Oral Anticoagulants Beyond Warfarin.

Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists, mostly warfarin, for the main indications for oral anticoagulation, prevention and treatment of venous thromboembolism, and prevention of embolic stroke in atrial fibrillation. While DOACs offer practical, fixed-dose anticoagulation in many patients, specific restrictions or contraindications may apply. DOACs are not sufficiently effective in high-thrombotic risk conditions such as antiphospholipid syndrome and mechanical heart valves. Patients with cancer-associated thrombosis may benefit from DOACs, but the bleeding risk, particularly in those with gastrointestinal or urogenital tumors, must be carefully weighed. In patients with frailty, excess body weight, and/or moderate-to-severe chronic kidney disease, DOACs must be cautiously administered and may require laboratory monitoring. Reversal agents have been developed and approved for life-threatening bleeding. In addition, the clinical testing of potentially safer anticoagulants such as factor XI(a) inhibitors is important to further optimize anticoagulant therapy in an increasingly elderly and frail population worldwide.

Hemocompatibility and biophysical interface of left ventricular assist devices and total artificial hearts.

ABSTRACT: Over the past 2 decades, there has been a significant increase in the utilization of long-term mechanical circulatory support (MCS) for the treatment of cardiac failure. Left ventricular assist devices (LVADs) and total artificial hearts (TAHs) have been developed in parallel to serve as bridge-to-transplant and destination therapy solutions. Despite the distinct hemodynamic characteristics introduced by LVADs and TAHs, a comparative evaluation of these devices regarding potential complications in supported patients, has not been undertaken. Such a study could provide valuable insights into the complications associated with these devices. Although MCS has shown substantial clinical benefits, significant complications related to hemocompatibility persist, including thrombosis, recurrent bleeding, and cerebrovascular accidents. This review focuses on the current understanding of hemostasis, specifically thrombotic and bleeding complications, and explores the influence of different shear stress regimens in long-term MCS. Furthermore, the role of endothelial cells in protecting against hemocompatibility-related complications of MCS is discussed. We also compared the diverse mechanisms contributing to the occurrence of hemocompatibility-related complications in currently used LVADs and TAHs. By applying the existing knowledge, we present, for the first time, a comprehensive comparison between long-term MCS options.

Factor XI deficiency: phenotypic age-related considerations and clinical approach towards bleeding risk assessment.

ABSTRACT: Factor XI (FXI) deficiency is a rare bleeding disorder that presents complex challenges in patient assessment and bleeding risk management. Despite generally causing mild to moderate bleeding symptoms, clinical manifestations can vary, and bleeding tendency does not always correlate with FXI plasma levels or genotype. Our manuscript delves into the age-related nuances of FXI deficiency across an individual's lifespan. We emphasize issues faced by specific groups, including neonates and females of reproductive age experiencing abnormal uterine bleeding and postpartum hemorrhage. Older patients present unique challenges and concerns related to the management of bleeding as well as thrombotic complications. The current assortment of diagnostic laboratory assays shows limited success in predicting bleeding risk in the perisurgical setting of patients with FXI deficiency. This review explores the intricate interplay between individual bleeding profiles, surgical sites, and FXI activity levels. We also evaluate the accuracy of existing laboratory assays in predicting bleeding and discuss the potential role of investigational global assays in perioperative assessment. Furthermore, we outline our suggested diagnostic approach to refine treatment strategies and decision making. Available treatment options are presented, including antifibrinolytics, replacement products, and recombinant activated FVII. Finally, we discuss promising nonreplacement therapies for the treatment of rare bleeding disorders that can potentially address the challenges faced when managing FXI deficiency-related bleeding complications.

Efficacy and Safety of Non-Vitamin-K Antagonist Oral Anticoagulants Versus Warfarin Across the Spectrum of Body Mass Index and Body Weight: An Individual Patient Data Meta-Analysis of 4 Randomized Clinical Trials of Patients With Atrial Fibrillation.

