The importance and evolution of bleeding disorder registries.

Registries are excellent sources of data to address questions that are typically not evaluated in randomized clinical trials, including natural history, disease prevalence, treatment approaches and adverse events, and models of care. Global and regional registries can provide data to identify differences in outcomes and in haemophilia care between countries, economic settings, and regions, while facilitating research and data sharing. In this manuscript, we highlight five bleeding disorder registries: Country registries from Australia and China, Paediatric Network on Haemophilia Management (PedNet) data on children who have received emicizumab, data from the European Haemophilia Safety Surveillance (EUHASS) system, and data on women and girls with haemophilia from the World Federation of Haemophilia (WFH) registries. Data from these and other bleeding disorder registries have been and will continue to be used to advance patient care, understand treatment patterns and adverse reactions, and identify areas of increased need and focus.

Bleeding control improves after switching to emicizumab: Real-world experience of 177 children in the PedNet registry.

INTRODUCTION: Despite the rapid uptake of emicizumab in the paediatric haemophilia A (HA) population, real-world data on the safety and efficacy is limited. AIM: To report on bleeding and safety in paediatric patients receiving emicizumab prophylaxis. METHODS: Data were extracted from the multicentre prospective observational PedNet Registry (NCT02979119). Children with haemophilia A, and ≥50 FVIII exposures or inhibitors present receiving emicizumab maintenance therapy were analysed. Data were summarized as medians with interquartile range (IQR, P25-P75). Mean (95% confidence interval (CI)), annualized (joint) bleeding rate (A(J)BR) during emicizumab and ≤2 years before emicizumab prophylaxis were modelled and compared using negative binomial regression. RESULTS: Total of 177 patients started emicizumab at median 8.6 years (IQR 4.8-13.1), most had no FVIII inhibitors (64%). Follow up before emicizumab was median: 1.68 years (IQR: 1.24-1.90) and during emicizumab: 1.32 years (IQR: .94-2.11). In patients without inhibitors, mean ABR reduced after starting emicizumab from 2.41 (CI 1.98-2.95) to 1.11 (CI .90-1.36, p < .001), while AJBR reduced from.74 (CI .56-.98) to.31 (CI .21-.46, p < .001). Concordantly, in patients with inhibitors, mean ABR reduced from 5.08 (CI 4.08-6.38) to .75 (CI .56-1.01, p < .001), while AJBR reduced from 1.90 (CI 1.42-2.58) to .34 (CI .21-.56, p < .001). Five emicizumab-related adverse events were reported (3% of the cohort), including one patient with antidrug antibodies. CONCLUSION: This study showed improved bleeding control compared to previous treatment and a favourable safety profile during emicizumab therapy in paediatric haemophilia A patients.

Limited value of testing for factor XIII and α2-antiplasmin deficiency in patients with a bleeding disorder of unknown cause.

INTRODUCTION: In patients with an increased bleeding tendency, extensive diagnostic blood testing is often performed. When results of tier 1 assays of primary haemostasis are normal, protocols recommend additional testing to rule out rare disorders including coagulation factor XIII (FXIII) and α2-antiplasmin (α2AP) deficiency. AIM: To evaluate the added diagnostic value of FXIII and α2AP levels in patients with a bleeding disorder of unknown cause (BDUC). METHODS: A retrospective monocentre cohort study between August 2011 and August 2023 was conducted. In all patients with bleeding tendencies and normal diagnostic tests for von Willebrand disease and platelet function, FXIII and α2AP were measured. RESULTS: We included 158 consecutive patients; mean ISTH-BAT scores were 8.2 (SD ± 3.7) in children, 6.2 (SD ± 2.1) in men and 10.6 (SD ± 3.3) in women. Median age was 37 (range 5-79) years, 88.6% of patients were female. Patients displayed median FXIII activity of 111% (IQR = 97-131) and median α2AP activity of 112% (IQR = 103-119). Three (1.9%) patients had FXIII levels < 50%, respectively 43%, 45% and 46%. Corresponding ISTH-BAT scores were 7, 12 and 14. No α2AP levels < 60% was observed. No significant association was found between FXIII levels and ISTH-BAT scores. CONCLUSION: In our cohort of BDUC patients, no clinical relevant FXIII deficiencies were detected; absolute values were well above the 30% cutoff considered adequate for normal haemostasis. No α2AP deficiencies were detected. These data suggest that in BDUC patients, measuring FXIII or AP activity is of limited value.

