Rilzabrutinib, an Oral BTK Inhibitor, in Immune Thrombocytopenia.

BACKGROUND: Rilzabrutinib, an oral, reversible covalent inhibitor of Bruton's tyrosine kinase, may increase platelet counts in patients with immune thrombocytopenia by means of dual mechanisms of action: decreased macrophage (Fcγ receptor)-mediated platelet destruction and reduced production of pathogenic autoantibodies. METHODS: In an international, adaptive, open-label, dose-finding, phase 1-2 clinical trial, we evaluated rilzabrutinib therapy in previously treated patients with immune thrombocytopenia. We used intrapatient dose escalation of oral rilzabrutinib over a period of 24 weeks; the lowest starting dose was 200 mg once daily, with higher starting doses of 400 mg once daily, 300 mg twice daily, and 400 mg twice daily. The primary end points were safety and platelet response (defined as at least two consecutive platelet counts of ≥50×103 per cubic millimeter and an increase from baseline of ≥20×103 per cubic millimeter without the use of rescue medication). RESULTS: Sixty patients were enrolled. At baseline, the median platelet count was 15×103 per cubic millimeter, the median duration of disease was 6.3 years, and patients had received a median of four different immune thrombocytopenia therapies previously. All the treatment-related adverse events were of grade 1 or 2 and transient. There were no treatment-related bleeding or thrombotic events of grade 2 or higher. At a median of 167.5 days (range, 4 to 293) of treatment, 24 of 60 patients (40%) overall and 18 of the 45 patients (40%) who had started rilzabrutinib treatment at the highest dose met the primary end point of platelet response. The median time to the first platelet count of at least 50×103 per cubic millimeter was 11.5 days. Among patients with a primary platelet response, the mean percentage of weeks with a platelet count of at least 50×103 per cubic millimeter was 65%. CONCLUSIONS: Rilzabrutinib was active and associated with only low-level toxic effects at all dose levels. The dose of 400 mg twice daily was identified as the dose for further testing. Overall, rilzabrutinib showed a rapid and durable clinical activity that improved with length of treatment. (Funded by Sanofi; ClinicalTrials.gov number, NCT03395210; EudraCT number, 2017-004012-19.).

Could machine learning revolutionize how we treat immune thrombocytopenia?

The absence of reliable biomarkers in immune thrombocytopenia (ITP) complicates treatment choice, necessitating a trial-and-error approach. Machine learning (ML) holds promise for transforming ITP treatment by analysing complex data to identify predictive factors, as demonstrated by Xu et al.'s study which developed ML-based models to predict responses to corticosteroids, rituximab and thrombopoietin receptor agonists. However, these models require external validation before can be adopted in clinical practice. Commentary on: Xu et al. A novel scoring model for predicting efficacy and guiding individualised treatment in immune thrombocytopenia. Br J Haematol 2024; 205:1108-1120.

Risk of fractures and use of bisphosphonates in adult patients with immune thrombocytopenia-A nationwide population-based study.

Corticosteroids remain the first-line treatment of immune thrombocytopenia (ITP), but increase the risk of osteoporosis and fractures. Bisphosphonates are used for the treatment of osteoporosis, but their usage among patients with ITP has not been systemically described. We investigated the risk of fractures and the use of bisphosphonates in adult patients with primary (pITP) and secondary ITP (sITP) compared with matched comparators in a nationwide registry-based cohort study. We identified 4030 patients with pITP (median age 60 years [IQR, 40-74]), 550 with sITP (median age 59 years [IQR, 43-74]) and 182 939 age-sex-matched general population comparators. All individuals were followed for incident fractures. Bisphosphonate use was estimated for calendar-years and in temporal relation to the ITP diagnosis. Adjusted cause-specific hazard ratio (csHR) for any fracture was 1.37 (95% confidence interval [CI] 1.23; 1.54) for pITP and 1.54 (1.17; 2.03) for sITP. The first-year csHR was 1.82 (1.39; 2.40) for pITP and 2.78 (1.58; 4.91) for sITP. Bisphosphonate use over calendar-years and in the early years following ITP diagnosis was higher among patients with ITP diagnosis compared with the general population. In conclusion, the risk of fractures and the use of bisphosphonates are higher in patients with ITP compared with the general population.