BACKGROUND: The efficacy and safety of non-vitamin-K antagonist oral anticoagulants (NOACs) across the spectrum of body mass index (BMI) and body weight (BW) remain uncertain. METHODS: We analyzed data from COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation), which pooled patient-level data from the 4 pivotal randomized trials of NOAC versus warfarin in patients with atrial fibrillation. The primary efficacy and safety outcomes were stroke or systemic embolic events (stroke/SEE) and major bleeding, respectively; secondary outcomes were ischemic stroke/SEE, intracranial hemorrhage, death, and the net clinical outcome (stroke/SEE, major bleeding, or death). Each outcome was examined across BMI and BW. Because few patients had a BMI <18.5 kg/m2 (n=598), the primary analyses were restricted to those with a BMI ≥18.5 kg/m2. RESULTS: Among 58 464 patients, the median BMI was 28.3 (interquartile range, 25.2-32.2) kg/m2, and the median BW was 81.0 (interquartile range, 70.0-94.3) kg. The event probability of stroke/SEE was lower at a higher BMI irrespective of treatment, whereas the probability of major bleeding was lower at a higher BMI with warfarin but relatively unchanged across BMI with NOACs. NOACs reduced stroke/SEE overall (adjusted hazard ratio [HRadj], 0.80 [95% CI, 0.73-0.88]; P<0.001), with a generally consistent effect across BMI (Ptrend across HRs, 0.48). NOACs also reduced major bleeding overall (HRadj, 0.88 [95% CI, 0.82-0.94]; P<0.001), but with attenuation of the benefit at a higher BMI (trend test across BMI [Ptrend], 0.003). The overall treatment effects of NOACs versus warfarin for secondary outcomes were consistent across BMI, with the exception of the net clinical outcome and death. While these outcomes were overall reduced with NOACs (net clinical outcome, HRadj, 0.91 [95% CI, 0.87-0.95]; P<0.001; death, HRadj, 0.91 [95% CI, 0.86-0.97]; P=0.003), these benefits were attenuated at higher BMI (Ptrend, 0.001 and 0.08, respectively). All findings were qualitatively similar when analyzed across BW. CONCLUSIONS: The treatment effect of NOACs versus warfarin in atrial fibrillation is generally consistent for stroke/SEE across the spectrum of BMI and BW, whereas the reduction in major bleeding is attenuated in those with higher BMI or BW. Death and the net clinical outcome are overall reduced with NOACs over warfarin, although there remain uncertainties for these outcomes at a very high BMI and BW.

Strokes Averted by Intravenous Thrombolysis: A Secondary Analysis of a Prospective, Multicenter, Controlled Trial of Mobile Stroke Units.

OBJECTIVE: This study was undertaken to examine averted stroke in optimized stroke systems. METHODS: This secondary analysis of a multicenter trial from 2014 to 2020 compared patients treated by mobile stroke unit (MSU) versus standard management. The analytical cohort consisted of participants with suspected stroke treated with intravenous thrombolysis. The main outcome was a tissue-defined averted stroke, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis and no acute infarction/hemorrhage on imaging. An additional outcome was stroke with early symptom resolution, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis. RESULTS: Among 1,009 patients with a median last known well to thrombolysis time of 87 minutes, 159 (16%) had tissue-defined averted stroke and 276 (27%) had stroke with early symptom resolution. Compared with standard management, MSU care was associated with more tissue-defined averted stroke (18% vs 11%, adjusted odds ratio [aOR] = 1.82, 95% confidence interval [CI] = 1.13-2.98) and stroke with early symptom resolution (31% vs 21%, aOR = 1.74, 95% CI = 1.12-2.61). The relationships between thrombolysis treatment time and averted/early recovered stroke appeared nonlinear. Most models indicated increased odds for stroke with early symptom resolution but not tissue-defined averted stroke with earlier treatment. Additionally, younger age, female gender, hyperlipidemia, lower National Institutes of Health Stroke Scale, lower blood pressure, and no large vessel occlusion were associated with both tissue-defined averted stroke and stroke with early symptom resolution. INTERPRETATION: In optimized stroke systems, 1 in 4 patients treated with thrombolysis recovered within 24 hours and 1 in 6 had no demonstrable brain injury on imaging. ANN NEUROL 2024;95:347-361.

Stroke and bleeding risk in atrial fibrillation with CHA2DS2-VASC risk score of one: the Norwegian AFNOR study.

BACKGROUND AND AIMS: The benefit of oral anticoagulant (OAC) therapy in atrial fibrillation (AF) and intermediate stroke risk is debated. In a nationwide Norwegian cohort with a non-sex CHA2DS2-VASc risk score of one, this study aimed to investigate (i) stroke and bleeding risk in AF patients with and without OAC treatment, and (ii) the risk of stroke in non-anticoagulated individuals with and without AF. METHODS: A total of 1 118 762 individuals including 34 460 AF patients were followed during 2011-18 until ischaemic stroke, intracranial haemorrhage, increased CHA2DS2-VASc score, or study end. One-year incidence rates (IRs) were calculated as events per 100 person-years (%/py). Cox regression models provided adjusted hazard ratios (aHRs [95% confidence intervals]). RESULTS: Among AF patients, the ischaemic stroke IR was 0.51%/py in OAC users and 1.05%/py in non-users (aHR 0.47 [0.37-0.59]). Intracranial haemorrhage IR was 0.28%/py in OAC users and 0.19%/py in non-users (aHR 1.23 [0.88-1.72]). Oral anticoagulant use was associated with an increased risk of major bleeding (aHR 1.37 [1.16-1.63]) but lower risk of the combined outcome of ischaemic stroke, major bleeding, and mortality (aHR 0.57 [0.51-0.63]). Non-anticoagulated individuals with AF had higher risk of ischaemic stroke compared to non-AF individuals with the same risk profile (aHR 2.47 [2.17-2.81]). CONCLUSIONS: In AF patients at intermediate risk of stroke, OAC use was associated with overall favourable clinical outcomes. Non-anticoagulated AF patients had higher risk of ischaemic stroke compared to the general population without AF with the same risk profile.

