MO200: Risk of Complications after Percutaneous Native Kidney Biopsy in Patients Receiving Anti-Platelet Agents
Authors: Fontana Francesco , Cazzato Silvia , Giaroni Francesco , Alfano Gaetano , Cappelli Gianni , Donati Gabriele 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Although discontinuation of antiplatelet agents at least 5 days before kidney biopsy is recommended by most guidelines and commonly advised by nephrologists, the evidence behind this practice is very low. Indeed, few non-randomized studies previously showed a similar rate of bleeding after kidney biopsy in patients who received aspirin and those who did not. Withdrawal of antiplatelet agents has been associated with an immediate and substantial increase in cardiovascular events, especially in patients at risk for coronary heart disease.

METHOD
We conducted a single centre retrospective cross-sectional study comparing the risk of complications after percutaneous ultrasound-assisted native kidney biopsy in patients who received antiplatelet agents within 5 days from biopsy and those who did not; the study was approved by local Ethical Committee (protocol 1321/2020/OSS*/AOUMO). The main outcome was the difference in the proportion of major complications (any of the following: red blood cells transfusion, need for selective arterial embolization, surgical revision, nephrectomy). Secondary outcomes were: difference in the proportion of minor complications (drop in haemoglobin &gt;2 g/dL, bladder tamponade, macrohematuria, need for angio-CT scan, hematoma &gt;3 cm), difference in the proportion of complications between patients who received antiplatelet agents within 48 h and those who received them within 3–5 days from biopsy, identification of independent factors predictive of major complication.

RESULTS
We analszed 769 percutaneous native kidney biopsies performed by nephrologists from 1 January 2010 to 31 December 2020 in 741 patients; 113 procedures (14.69%) were conducted under antiplatelet therapy (within 5 days from biopsy). Demographical, clinical and laboratory characteristics of the whole cohort and dividing patients according to antiplatelet therapy status (absent or within 5 days from biopsy) are reported in Table 1; most patients (83.17%) on antiplatelet were receiving low-dose aspirin. A single (or a combination of more) major complication occurred in 17/656 (2.59%) of patients without and in 4/113 (3.54%) patients with antiplatelet therapy, with non-significant difference between groups (percentage point difference 1%, 95% CI –2% to 4%, P = .57); no deaths were attributable to the biopsy procedure. There were 103/656 (15.7%) minor complications in patients without and 14/113 (12.39%) in patients with antiplatelet therapy, with non-significant difference between groups (percentage point difference 3%, 95% CI –10% to 4%, P = .37). In patients treated with antiplatelet within 5 days from biopsy, we encountered no significant difference in the proportion of major or minor complications in those who received therapy in the last 48 h or 3–5 days before the procedure. The final multivariate stepwise logistic regression model for the prediction of major complication included two variables (platelets &lt;120*10^3, eGFR); the model was logit(p) = –2668 + 2383*(platelets &lt; 120*10^3)-0036*eGFR, where P is the probability of having a major complication after kidney biopsy (see Table 2 for univariate and multivariate analysis). This model produced an AUC of 0808 (95% CI 0.724–0.89).

CONCLUSION
Receiving anti-platelet therapy (in particular, low-dose aspirin) within 5 days from percutaneous native kidney biopsy did not increase the risk of major or minor complications in our cohort. Platelet count &lt; 120*10^3/µL and lower eGFR were significantly associated with an increased risk for major complication.