The necessity of repeat testing for von Willebrand disease in adult patients with mild to moderate bleeding disorders.

BACKGROUND: In patients with mild-to-moderate bleeding disorders (MBD), von Willebrand disease (VWD) is diagnosed at von Willebrand factor (VWF) levels ≤50 IU/dL. Although VWF levels are unstable, repeated testing for VWD diagnosis is not necessarily advised in recent guidelines. OBJECTIVES: To analyze the relevance of repeated VWF testing to diagnose VWD in patients with MBD. METHODS: Data of 277 patients with MBD from the Vienna Bleeding Biobank with at least 2 separate assessments of VWF antigen (VWF:Ag) and activity (VWF:Act) were analyzed. RESULTS: In repeated VWF measurements, 36 patients (13.0%) had "changing" VWF levels (≤/>50 IU/dL), 27 (9.7%) had persistent levels ≤50 IU/dL ("pathologic"), and 214 (77.3%) had levels >50 IU/dL ("normal"). Of the 36 changing patients, 22 (61%) were diagnosed with VWD at baseline, whereas the others only met VWD diagnostic criteria at repeated measurements. Using logistic regression, we estimated a probability of change of 26.4% (95% CI, 12.5-47.4) at baseline VWF levels of 30 IU/dL, 50.8% (95% CI, 35.6-65.8) at 50 IU/dL, 18.8% (95% CI, 12.3-27.6) at 60 IU/dL, and 1.2% (95% CI, 0.3-4.9) at 80 IU/dL. Baseline VWF was a strong predictor for changing status (Χ2 = 49.9; P < .001), while age, sex, Vicenza score, and blood type O had limited added value (Χ2 = 5.1; P = .278). Baseline VWF:Ag or VWF:Act cutoffs of 80 IU/dL had negative predictive values of 98.1% and 99.1% for changing status, respectively. CONCLUSION: Our data emphasize an overlap between patients with VWD and MBD with bleeding disorder of unknown cause and underline the need for repeated VWF testing, especially in patients with VWF levels <80 IU/dL.

Pharmacokinetic-guided versus standard prophylaxis in hemophilia: a systematic review and meta-analysis.

BACKGROUND: With population pharmacokinetic (PK) modeling more readily available and PK-guided prophylaxis endorsed by current hemophilia guidelines, we conducted a systematic review to summarize current evidence in the literature. OBJECTIVES: To assess the efficacy of PK-guided compared with non-PK-guided prophylaxis. METHODS: We did not restrict inclusion to specific study design labels and included all studies consisting of at least one distinct cohort arm receiving PK-guided prophylaxis. We searched the following databases from inception to date of search: MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and the EU Clinical Trial Register. Following title, abstract, and full-text screening conducted independently by 2 review authors, we summarized studies qualitatively and synthesized included randomized clinical trials (RCTs) quantitatively by fitting random-effects models. RESULTS: Search of databases on February 3, 2023, yielded 25 studies fitting our inclusion criteria. Of those, only 2 RCTs and 17 nonrandomized studies included a standard prophylaxis comparator group. Furthermore, risk of bias in the latter was substantial, primarily due to before-after study designs and retrospective comparator groups. Thus, nonrandomized studies were only presented qualitatively. A random-effects meta-analysis of the 2 identified RCT remained inconclusive with regards to bleeding outcomes (ratio of means, 1.15; 95% CI, 0.85-1.56) and factor consumption (ratio of means, 0.82; 95% CI, 0.58-1.18). CONCLUSION: Evidence in the literature suggesting a clinical benefit of PK-guided over standard fixed-dose prophylaxis was weak and mainly found in nonrandomized studies limited by lack of concurrent controls, heterogeneity in outcome reporting, small sample sizes, and high risk of bias.

Hemostatic biomarkers associated with postpartum hemorrhage: a systematic review and meta-analysis.