Rivaroxaban Plus Aspirin Versus Aspirin Alone After Endovascular Revascularization for Symptomatic PAD: Insights From VOYAGER PAD.

BACKGROUND: Rivaroxaban plus aspirin compared with aspirin alone reduced major cardiac and ischemic limb events after lower extremity revascularization (LER) in the VOYAGER PAD (Vascular Outcomes Study of ASA Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for Peripheral Artery Disease) trial. The effect has not been described in patients undergoing endovascular LER. METHODS: The VOYAGER PAD trial randomized 6564 patients with symptomatic peripheral artery disease to a double-blinded treatment with 2.5 mg of rivaroxaban BID or matching placebo and 100 mg of aspirin daily. The primary efficacy outcome was a composite of acute limb ischemia, major amputation of a vascular pathogenesis, myocardial infarction, ischemic stroke, or cardiovascular death. The principal safety end point was Thrombolysis in Myocardial Infarction major bleeding. A prespecified subgroup of patients who underwent endovascular revascularization was included. RESULTS: Endovascular LER occurred in 4379 (66.7%) patients and surgical LER in 2185 (33.3%). Over a 3-year follow-up, rivaroxaban reduced the risk of the primary outcome by 15% (hazard ratio [HR], 0.85 [95% CI, 0.76-0.96]) with an absolute risk reduction of 0.92% at 6 months and 1.04% at 3 years and a consistent benefit in those receiving endovascular (HR, 0.89 [95% CI, 0.76-1.03]) or surgical LER (HR, 0.81 [95% CI, 0.67-0.98]; P interaction=0.43). For endovascular-treated patients, rivaroxaban reduced the risk of acute limb ischemia or major amputation of a vascular pathogenesis by 30% (HR, 0.70 [95% CI, 0.54-0.90]; P=0.005) with an absolute risk reduction of 1.0% at 6 months and 2.0% at 3 years compared with aspirin alone. Among endovascular-treated patients, the median duration of concomitant dual antiplatelet therapy with clopidogrel treatment was 31 days (interquartile range, 30-58). There was a consistent benefit for rivaroxaban regardless of background clopidogrel. Thrombolysis in Myocardial Infarction major bleeding was significantly higher for the rivaroxaban and aspirin group for the endovascular cohort (HR, 1.66 [95% CI, 1.06-2.59]) with an absolute risk increase of 0.9% at 3 years with no increase in intracranial or fatal bleeding observed (HR, 0.86 [95% CI, 0.40-1.87]; P=0.71). Mortality with rivaroxaban was higher in the endovascular-treated patients (HR, 1.24 [95% CI, 1.02-1.52]), although this finding was isolated to specific regions. CONCLUSIONS: Rivaroxaban added to aspirin or dual antiplatelet therapy after LER for peripheral artery disease reduces ischemic risk and increases major bleeding without an increased risk of intracranial or fatal bleeding. These benefits are consistent in those treated with endovascular and surgical approaches with significant benefits for major adverse limb events. These data support the use of rivaroxaban in addition to aspirin or dual antiplatelet therapy after endovascular intervention for symptomatic peripheral artery disease.

Edoxaban for 12 Months Versus 3 Months in Patients With Cancer With Isolated Distal Deep Vein Thrombosis (ONCO DVT Study): An Open-Label, Multicenter, Randomized Clinical Trial.

