Comparison among three different bleeding scores and the thrombin generation assay to assess the different hemorrhagic phenotypes in patients with FVII deficiency

Defining the bleeding risk in patients with FVII-deficiency is not easy. Aim of this study is to define correlation and differences between three different scores and the thrombin generation assay (TGA) in correctly evaluating the hemorrhagic phenotype in a group of FVII-deficient patients. Fifty-seven patients patients with FVII-deficiency whose hemorrhagic phenotype was assessed by Mariani, ISTH/SSC- Bleeding Assessment Tool (BAT) and Di Minno scores, and by the TGA, were enrolled in this study. TGA parameters (LagTime, Peak, ttPeak, ETP - endogenous thrombin potential) highlighted how both LagTime and ttPeak can discriminate major bleeders from the others, while the same conclusion could not be reached by the ETP and Peak. However, no TGA parameter was found to be useful in separating the mild hemorrhagic phenotype from the moderate one. Scores and TGA were found to be able to only define the severe hemorrhagic phenotypes. None of the methods was able to exactly discriminate the other phenotypes. Given these results, there is therefore a risk of either underestimating or overestimating the potential bleeding risk in patients with non-severe FVII-deficiency.