women who can safely discontinue anticoagulants after completing 5-12 months of anticoagulant treatment for unprovoked venous thromboembolism. The VIDAS®d-Dimer (DD) assay, a component of the rule, was used in the derivation and validation of the rule at half the usual diagnostic cut-point for exclusion of venous thrombosis. It is unknown if other commercial DD assays used at a corresponding cut-point will categorize patients at high concordance with the VIDAS® DD. OBJECTIVE: To determine if other available automated quantitative DD assays have high enough concordance with the VIDAS® DD assay to allow their use within the "HERDOO2" clinical decision rule. METHODS: Frozen plasma samples from a sub-set (n = 248) of female participants in the "HERDOO2" validation study were tested using five DD assays: VIDAS®, Innovance®, HemosIL®, Tina-quant® and Liatest®, with duplicate testing for 50 samples. First, using the mean DD for 50 samples with duplicate results, we determined the optimal cut-point values for each test that corresponded with a VIDAS® DD result of 250 µg/L using linear regression analysis. Next, kappa analysis was conducted on the DD results of the remaining 198 samples to determine concordance between each tested DD at the respective optimal cut-point and the VIDAS® DD at 250 µg/L. In a separate analysis we determined the concordance at half the usual venous thrombosis exclusion cut-point. RESULTS: Regression analysis of the DD results in 50 samples identified the optimal cut-point for each DD assay to match a VIDAS® DD cut-point of 250 µg/L: Innovance® 177 µg/L, Liatest® 233 µg/L, Tina-quant® 48 µg/L and HemosIL® 56 µg/L. Next, in 198 different samples, the concordance of VIDAS® DD (≥250 µg/L or <250 µg/L) was explored at the optimal cut-point of the other DD assays. The concordance was poor for all DD assays: Innovance® (kappa 0.38 (95% CI, 0.26-0.51)), Liatest® (kappa 0.38 (95% CI, 0.25-0.50)), HemosIL® (kappa 0.36 (95% CI, 0.23-0.49)) and Tina-quant® (kappa 0.30 (95% CI, 0.16-0.43)). Similar poor concordance was identified using half of the diagnostic DD cut-point for each tested assay: Innovance® (kappa 0.44 (95% CI, 0.32-0.56)), Liatest® (kappa 0.38 (95% CI, 0.25-0.51)), HemosIL® (kappa 0.04 (95% CI, -0.01-0.08)) and Tina-quant® (kappa 0.04 (95% CI, -0.004-0.07)). CONCLUSION: The "HERDOO2 rule" is the only prospectively validated clinical decision rule that can be used to identify low-risk women with unprovoked venous thrombosis who can safely discontinue anticoagulants. An important implementation issue is whether any commercial DD assay can be used in the HERDOO2 rule, and at what cut-point. Our analysis shows that the HemosIL®, Innovance®, Liatest® and Tina-quant® DD assays should not be used in the "HERDOO2" rule due to poor concordance with the VIDAS® DD assay and unacceptable misclassification of women at high and low risk of recurrent venous thrombosis.

Initial strides for invent-VTE: Towards global collaboration to accelerate clinical research in venous thromboembolism.

Venous thromboembolism (VTE) represents a major global burden of disease and requires collaborative efforts to conduct large, high-quality investigator-initiated and academically sponsored studies addressing the most relevant clinical questions. Owing to increasing regulatory requirements, the highly competitive nature of peer-reviewed funding and costs associated with conducting large, multinational clinical trials, completing practice-changing research constitutes a growing challenge for clinical investigators. As clinical trialists interested in VTE, we founded INVENT (International Network of Venous Thromboembolism Clinical Research Networks) in an effort to promote and accelerate patient-oriented, investigator-initiated, international collaborative research, to identify, prioritize and answer key clinical research questions for patients with VTE. We report on our activities to formalize the INVENT network and our accomplishments in our first year.

Guiding curriculum development of a national research training program in thrombosis medicine: A needs assessment involving faculty and trainees.

BACKGROUND: Several barriers exist for training and retention of clinician scientists, including difficulty in navigating research-related tasks in the workplace and insufficient mentorship. OBJECTIVE: Our aim was to identify what core research knowledge and skills are important for the success of clinician scientists in thrombosis research, and trainees' perceived confidence in those skills, in order to develop a targeted educational intervention. METHODS: A pre-tested online survey was administered to trainees and research faculty of the Canadian thrombosis research network, CanVECTOR, between September 2016 and June 2017. The importance (research faculty) and confidence (trainees) of 45 research knowledge/skills were measured using a 5-point Likert scale. RESULTS: The survey response rate was 49% (28/57) for research faculty and 100% (10/10) for trainees. All research faculty rated developing a good research question, grant writing and writing strategies for successful publication as 'very' or 'extremely' important for trainees to learn to better transition in becoming independent researchers. Other important areas included practical aspects of research. A qualitative thematic analysis of open text responses identified 'time management' and 'leadership and teamwork' as additional important research skills. Confidence reported for each topic varied across trainees. There were three research knowledge and/or skills that ≥75% of research faculty deemed highly important and ≥50% of trainees reported lacking confidence in: grant writing, the peer-review grant process, and knowledge translation strategies. CONCLUSIONS: Developing a good research question, communicating research ideas and results and the practical aspects of research are important areas to focus future efforts in thrombosis research training.

