Effects of Oral Protein Load on Kidney Function in Patients Undergoing Cardiac Surgery

Effects of Preoperative High Oral Protein Load on Short- and Long-term Renal Outcomes Following Cardiac Surgery - a Matched Case-control Study

Acute kidney injury (AKI) occurs in approximately one-third of patients undergoing cardiac surgery (CS), and represents one of the most significant negative predictors of patient outcome in this population. In the healthy adult, a high protein meal is known to enhance glomerular filtration rate and is mediated by an increase in renal blood flow. The investigators hypothesized that preoperative oral protein load may precondition the kidneys for upcoming insults and reduce the rate of postoperative AKI and long-term renal outcome.

Study Overview

• Status: Completed
• Conditions: Acute Kidney Injury
• Intervention / Treatment: Other: None intervention

Detailed Description

Acute kidney injury (AKI) occurs in approximately one-third of patients undergoing cardiac surgery (CS), and represents one of the most significant negative predictors of patient outcome in this population. To date, there is no therapy to prevent AKI. In the healthy adult, a high protein meal is known to enhance glomerular filtration rate (GFR) and is mediated by an increase in renal blood flow. The investigators hypothesized that preoperative oral protein load may induce an adaptive response of the kidneys, and precondition the kidneys for upcoming insults. In the present study, the investigators aimed to compare the prevalence and severity of AKI in patients undergoing oral high protein load of the 'Preoperative Renal Functional Reserve Predict Risk of AKI after Cardiac Operation' study to age- and gender-matched "controls" who had a standard preoperative care the day prior to surgery within the same period (November 2014-October 2015) at San Bortolo Hospital, Vicenza, Italy. Both groups were followed 1 year post-discharge to evaluate long-term renal outcomes.

• Study Type: Observational
• Enrollment (Actual): 214

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Adult patients with estimated GFR ≥60 ml/min/1.73 m2 (CKD-Epidemiology Collaboration equation) undergoing elective cardiac surgery (coronary artery bypass, valve replacements, combined or other surgery, with cardiopulmonary bypass) between November 2014 and October 2015 at the San Bortolo Hospital, Vicenza, Italy

Description

Inclusion Criteria:

1. Subjects older than 18 years undergoing elective cardiac surgery
2. Subjects older than 18 years with an estimated eGFR >60 ml/min/1.73 m2 (CKD-EPI)
3. Subjects who signed informed consent forms

Exclusion Criteria:

1. Pregnancy
2. Chronic kidney disease ≥ stage III (KDIGO criteria)
3. Preexisting acute kidney injury (as determined by all available serum creatinine values from hospital and outpatient medical records within the previous 90 days)
4. Solitary kidney
5. Diabetes mellitus type 1
6. Recent cardiac arrest or myocardial infarction up to 7 days before surgery
7. Liver failure or cirrhosis
8. Total parenteral nutrition
9. Haemoglobin <11 g/dl
10. Sepsis
11. History of malabsorption, chronic inflammatory bowel disease, short bowel, or pancreatic insufficiency
12. Transplant donor or recipient
13. Active autoimmune disease with renal involvement
14. Rhabdomyolysis
15. Prostate hypertrophy with International Prostate Symptom Score ≥20
16. Transcatheter aortic valve implantation
17. Active neoplasm
18. Patients who did not pause angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers or received non-steroidal anti-inflammatory drugs a minimum of 48 hours before hospital admission.
19. Patients who received intravenous radiocontrast agents within the 72 hours before hospital admission.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cardiac Surgery; 214 adult patients with estimated GFR ≥60 ml/min/1.73 m2 (CKD-Epidemiology Collaboration equation) undergoing elective cardiac surgery (coronary artery bypass, valve replacements, combined or other surgery, with cardiopulmonary bypass) between November 2014 and October 2015 at the San Bortolo Hospital, Vicenza, Italy	Other: None intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Occurrence of AKI after cardiac surgery	using full Kidney Disease: Improving Global Outcomes criteria	7 days
Long-term change in estimated GFR	using CKD-Epidemiology Collaboration creatinine formula	3 months and 1 year after cardiac surgery

Collaborators and Investigators

• Sponsor: University of Giessen
• Investigators: Study Director: Claudio Ronco, MD, International Renal Research Institute of Vicenza, Vicenza, Italy

Publications and helpful links

General Publications

• Zarbock A, Schmidt C, Van Aken H, Wempe C, Martens S, Zahn PK, Wolf B, Goebel U, Schwer CI, Rosenberger P, Haeberle H, Gorlich D, Kellum JA, Meersch M; RenalRIPC Investigators. Effect of remote ischemic preconditioning on kidney injury among high-risk patients undergoing cardiac surgery: a randomized clinical trial. JAMA. 2015 Jun 2;313(21):2133-41. doi: 10.1001/jama.2015.4189.
• Husain-Syed F, Emlet DR, Wilhelm J, Danesi TH, Ferrari F, Bezerra P, Lopez-Giacoman S, Villa G, Tello K, Birk HW, Seeger W, Giavarina D, Salvador L, Fuhrman DY, Kellum JA, Ronco C; IRRIV-AKI Study Group. Effects of preoperative high-oral protein loading on short- and long-term renal outcomes following cardiac surgery: a cohort study. J Transl Med. 2022 May 10;20(1):204. doi: 10.1186/s12967-022-03410-x.
• Sharma A, Zaragoza JJ, Villa G, Ribeiro LC, Lu R, Sartori M, Faggiana E, de Cal M, Virzi GM, Corradi V, Brocca A, Husain-Syed F, Brendolan A, Ronco C. Optimizing a kidney stress test to evaluate renal functional reserve. Clin Nephrol. 2016 Jul;86(7):18-26. doi: 10.5414/CN108497.

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2014
• Primary Completion (Actual): October 31, 2015
• Study Completion (Actual): November 24, 2016

Study Registration Dates

• First Submitted: March 30, 2017
• First Submitted That Met QC Criteria: March 30, 2017
• First Posted (Actual): April 5, 2017

Study Record Updates

• Last Update Posted (Actual): November 20, 2018
• Last Update Submitted That Met QC Criteria: November 18, 2018
• Last Verified: November 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Kidney Diseases; Urologic Diseases; Renal Insufficiency; Acute Kidney Injury
• Other Study ID Numbers: 79/16 F

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All IPD that underlie results in a publication
• IPD Sharing Time Frame: Starting immediately after results have been published
• IPD Sharing Access Criteria: by email request to first author
• IPD Sharing Supporting Information Type: SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No