Platelet response to romiplostim amongst patients with newly diagnosed, persistent, and chronic immune thrombocytopenia in routine clinical practice in Denmark, Sweden, and Norway.

Patient characteristics and platelet responses at romiplostim initiation according to the duration of immune thrombocytopenia (ITP) are poorly understood. Amongst romiplostim-exposed adults with ITP lasting ≥6 months during 2009-2018 in Denmark, Sweden, and Norway, we examined characteristics at romiplostim initiation, romiplostim dosage, and durable platelet response (≥75% of measurements ≥50 × 109/L at 14-24 weeks) for subcohorts with newly diagnosed (duration <3 months), persistent (3-12 months), or chronic (>12 months) ITP initiating romiplostim. The 285 romiplostim initiators comprised 81 (28%) with newly diagnosed, 47 (16%) with persistent, and 157 (55%) with chronic ITP. More patients with newly diagnosed ITP than longer ITP duration, had low comorbidity levels, two or more prior ITP therapies, and previous bleeding requiring hospitalisation. The median romiplostim doses were similar across subcohorts. During treatment, median platelet counts were similar across subcohorts (75-76 × 109/L), and the durable platelet response was 64.6%, 52.9%, and 52.7% for newly diagnosed, persistent, and chronic ITP, respectively. After treatment cessation, the median platelet count was 138 × 109/L, 68 × 109/L, and 71 × 109/L, respectively. In conclusion, newly diagnosed patients, compared with romiplostim initiators with longer disease duration, had more severe ITP, higher frequency of durable platelet response, and higher median platelet count after cessation.

Avatrombopag plus fostamatinib combination as treatment in patients with multirefractory immune thrombocytopenia.

Immune thrombocytopenia (ITP) refractory to multiple therapies may require a combination of drugs targeting different mechanisms and targets. In this retrospective, multicentre, international study, we report the safety and effectiveness of avatrombopag and fostamatininb in combination administered to 18 patients with multirefractory ITP. Overall, the combination response was achieved in 15 patients (83.3%), with a median time from combination start to best response of 15 days (IQR: 8-35 days). After a median follow-up of 256 days (IQR: 142.8-319), 5 patients relapsed (26.7%), all during tapering or stopping one drug. Adverse events were described in 6 of 18 patients (33%).

Risk-based and individualised management of bleeding and thrombotic events in adults with primary immune thrombocytopenia (ITP).

Although bleeding is one of the main symptoms of primary immune thrombocytopenia (ITP), risk factors for bleeding have yet to be fully established. Low platelet count (PC; <20-30 × 109 /L) is generally indicative of increased risk of bleeding. However, PC and bleeding events cannot be fully correlated; many other patient- and disease-related factors are thought to contribute to increased bleeding risk. Furthermore, even though ITP patients have thrombocytopenia and are at increased risk of bleeding, ITP also carries higher risk of thrombotic events. Factors like older age and certain ITP treatments are associated with increased thrombotic risk. Women's health in ITP requires particular attention concerning haemorrhagic and thrombotic complications. Management of bleeding/thrombotic risk, and eventually antithrombotic therapies in ITP patients, should be based on individual risk profiles, using a tailored, patient-centric approach. Currently, evidence-based recommendations and validated tools are lacking to support decision-making and help clinicians weigh risk of bleeding against thrombosis. Moreover, evidence is lacking about optimal PC for achieving haemostasis in invasive procedures settings. Further research is needed to fully define risk factors for each event, enabling development of comprehensive risk stratification approaches. This review discusses risk-based and individualised management of bleeding and thrombosis risk in adults with primary ITP.

Sustained response off-treatment in eltrombopag-treated adult patients with ITP who are refractory or relapsed after first-line steroids: Primary, final, and ad-hoc analyses of the Phase II TAPER trial.

