Bleeding risk for patients with haemophilia under antithrombotic therapy. Results of the French multicentric study ERHEA

Management strategies in persons with inherited haemophilia requiring antithrombotic therapy: A scoping review

BACKGROUND

Thromboembolic events are increasingly reported in the aging haemophilia population. The purpose of this study was to understand current practices and identify knowledge and research gaps in the management of persons with haemophilia requiring antithrombotic therapy for cardiovascular disorders (CVD) or venous thromboembolism (VTE).

METHODS

We searched MEDLINE, EMBASE and Scopus for studies reporting on more than two patients with inherited haemophilia A or B, without inhibitors, requiring antithrombotic therapy for CVD or VTE. Data were extracted by two independent reviewers and analysed using descriptive statistics and narrative synthesis.

RESULTS

We included 32 studies reporting on 432 persons with haemophilia. Three themes described the observed practice variation: (1) Difficulty weighing competing bleeding and thrombotic risks; (2) Tensions in providing standards of care and minimizing bleeding risk; (3) Advocacy for individualized strategies and multidisciplinary care. Different management strategies were used to treat persons with haemophilia in the setting of thromboembolic events, such as avoiding or choosing lower intensity antithrombotic therapy, or procedural alternatives to antithrombotic therapy. Initiation or alteration in haemostatic therapies along with antithrombotic therapy were common strategies and reported in 30 studies. However, data on target factor levels and bleeding and thrombotic events were largely missing.

DISCUSSION

Our scoping review highlights unmet needs in the management of an aging population of persons with haemophilia with increasing prevalence of CVD and VTE. Management is inconsistent and divergent from those of non-haemophilic patients. Prospective data are needed to inform optimal and evidence-based management strategies of CVD and VTE in persons with haemophilia.

Machine learning model for predicting physical activity related bleeding risk in Chinese boys with haemophilia A

BACKGROUND

Physical activity is a crucial part of an active lifestyle for haemophiliac children. However, the fear of bleeds has been identified as barriers to participating physical activity for haemophiliac children even with prophylaxis. Lack of evidence and metrics driven by data is key problem.

OBJECTIVES

We aim to develop machine learning models based on clinical data with multiple potential factors considered to predict risk of physical activity bleeding for haemophilia children with prophylaxis.

METHODS

From this cohort study, we collected information on 98 haemophiliac children with adequate prophylaxis (trough FVIII:C level > 1 %). The involved potential predictor variables include demographic information, treatment information, physical activity, joint evaluation, and pharmacokinetic parameters, etc. We applied CoxPH, Random Survival Forests (RSF) and DeepSurv to construct prediction models for the risk of bleeding during physical activities. All three survival analysis models were internally and externally validated.

RESULTS

A total of 98 patients were enrolled in this study. Their median age was 7.9 (5.5, 10.2) years. The CoxPH, RSF and DeepSurv models' discriminative and calibration abilities were all high, and the RSF model had the best performance (Internal validation: C-index, 0.7648 ± 0.0139; Brier Score, 0.1098 ± 0.0015; External validation: C-index, 0.7260 ± 0.0154; Brier Score, 0.0930 ± 0.0018). The prediction curves demonstrated that the developed RSF model can distinguish the risks well between bleeding and non-bleeding patients, as well as patients with different levels of physical activity. Meanwhile, the feature importance analysis confirmed that physical activity bleeding was deduced by comprehensive effects of various factors, and the importance of different factors on bleeding outcome is discrepant.

CONCLUSIONS

This study revealed from the mechanism that it is necessary to incorporate multiple factors to accurately predict physical activity related bleeding risk. In clinical practice, the designed machine learning models can provide guidance for children with haemophilia A to positively participate in physical activity.

Cardiovascular Risk Scores among Asymptomatic Adults with Haemophilia

BACKGROUND

The mortality rate of Brazilian people with haemophilia (PwH) is decreasing, but the relative incidence of deaths associated with cardiovascular disease (CVD) is increasing.

OBJECTIVES

We aimed to describe the CVD risk score of PwH according to Pooled Cohort Equations Risk (PCER) Calculator tool and its treatment recommendations. We also compared the PCER estimates with the respective Framingham Risk Score (FRS).

METHODS

This cross-sectional study included male PwH ≥ 40 years treated at the Comprehensive Haemophilia Treatment Centre of Pernambuco (Recife/Brazil). PwH with a previous CVD event or a low-density lipid cholesterol ≥ 5.0 mmol/L were excluded. Interviews, medical file reviews, and blood tests were performed. The PCER tool was used to estimate the CVD risk and compare it with the respective FRS. A p-value < 0.05 was accepted as statistically significant.

RESULTS

Thirty PwH were included. Median age was 51.5 [interquartile range-IQR; 46.0-59.5] years. The prevalence of obesity, systemic arterial hypertension, diabetes mellitus, hypertriglyceridaemia, hypercholesterolaemia, and hypoHDLaemia were 20%, 67%, 24%, 14%, 47%, and 23%, respectively. The median PCER score was 6.9% [IQR; 3.1-13.2], with 50% having a high risk (PCER ≥ 7.5%). Statin use was suggested for 54% of PwH. Blood pressure was poorly controlled in 47% of PwH. The agreement between PCER and FRS was 80% (κ = 0.60; p = 0.001).

CONCLUSIONS

Half of the male people with haemophilia aged 40 years or older had a 10-year high risk of developing CVD with strong recommendations to improve control of dyslipidaemia and blood pressure.

Safety, tolerability, and effectiveness of anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia

BACKGROUND

Antithrombotic therapy (anticoagulation and antiplatelet therapy) is frequently needed in patients with hereditary hemorrhagic telangiectasia (HHT); however, data describing and guiding its use are very limited.