Postpartum hemorrhage (PPH) is a leading cause of maternal morbi-mortality. Although obstetric risk factors are well described, the impact of predelivery hematologic and hemostatic biomarkers remains incompletely understood. In this systematic review, we aimed to summarize the available literature on the association between predelivery hemostatic biomarkers and PPH/severe PPH. Searching MEDLINE, EMBASE, and CENTRAL databases from inception to October 2022, we included observational studies on unselected pregnant women without bleeding disorder reporting on PPH and on predelivery hemostatic biomarkers. Two review authors independently performed title, abstract and full-text screening, upon which quantitative syntheses of studies reporting on the same hemostatic biomarker were conducted, calculating the mean difference (MD) between women with PPH/severe PPH and controls. A search on 18 October 2022 yielded 81 articles fitting our inclusion criteria. The heterogeneity between studies was considerable. With regard to PPH, the estimated average MD in the investigated biomarkers (platelets, fibrinogen, hemoglobin, Ddimer, activated partial thromboplastin time, and prothrombin time) were not statistically significant. Women who developed severe PPH had lower predelivery platelets than controls (MD = -26.0 109/L; 95% confidence interval, -35.8 to -16.1), whereas differences in predelivery fibrinogen concentration (MD = -0.31 g/L; 95% confidence interval, -0.75 to 0.13) and levels of factor XIII or hemoglobin were not statistically significant in women with and without severe PPH. Predelivery platelet counts were, on average, lower in women with severe PPH compared with controls, suggesting the potential usefulness of this biomarker for predicting severe PPH. This trial was registered at the International Prospective Register of Systematic Reviews as CRD42022368075.

Bleeding phenotype in nonsevere hemophilia by International Society on Thrombosis and Haemostasis bleeding assessment tool, bleeding frequency, and the joint status.

Background: Although the phenotype of severe hemophilia has been well studied, there are still knowledge gaps in nonsevere hemophilia. Objectives: The objective of this study was to characterize the clinical bleeding phenotype in nonsevere hemophilia and its association with different factor VIII/IX assessments. Methods: This was a cross-sectional, multicenter study to investigate the bleeding phenotype in adults with nonsevere hemophilia by the number of bleeding and joint bleeding in the past 5 years, a joint score, and the International Society on Thrombosis and Haemostasis bleeding assessment tool (ISTH-BAT). Factor levels were analyzed by 1-stage (lowest in history and at study inclusion) and chromogenic assay (at study inclusion). Patients were enrolled between March 2015 and May 2019. Results: Of the 111 patients (86 with mild and 25 with moderate hemophilia), 57 patients (54.8%) reported any bleeding and 24 (23.1%) any joint bleeding in the past 5 years. A joint score ≥1 was found in 44 patients (41.9%), an ISTH-BAT ≥4 in 100 patients (90.1%), and an ISTH-BAT joint item ≥1 in 50 patients (45.0%). Within the ISTH-BAT, muscle and joint bleeds showed the largest difference between mild and moderate hemophilia. The lowest factor VIII/IX level in patients' history was best associated with bleeding outcomes. Factor was inversely associated with joint bleeds (incidence rate ratio 0.88; 95% CI, 0.79-0.98), joint score, and ISTH-BAT (odds ratios from proportional odds ordinal logistic regression 0.92; 95% CI, 0.87-0.97; and 0.89; 95% CI, 0.86-0.93, respectively). Conclusion: The occurrence of joint bleeding differentiated persons with mild and moderate hemophilia. The ISTH-BAT and lowest factor in patients' history provided valuable information of the bleeding phenotype in nonsevere hemophilia.

Circulatory miR-411-5p as a Novel Prognostic Biomarker for Major Adverse Cardiovascular Events in Patients with Atrial Fibrillation.

