Viscoelastic testing in patients with very rare bleeding disorders of secondary hemostasis, a scoping review

Abstract

Introduction

Very rare bleeding disorders (VRBDs) are hereditary disorders which cause increased risk of bleeding. In general, VRBDs consists of rare platelet function disorders, very rare coagulation factor deficiencies (other than Factor (F) VIII or FIX) and disorders of the fibrinolytic pathway. The rarity of these disorders along with the scarcity of specialized hemostasis laboratories capable to perform the necessary diagnostic tests, results in significant challenges in diagnosing and monitoring patients with VRBD. Viscoelastic testing could potentially address these challenges.

Aim

This scoping review aims to assess the validity of viscoelastic assays for diagnosing, monitoring, and risk prediction in patients with VRBDs in the secondary hemostasis.

Methods

Relevant studies were identified on PubMed and categorized based on the clinical scenario addressed in the study.

Results

Viscoelastic assays can consistently detect severe factor deficiencies, but the sensitivity is lower in patients with mild factor deficiencies. In addition to the residual factor activity, sensitivity depends on the specific viscoelastic assay used and the potential underlying genetic abnormality. Only in FXI deficiency, multiple reports reveal correlations between assay outcomes and clinical phenotype, though clinical benefit of these findings is limited by the mild strength of these correlations. In many studies, viscoelastic assays were able to monitor the effects of treatment, but just a few found associations between the assay results and risk prediction.

Conclusion

Severe coagulation factor deficiencies can reliably be ruled out based on viscoelastic assays. Low-quality evidence showed benefit of these assays in monitoring treatment and risk prediction in VRBDs.