Acute bleeding complications in patients after hematopoietic stem cell transplantation with prophylactic platelet transfusion triggers of 10 × 10⁹ and 20 × 10⁹ per L

BACKGROUND: Prophylactic platelet (PLT) transfusions are given as a standard care in patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT). This retrospective analysis evaluates utilization of blood transfusions, risk of bleeding, and survival in 480 HSCT patients at 10 × 10⁹ and 20 × 10⁹ per L prophylactic trigger levels. STUDY DESIGN AND METHODS: A total of 224 patients received prophylactic PLT transfusions at 20 × 10⁹ per L threshold (1997-1998, SP1); 256 patients had prophylaxis at 10 × 10 ⁹ per L (1999-2001, SP2). Bleeding scores were assigned daily. RESULTS: A slight reduction in PLT transfusions per patient in SP2 compared with SP1 was not statistically significant (odds ratio, 0.82; 95% confidence interval, 0.51-1.33; p = 0.416), yet a significantly higher proportion of patients in SP2 had PLT counts less than or equal to 10 × 10⁹ per L compared to SP1 (p < 0.001). In patients who bled, however, there was no excess exposure to low PLT counts before bleeding started. A substantial number of patients who bled received PLT transfusions above the goal before bleeding started (82.9% in SP2, 41.5% in SP1) because of medical complications that associated with increased risk of bleeding. Bleeding incidence was similar in both study periods (21.9% in SP1, 16.4% in SP2; p = 0.526). Bleeding was significantly associated with reduced survival in both study periods. CONCLUSIONS: Patients who bled were usually placed on a higher threshold before the onset of their major bleeding event and were not exposed to additional risk of bleeding from thrombocytopenia. Similarity in bleeding incidence between study periods appears to associate with adjustments to high-risk conditions and may not reflect consequences of the lower transfusion threshold.