The risk stratification of patients with atrial fibrillation (AF) for subsequent cardiovascular events could help in guiding prevention strategies. In this study, we aimed at investigating circulating microRNAs as prognostic biomarkers for major adverse cardiovascular events (MACE) in AF patients. We conducted a three-stage nested case-control study within the framework of a prospective registry, including 347 AF patients. First, total small RNA-sequencing was performed in 26 patients (13 cases with MACE) and the differential expression of microRNAs was analyzed. Seven candidate microRNAs with promising results in a subgroup analysis on cardiovascular death were selected and measured via using RT-qPCR in 97 patients (42 cases with cardiovascular death). To further validate our findings and investigate broader clinical applicability, we analyzed the same microRNAs in a subsequent nested case-control study of 102 patients (37 cases with early MACE) by using Cox regression. In the microRNA discovery cohort (n = 26), we detected 184 well-expressed microRNAs in circulation without overt differential expression between the cases and controls. A subgroup analysis on cardiovascular death revealed 26 microRNAs that were differentially expressed at a significance level < 0.05 (three of which with an FDR-adjusted p-value <0.05). We, therefore, proceeded with a nested case-control approach (n = 97) focusing on patients with cardiovascular death and selected, in total, seven microRNAs for further RT-qPCR analysis. One microRNA, miR-411-5p, was significantly associated with cardiovascular death (adjusted HR (95% CI): 1.95 (1.04-3.67)). Further validation (n = 102) in patients who developed early MACE showed similar results (adjusted HR (95% CI) 2.35 (1.17-4.73)). In conclusion, circulating miR-411-5p could be a valuable prognostic biomarker for MACE in AF patients.

The von Willebrand factor-binding aptamer rondaptivon pegol as a treatment for severe and nonsevere hemophilia A.

Factor VIII (FVIII) circulates in a noncovalent complex with von Willebrand Factor (VWF), the latter determining FVIII half-life. The VWF-binding aptamer rondaptivon pegol (BT200) increases plasma levels of VWF/FVIII in healthy volunteers. This trial assessed its safety, pharmacokinetics, and pharmacodynamics in hemophilia A. Nineteen adult patients (ages 20-62 years, 4 women) with hemophilia A (8 mild, 2 moderate, and 9 severe) received subcutaneous injections of rondaptivon pegol. After an initial fixed dose of 3 mg on days 0 and 4, patients received weekly doses of 2 to 9 mg until day 28. Severe hemophilia A patients underwent sparse-sampling population pharmacokinetics individual profiling after the final dose of rondaptivon pegol. Adverse events, pharmacokinetics, and pharmacodynamics were assessed. FVIII activity and VWF levels were measured. All patients tolerated rondaptivon pegol well. The geometric mean half-life of rondaptivon pegol was 5.4 days and rondaptivon pegol significantly increased VWF levels. In severe hemophilia A, 6 doses of rondaptivon pegol increased the half-lives of 5 different FVIII products from a median of 10.4 hours to 31.1 hours (range, 20.8-56.0 hours). Median FVIII increased from 22% to 48% in mild hemophilia A and from 3% to 7.5% in moderate hemophilia A. Rondaptivon pegol is a first-in-class prohemostatic molecule that extended the half-life of substituted FVIII approximately 3-fold and increased endogenous FVIII levels approximately 2-fold in hemophilia patients. This trial was registered at www.clinicaltrials.gov as #NCT04677803.

Factor XI Inhibitors for Prevention and Treatment of Venous Thromboembolism: A Review on the Rationale and Update on Current Evidence.