BACKGROUND: The optimal duration of anticoagulation therapy for isolated distal deep vein thrombosis in patients with cancer is clinically relevant, but the evidence is lacking. The prolonged anticoagulation therapy could have a potential benefit for prevention of thrombotic events; however, it could also increase the risk of bleeding. METHODS: In a multicenter, open-label, adjudicator-blinded, randomized clinical trial at 60 institutions in Japan, we randomly assigned patients with cancer with isolated distal deep vein thrombosis, in a 1-to-1 ratio, to receive either a 12-month or 3-month edoxaban treatment. The primary end point was a composite of a symptomatic recurrent venous thromboembolism (VTE) or VTE-related death at 12 months. The major secondary end point was major bleeding at 12 months, according to the criteria of the International Society on Thrombosis and Haemostasis. The primary hypothesis was that a 12-month edoxaban treatment was superior to a 3-month edoxaban treatment with respect to the primary end point. RESULTS: From April 2019 through June 2022, 604 patients were randomized, and after excluding 3 patients who withdrew consent, 601 patients were included in the intention-to-treat population: 296 patients in the 12-month edoxaban group and 305 patients in the 3-month edoxaban group. The mean age was 70.8 years, 28% of the patients were men, and 20% of the patients had symptoms of deep vein thrombosis at baseline. The primary end point of a symptomatic recurrent VTE event or VTE-related death occurred in 3 of the 296 patients (1.0%) in the 12-month edoxaban group and in 22 of the 305 patients (7.2%) in the 3-month edoxaban group (odds ratio, 0.13; 95% CI, 0.03-0.44). The major secondary end point of major bleeding occurred in 28 of the 296 patients (9.5%) in the 12-month edoxaban group and in 22 of the 305 patients (7.2%) in the 3-month edoxaban group (odds ratio, 1.34; 95% CI, 0.75-2.41). The prespecified subgroups did not affect the estimates on the primary end point. CONCLUSIONS: In patients with cancer with isolated distal deep vein thrombosis, 12 months was superior to 3 months for an edoxaban treatment with respect to the composite outcome of a symptomatic recurrent VTE or VTE-related death. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03895502.

Trial Readiness of Cavernous Malformations With Symptomatic Hemorrhage, Part II: Biomarkers and Trial Modeling.

BACKGROUND: Quantitative susceptibility mapping (QSM) and dynamic contrast-enhanced quantitative perfusion (DCEQP) magnetic resonance imaging sequences assessing iron deposition and vascular permeability were previously correlated with new hemorrhage in cerebral cavernous malformations. We assessed their prospective changes in a multisite trial-readiness project. METHODS: Patients with cavernous malformation and symptomatic hemorrhage (SH) in the prior year, without prior or planned lesion resection or irradiation were enrolled. Mean QSM and DCEQP of the SH lesion were acquired at baseline and at 1- and 2-year follow-ups. Sensitivity and specificity of biomarker changes were analyzed in relation to predefined criteria for recurrent SH or asymptomatic change. Sample size calculations for hypothesized therapeutic effects were conducted. RESULTS: We logged 143 QSM and 130 DCEQP paired annual assessments. Annual QSM change was greater in cases with SH than in cases without SH (P=0.019). Annual QSM increase by ≥6% occurred in 7 of 7 cases (100%) with recurrent SH and in 7 of 10 cases (70%) with asymptomatic change during the same epoch and 3.82× more frequently than clinical events. DCEQP change had lower sensitivity for SH and asymptomatic change than QSM change and greater variance. A trial with the smallest sample size would detect a 30% difference in QSM annual change during 2 years of follow-up in 34 or 42 subjects (1 and 2 tailed, respectively); power, 0.8, α=0.05. CONCLUSIONS: Assessment of QSM change is feasible and sensitive to recurrent bleeding in cavernous malformations. Evaluation of an intervention on QSM percent change may be used as a time-averaged difference between 2 arms using a repeated measures analysis. DCEQP change is associated with lesser sensitivity and higher variability than QSM. These results are the basis of an application for certification by the US Food and Drug Administration of QSM as a biomarker of drug effect on bleeding in cavernous malformations. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03652181.

Baseline Stroke Risk and Efficacy of Dual-Antiplatelet Therapy: A Post Hoc Analysis of the POINT Trial.