Immune thrombocytopenia (ITP) is characterized by reduced platelet count due to increased destruction and is categorized according to the time following diagnosis (newly diagnosed, persistent, chronic). First-line corticosteroid therapy is associated with transient response, high relapse rates, and considerable toxicity. TAPER (NCT03524612) is a Phase II, prospective, single-arm trial investigating whether eltrombopag can induce a sustained response off-treatment (SRoT) in adult patients with ITP after first-line corticosteroid failure. This study defines SRoT as an off-treatment period wherein platelet count remains above 30 × 109 /L in the absence of bleeding or rescue therapy. The primary endpoint was the proportion of patients who achieved SRoT until Month 12, which was 30.5% (n = 32/105; p < .0001 testing hypothesis H1: proportion >15%) following eltrombopag tapering and discontinuation, and median SRoT duration was ~8 months until Month 12. Median platelet count increased within 1 month of treatment and remained elevated until Month 12. Quality of life improved within 3 months and was maintained. Headache (21%) was the most common adverse event. None of the 4 deaths reported were considered treatment-related. In summary, ~one-third of patients achieved SRoT until Month 12 following eltrombopag tapering and discontinuation. An ad-hoc early-use analysis, stratified by ITP duration at baseline, assessed initial hematologic responses and safety. Results suggest that eltrombopag has similar efficacy in newly diagnosed and later stages of ITP. In follow-up until Month 24, a median SRoT duration of ~22 months was observed (n = 20). The safety profile was comparable across analyses and ITP duration groups and aligned with its well-established safety profile.

Trajectory of cardiac troponin T following moderate-to-severe COVID-19 and the association with cardiac abnormalities.

BACKGROUND: COVID-19 has been associated with cardiac troponin T (cTnT) elevations and changes in cardiac structure and function, but the link between cardiac dysfunction and high-sensitive cardiac troponin T (hs-cTnT) in the acute and convalescent phase is unclear. OBJECTIVE: To assess whether hs-cTnT concentrations are associated with cardiac dysfunction and structural abnormalities after hospitalization for COVID-19, and to evaluate the performance of hs-cTnT to rule out cardiac pathology. METHODS: Patients hospitalized with COVID-19 had hs-cTnT measured during the index hospitalization and after 3-and 12 months, when they also underwent an echocardiographic study. A subset also underwent cardiovascular magnetic resonance imaging (CMR) after 6 months. Cardiac abnormalities were defined as left ventricular hypertrophy or dysfunction, right ventricular dysfunction, or CMR late gadolinium. RESULTS: We included 189 patients with hs-cTnT concentrations measured during hospitalization for COVID-19, and after 3-and 12 months: Geometric mean (95%CI) 13 (11-15) ng/L, 7 (6-8) ng/L and 7 (6-8) ng/L, respectively. Cardiac abnormalities after 3 months were present in 45 (30%) and 3 (8%) of patients with hs-cTnT ≥ and < 5 ng/L at 3 months, respectively (negative predictive value 92.3% [95%CI 88.5-96.1%]). The performance was similar in patients with and without dyspnea. Hs-cTnT decreased from hospitalization to 3 months (more pronounced in intensive care unit-treated patients) and remained unchanged from 3 to 12 months, regardless of the presence of cardiac abnormalities. CONCLUSION: Higher hs-cTnT concentrations in the convalescent phase of COVID-19 are associated with the presence of cardiac pathology and low concentrations (< 5 ng/L) may support in ruling out cardiac pathology following the infection.

Diagnostic management of acute pulmonary embolism: a prediction model based on a patient data meta-analysis.

