Why is a bleeding assessment tool and family history of bleeding often not performed in patients at high risk of serious bleeding, such as those with undiagnosed type 2B von Willebrand disease?

Bleeding Assessment Tools and Family History Are Underutilized Despite High Risk of Serious Bleeding

Bleeding assessment tools (BATs) and family history evaluation should be routinely implemented in clinical practice for all patients at risk of serious bleeding, as these are critical for identifying conditions like type 2B von Willebrand disease that can lead to significant morbidity and mortality if undiagnosed. 1

Current Practice Gaps in Bleeding Risk Assessment

The underutilization of bleeding assessment tools and family history evaluation in clinical practice stems from several key factors:

1. Lack of Standardized Approach: Despite guidelines recommending structured bleeding assessments, there is considerable heterogeneity in clinical practice regarding the approach to patients with bleeding tendencies 1.

2. Misinterpretation of Guidelines: Recent guidelines from the American Society of Hematology, ISTH, National Hemophilia Foundation, and World Federation of Hemophilia recommend using BATs to document bleeding symptoms but not as the sole criterion for ordering further blood testing 1. This nuanced recommendation may be misinterpreted as diminishing the importance of BATs.

3. Resource Constraints: Comprehensive bleeding assessments and specialized laboratory testing are resource-intensive and may not be readily available in all clinical settings 1.

4. Diagnostic Challenges: Conditions like type 2B von Willebrand disease present with heterogeneous clinical manifestations that can be difficult to identify without specialized testing 2, 3.

Importance of Bleeding Assessment Tools

Bleeding assessment tools provide critical advantages:

• Standardization: The ISTH BAT score provides a standardized approach to evaluate bleeding phenotypes (normal scores: <3 in children, <6 in adult females, <4 in adult males) 1.

• High Negative Predictive Value: When properly implemented, BATs have excellent negative predictive values (92-95%) for ruling out significant bleeding disorders 4, 5.

• Early Identification: In pediatric populations, a BAT score ≥3 has shown 97.2% sensitivity and 97.1% specificity for identifying children likely to have VWD 5.

Importance of Family History Assessment

Family history evaluation is crucial but often inadequately performed:

• High Clinical Value: Nearly all hemostasis experts (98%) recognize family history as an important clinical consideration for assessment of mild bleeding disorders 1.

• Inheritance Patterns: Type 2B VWD follows an autosomal dominant inheritance pattern, making family screening particularly valuable 3.

• Variable Penetrance: Within families with the same genetic mutation, phenotypic expression can vary significantly, as demonstrated in cases where siblings with identical mutations present with different clinical manifestations 6.

Diagnostic Algorithm for Bleeding Risk Assessment

1. Initial Screening Questions:

   • Have you or a blood relative needed medical attention for a bleeding problem?
   • Do you have a blood relative with a bleeding disorder?
   • Have you had prolonged bleeding after surgery, dental extractions, or trauma?

2. Comprehensive Bleeding Assessment:

   • Implement a standardized BAT (preferably ISTH BAT)
   • Document specific bleeding symptoms: mucocutaneous bleeding, menorrhagia, epistaxis, easy bruising, post-surgical bleeding
   • Assess for comorbidities that may affect bleeding risk (hypermobility, liver disease)
   • Evaluate medication use that may affect hemostasis (NSAIDs, aspirin)

3. Family History Evaluation:

   • Document bleeding symptoms in first-degree relatives
   • Note any diagnosed bleeding disorders in the family
   • Consider testing family members of patients with confirmed bleeding disorders

4. Laboratory Testing:

   • Initial tests: CBC, PT, PTT, VWF antigen, VWF ristocetin cofactor activity (VWF:RCo), factor VIII
   • Calculate VWF:RCo/VWF:Ag ratio (ratio <0.5-0.7 suggests type 2 VWD)
   • For suspected type 2B VWD: RIPA at low concentrations of ristocetin and VWF multimer analysis

Pitfalls to Avoid

• Overlooking Mild Symptoms: Even mild bleeding symptoms can indicate underlying disorders like type 2B VWD 1.

• Ignoring Family History: Family history is critical for diagnosis but is often inadequately assessed 1.

• Relying on Normal Initial Tests: A normal VWF:RCo/VWF:Ag ratio and negative RIPA at 0.5 mg/mL do not rule out type 2B VWD 7.

• Inappropriate Use of DDAVP: In type 2B VWD, DDAVP can exacerbate thrombocytopenia and is contraindicated 8, 3.

• Failing to Consider Pregnancy Risks: Thrombocytopenia in type 2B VWD can worsen during pregnancy, requiring special management 3.

By implementing comprehensive bleeding assessment tools and thorough family history evaluation in clinical practice, healthcare providers can significantly improve the identification of patients with serious bleeding disorders, particularly those with conditions like type 2B von Willebrand disease, ultimately reducing morbidity and mortality associated with these conditions.