BACKGROUND: High-risk transient ischemic attacks and minor ischemic strokes are followed by a variable risk of ischemic stroke. We aimed to determine how baseline stroke risk modified the efficacy of clopidogrel-aspirin (referred to here as dual-antiplatelet therapy [DAPT]) for transient ischemic attack and minor ischemic stroke. METHODS: We performed an unplanned secondary analysis of the POINT trial (Platelet-Oriented Inhibition in New Transient Ischemic Attack and Minor Ischemic Stroke). We first evaluated the associations of the CHA2DS2-VASc and stroke prognosis instrument II (SPI-II) scores with the risk of incident ischemic stroke and major hemorrhage (intracranial hemorrhage or major systemic hemorrhage). We then tested for heterogeneity of the relative and absolute treatment effect of DAPT relative to aspirin across low- and high-risk patient subgroups. RESULTS: A total of 4841 trial participants were included in this analysis, with 2400 participants assigned to treatment with short-term DAPT and 2430 participants to treatment with aspirin and placebo. The dichotomized SPI-II score, but not the CHA2DS2-VASc score (P=0.18), was associated with the risk of incident ischemic stroke. A high-risk SPI-II score (>3) was associated with greater risk of incident ischemic stroke (hazard ratio of incident ischemic stroke relative to low-risk SPI-II score of 1.84 [95% CI, 1.44-2.35]; P<0.001) and numerically greater risk of major hemorrhage though not meeting statistical significance (hazard ratio, 1.80 [95% CI, 0.90-3.57]; P=0.10). The relative risk reduction with DAPT was similar across SPI-II strata (Pinteraction=0.31). The absolute risk reduction for ischemic stroke with DAPT compared with aspirin was nearly 4-fold higher (2.80% versus 0.76%; number needed to treat, 31 versus 131) in the high-risk SPI-II stratum relative to the low-risk stratum. The absolute risk increase for major hemorrhage with DAPT compared with aspirin was 3-fold higher (0.84% versus 0.30%; number needed to harm, 119 versus 331) in the high-risk SPI-II stratum relative to the low-risk stratum. CONCLUSIONS: Stratification by baseline stroke risk identifies a patient subgroup that derives greater absolute benefit from treatment with DAPT. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00991029.

Acquired haemophilia A in paediatric patients: A retrospective French cohort of eight cases.

Acquired haemophilia A (AHA) is a rare haemorrhagic disease characterised by new-onset haemorrhagic symptoms associated with a dramatic decrease in factor VIII levels and an anti-factor VIII neutralising autoantibody concentration >0.6 Bethesda units. Elderly people are often affected, whereas children are rarely affected; the paediatric incidence reported in the literature is about 0.045 case/million/year. For some time, the paediatric standard of care has been that for adults, but clinicians have often reported poor outcomes. Here, we describe the largest retrospective paediatric AHA cohort assembled to date, including eight patients diagnosed in France from 2000 to 2020.

Safety and Efficacy of Reduced-Dose Versus Full-Dose Alteplase for Acute Pulmonary Embolism: A Multicenter Observational Comparative Effectiveness Study.

OBJECTIVES: Systemic thrombolysis improves outcomes in patients with pulmonary embolism (PE) but is associated with the risk of hemorrhage. The data on efficacy and safety of reduced-dose alteplase are limited. The study objective was to compare the characteristics, outcomes, and complications of patients with PE treated with full- or reduced-dose alteplase regimens. DESIGN: Multicenter retrospective observational study. SETTING: Tertiary care hospital and 15 community and academic centers of a large healthcare system. PATIENTS: Hospitalized patients with PE treated with systemic alteplase. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Pre- and post-alteplase hemodynamic and respiratory variables, patient outcomes, and complications were compared. Propensity score (PS) weighting was used to adjust for imbalances of baseline characteristics between reduced- and full-dose patients. Separate analyses were performed using the unweighted and weighted cohorts. Ninety-eight patients were treated with full-dose (100 mg) and 186 with reduced-dose (50 mg) regimens. Following alteplase, significant improvements in shock index, blood pressure, heart rate, respiratory rate, and supplemental oxygen requirements were observed in both groups. Hemorrhagic complications were lower with the reduced-dose compared with the full-dose regimen (13% vs. 24.5%, p = 0.014), and most were minor. Major extracranial hemorrhage occurred in 1.1% versus 6.1%, respectively ( p = 0.022). Complications were associated with supratherapeutic levels of heparin anticoagulation in 37.5% of cases and invasive procedures in 31.3% of cases. The differences in complications persisted after PS weighting (15.4% vs. 24.7%, p = 0.12 and 1.3% vs. 7.1%, p = 0.067), but did not reach statistical significance. There were no significant differences in mortality, discharge destination, ICU or hospital length of stay, or readmission after PS weighting. CONCLUSIONS: In a retrospective, PS-weighted observational study, when compared with the full-dose, reduced-dose alteplase results in similar outcomes but fewer hemorrhagic complications. Avoidance of excessive levels of anticoagulation or invasive procedures should be considered to further reduce complications.