Quantitative MRI assessment of joint effusion using T2-relaxometry at 3 Tesla: a feasibility and reproducibility study.

OBJECTIVE: T2-relaxometry could differentiate between physiological and haemorrhagic joint effusion (≥ 5% blood) in vitro. Are quantitative T2-relaxation time measurements of synovial fluid feasible and reproducible in vivo in clinically bleed-free joints of men with haemophilia? MATERIALS AND METHODS: In this cross-sectional study, we measured T2-relaxation times of synovial fluid in clinically bleed-free ankles, knees or elbows of men with severe haemophilia A using a T2-mapping sequence (duration ≤ 7 min) at 3 Tesla MRI. Manual and circular regions of interest (ROI) were drawn in the synovial fluid of each joint by two independent observers to measure T2-relaxation times. Measurement feasibility was expressed as the success rate of the measurements by both observers. The interobserver and intraobserver reproducibility of the measurements were evaluated by the intraclass correlation coefficient of absolute agreement (ICC) and the limits of agreement (LoA) from Bland Altman analysis. RESULTS: We evaluated 39 clinically bleed-free joints (11 ankles, 12 knees, 16 elbows) of 39 men (median age, 24 years; range 17-33) with severe haemophilia A. The success rate of the T2-measurements was ≥ 90%. Interobserver reliability was good to excellent (manual ROI: ICC = 0.92, 95% CI 0.76-0.97; circular ROI: ICC = 0.82, 95% CI 0.66-0.91) and interobserver agreement was adequate (manual ROI: LoA = 71 ms; circular ROI: LoA = 146 ms). Intraobserver reliability was good to excellent (manual ROI: ICC = 0.78, 95% CI - 0.06-0.94; circular RO: ICC = 0.99, 95% CI 0.98-0.99) and intraobserver agreement was good (manual ROI: LoA = 63 ms; circular ROI: LoA = 41 ms). CONCLUSION: T2-relaxometry of synovial fluid in haemophilia patients is feasible with good interobserver and intraobserver reproducibility.

No immunological changes after factor VIII product switch: An in depth analysis in haemophilia A patients.

BACKGROUND: A challenging complication in the treatment of haemophilia A is the formation of neutralizing anti-FVIII antibodies (inhibitors). There is ongoing debate on the effect of FVIII product and inhibitor risk, rendering patients and physicians reluctant to switch FVIII-products. AIM: This study aimed to evaluate changes in the immune profile of haemophilia A patients after switching FVIII products and their possible relation to inhibitor development. Secondary, FVIII efficacy after switching were assessed. METHODS: Patients, who switched FVIII-products between 2017-2019, were included in this single centre cohort study. Prospective comparison of immunoregulatory cells and markers by flow-cytometry before and after the switch was performed in a subgroup. For the total cohort clinical data regarding inhibitor development and FVIII efficacy 1 year before and after switching were retrospectively collected. RESULTS: One-hundred patients (including 39 with prospective immunological assessment) were analyzed, of which 31% switched from plasma-derived (pdFVIII) to recombinant standard half-life FVIII (SHL-rFVIII), 47% between different SHL-rFVIII, and 22% from pdFVIII/SHL-rFVIII to rFVIII-Fc. No remarkable changes in immunoregulatory cell functions were observed after switching, regardless the type of switch. None of the patients developed an inhibitor. FVIII efficacy, that is, FVIII usage, half-life and annual bleeding rate (ABR), was similar before and after switch for the SHL products, whereas rFVIII-Fc associated with a longer half-life (13.1 vs. 15.0 h) and lower ABR (3.0 vs. 1.0). CONCLUSIONS: Switching to a different FVIII product was not associated with inhibitor development, nor with differences in the immune profile. Switching to rFVIII-Fc lead to lower ABR.

