Bleeding risk after kidney biopsy with platelet inhibition

BACKGROUND AND HYPOTHESIS: Platelet inhibitor therapy is a relative contraindication to percutaneous kidney biopsies due to concerns about bleeding risk. Here we present an analysis of a prospective observational study on the risk of complications after native and transplant kidney biopsy with and without platelet inhibition. METHODS: 1103 consecutive biopsies between 2020 and 2025 at a single tertiary academic care center were included (26.0% in transplanted kidneys). Complications after biopsy were assessed and recorded before discharge, which was the day after the biopsy unless complications occurred. The primary outcome was serious complications, defined as any unplanned procedures or prolongation of the hospital stay. Secondary outcomes included hematuria, hematoma, placement of a Foley catheter, arteriovenous fistula, X-ray imaging, radiological intervention to stop bleeding, and transfusion. Bleeding was also classified according to the criteria of the International Society on Thrombosis and Hemostasis and Bleeding Academic Research Consortium. RESULTS: 43.0% of biopsies were performed in women, and 13.0% with continued platelet inhibition. Serious complications occurred in 4.3% of cases: native kidney biopsies, 5.0% vs. transplant biopsies, 2.1% (log odds ratio, -0.91; 95% confidence interval, -1.9 to -0.11; p = 0.040). Transfusion was required in 1.8% of cases. Female sex, right-lateral position, and native kidney biopsy were associated with complications. In multivariable logistic regression analysis, platelet inhibition was not associated with increased risk of serious complications (log odds ratio, -0.23; 95% confidence interval, -1.7 to 0.87; p = 0.7). The risk of transfusion was associated with low hemoglobin before biopsy, hematuria before biopsy, and biopsies performed with the patient sitting, but not platelet inhibition in multivariable regression. No patient died of a complication. CONCLUSION: Platelet inhibition is not statistically associated with increased risk of serious complications after kidney biopsy.