Correlation between IPSET-t risk at diagnosis and subsequent hemorrhage in patients with essential thrombocythemia; a single institution experience.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by an increased risk of thrombotic and hemorrhagic events, that represent the leading causes of mortality and morbidity. Currently, while thrombotic risk is assessed through the IPSET-t and r-IPSET scores, there is no specific prognostic tool used to predict hemorrhagic risk in ET. The aim of the study was to define incidence and risk factors connected to hemorrhagic events by retrospectively analyzing 308 ET patients diagnosed between 1996 and 2022 at the Division of Hematology of Udine and treated according to the current international guidelines. According to molecular status, 193 patients (62.7%) were JAK2 mutated, 66 (21.4%) had a CALR mutation, 14 (4.5%) had a MPL mutation, 21 patients (6.8%) were "triple negative," and 14 patients (4.5%) were not evaluable. According to IPSET-t score, 49.7% patients were at high, 24.3% at intermediate, and 26.0% at low-risk, respectively. Twelve (3.9%) patients experienced bleeding at ET diagnosis, while 24 (7.8%) had at least one hemorrhagic event during follow-up at a median time of 103 months (range: 1-309). Forty hemorrhagic events were totally recorded and defined as minor in 22 cases, moderate in 11 cases, and severe in 7 cases. Cumulative incidence (CI) of hemorrhage at 10 and 20 years was 6.0% and 12.0%, respectively. A statistically significant correlation between hemorrhagic risk and IPSET-t score emerged: 10 years hemorrhage CI was 3.2% for low-risk, 2.9% for intermediate-risk, and 9.8% for high-risk patients, respectively (p=0.002). We found no correlation between hemorrhagic risk and gender or mutational status. Results of our study highlight the validity of IPSET-t score in predicting individual hemorrhagic risk among ET patients, suggesting a possible role of IPSET-t scoring system as a global evaluator for vascular events in ET patients.

Assessment of rare bleeding disorders in adolescents with heavy menstrual bleeding.

INTRODUCTION: There are a significant number of patients with mucocutaneous bleeding, specifically heavy menstrual bleeding (HMB), who do not have a diagnosed bleeding disorder. These patients receive nontargeted interventions and may have suboptimal treatments. Functional assays, particularly for fibrinolytic and rare platelet function defects, are not robust and not readily available. AIM: We aimed to prospectively evaluate the prevalence of genetic defects associated with rare bleeding disorders and describe alterations of coagulation and fibrinolysis in a cohort of adolescents with HMB. METHODS: We performed a prospective observational cohort study of patients with HMB and unexplained bleeding. The study utilized a next generation sequencing panel and investigational global assays of coagulation and fibrinolysis. Additionally, specific functional assays were performed to help characterize novel variants that were identified. RESULTS: In 10 of the 17 patients (∼59%), genetic variants were identified on molecular testing. Thrombin generation by calibrated thromboelastography was not significantly altered in this patient population. The clot formation and lysis assay showed a trend towards increased fibrinolysis with rapid phase of decline in 23% of the patients. Further corresponding functional assays and study population are described. CONCLUSION: Our study describes a unique correlative model in a homogenous cohort of patients with HMB and unexplained bleeding which may inform future diagnostic algorithms, genotype-phenotype correlations as well as aid in specific targeted treatment approaches. Larger future studies may inform risk stratification of patients and improve health related outcomes in patients with HMB.

Indirect treatment comparisons of the gene therapy etranacogene dezaparvovec versus extended half-life factor IX therapies for severe or moderately severe haemophilia B.

INTRODUCTION: Etranacogene dezaparvovec gene therapy for haemophilia B demonstrated superior efficacy at 24 months in reducing bleeds versus a ≥6-month lead-in period of prophylaxis with FIX products in the phase 3 trial, HOPE-B. In the absence of head-to-head comparisons of etranacogene dezaparvovec versus FIX products, indirect treatment comparisons (ITC) can be used. AIM: To compare the efficacy of etranacogene dezaparvovec versus rIX-FP, rFIXFc and N9-GP using ITC, and support HOPE-B results. METHODS: Data were leveraged from Phase 3 pivotal trials: HOPE-B, PROLONG-9FP, B-LONG and Paradigm 2. Annualised bleeding rates (ABR), spontaneous (AsBR) and joint (AjBR) bleeding rates, percentage of patients with no bleeds, and FIX consumption were assessed using inverse probability of treatment weighting and matching adjusted indirect comparisons. RESULTS: Etranacogene dezaparvovec demonstrated statistically significantly lower bleeding rates versus all comparators. Rate ratios for ABR, AsBR and AjBR versus rIX-FP were 0.19 (p < .0001), 0.08 (p < .0001) and 0.09 (p < .0001), respectively. Rate ratios for ABR, AsBR and AjBR versus rFIXFc were 0.14 (p < .0001), 0.13 (p = .0083) and 0.15 (p = .0111), respectively. Rate ratios for ABR and AsBR, versus N9-GP were 0.24 (p = .0231) and 0.13 (p = .0071), respectively. Etranacogene dezaparvovec demonstrated significantly higher percentage of patients with no bleeds versus rIX-FP and rFIXFc; odds ratios: 17.60 (p < .0001) and 5.65 (p = .0037), respectively. Etranacogene dezaparvovec resulted in significantly lower FIX consumption than all comparators. CONCLUSIONS: ITC suggests that etranacogene dezaparvovec offers patients with haemophilia B (≤2% of normal FIX expression) a single dose treatment that can significantly reduce bleeding rates and eliminate routine infusions associated with FIX therapies.