AIMS: Risk stratification is used for decisions regarding need for imaging in patients with clinically suspected acute pulmonary embolism (PE). The aim was to develop a clinical prediction model that provides an individualized, accurate probability estimate for the presence of acute PE in patients with suspected disease based on readily available clinical items and D-dimer concentrations. METHODS AND RESULTS: An individual patient data meta-analysis was performed based on sixteen cross-sectional or prospective studies with data from 28 305 adult patients with clinically suspected PE from various clinical settings, including primary care, emergency care, hospitalized and nursing home patients. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict objectively confirmed PE at baseline or venous thromboembolism (VTE) during follow-up of 30 to 90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value <0.10. Discrimination (c-statistic with 95% confidence intervals [CI] and prediction intervals [PI]) and calibration (outcome:expected [O:E] ratio and calibration plot) were evaluated based on internal-external cross-validation. The accuracy of the model was subsequently compared with algorithms based on the Wells score and D-dimer testing. The final model included age (in years), sex, previous VTE, recent surgery or immobilization, haemoptysis, cancer, clinical signs of deep vein thrombosis, inpatient status, D-dimer (in µg/L), and an interaction term between age and D-dimer. The pooled c-statistic was 0.87 (95% CI, 0.85-0.89; 95% PI, 0.77-0.93) and overall calibration was very good (pooled O:E ratio, 0.99; 95% CI, 0.87-1.14; 95% PI, 0.55-1.79). The model slightly overestimated VTE probability in the lower range of estimated probabilities. Discrimination of the current model in the validation data sets was better than that of the Wells score combined with a D-dimer threshold based on age (c-statistic 0.73; 95% CI, 0.70-0.75) or structured clinical pretest probability (c-statistic 0.79; 95% CI, 0.76-0.81). CONCLUSION: The present model provides an absolute, individualized probability of PE presence in a broad population of patients with suspected PE, with very good discrimination and calibration. Its clinical utility needs to be evaluated in a prospective management or impact study. REGISTRATION: PROSPERO ID 89366.

Refractory immune thrombocytopenia in adults: Towards a new definition.

Immune thrombocytopenia (ITP) is an autoimmune haematological disorder characterized by immune-mediated thrombocytopenia and a variable risk of bleeding. Despite the availability of multiple treatment options, some patients are considered refractory since they do not achieve a platelet count response to multiple treatments and are at risk of bleeding. The term 'refractory' has been used to identify this patient group; however, with the advent of multiple lines of treatment, its meaning has become ambiguous. To address this issue, we reviewed previous definitions of refractory ITP, solicited the views of ITP experts and collected data from registries to inform a definition. Twenty ITP experts who attended the 7th Expert Meeting of the Intercontinental Cooperative ITP Study Group in September 2022 answered a web-based survey: 95% felt that there was a need for a new definition of refractory ITP for clinical and research purposes. The use of the term refractory, accompanied by a clear indication of the type and timing of failed treatments, was supported by 85% of respondents. Preliminary data on the frequency of refractory patients from the McMaster and Norwegian ITP Registries demonstrated that the proportion of adult ITP patients who had failed first-line therapy, rituximab, thrombopoietin receptor agonists, any immune suppressant medication and splenectomy ranged from 0.4% to 3.8%. We propose a definition of refractory ITP that could be evaluated in future studies.

Incidence and determinants of venous thromboembolism over 90 days in hospitalized and nonhospitalized patients with COVID-19.

INTRODUCTION: COVID-19 is associated with an increased risk of venous thromboembolism (VTE), but there is great variation among reported incidence rates. Most previous studies have focused on hospitalized patients with COVID-19, and only a few reports are from population-based registries. METHODS: We studied the 90-day incidence of VTE, associated risk factors and all-cause mortality in hospitalized and nonhospitalized patients with COVID-19 in a nationwide cohort. Data on hospitalizations and outpatient visits were extracted from two national registries with mandatory reporting linked by a unique national identification number carried by all Norwegian residents. We performed Cox proportional hazards regression to determine risk factors for VTE after infection with SARS-CoV-2. RESULTS: Our study included 30,495 patients with positive SARS-CoV-2 polymerase chain reaction with a mean (SD) age of 41.9 (17.3) years, and 53% were males. Only 2081 (6.8%) were hospitalized. The 90-day incidence of VTE was 0.3% (95% CI: 0.21-0.33) overall and 2.9% (95% CI: 2.3-3.7) in hospitalized patients. Age (hazard ratio [HR] 1.28 per decade, 95% CI: 1.11-1.48, p < 0.05), history of previous VTE (HR 4.69, 95% CI: 2.34-9.40, p < 0.05), and hospitalization for COVID-19 (HR 23.83, 95% CI: 13.48-42.13, p < 0.05) were associated with risk of VTE. CONCLUSIONS: The 90-day incidence of VTE in hospitalized and nonhospitalized patients with COVID-19 was in the lower end compared with previous reports, with considerably higher rates in hospitalized than nonhospitalized patients. Risk factors for VTE were consistent with previously reported studies.

