Impact of tranexamic acid on postpartum hemorrhage in type 1 von Willebrand disease treated with recombinant VWF.

abstractPostpartum hemorrhage (PPH) affects up to 44% of women with von Willebrand disease (VWD) despite von Willebrand factor (VWF) replacement. Because tranexamic acid (TXA) reduced PPH-related deaths in the WOMAN trial, we assessed whether TXA combined with rVWF vs rVWF alone prevents PPH in VWD. VWD-Woman, a phase 3, open-label, randomized pilot trial, enrolled pregnant women with VWD, aged ≥18 years (von Willebrand Factor Ristocetin Cofactor activity [VWF:RCo] of <0.50 IU/mL, bleeding history). Participants received IV rVWF 80 IU/kg at delivery and postpartum days 1 and 2, with or without TXA (1 g within 3 hours of delivery). The primary outcome was quantitative blood loss (QBL) at delivery. Secondary outcomes included 21-day pictorial blood assessment chart (PBAC) scores, hemoglobin changes, transfusions, hysterectomy, and safety. Of 103 screened, 40 were eligible, and 20 enrolled (10 per group), 100% were iron-deficient. Mean QBL was similar (TXA + rVWF: 727.0 mL; 95% CI, 434.5-1019.5] vs rVWF: 539.7 mL [95% CI, 132.8-946.6]; P = 0.41), as were rates of PPH (30% in both groups). No differences were observed in hemoglobin change (-1.90 g/dL vs -1.42 g/dL, P = 0.49) or 21-day PBAC score (467.1 vs 344.8, P = 0.32). Stratified analyses showed no differences by age, body mass index, VWF activity, or delivery type. No serious adverse events or thrombosis occurred. TXA plus rVWF is feasible and safe in type 1 VWD, but in this small pilot study, was not associated with a reduction in PPH compared with rVWF alone. Iron deficiency is prevalent. Further studies are needed to improve PPH prevention in VWD. This trial was registered at www.ClinicalTrials.gov as #NCT04344860.