Screening for subclinical synovial proliferation in haemophilia: A systematic review and meta-analysis comparing physical examination and ultrasound.

INTRODUCTION: Ultrasound is increasingly used as addition to physical examination for detection of subclinical joint changes in haemophilia. However, the added value of ultrasound to physical examination for detecting synovial proliferation is not fully established. AIM: To determine the diagnostic accuracy of swelling at physical examination for ultrasound-detected synovial proliferation in haemophilia. METHODS: PubMed and EMBASE were searched up to 2 August 2022. Studies reporting original data on occurrence of swelling at physical examination and synovial proliferation on ultrasound of index joints in persons with haemophilia were included. Risk of bias and applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Diagnostic accuracy parameters of swelling at physical examination for ultrasound-detected synovial proliferation were determined. Summary sensitivity and specificity were calculated using a bivariate random-effects model. RESULTS: Fifteen studies reporting on swelling at physical examination and synovial proliferation on ultrasound in 2890 joints of 627 patients were included. Prevalence of subclinical synovial proliferation ranged between 0% and 55%. Sensitivity of swelling was low [summary estimate .34; 95% confidence interval (CI) .24-.46], while specificity was high (summary estimate .97; CI .92-.99). Predictive values varied widely due to inter-study differences in prevalence of synovial proliferation. CONCLUSION: Joint swelling has low sensitivity for presence of ultrasound-detected synovial proliferation in haemophilia, suggesting underestimation of synovial proliferation by physical examination alone. Consequently, ultrasound screening may generate important information on synovial changes which would otherwise remain undetected.

Monitoring recovery of joints after bleeding: Physical examination and ultrasound are complementary.

AIM: Traditionally, recovery after a joint bleed in people with bleeding disorders is evaluated by clinical symptoms. Following a bleed, however, asymptomatic joints may still show synovial hypertrophy and effusion on ultrasound. We evaluated the duration of full recovery from a joint bleed. Additionally, we determined how recovery differed when assessed by physical examination and ultrasound. METHODS: In this retrospective cohort study, we investigated joint bleeds in elbows, knees and ankles of people with haemophilia or Von Willebrand disease who attended the Van Creveldkliniek between 2016 and 2021. Physical examination (warmth, swelling, range of motion and gait) and ultrasound (effusion and synovial hypertrophy) were performed within 7 days after the onset of the bleed, 1 week after the first examination and monthly thereafter until patients had recovered fully. Joint bleeds were treated in line with the current international treatment guidelines. RESULTS: We evaluated 30 joint bleeds in 26 patients. The median recovery time was 1 month (range 0.3-5 months). In 47% of the joint bleeds, the recovery took longer than 1 month. The moment of recovery based on physical examination and ultrasound differed in 27% of bleeds. Both persistent abnormalities at physical examination in joints with normalized ultrasounds and persistent ultrasound findings in clinically recovered joints occurred. CONCLUSION: Joint bleed recovery can take long and recovery times differed per bleed. Recovery differed when assessed by physical examination or ultrasound. Therefore, both should be used to closely monitor recovery of joint bleeds and offer personalized care.

Can motor proficiency testing predict sports injuries and sports-induced bleeds in people with haemophilia?

INTRODUCTION: Predicting the risk of sports injuries and sports-induced bleeds (SIBs) in people with haemophilia (PWH) may support clinical counselling. AIM: To assess the association between motor proficiency testing and sports injuries and SIBs and to identify a specific set of tests for predicting injury risk in PWH. METHODS: In a single centre, prospective study male PWH aged 6-49 playing sports ≥1x/week were tested for running speed and agility, balance, strength and endurance. Test results below -2Z were considered poor. Sports injuries and SIBs were collected for 12 months while 7 days of physical activity (PA) for each season was registered with accelerometers. Injury risk was analysed according to test results and type of physical activity (%time walking, cycling, running). Predictive values for sports injuries and SIBs were determined. RESULTS: Data from 125 PWH (mean [± SD] age: 25 [± 12], 90% haemophilia A; 48% severe, 95% on prophylaxis, median factor level: 2.5 [IQR 0-15]IU/dl) were included. Few participants (n = 19, 15%) had poor scores. Eighty-seven sports injuries and 26 SIBs were reported. Poor scoring participants reported 11/87 sports injuries and 5/26 SIBs. The current tests were poor predictors of sports injuries (Range PPV: 0%-40%), or SIBs (PPV: 0%-20%). PA type was not associated with season (activity seasonal p values > .20) and type of PA was not associated with sports injuries or SIBs (Spearman's rho < .15). CONCLUSION: These motor proficiency- and endurance tests were unable to predict sports injuries or SIBs in PWH, potentially due to few PWH with poor results and low numbers of sports injuries and SIBs.