Measuring Quality of Life after Venous Thromboembolism: Who, When, and How?

There is a growing body of evidence revealing that many patients with a history of venous thromboembolism (VTE) suffer from long-lasting sequelae such as post-thrombotic syndrome and post-pulmonary embolism syndrome. These two syndromes are detrimental to patients as they affect their quality of life (QOL). From this perspective, monitoring QOL may play a crucial role to improve quality care in VTE patients. Many studies have explored possible temporal relations between VTE episodes and decreased functional status and/or QOL. However, studies exploring the implementation of QOL and functional status questionnaires in clinical practice are scarce. In this context, we discuss possible perspectives synthetized from available literature regarding in whom, when, and how QOL could be measured in clinical practice.

How I treat primary ITP in adult patients who are unresponsive to or dependent on corticosteroid treatment.

Approximately 80% of adult patients with immune thrombocytopenia (ITP) have treatment failure with corticosteroids or become dependent on them and require second-line therapy. Several new and effective therapies have been introduced during the past decade and our understanding of disease burden and its effect on quality of life has expanded. It is now recommended that splenectomy, the standard second-line therapy for decades, be delayed for at least 12 to 24 months, allowing for more patients to achieve remission on medical therapies before considering surgery. It is highly recommended that medical therapies be used that have abundant clinical trial evidence, such as the thrombopoietin receptor agonists (TPO-RAs) rituximab and fostamatinib. Unfortunately, there are no reliable biomarkers that help in treatment selection. These therapeutic medical options have variable efficacy, safety profiles, mechanisms of action, and modes of administration. This enables and mandates an individualized approach to treatment, where patient involvement, preferences and values have become central to the process of choosing the appropriate therapy. Both TPO-RAs and fostamatinib are maintenance therapies, whereas rituximab is given for a limited number of doses. Although the response is usually maintained while receiving a TPO-RA or fostamatinib therapy, half of rituximab responders will no longer respond 1 to 2 years after administration and require retreatment or other therapy.

Recent advances in understanding spleen tyrosine kinase (SYK) in human biology and disease, with a focus on fostamatinib.

Spleen tyrosine kinase (SYK) is an important regulatory molecule of signal transduction pathways involved in the pathogenesis of autoimmune diseases such as immune thrombocytopenia (ITP), and the SYK-signaling pathway has emerged as a potential target for the treatment of numerous diseases. The aim of this narrative review is to summarize the biological properties of SYK and its involvement in disease pathways, provide an update on SYK inhibitors in the treatment of ITP, and consider other potential applications. Fostamatinib, the only licensed SYK inhibitor to date, produces clinical response in ITP patients, including those who are refractory to other treatments. It appears to reduce the risk of thrombotic events and may therefore be a drug to consider for patients with an increased thrombotic risk. Encouraging results have also been obtained in the treatment of warm autoimmune hemolytic anemia. Several other SYK inhibitors have entered clinical trials for a range of indications, reflecting the ability of these drugs to affect multiple signaling pathways. SYK inhibitors have the potential to target several aspects of COVID-19 pathogenesis including thrombosis, without affecting normal hemostasis, and data from the first study of fostamatinib in COVID-19 are encouraging. It is hoped that ongoing trials in autoimmune indications other than ITP, as well as in hematological malignancies and other disorders, confirm the promise of SYK inhibitors.