Low-molecular-weight heparin and recurrent placenta-mediated pregnancy complications: a meta-analysis of individual patient data from randomised controlled trials.

BACKGROUND: Placenta-mediated pregnancy complications include pre-eclampsia, late pregnancy loss, placental abruption, and birth of a small-for-gestational-age (SGA) neonate. These complications are leading causes of maternal, fetal, and neonatal morbidity and mortality in high-income countries. Affected women are at high risk of recurrence in subsequent pregnancies; however, effective strategies to prevent recurrence are absent. Findings from our previous study-level meta-analysis suggested that low-molecular-weight heparin reduced the risk of recurrent placenta-mediated pregnancy complications. However, we identified significant heterogeneity in the results, possibly due to trial design or inclusion criteria. To identify which patients benefit from, and which outcomes are prevented by, low-molecular-weight heparin, we did an individual patient data meta-analysis. METHODS: We did a systematic review in May, 2013, which identified eight eligible randomised trials done between 2000 and 2013 of low-molecular-weight heparin to prevent recurrent placenta-mediated pregnancy complications. We excluded studies on the basis of the wrong population, the study being ongoing, inability to confirm eligibility of participants, intervention stopped too early, and no response from the principal investigator. We requested individual patient data from the study authors for eligible women (women pregnant at the time of the study with a history of previous pregnancy that had been complicated by one or more of the following: pre-eclampsia, placental abruption, birth of an SGA neonate [<10th percentile], pregnancy loss after 16 weeks' gestation, or two losses after 12 weeks' gestation) and recoded, combined, and analysed the data for our meta-analysis. The primary outcome was a composite of early-onset (<34 weeks) or severe pre-eclampsia, birth of an SGA neonate (<5th percentile), late pregnancy loss (≥20 weeks' gestation), or placental abruption leading to delivery, assessed on an intention-to-treat basis. We assessed risk of bias with the Cochrane Risk of Bias tool. This study is registered with PROSPERO, number CRD42013006249. FINDINGS: We analysed data from 963 eligible women in eight trials: 480 randomly assigned to low-molecular-weight heparin and 483 randomly assigned to no low-molecular-weight heparin. Overall, the risk of bias was not substantial enough to affect decisions regarding trial inclusion. Participants were mostly white (795/905; 88%) with a mean age of 30·9 years (SD 5·0) and 403/963 (42%) had thrombophilia. In the primary analysis, low-molecular-weight heparin did not significantly reduce the risk of recurrent placenta-mediated pregnancy complications (low-molecular-weight heparin 62/444 [14%] versus no low-molecular-weight heparin 95/443 (22%) absolute difference -8%, 95% CI -17·3 to 1·4, p=0·09; relative risk 0·64, 95% CI 0·36-1·11, p=0·11). We noted significant heterogeneity between single-centre and multicentre trials. In subgroup analyses, low-molecular-weight heparin in multicentre trials reduced the primary outcome in women with previous abruption (p=0·006) but not in any of the other subgroups of previous complications. INTERPRETATION: Low-molecular-weight heparin does not seem to reduce the risk of recurrent placenta-mediated pregnancy complications in at-risk women. However, some decreases in event rates might have been too small for the power of our study to explore. FUNDING: Canadian Institutes of Health Research.

A simple method to identify patients on long-term warfarin who may derive the most benefit from new oral anticoagulants.

In many countries, new oral anticoagulants are only covered for patients with suboptimal anticoagulation control on vitamin K antagonists (VKAs). The quality of VKA management is often reported using the time in therapeutic range (TTR). We sought to predict a TTR 65% or less using a surrogate measure [number of changes in VKA dose and number of international normalized ratio (INR) tests] that could be easily determined by primary care physicians. This cross-sectional study included consecutive patients whose VKA therapy was managed in a specialized anticoagulation clinic. Patients were dichotomized according to their TTR in the past 6 months (TTR > or ≤ 65%). The ability of the number of INR tests and VKA dose changes to predict TTR group was assessed using receiver-operating characteristics (ROC) curve analysis. The analyses included 1381 patients with a median age of 63 years. The mean TTR was 81% (interquartile range 70-90) and 17.4% of patients had a TTR 65% or more. Based on the ROC curve, patients were stratified according to whether they had either 3 or more dose changes or 9 or more INR tests within the last 6 months. The sensitivity to identify patients with TTR 65% or less was 87% and the specificity was 63%. The number of dose changes and the number of INR tests might be used as indicators of TTR; they could offer a simple way for clinicians to identify patients who are good candidates for the new oral anticoagulants. However, external validation studies in different clinical settings are needed to confirm these findings.