Liver-related complications before and after successful treatment of chronic hepatitis C virus infection in people with inherited bleeding disorders.

INTRODUCTION: With availability of direct-acting antivirals (DAA), most persons with inherited bleeding disorders are currently cured of hepatitis C virus (HCV) infection. The risk of liver-related complications following HCV cure has not been reported for this population. AIM: Reporting liver-related complications during long-term chronic HCV infection and following sustained virological response (SVR) in this population. METHODS: Retrospective follow-up of a prospective single-centre cohort of HCV antibody-positive persons with inherited bleeding disorders. Primary endpoint was liver-related complications [hepatocellular carcinoma (HCC), decompensated cirrhosis, bleeding gastroesophageal varices]. Liver-related complications were reported separately during chronic HCV and following SVR, stratified for interferon-based and DAA-based SVR. RESULTS: In total 309/381 (81%) HCV antibody-positive individuals developed chronic HCV infection. Median follow-up was 44 years [interquartile range (IQR): 34-50]. Liver-related complications occurred in 36/309 (12%) of individuals with chronic HCV infection after median 31 years of chronic infection. Of 199 individuals with SVR, 97 were cured with interferon-based regimens and 102 with DAA after median infection durations of 29 and 45 years, respectively. At end of follow-up, respectively, 21% and 42% had advanced fibrosis or cirrhosis. Post-SVR, seven (4%) individuals had a liver-related complication, mainly HCC (n = 4). Incidence of liver-related complications per 100 patient-years post-SVR follow-up was .2 for interferon-cured and 1.0 for DAA-cured individuals (p = .01). CONCLUSION: Successful HCV treatment does not eliminate the risk of liver-related complications in persons with inherited bleeding disorders. Due to higher baseline risk, incidence was higher after DAA than interferon-based SVR. We advise continuing HCC surveillance post-SVR in all with advanced fibrosis or cirrhosis.

Dilemmas on emicizumab in children with haemophilia A: A survey of strategies from PedNet centres.

INTRODUCTION: Haemophilia A care has changed with the introduction of emicizumab. Experience on the youngest children is still scarce and clinical practice varies between haemophilia treatment centres. AIM: We aimed to assess the current clinical practice on emicizumab prophylaxis within PedNet, a collaborative research platform for paediatricians treating children with haemophilia. METHODS: An electronic survey was sent to all PedNet members (n = 32) between October 2022 and February 2023. The survey included questions on the availability of emicizumab, on the practice of initiating prophylaxis in previously untreated or minimally treated patients (PUPs or MTPs) and emicizumab use in patients with or without inhibitors. RESULTS: All but four centres (28/32; 88%) responded. Emicizumab was available in clinical practice in 25/28 centres (89%), and in 3/28 for selected patients only (e.g. with inhibitors). Emicizumab was the preferred choice for prophylaxis in PUPs or MTPs in 20/25 centres; most (85%) started emicizumab prophylaxis before 1 year of age (30% before 6 months of age) and without concomitant FVIII (16/20; 80%). After the loading dose, 13/28 centres administered the recommended dosing, while the others adjusted the interval of injections to give whole vials. In inhibitor patients, the use of emicizumab during ITI was common, with low-dose ITI being the preferred protocol. CONCLUSION: Most centres choose to initiate prophylaxis with emicizumab before 12 months of age and without concomitant FVIII. In inhibitor patients, ITI is mostly given in addition to emicizumab, but there was no common practice on how to proceed after successful ITI.