Extracorporeal life support without systemic anticoagulation: a nitric oxide-based non-thrombogenic circuit for the artificial placenta in an ovine model.

BACKGROUND: Clinical translation of the extracorporeal artificial placenta (AP) is impeded by the high risk for intracranial hemorrhage in extremely premature newborns. The Nitric Oxide Surface Anticoagulation (NOSA) system is a novel non-thrombogenic extracorporeal circuit. This study aims to test the NOSA system in the AP without systemic anticoagulation. METHODS: Ten extremely premature lambs were delivered and connected to the AP. For the NOSA group, the circuit was coated with DBHD-N2O2/argatroban, 100 ppm nitric oxide was blended into the sweep gas, and no systemic anticoagulation was given. For the Heparin control group, a non-coated circuit was used and systemic anticoagulation was administered. RESULTS: Animals survived 6.8 ± 0.6 days with normal hemodynamics and gas exchange. Neither group had any hemorrhagic or thrombotic complications. ACT (194 ± 53 vs. 261 ± 86 s; p < 0.001) and aPTT (39 ± 7 vs. 69 ± 23 s; p < 0.001) were significantly lower in the NOSA group than the Heparin group. Platelet and leukocyte activation did not differ significantly from baseline in the NOSA group. Methemoglobin was 3.2 ± 1.1% in the NOSA group compared to 1.6 ± 0.6% in the Heparin group (p < 0.001). CONCLUSIONS: The AP with the NOSA system successfully supported extremely premature lambs for 7 days without significant bleeding or thrombosis. IMPACT: The Nitric Oxide Surface Anticoagulation (NOSA) system provides effective circuit-based anticoagulation in a fetal sheep model of the extracorporeal artificial placenta (AP) for 7 days. The NOSA system is the first non-thrombogenic circuit to consistently obviate the need for systemic anticoagulation in an extracorporeal circuit for up to 7 days. The NOSA system may allow the AP to be implemented clinically without systemic anticoagulation, thus greatly reducing the intracranial hemorrhage risk for extremely low gestational age newborns. The NOSA system could potentially be applied to any form of extracorporeal life support to reduce or avoid systemic anticoagulation.

Bleeding phenotype and hemostatic evaluation by thrombin generation in children with Noonan syndrome: A prospective study.

BACKGROUND: This study aimed to evaluate the bleeding phenotype and to conduct a comprehensive hemostatic evaluation in individuals with Noonan syndrome (NS), a dominantly inherited disorder caused by pathogenic variants in genes associated with the Ras/MAPK signaling pathway. METHODS: Children with a genetically confirmed diagnosis of NS underwent clinical evaluation, routine laboratory tests, platelet function testing, and thrombin generation (TG) assessment. RESULTS: The study included 24 children. The most frequently reported bleeding symptoms were easy bruising and epistaxis, while bleeding complications were observed in 15% of surgical procedures. Various hemostatic abnormalities were identified, including platelet dysfunction, von Willebrand disease, and clotting factor deficiencies. Abnormal platelet function was observed in 50% of the patients, and significantly lower TG parameters were found compared to controls. However, no significant correlation was observed between bleeding symptoms and TG results. CONCLUSIONS: The study suggests that the bleeding diathesis in NS is multifactorial, involving both platelet dysfunction and deficiencies of plasma coagulation factors. The potential role of TG assay as an ancillary tool for predicting bleeding tendencies in individuals with NS undergoing surgery warrants further investigation.

Real-world experience of direct oral anticoagulant use in a single pediatric center.

BACKGROUND: Pediatric venous thromboembolism has increased by 130%-200%, specifically in hospitalized children, and direct oral anticoagulants (DOACs) offer several therapeutic advantages. METHODS: This study aims to evaluate the real-world epidemiological and outcome data from a retrospective review of pediatric patients treated with DOACs from January 1, 2013 to December 31, 2022. In this single-center, IRB-approved study, 65 patients were identified and analyzed using SPSS statistical software, and a descriptive statistical analysis was conducted. RESULTS: Of the 65 patients, 37% were on apixaban, 61.5% were on rivaroxaban, and 1.5% were on dabigatran. Per the 2023 ISTH outcome definitions, one (2%) patient had a major bleeding episode, six (9%) had clinically relevant non-major bleeding, three (5%) patients had patient-important heavy menstrual bleeding (HMB), and one (1.5%) patient had minor bleeding. Seven (19%) of 37 postmenarchal patients had evidence of HMB. Six (9.2%) patients had recurrent venous thromboembolism while on a DOAC (one was on apixaban, and five were on rivaroxaban) and were transitioned to other forms of anticoagulation. CONCLUSION: Thus, bleeding rates after DOAC therapy are comparable to previous DOAC trials, as well as other anticoagulants in pediatrics. HMB is an important outcome measure and should continue to be investigated. This study reports a higher rate of recurrent thrombosis (9.2%) compared to other trials. However, this observation may be attributed to patients who had ongoing risk factors, as well as a longer duration of study follow-up. Additional multicentered outcome studies evaluating DOAC use in children are needed to determine long-term recurrence and HMB risks.