OBJECTIVES

To investigate the safety, tolerability, and effectiveness of antithrombotic therapy in HHT in a cohort large enough to compare agents, evaluate for baseline predictors of premature discontinuation, and evaluate hematologic support requirements and healthcare utilization before and after antithrombitc therapy initiation.

METHODS

We performed a multicenter observational cohort study characterizing the outcomes of antithrombic therapy in adults with HHT.

RESULTS

A total of 119 patients with HHT with 187 discrete antithrombotic therapy episodes were included. Of these, 59 patients (50%) dose-reduced and/or prematurely discontinued therapy (including 52 patients [44%] who discontinued) due to worsened bleeding complications. Initiation at reduced dose intensity had a similar premature discontinuation rate (49%) as initiation at standard dose intensity (43%). In a multivariable logistic model, a history of gastrointestinal bleeding was associated with 3.25-fold odds of discontinuation (p = .001). Hemoglobin was significantly lower (10.8 g/dL vs 12.2 g/dL, p < .001), and the need for hematologic support (intravenous iron and/or red blood cell transfusion) was significantly higher (29 patients vs 12 patients, p = .004) in the 3 months after antithrombotic therapy initiation vs the 3 months before; emergency department visits and hospital admissions due to bleeding also increased. The rates of dose-reduction and/or premature discontinuation were similar regardless of the anticoagulant class (warfarin, 46%; heparin-based, 48%; direct oral anticoagulants, 44%) or with multiple simultaneous agents (44%) but were slightly lower with single-agent antiplatelet therapy (37%). Thromboembolism despite receiving antithrombotic therapy was common (18 patients, 15%) with varying outcomes.

CONCLUSION

Antithrombotic therapy is challenging in HHT, resulting in objectively higher morbidity and health care utilization from worsened bleeding. Discontinuation rates approached 50% regardless of the dose intensity at initiation or type of antithrombotic agent used and were higher in patients with a gastrointestinal bleeding history.

Risk factors for bleeding in people living with hemophilia A and B treated with regular prophylaxis: A systematic review of the literature

BACKGROUND

Knowledge about the risk for bleeding in patients with hemophilia (PWH) would be relevant for patients, stakeholders, and policy makers.

OBJECTIVES

To perform a systematic review of the literature on risk assessment models (RAMs) and risk factors for bleeding in PWH on regular prophylaxis.

METHODS

We searched Medline, Embase, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from inception through August 2019. In duplicate, reviewers screened the articles for inclusion, extracted data, and assessed the risk for bias using the Quality in Prognostic Studies (QUIPS) tool. A qualitative synthesis of the results was not performed due to high heterogeneity in risk factors, outcomes definition and measurement, and statistical analysis of the results.

RESULTS

From 1843 search results, 10 studies met the inclusion criteria. No RAM for the risk for bleeding in PWH was found. Most studies included only PWH A or both PWH A and B and were conducted in North America or Europe. Only one study had a low risk for bias in all the domains. Eight categories of risk factors were identified. The risk for bleeding was increased when factor levels were lower and in people with a significant history of bleeding or who engaged in physical activities involving contact.

CONCLUSIONS

Our findings suggest that plasma factor levels, history of bleeds, and physical activity should be considered for the derivation analysis when building a RAM for bleeding in PWH, and the role of other risk factors, including antithrombotic treatment and obesity, should be explored.

Management of comorbidities in haemophilia

With the introduction of clotting factor concentrates in the early 1970s, significant improvements in quality of life and life expectancy of persons with haemophilia (PWH) were realized. Unfortunately, as a result of transmission of HIV and hepatitis C virus (HCV) by contaminated concentrates in the 1980s, many of these gains were lost. Now with four decades of PWH unexposed to contaminated factor products and current treatments capable of suppressing and eliminating HIV and HCV, respectively, the survival rate is once again increasing. In addition to the usual comorbidities associated with advanced age in the general population, several specific issues occur in patients with bleeding disorders. This manuscript explores the incidence and management of the comorbidities of the ageing PWH with a focus on cardiovascular disease and osteoporosis.

Direct oral anticoagulants for atrial fibrillation in patients with congenital factor VII deficiency

The management of anticoagulant therapy (OAT) in patients with factor VII (FVII) deficiency is a very challenging clinical issue, as warfarin further reduces FVII levels, thus potentially increasing bleeding risk. On the other hand, the International Normalized Ratio test is misleading in such patients, as they do not reflect the actual level of global inhibition of the coagulation system. We report here three cases of patients with a moderate FVII deficiency and receiving direct oral anticoagulants (DOAC) for prevention of cardioembolism in atrial fibrillation. Of note, two of them experienced a treatment failure while on warfarin, while DOAC treatment was not associated with thrombotic or hemorrhagic adverse events. DOAC are very attractive for the management of OAT in FVII deficient patients, because they do not require monitoring by tests affected by the inherited defect, and their mechanism of action is FVII-independent.

Haemophilia and ageing

Advances in the development of effective and safe treatments for haemophilia over the last 50 years have resulted in a significant increase in the life expectancy of persons with haemophilia (PWH). The management of this new cohort of middle-aged and elderly PWH is challenging because of the opposing risks of haemophilia and age-related cardiovascular disease and malignancy. Furthermore, this cohort of ageing PWH has the additional comorbidities of human immunodeficiency virus/hepatitis C and chronic haemophilic arthropathy. This article reviews the prevalence, underlying mechanisms and treatment strategies for managing these comorbidities. International collaboration is essential for registry data and further prospective trials to inform optimal evidence-based management for this rare disorder in the future.