Immune thrombocytopenia (ITP) is an autoimmune disease that usually happens when your immune system mistakenly attacks and destroys platelets, which are cells that help blood to clot. Individuals with ITP can experience easy or excessive bruising and bleeding. Scientists have identified that an enzyme called spleen tyrosine kinase (SYK) is involved in numerous biological processes that are associated with the immune system response, inflammation, and some types of cancer in humans. Therefore, it has become a target for new drugs which inhibit the action of SYK. In this review article, the authors provide a summary of the biological properties and actions of SYK and its involvement in various diseases, discuss information about drugs that have been developed as SYK inhibitors for the treatment of ITP, and consider other potential uses for drugs that inhibit SYK. Although several drugs are being developed, the only SYK inhibitor that is currently available for the treatment of ITP is a drug called fostamatinib. In patients with ITP, including those who no longer respond to other treatments, fostamatinib has been shown to improve platelet counts and reduce bleeding events. Researchers are also currently investigating the use of drugs that inhibit SYK, including fostamatinib, for the potential treatment of other diseases associated with inflammation (e.g. rheumatoid arthritis, COVID-19), autoimmunity (e.g. warm autoimmune hemolytic anemia), and blood cancers (e.g. lymphoma, chronic lymphocytic leukemia, and acute myeloid leukemia).

Complement activation negatively affects the platelet response to thrombopoietin receptor agonists in patients with immune thrombocytopenia: a prospective cohort study.

Increased platelet destruction is central in the pathogenesis of immune thrombocytopenia. However, impaired platelet production is also relevant and its significance underlies the rationale for treatment with thrombopoietin receptor agonists (TPO-RAs). Previous studies have associated enhanced complement activation with increased disease severity. Additionally, treatment refractoriness has been demonstrated to resolve by the administration of complement-targeted therapeutics in a subset of patients. The association between complement activation and the platelet response to TPO-RA therapy has previously not been investigated. In this study, blood samples from patients with immune thrombocytopenia (n = 15) were prospectively collected before and two, six and 12 weeks after the initiation of TPO-RA therapy. Plasma levels of complement degradation product C4d and soluble terminal complement complexes were assessed. Patients with significantly elevated baseline levels of terminal complement complexes exhibited more often an inadequate platelet response (p = .04), were exclusively subjected to rescue therapy with intravenous immunoglobulin (p = .02), and did not respond with a significant platelet count increase during the study period. C4d showed a significant (p = .01) ability to distinguish samples with significant terminal complement activation, implying engagement of the classical complement pathway. In conclusion, elevated levels of complement biomarkers were associated with a worse TPO-RA treatment response. Larger studies are needed to confirm these results. Biomarkers of complement activation may prove valuable as a prognostic tool to predict which patients that potentially could benefit from complement-inhibiting therapy in the future.

What is the context?Primary immune thrombocytopenia (ITP) is a potentially serious illness associated with an increased risk of bleeds. Manifestations range from confined skin bruising to life-threatening intracranial hemorrhages.It is an acquired immune disorder characterized by increased destruction and impaired production of platelets.Treatments aim at suppressing the destruction and supporting the production of platelets.Thrombopoietin receptor agonists (TPO-RA) are medically approved platelet growth factors that contribute to the generation of new platelets.The complement system is an evolutionary preserved part of innate immunity.Previous studies have indicated that complement activation may be an important contributor to disease and that the administration of complement-inhibiting therapy improves the platelet count in a subset of patients with primary ITP.What is new? The potential association between complement activation and a poor platelet response to TPO-RA therapy in primary ITP has not been previously studied.In fifteen patients with primary ITP starting TPO-RA therapy, we prospectively followed the platelet response and levels of complement biomarkers for 12 weeks.We showed that patients with high levels of complement biomarkers exhibited a worse treatment response during the study period.What is the impact?Our results suggest that levels of complement biomarkers may be valuable to predict which patients with treatment-refractory ITP that potentially could benefit from complement-inhibiting therapy in the futureLarger studies are needed to confirm our results.

Safety and Efficiency of Diagnostic Strategies for Ruling Out Pulmonary Embolism in Clinically Relevant Patient Subgroups : A Systematic Review and Individual-Patient Data Meta-analysis.