Early ambulation protocol after diagnostic transfemoral cerebral angiography: an evidence-based practice project.

BACKGROUND: No uniform consensus has been achieved regarding the ambulation protocol after transfemoral cerebral angiography (TFA). Until now, in most hospitals patients are prescribed 8-12 h strict immobilization along with bed rest in the supine position after TFA in China, which causes great discomfort to patients. OBJECTIVE: To evaluate the effect of an evidence-based early ambulation protocol on the prevention of vascular complications and general discomfort in patients following transfemoral cerebral angiography (TFA). METHODS: A prospective quasi-experimental study was conducted on 214 patients undergoing TFA with manual compression. Patients in the experimental group were placed supine position for 2 h with a sandbag placed on the wound dressing, followed by a semi-seated position for another 2 h. After this period, patients took 2 h bed rest (move freely) with the sandbag removed, and were allowed to get out of bed 6 h after TFA. Patients in the control group were restricted to an 8 h bed rest in a supine position with the affected leg straight and immobilized. The vascular complications (bleeding, hematoma, ecchymosis) and levels of comfort (low back pain, leg pain, and blood pressure) were evaluated after the procedure. Numeric Rating Scale (NRS) pain scores, systolic blood pressure (SBP); diastolic blood pressure (DBP) were measured hourly for 8 h after TFA. RESULTS: There was no significant difference in the two groups with regard to vascular complications including bleeding events (P = 0.621), bleeding volume (P = 0.321), and area of hematoma (P = 0.156). The area of ecchymosis in the experimental group was significantly smaller than the control group (P = 0.031). Compared with the control group, the NRS score for low back pain in the 4th, 5th, 6th, 7th, and 8th hour after TFA were significantly lower (P < 0.05), and the NRS score for leg pain in the 5th, 6th, 7th, 8th hour after TFA were significantly lower (P < 0.05). The SBP and DBP in the 6th, 7th, and 8th hour after TFA were significantly lower than the control group (all P < 0.05). CONCLUSIONS: The evidence-based early ambulation protocol can effectively and safely increase comfort and decrease the pain level for patients undergoing TFA, without change in the incidence of vascular complications.

Dengue fever ophthalmic manifestations: A review and update.

Dengue fever, the most common arbovirus disease, affects an estimated 390 million people annually. Dengue virus (DENV) is an RNA virus of the Flaviviridae family with four different serotypes. Dengue haemorrhagic fever is the deadliest form of dengue infection and is characterised by thrombocytopaenia, hypotension, and the possibility of multi-system organ failure. The mechanism hypothesised for DENV viral replication is intrinsic antibody-dependent enhancement, which refers to Fcγ receptor-mediated viral amplification. This hypothesis suggests that the internalisation of DENV through the Fcγ receptor inhibits antiviral genes by suppressing type-1 interferon-mediated antiviral responses. DENV NS1 antibodies can promote the release of various inflammatory mediators in the nuclear transcription factor pathway (NF-κB-dependent), including monocyte chemoattractant protein (MCP)-1, interleukin (IL)-6, and IL-8. As a result, MCP-1 increases ICAM-1 expression and facilitates leukocyte transmigration. In addition, anti-DENV NS1 antibodies induce endothelial cell apoptosis via a nitric oxide-regulated pathway. A chain reaction involving pre-existing DENV heterotypic antibodies and innate immune cells causes dysfunction in complement system activity and contributes to the action of autoantibodies and anti-endothelial cells, resulting in endothelial cell dysfunction, blood-retinal barrier breakdown, haemorrhage, and plasma leakage. A spectrum of ocular diseases associated with DENV infection, ranging from haemorrhagic to inflammatory manifestations, has been reported in the literature. Although rare, ophthalmic manifestations can occur in both the anterior and posterior segments and are usually associated with thrombocytopenia. The most common ocular complication is haemorrhage. However, ophthalmic complications, such as anterior uveitis and vasculitis, suggest an immune-mediated pathogenesis.