Clotting factor activity levels and bleeding risk in people with haemophilia playing sports.

BACKGROUND: Improved treatment options for people with haemophilia (PWH) have increased the possibilities for sports participation, but the risk of sports-induced bleeding (SIB) is still considered considerable by many. AIM: To assess sports associated injury- and bleeding risk in PWH and to assess clotting levels associated with safe sports participation. METHODS: Sports injuries and SIBs were prospectively collected for 12 months in PWH aged 6-49 without inhibitors playing sports at least once weekly. Injuries were compared according to factor levels, severity, joint health, sports risk category and sports intensity. Factor activity at the time of injury was estimated using a pharmacokinetic model. RESULTS: 125 participants aged 6-49 (41 children, 90% haemophilia A; 48% severe, 95% severe on prophylaxis) were included. Sports injuries were reported by 51 participants (41%). Most participants (62%) reported no bleeds at all and only 16% reported SIBs. SIBs were associated with factor levels at time of injury (OR: 0.93/%factor level (CI 0.88-0.99); p = .02), but not with haemophilia severity (OR: 0.62 (CI 0.20-1.89); p = .40), joint health, sports risk category or sports intensity. PWH with factor levels <10% during sports injury had a bleeding risk of 41% versus 20% in those with higher (>10%) factor levels. CONCLUSION: The results of this study emphasize the importance of clotting factor levels in prevention of bleeds. This information is vital for patient counselling and tailoring prophylactic treatment with clotting factors and non-replacement therapy.

Subclinical synovial proliferation in patients with severe haemophilia A: The value of ultrasound screening and biochemical markers.

AIM: Subclinical bleeding and inflammation play a role in progression of haemophilic arthropathy. Synovial proliferation is predictive of joint bleeding and its early detection may guide treatment changes and prevent arthropathy progression. This study evaluated the prevalence of active and inactive subclinical synovial proliferation and investigated potential biochemical blood/urine markers to identify patients with active subclinical synovial proliferation. METHODS: This cross-sectional study included patients with severe haemophilia A born 1970-2006 who were evaluated during routine clinic visits. Patients with (a history of) inhibitors or recent joint bleeding were excluded. Elbows, knees and ankles were examined for subclinical synovial proliferation by ultrasound and physical examination. Active synovial proliferation was distinguished from inactive synovial proliferation using predefined criteria. Blood/urine biochemical markers (serum osteopontin, sVCAM-1, Coll2-1, COMP, CS846, TIMP, and urinary CTX-II) were compared individually and as combined indexes between patients with and without active synovial proliferation. RESULTS: This cohort consisted of 79 patients with a median age of 31 years (range 16.5-50.8 years) with 62/79 (78%) of the patients using continuous prophylaxis. The annualized joint bleeding rate over the last 5 years was .6 (.2-1.1). Active (17/79, 22%) and inactive subclinical synovial proliferation (17/79, 22%) were both prevalent in this cohort. Biochemical markers were not correlated with active subclinical synovial proliferation. CONCLUSION: Subclinical synovial proliferation, both active and inactive, was prevalent in patients with severe haemophilia A with access to prophylaxis and would be overlooked without routinely performed ultrasounds. Biochemical markers were unable to identify patients with active subclinical synovial proliferation.

Bone mineral density in haemophilia - a multicentre study evaluating the impact of different replacement regimens.

