E1158. The Impact of Blood Pressure on the Risk of Major Hemorrhagic Complication After Renal Transplant Biopsy
  1. Winston Wang; Mayo Clinic Arizona
  2. Anika Patel; Mayo Clinic Arizona
  3. Nan Zhang; Mayo Clinic Arizona
  4. Scott Young; Mayo Clinic Arizona
  5. Nirvikar Dahiya; Mayo Clinic Arizona
  6. J. Scott Kriegshauser; Mayo Clinic Arizona
  7. Maitray Patel; Mayo Clinic Arizona
Previous literature has not show any statistically significant difference in major hemorrhagic complication of renal transplant biopsy in patients who had elevated systolic or diastolic blood pressure compared to normotensive patients, but the data is limited, based on only 4 complications. We aim to expand on this data.

Materials and Methods:
Retrospective review of the electronic medical record for consecutive patients undergoing US-guided renal transplant biopsies from 08/01/2015 to 7/31/2017, recording the systolic (SBP), diastolic (SBP), and mean arterial (MAP) blood pressure for each patient prior to biopsy (before entry into the procedure room). During the study period, there was no blood pressure threshold used to cancel the biopsy. The development of a major bleeding complication (Common Terminology Classification for Adverse Events grade 3 or higher) was recorded. The risk of complication as a function of SBP, DBP, and MAP were analyzed using Kruskal-Wallis rank sum test. The optimum threshold for differentiating patients based on risk of bleeding complication was determined using risk dichotimization based on ROC analysis with optimum cut-off points weighted for specificity chosen by Youden index, with odds ratio estimated using Firth logistic regression. Statistical significance was set at p < 0.05.

Of 1698 consecutive biopsies during the study period, 1689 biopsies on 958 patients (547 men, 411 women) met the inclusion criteria. There were 10 bleeding complications (10/1689, 0.59%). For the 1679 biopsies without complication, the mean, median, interquartile range, and full range of SBP, DBP, and MAP were: (1) SBP: 140.1 mm Hg, 139 mm Hg, 127-153 mm Hg, 90-218 mm Hg; (2) DBP: 76.9 mm Hg, 77 mm Hg, 68-86 mm Hg, 36129 mm Hg; (3) MAP: 97.9 mm Hg, 98 mm Hg, 90-106 mm Hg, 62-144 mm Hg. For the 10 biopsies with complication, the mean, median, interquartile range, and full range of SBP, DBP, and MAP were: (1) SBP: 145.4 mm Hg, 145.5 mm Hg, 133-154 mm Hg, 112-180 mm Hg; (2) DBP: 82.7 mm Hg, 84.5 mm Hg, 79-88 mm Hg, 59-96 mm Hg; (3) MAP: 102.9 mm Hg, 104 mm Hg, 97-110 mm Hg, 89-117 mm Hg. There was no statistically significant difference between biopsies with complication compared to those without complication for the SBP (p=0.351), DBP (p=0.088), or MAP (p=0.132). Based on risk dichotomization criteria, the odds ratio for hemorrhagic complication when the patient had SBP >= 180 mm Hg, DBP >= 95 mm Hg, and MAP >= 116 mm Hg was 75.63 (95% CI 6.87-516.8, p = 0.002).

While the rate of hemorrhagic complication from renal transplant biopsy is low, and there is no statistically significant threshold for increased biopsy risk based on SBP, DBP, or MAP alone, when these metrics are combined, the risk of complication is significantly higher when the SBP is >= 180 mm Hg, DBP is >= 95 mm Hg, and MAP is >= 116 mm Hg.