Angiotensin 2 for AKI After OLT

December 20, 2023 updated by: Colby Tanner, MD, University of California, Los Angeles

Intraoperative Angiotensin 2 for the Prevention of Kidney Injury After Liver Transplant

Kidney injury is a common complication following liver transplantation and is associated with a higher complication rate and increased risk of death. While there are many factors that likely contribute to kidney injury in the perioperative period, a relative low serum level of angiotensin 2 (Ang 2) (a protein hormone that causes blood vessels to narrow) found in patients with liver cirrhosis (late stage of liver damage) may increase their risk of developing acute kidney injury (sudden episode of kidney failure or damage). We propose to investigate how early administration of Ang 2, a new vasopressor drug approved by the FDA in December 2017 for patients with low blood pressure, during the intra-operative period of liver transplant surgery affects the rate of kidney injury after transplantation. Patients who are deemed appropriate candidates for the study will be randomized 1:1 to the treatment and control groups. The intervention period of the study will occur in the operating room during transplant surgery and will be performed by their anesthesiologists. In the Treatment group, patients will receive Ang 2 infusions in addition to other standard vasopressors while patients in the control group will receive standard vasopressors alone. The infusion of Ang 2 in the treatment group will continue through the duration of the surgery and will be stopped prior to leaving the operating room. Both the treatment group and the control group will then be followed for 14 days to evaluate rates of kidney injury and to look for any complications. The follow up period will be extended to 28 days to look at in-hospital mortality rates in both groups. The daily follow up analysis will occur while the enrolled patients are inpatient following their transplantation surgery and will be done by looking at lab values and other data that is routinely gathered by their managing teams. This study will serve as a pilot study to evaluate feasibility of our protocol and to collect some preliminary data on the use of Ang 2 in this patient population. As such we plan to enroll approximately 30 patients who have accepted an offer to receive a donor liver. We hope to reach our goal enrollment within 5 months of starting the study.

Study Overview

Detailed Description

Acute kidney injury is a common perioperative complication following liver transplantation with an incidence of approximately 55%. Due to the complex physiologic derangements present in cirrhotic patients, multiple etiologies and processes may contribute, including chronic and acute hepatorenal syndrome, ATN, renal toxic medication administration, microvascular circulatory dysfunction from vasopressors, and hypoperfusion from the vasodilatory and hypovolemic forms of shock that are common during liver transplantation. While some of the risk factors for these causes of AKI can be mitigated, our current area of investigation revolves around the modulation of the renin-angiotensin system in the prevention of perioperative AKI. In cirrhosis, poor renal blood flow causes an increase in circulating levels plasma renin. However, recent studies suggest low levels of angiotensinogen and angiotensin 2, which are associated with AKI in cirrhotic patients5 and may contribute to the risk of perioperative AKI in liver transplant patients.

Angiotensin 2 was approved for clinical use as a vasopressor in 2017. The efficacy of angiotensin 2 at increasing systemic blood pressure in patients with vasodilatory shock was demonstrated by the ATHOS 3 trial. This study found that the addition of angiotensin 2 increased MAP by close to 10mmHg compared to placebo (12.5 vs 2.9 mmHg p< 0.001) and allowed for a decrease in other vasopressor utilization. Post-hoc analysis of the ATHOS-3 trial by Tumlin et al demonstrated that patients in vasodilatory shock with AKI had higher rates of recovery from AKI and fewer days requiring dialysis than those who did not receive angiotensin 2.

As vasodilatory shock is common among patients undergoing LT, this finding is relevant to our patient population. We hypothesize that angiotensin 2 will reduce AKI in patients undergoing LT, where vasodilatory shock is also very common.

Hypothesis: We propose that a relative deficiency of angiotensin 2 predisposes cirrhotic patients to develop acute kidney injury following liver transplantation. We hypothesize that initiating angiotensin 2 infusion as a short duration infusion during the intra-operative period of liver transplant surgery will decrease the incidence of postoperative acute kidney injury.

Aim1: Evaluate the efficacy of Angiotensin 2 to reduce incidence of acute kidney injury (AKI) following liver transplantation. Rates of recovery from AKI in patients with septic shock have been established in post-hoc analysis of the ATHOS-3 study. With high rates of AKI following transplant surgery as well as a patient population with predisposition for AKI in part due to a relative angiotensin 2 deficiency, we hope to demonstrate that the addition of angiotensin 2 to standard vasopressor regimens during transplant surgery decreases the incidence of postoperative AKI.