AIM: The aim of this study was to investigate if prophylactic treatment in severe haemophilia impact on bone mineral densisty (BMD) in adults with haemophilia A/B. METHODS: Subjects with haemophilia (n = 120) underwent bone-density measurement and clinical data was collected. BMD in subjects with severe haemophilia on high-dose prophylaxis (n = 41) was compared to BMD in subjects with mild haemophilia (n = 33) and to severe haemophilia treated with intermediate-dose prophylaxis (n = 32) or on-demand replacement therapy (n = 14). RESULTS: Subjects with severe haemophilia on high-dose prophylaxis showed BMD at total hip comparable to subjects with mild haemophilia (median BMD 955.8 and 977.4 mg/cm2 (P = .17), respectively). No difference in BMD was found related to type of prophylactic regimen (median BMD 955.8 and 942.4 mg/cm2 , in high-dose and intermediate dose groups, respectively; P = .70). Subjects with severe disease treated on-demand had significantly lower BMD compared to subjects on a high-dose prophylactic regimen (median BMD 771.8 and 955.8 mg/cm2 (P = .001), respectively). BMD decreased significantly with age, regardless of severity of haemophilia disease. In a multivariate analysis, adjusted for disease status and age, type of prophylactic regimen was not significantly associated with osteoporosis development. CONCLUSION: We show that BMD differs in persons with severe haemophilia on propylaxis as compared to those treated on-demand, but that type of prophylactic regimen does not reflect on BMD. The difference between treatment groups was mainly explained by an age difference between groups. However, patients on prophylaxis displayed a high degree of normal BMD not far from mild haemophilia at comparative age.

Long-term joint outcomes in adolescents with moderate or severe haemophilia A.

INTRODUCTION: Favourable joint outcomes are expected with modern haemophilia A (HA) management. Evaluation of long-term treatment outcomes is hampered by the delay between bleeding episodes during childhood and resulting joint outcomes in adulthood. AIM: To measure the long-term joint health of adolescents with moderate and severe HA, according to severity and inhibitor status. METHODS: Pilot cross-sectional study of five European PedNet centres in moderate and severe HA patients aged 10-19 years. Structured assessment of joint status by physical examination (HJHS) and ultrasound (HEAD-US). RESULTS: In total, 141 HA patients were evaluable, 100 without inhibitors (81 severe, 19 moderate HA), and 41 severe HA with current/past inhibitors. On physical examination, 12/81 (15%) of severe HA without inhibitors, 3/19 (16%) of moderate HA, and 13/41 (32%) of severe HA patients with inhibitors exhibited joint abnormalities. Inhibitor persistence, longer inhibitor duration, and a high peak inhibitor level were associated with impaired joint health. Ultrasound showed joint damage (bone or cartilage) in 13/49 (27%) of severe HA without inhibitors, 1/12 (8%) of moderate HA, and 10/28 (36%) of severe HA patients with inhibitors. A discordant ankle evaluation by ultrasound versus physical examination was present in 53/169 joints (31%). CONCLUSIONS: Most adolescents with severe or moderate HA show favourable joint health. Future research with combined ultrasound and/or MRI is needed to better understand joint outcomes in the remaining patients. Patents with inhibitors showed a two-fold increased proportion with joint deterioration. Ultrasound paired with physical examination increases sensitivity for detection of joint damage.

Validation of the pedHALshort and HALshort in Dutch children and adults with haemophilia.

INTRODUCTION: The Haemophilia Activities List (HAL) and paediatric HAL assess self-reported limitations in various daily activities. To reduce patient burden, shorter versions of the pedHAL (22 items) and HAL (18 items) have been developed. AIM: This study aimed to determine the agreement between the pedHAL/HALfull and pedHAL/HALshort and construct validity and internal consistency of the pedHAL/ HALshort in persons with haemophilia (PWH). METHODS: A cross-sectional secondary analysis of the Hemophilia in the Netherlands-6 national survey was performed. Adult and paediatric PWH completed the original pedHAL/HALfull , from which pedHAL/ HALshort were derived. Score differences between the original and short versions were calculated. Construct validity was studied by testing hypotheses regarding the relationship of the pedHAL/HALshort with the pedHAL/HALfull , Haemophilia & Exercise Project Test-Questionnaire (HEP-Test-Q), Canadian Haemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) and RAND 36-item Health Survey (RAND-36) (convergent/discriminant validity) as well as its ability to discriminate between subgroups (known-group validity). Internal consistency was assessed with Cronbach's α. RESULTS: We included 113 children (median 10y [range 4-17], 53% severe haemophilia) and 691 adults (median 51y [range 18-88], 35% severe). Scores of the pedHAL/HALfull and pedHAL/HALshort were similar with high correlations (>0.9). Construct validity was confirmed for the pedHAL/HALshort . The HALshort was able to discriminate between different disease severities and ages. Cronbach's α of the pedHAL/HALshort was 0.95-0.97. CONCLUSION: This study confirmed the agreement between the pedHAL/HALfull and the pedHAL/HALshort and the construct validity of the pedHAL/HALshort . The next step is to study construct validity of the pedHAL/HALshort when administered as short forms.