BACKGROUND: How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown. PURPOSE: To evaluate the safety and efficiency of the Wells and revised Geneva scores combined with fixed and adapted D-dimer thresholds, as well as the YEARS algorithm, for ruling out acute PE in these subgroups. DATA SOURCES: MEDLINE from 1 January 1995 until 1 January 2021. STUDY SELECTION: 16 studies assessing at least 1 diagnostic strategy. DATA EXTRACTION: Individual-patient data from 20 553 patients. DATA SYNTHESIS: Safety was defined as the diagnostic failure rate (the predicted 3-month VTE incidence after exclusion of PE without imaging at baseline). Efficiency was defined as the proportion of individuals classified by the strategy as "PE considered excluded" without imaging tests. Across all strategies, efficiency was highest in patients younger than 40 years (47% to 68%) and lowest in patients aged 80 years or older (6.0% to 23%) or patients with cancer (9.6% to 26%). However, efficiency improved considerably in these subgroups when pretest probability-dependent D-dimer thresholds were applied. Predicted failure rates were highest for strategies with adapted D-dimer thresholds, with failure rates varying between 2% and 4% in the predefined patient subgroups. LIMITATIONS: Between-study differences in scoring predictor items and D-dimer assays, as well as the presence of differential verification bias, in particular for classifying fatal events and subsegmental PE cases, all of which may have led to an overestimation of the predicted failure rates of adapted D-dimer thresholds. CONCLUSION: Overall, all strategies showed acceptable safety, with pretest probability-dependent D-dimer thresholds having not only the highest efficiency but also the highest predicted failure rate. From an efficiency perspective, this individual-patient data meta-analysis supports application of adapted D-dimer thresholds. PRIMARY FUNDING SOURCE: Dutch Research Council. (PROSPERO: CRD42018089366).

[Factor Xa inhibitors in the prevention and treatment of venous thromboembolism in cancer patients]. / Faktor Xa-hemmere til forebygging og behandling av venøs tromboembolisme ved kreft.

Venous thromboembolism is a common complication of cancer. The prevalence varies according to cancer type and increases proportionally with the stage of cancer. In the past 15-20 years, low molecular weight heparin has been recommended as the first-line treatment. New international guidelines now allow for use of direct factor Xa inhibitors both as prophylaxis and treatment for venous thromboembolism. Prophylaxis should as a general rule only be initiated in patients with moderate to high risk. Bleeding risk assessment is important before starting anticoagulation. Both thrombosis and bleeding risk can change and should therefore be assessed on an ongoing basis. In this clinical review, use of anticoagulation therapy in cancer patients is discussed with particular emphasis on the use of direct factor Xa inhibitors.

Ruling out pulmonary embolism across different healthcare settings: A systematic review and individual patient data meta-analysis.

BACKGROUND: The challenging clinical dilemma of detecting pulmonary embolism (PE) in suspected patients is encountered in a variety of healthcare settings. We hypothesized that the optimal diagnostic approach to detect these patients in terms of safety and efficiency depends on underlying PE prevalence, case mix, and physician experience, overall reflected by the type of setting where patients are initially assessed. The objective of this study was to assess the capability of ruling out PE by available diagnostic strategies across all possible settings. METHODS AND FINDINGS: We performed a literature search (MEDLINE) followed by an individual patient data (IPD) meta-analysis (MA; 23 studies), including patients from self-referral emergency care (n = 12,612), primary healthcare clinics (n = 3,174), referred secondary care (n = 17,052), and hospitalized or nursing home patients (n = 2,410). Multilevel logistic regression was performed to evaluate diagnostic performance of the Wells and revised Geneva rules, both using fixed and adapted D-dimer thresholds to age or pretest probability (PTP), for the YEARS algorithm and for the Pulmonary Embolism Rule-out Criteria (PERC). All strategies were tested separately in each healthcare setting. Following studies done in this field, the primary diagnostic metrices estimated from the models were the "failure rate" of each strategy-i.e., the proportion of missed PE among patients categorized as "PE excluded" and "efficiency"-defined as the proportion of patients categorized as "PE excluded" among all patients. In self-referral emergency care, the PERC algorithm excludes PE in 21% of suspected patients at a failure rate of 1.12% (95% confidence interval [CI] 0.74 to 1.70), whereas this increases to 6.01% (4.09 to 8.75) in referred patients to secondary care at an efficiency of 10%. In patients from primary healthcare and those referred to secondary care, strategies adjusting D-dimer to PTP are the most efficient (range: 43% to 62%) at a failure rate ranging between 0.25% and 3.06%, with higher failure rates observed in patients referred to secondary care. For this latter setting, strategies adjusting D-dimer to age are associated with a lower failure rate ranging between 0.65% and 0.81%, yet are also less efficient (range: 33% and 35%). For all strategies, failure rates are highest in hospitalized or nursing home patients, ranging between 1.68% and 5.13%, at an efficiency ranging between 15% and 30%. The main limitation of the primary analyses was that the diagnostic performance of each strategy was compared in different sets of studies since the availability of items used in each diagnostic strategy differed across included studies; however, sensitivity analyses suggested that the findings were robust. CONCLUSIONS: The capability of safely and efficiently ruling out PE of available diagnostic strategies differs for different healthcare settings. The findings of this IPD MA help in determining the optimum diagnostic strategies for ruling out PE per healthcare setting, balancing the trade-off between failure rate and efficiency of each strategy.

