Bleeding risk and prediction model to predict bleeding risk of tissue biopsy for definitive diagnosis in patients with suspected amyloidosis

Introduction: Bleeding from the affected organs is a common manifestation of amyloidosis. The risk for perioperative bleeding in patients with amyloidosis remains controversial. In this study, we aimed to compare the bleeding risk of tissue biopsies for a definitive diagnosis between patients with and without amyloidosis, identify risk factors, and generate a prediction model for bleeding risk in these patients. Methods: We enrolled patients aged >15 years who had amyloidosis as part of their differential diagnosis before tissue biopsy. After obtaining histopathological reports, we randomly selected patients with and without amyloidosis at a ratio of 4:1. Results: A total of 360 patients were enrolled before tissue biopsy. Bleeding complications were observed in 5.6% and 4.2% of patients with and without amyloidosis, respectively. Amyloidosis was not associated with an increased perioperative bleeding risk (adjusted odds ratio 1.19; 95% confidence interval 0.17-8.41, p = 0.859). Kidney biopsy was a significant risk factor for perioperative bleeding in tissue biopsies. A KiHPL model was generated to predict the bleeding risk. The area under the curve was 0.87, with a good calibration plot for this model. Conclusions: Amyloidosis is not associated with an increased risk of bleeding in tissue biopsies. The KiHPL model can predict the bleeding risk of tissue biopsies for a definitive diagnosis in patients with suspected amyloidosis.