Alternatives for Vitamin K Antagonists as Thromboprophylaxis for Mechanical Heart Valves and Mechanical Circulatory Support Devices: A Systematic Review.

The holy grail of anticoagulation in patients with intracardiac devices, such as mechanical heart valves (MHVs) and left ventricular assist devices (LVADs), comprises safe prevention of thrombosis without interrupting normal hemostasis. Device-induced thrombosis and anticoagulant-related bleeding problems are dreaded complications that may cause a significantly reduced quality of life and increased morbidity and mortality. Vitamin K antagonists are the current standard for oral anticoagulation therapy in patients with MHVs and LVADs. Even within the therapeutic range, hemorrhage is the primary complication of these drugs, which emphasizes the need for safer anticoagulants for the prevention of device-induced thrombosis. Device-induced thrombosis is a complex multifactorial phenomenon that likely requires anticoagulant therapy targeting multiple pathways. Here, we review the preclinical and clinical data describing the efficacy of a variety of anticoagulants as thromboprophylaxis after implantation of intracardiac devices.

Inhibitor incidence in an unselected cohort of previously untreated patients with severe haemophilia B: a PedNet study.

The incidence of FIX inhibitors in severe hemophilia B (SHB) is not well defined. Frequencies of 3-5% have been reported but most studies to date were small, including patients with different severities, and without prospective follow-up for inhibitor incidence. Study objective was to investigate inhibitor incidence in patients with SHB followed up to 500 exposure days (ED), the frequency of allergic reactions, and the relationship with genotypes. Consecutive previously untreated patients (PUPs) with SHB enrolled into the PedNet cohort were included. Detailed data was collected for the first 50 ED, followed by annual collection of inhibitor status and allergic reactions. Presence of inhibitors was defined by at least two consecutive positive samples. Additionally, data on factor IX gene mutation was collected. 154 PUPs with SHB were included; 75% were followed until 75 ED, and 43% until 500 ED. Inhibitors developed in 14 patients (7 high-titre). Median number of ED at inhibitor manifestation was 11 (IQR 6.5-36.5). Cumulative inhibitor incidence was 9.3% (95%CI 4.4-14.1) at 75 ED, and 10.2% (5.1-15.3) at 500 ED. Allergic reactions occurred in 4 (28.6%) inhibitor patients. Missense mutations were most frequent (46.8%) overall but not associated with inhibitors. Nonsense mutations and deletions with large structural changes comprised all mutations among inhibitor patients and were associated with an inhibitor risk of 26.9% and 33.3%, respectively. In an unselected, well-defined cohort of PUPs with SHB, cumulative inhibitor incidence was 10.2% at 500 ED. Nonsense mutations and large deletions were strongly associated with the risk of inhibitor development. The PedNet Registry is registered at clinicaltrials.gov; identifier: NCT02979119.

Assessing the test-retest reliability and smallest detectable change of the Haemophilia Activities List.

INTRODUCTION: The Haemophilia Activities List (HAL) is a preferred instrument to measure self-reported limitations in activities in persons with haemophilia (PWH). Information on reliability and interpretability of HAL scores is lacking. AIM: To examine the test-retest reliability and smallest detectable change (SDC) of the HAL in adult PWH. METHODS: Fifty adult (≥18 years) persons with mild to severe haemophilia completed the HAL (42 items, 7 domains, optimum 100) at baseline (T0) and 3-4 weeks later (T1). The intraclass correlation coefficient (ICC) and SDC were calculated for sum and component scores. RESULTS: Fifty persons with haemophilia were included (median age 49 years; 92% haemophilia A; 70% severe haemophilia). The median (interquartile ranges) HAL sum score was 77 (62 to 99) at T0 and 81 (64 to 98) at T1. Reliability was good with ICCs for sum and component scores >0.9. The SDC for the sum score was 10.2, for the upper extremity component score 9.2, for the basic lower extremity component score 16.7 and for the complex lower extremity component score 13.4. CONCLUSION: The HAL has a good reliability for the sum and component scores. Score changes of the normalized sum HAL score greater than the SDC 10.2 indicate that the change was not a result of measurement error.