Use of thrombopoietin receptor agonists for immune thrombocytopenia in pregnancy: results from a multicenter study.

Management of immune thrombocytopenia (ITP) during pregnancy can be challenging because treatment choices are limited. Thrombopoietin receptor agonists (Tpo-RAs), which likely cross the placenta, are not recommended during pregnancy. To better assess the safety and efficacy of off-label use of Tpo-RAs during pregnancy, a multicenter observational and retrospective study was conducted. Results from 15 pregnant women with ITP (pregnancies, n = 17; neonates, n = 18) treated with either eltrombopag (n = 8) or romiplostim (n = 7) during pregnancy, including 2 patients with secondary ITP, were analyzed. Median time of Tpo-RA exposure during pregnancy was 4.4 weeks (range, 1-39 weeks); the indication for starting Tpo-RAs was preparation for delivery in 10 (58%) of 17 pregnancies, whereas 4 had chronic refractory symptomatic ITP and 3 were receiving eltrombopag when pregnancy started. Regarding safety, neither thromboembolic events among mothers nor Tpo-RA-related fetal or neonatal complications were observed, except for 1 case of neonatal thrombocytosis. Response to Tpo-RAs was achieved in 77% of cases, mostly in combination with concomitant ITP therapy (70% of responders). On the basis of these preliminary findings, temporary off-label use of Tpo-RAs for severe and/or refractory ITP during pregnancy seems safe for both mother and neonate and is likely to be helpful, especially before delivery.

Magnetic resonance imaging for diagnosis of recurrent ipsilateral deep vein thrombosis.

The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) is challenging, because persistent intravascular abnormalities after previous DVT often hinder a diagnosis by compression ultrasonography. Magnetic resonance direct thrombus imaging (MRDTI), a technique without intravenous contrast and with a 10-minute acquisition time, has been shown to accurately distinguish acute recurrent DVT from chronic thrombotic remains. We have evaluated the safety of MRDTI as the sole test for excluding recurrent ipsilateral DVT. The Theia Study was a prospective, international, multicenter, diagnostic management study involving patients with clinically suspected acute recurrent ipsilateral DVT. Treatment of the patients was managed according to the result of the MRDTI, performed within 24 hours of study inclusion. The primary outcome was the 3-month incidence of venous thromboembolism (VTE) after a MRDTI negative for DVT. The secondary outcome was the interobserver agreement on the MRDTI readings. An independent committee adjudicated all end points. Three hundred five patients were included. The baseline prevalence of recurrent DVT was 38%; superficial thrombophlebitis was diagnosed in 4.6%. The primary outcome occurred in 2 of 119 (1.7%; 95% confidence interval [CI], 0.20-5.9) patients with MRDTI negative for DVT and thrombophlebitis, who were not treated with any anticoagulant during follow-up; neither of these recurrences was fatal. The incidence of recurrent VTE in all patients with MRDTI negative for DVT was 1.1% (95% CI, 0.13%-3.8%). The agreement between initial local and post hoc central reading of the MRDTI images was excellent (κ statistic, 0.91). The incidence of VTE recurrence after negative MRDTI was low, and MRDTI proved to be a feasible and reproducible diagnostic test. This trial was registered at www.clinicaltrials.gov as #NCT02262052.