Aim 2: Evaluate the safety of angiotensin 2 in cirrhotic patients. While cirrhotic patients were included in the two largest studies of synthetic angiotensin 2 (ATHOS-1 and ATHOS-3), those with MELD > 40 were excluded, and no specific subgroup analysis was done. While several case reports of safe administration of angiotensin 2 in patients with cirrhosis have been published, we hope to further investigate its safety during liver transplant surgery. We hypothesize that angiotensin 2 can safely be administered in cirrhotic patients

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • California
      • Los Angeles, California, United States, 90095
        • Michael Y Lin

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

A. End stage liver disease (ESLD) with acceptance of organ allocation offer. B. Stable renal function in the 48 hours prior to transplant (defined as < 30% change in serum creatinine) C. Adult patients > 18 years old

Exclusion Criteria:

A. Active use of renal replacement therapies B. Recent (within last 3 months) history of CVA or MI C. Patients with hypercoagulable state as evidenced by pre-existing venous thromboembolism or known thrombophilia (Antiphospholipid syndrome, Factor V- Leiden etc.) D. Combined liver transplant and intrathoracic surgery cases (not including chest tube placement) E. Multiple organ transplantation F. Congestive heart failure defined as left ventricular ejection fraction <45% G. Inability to obtain consent from the patient or surrogate H. Known allergy or sensitivity to any study medication I. Hepatocellular Carcinoma

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Intervention
Patients assigned to the study group will receive Ang 2 infusion in addition to standard vasopressor regimen. Ang 2 is currently approved at UCLA as a second line vasopressor and will be used as such for the purposes of our study. Hemodynamic goals will be established at the beginning of the case by the anesthesiology and surgical teams. Ang 2 will be started as a second vasopressor once the norepinephrine dose has reached 0.05mcg/kg/min. Ang 2 will be initiated at a starting dose of 5ng/kg/min. That dose will be up titrated one time to 10ng/kg/min as vasopressor requirements escalate. Once a patient is on the 10ng/kg/min dose of ang 2, no additional up titration will be performed. Hemodynamic management will continue throughout the case with titration of other vasopressors as needed. Ang 2 will be continued throughout the intraoperative period but will be weaned off prior to leaving the operating room.
Angiotensin II infusion for Intraoperative management during liver transplantation
Vasopressor infusion for management of Intraoperative hypotension in liver transplantation.
Other Names:
  • Epinephrine
  • Vasopressin
Active Comparator: Control
Patients assigned to the control group will undergo intraoperative management with a standard vasopressor regimen composed of norepinephrine, vasopressin and epinephrine based on hemodynamic goals established by the surgical and anesthesia teams prior to surgery.
Vasopressor infusion for management of Intraoperative hypotension in liver transplantation.
Other Names:
  • Epinephrine
  • Vasopressin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Acute kidney Injury
Time Frame: Every day for 14 days following intervention
Measured by change in serum creatinine from baseline based on KDIGO criteria.
Every day for 14 days following intervention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Need for Renal Replacement therapies
Time Frame: Every day for 14 days following intervention
Every day for 14 days following intervention
In hospital mortalituy
Time Frame: 28 days
28 days
Urine output
Time Frame: 14 days
Urine output measured in ml
14 days
Vasopressor doses
Time Frame: 14 days
Vasopressor doses evaluated as norepinephrine equivalents
14 days
Adverse events
Time Frame: 14 days
deep vein thrombosis, pulmonary embolus, intracardiac thrombus, stroke, myocardial infarction, peripheral ischemia, hepatic artery thrombosis, mesenteric ischemia, infusion site reaction, new infection, intraoperative tachycardia, intraoperative acidosis, lactatemia
14 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 8, 2022

Primary Completion (Estimated)

September 1, 2024

Study Completion (Estimated)

December 1, 2024

Study Registration Dates

First Submitted

October 14, 2020

First Submitted That Met QC Criteria

October 14, 2020

First Posted (Actual)

October 19, 2020

Study Record Updates

Last Update Posted (Actual)

December 21, 2023

Last Update Submitted That Met QC Criteria

December 20, 2023

Last Verified

December 1, 2023

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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