A tailored intervention for illness acceptance improves adherence and quality of life in adults with haemophilia using prophylaxis.

INTRODUCTION: Adherence to prophylactic treatment (prophylaxis) in persons with haemophilia is challenging and has been reported at only ±50%. Acceptance problems are one of the main reasons for non-adherence in haemophilia. An evidence-based intervention was developed based on an acceptance and commitment therapy (ACT) approach. AIM: To evaluate a tailored intervention focused on illness acceptance in adults with haemophilia who were prescribed prophylaxis. METHODS: A pre-post study was executed in adults with haemophilia who were prescribed prophylaxis. A series of 8 2-hour group trainings were held, including 3-8 participants/series. Adherence (VERITAS-Pro, optimum 0), health-related quality of life (HRQoL, SF-36, optimum 100) and illness perception (BIPQ, optimum 0) were measured at start, after six months and 12 months and analysed using Wilcoxon signed-rank test. RESULTS: Twenty-four patients (median age 47 years, range 27-74) were included. After 12 months, adherence improved in 68% of patients, quality of life in 48% and illness perception in 31%. Adherence (total score) improved from 35 to 25 (P<0.01). HRQoL showed clinically relevant improvement in domains of social-functioning (P = 0.04), role-emotional, physical-functioning, role-physical and bodily pain. Illness perception improved statistically significant on domains of affect (P = 0.01), concern (P = 0.01) and understanding (P = 0.04). Patients evaluated the training useful, an eye-opener, a personal enrichment and insightful. CONCLUSION: The tailored group intervention resulted in significant improvement of adherence, quality of life and illness perception. Based on our current experience, we have implemented it in clinical practice and collaborate with the patient association to make it available for all Dutch people with haemophilia.

PROTECT VIII kids extension study: Long-term safety and efficacy of BAY 94-9027 (damoctocog alfa pegol) in children with severe haemophilia A.

INTRODUCTION: BAY 94-9027 (damoctocog alfa pegol; an extended half-life PEGylated recombinant factor VIII [FVIII]) demonstrated efficacy and safety in previously treated paediatric patients (PTPs) aged <12 years with severe haemophilia A in the PROTECT VIII Kids study (NCT01775618). AIM: To evaluate the long-term safety of BAY 94-9027 in PTPs aged <12 years at enrolment. METHODS: In the PROTECT VIII Kids study, boys <12 years with severe haemophilia A were enrolled in two age cohorts (6-<12 years and <6 years) and treated prophylactically twice weekly, every 5 days or every 7 days, with BAY 94-9027 for ≥50 exposure days (EDs). Patients who had completed ≥50 EDs and ≥6 months in the main study or 12-week safety expansion study were eligible to participate in the extension. Primary safety variable was frequency of inhibitor development; main efficacy variable was annualised bleeding rate (ABR). RESULTS: Of 73 PTPs from the main/expansion studies, 59 (81%) entered the extension phase for a median (range) duration of 5.0 (0.4-5.9) years. Overall, 39 patients completed ≥5 years of treatment. No patients developed FVIII inhibitors/anti-PEG antibodies, and two patients aged <6 years discontinued. Median ABR for total bleeds was 1.5 (<6 years) and 1.9 (6-<12 years). Total ABR improved in the extension vs. the main study. In the last 12 months of treatment, median spontaneous ABR was 0.0 in both age groups. CONCLUSIONS: BAY 94-9027 showed long-term safety and efficacy for the prevention and treatment of bleeds in younger and older paediatric patients with severe haemophilia A.