Although anticoagulation therapy has evolved from non-specific drugs (i.e., heparins and vitamin K antagonists) to agents that directly target specific coagulation factors (i.e., direct oral anticoagulants, argatroban, fondaparinux), thrombosis remains a leading cause of death worldwide. Direct oral anticoagulants (i.e., factor IIa- and factor Xa-inhibitors) now dominate clinical practice because of their favorable pharmacological profile and ease of use, particularly in venous thromboembolism (VTE) treatment and stroke prevention in atrial fibrillation. However, despite having a better safety profile than vitamin K antagonists, their bleeding risk is not insignificant. This is true for all currently available anticoagulants, and a high bleeding risk is considered a contraindication to anticoagulation. As a result, ongoing research focuses on developing future anticoagulants with an improved safety profile. Several promising approaches to reduce the bleeding risk involve targeting the intrinsic (or contact activation) pathway of coagulation, with the ultimate goal of preventing thrombosis without impairing hemostasis. Based on epidemiological data on hereditary factor deficiencies and preclinical studies factor XI (FXI) emerged as the most promising candidate target. In this review, we highlight unmet clinical needs of anticoagulation therapy, outlay the rationale and evidence for inhibiting FXI, discuss FXI inhibitors in current clinical trials, conduct an exploratory meta-analysis on their efficacy and safety, and provide an outlook on the potential clinical application of these novel anticoagulants.

Lupus anticoagulant test persistence over time and its associations with future thrombotic events.

Data on lupus anticoagulant (LA) test stability in patients persistently positive for LA are limited, and its implications on clinical outcomes are lacking. We investigated the rate and predictors of a negative LA test and whether experiencing a negative test affected a patient's risk of future thrombotic events or death in a prospective observational study of persistently LA+ patients. We followed 164 patients (84% women) for a median of 9.2 years and a total of 1438 follow-up visits. During the observation period, 50 thrombotic events (23 arterial and 27 venous events) occurred, and 24 patients died. Forty-six of the patients had at least 1 negative LA test during the observation period, corresponding to a 10-year cumulative incidence of a negative LA test of 28% (95% confidence interval, 20-35). The majority of patients with available follow-up after a negative LA test (n = 41) had at least 1 subsequent positive test for LA (n = 28/41, 68%). Vitamin K antagonist (VKA) treatment at baseline was associated with a negative LA test during follow-up. Using a multistate time-to-event model with multivariable adjustment, a negative LA test had no impact on a patient's prospective risk of thrombosis or mortality. We conclude that a negative LA test during observation cannot be used clinically to stratify a patient's risk for future events.

Growth differentiation factor-15 predicts major adverse cardiac events and all-cause mortality in patients with atrial fibrillation.

BACKGROUND: Growth-differentiation factor-15 (GDF-15) has recently been described as a potential biomarker for predicting risk of mortality and cardiovascular events in patients with atrial fibrillation (AF) but requires validation in clinical practice. METHODS: The study population consisted of 362 patients (mean age: 71 years, 37% women) with non-valvular AF included in a prospective cohort study. Relationship of GDF-15 with all-cause mortality and major adverse cardiac events (MACE) was analyzed using Cox regression. Survival analysis stratified by GDF-15 was based on national death records, while MACE was recorded at personal follow-up. Further, we evaluated the recently developed GDF-15 based prognostic score towards prediction of all-cause mortality (ABC-death score). RESULTS: Over a median observation period of 4.3 years, 81 (23.3%) patients died, and over a median personal follow-up of 316 days 47 MACE occurred. GDF-15 was independently associated with all-cause mortality (adjusted HR per double increase 2.33, 95%CI 1.74-3.13) and MACE (adjusted HR per double increase 2.33, 95%CI 1.60-3.39). GDF-15 levels, measured at follow-up, were similarly associated with mortality, and longitudinal measurements of GDF-15 did not significantly differ. Six-year survival probability of patients above vs. below the median GDF-15 level was 44% (95%CI 34-57) and 84% (95%CI 76-93), respectively. The ABC-death score revealed a C-statistic of 0.80. CONCLUSION: GDF-15 predicts risk of all-cause mortality and MACE in patients with non-valvular AF. Further, the ABC-death score showed good predictive accuracy in a "real-world" cohort. Therefore, introduction of GDF-15 into clinical practice would enhance risk prediction of morbidity and mortality in AF patients.