Impact of Obesity Status on Synthetic Angiotensin II (Giapreza®) Use in Kidney Transplantation

Introduction: Perioperative hypotension is common in kidney transplant recipients and linked with poor allograft outcomes. We use synthetic angiotensin II (AT2S) as the first-line vasopressor for these patients. Lack of evidence exist evaluating the impact of obesity on AT2S requirements and allograft function in this population. We hypothesize that kidney transplant patients with obesity require a longer AT2S duration, higher AT2S doses, and have increased rates of delayed graft function (DGF).


Methods: This retrospective, single-center, cohort study compared AT2S use and allograft function in kidney transplanted patients with and without obesity. Included patients were adults who underwent an isolated kidney transplant and required vasopressors perioperatively with AT2S. Data was collected from the date of transplant until 28 days post-operative. We identified 305 eligible patients from 1/2021-9/2024. Co-primary endpoints included differences in vasopressor duration, dose, and allograft function. Statistical analysis of study endpoints was assessed using descriptive and inferential statistics.


Results: 305 patients (N=179 obese, N=126 non-obese) were included with balanced baseline characteristics, except significant differences in race, diabetes, hemodialysis duration, and transplant duration (P < 0.05). AT2S duration (hours) [17 (3-52.3) vs. 6.5 (1.75-29.4) hours (P < 0.001)], total dose received (mcg) [2977.8 (1012.2-7327) vs. 1025.8 (282.6-1866.1) mcg (P < 0.001), and rates of delayed graft function 36.3% vs. 20.6% (P=0.003) were higher in patients with obesity. Linear regression showed pre-operative hemodialysis duration and post-operative propofol to be associated with both AT2S duration and dose (P < 0.05). Propofol dose, cold-ischemic time, vasopressor duration, and donor terminal Scr were associated with DGF (P < 0.05).


Conclusions: Obese kidney transplanted recipients required higher doses of AT2S for longer durations and had a higher incidence of DGF. This is consistent with prior evidence linking obesity to increased DGF risk. The higher doses may reflect longer transplant surgeries, more profound inflammatory response during surgery, or increased propofol requirements for obese patients. Further exploration is needed to investigate these observations.