Background: The bleeding time is frequently used to screen primary haemostasis before surgical procedures, although it poorly predicts the risk of hemorrhage. The platelet function analyzer (PFA), which is also used to screen primary haemostasis, has a higher sensitivity and other advantages, like patient friendliness, higher degree of objectivity and analytical reliability, but needs more extensive clinical validation.
Methods: We compared the predictive values of the PFA-CTs (closure times) and bleeding time for bleeding events after renal biopsy. We prospectively evaluated the complications in patients that underwent a renal biopsy and were screened with PFA in advance (n=170). For comparison we used a historical cohort of patients screened with the bleeding time (n=132).
Results: When the PFA-CTs were normal, 26.0% of the patients had a mild bleeding event after the biopsy, which did not differ from the event rate with a normal bleeding time (29.4%). When one or both PFA-CTs were prolonged, 51.3% of the patients had post-biopsy bleeding events independently of the measures to correct the closure time(s), significantly more than with either a prolonged bleeding time (26.7%) or normal PFA-CTs (26.0%).
Conclusion: For bleeding events, the PFA has a higher positive and similar negative predictive value compared to the bleeding time. Taken into account the additional advantages of the PFA like patient friendliness and better analytical qualities, we prefer the PFA over the bleeding time as a screening tool for primary haemostasis before performing a renal biopsy.