The Need of Renal Replacement Therapy and In-Hospital Mortality Incidence In Patients With Cardiac Surgery Associated Acute Kidney Injury: Retrospective Study
Conditions: Acute Kidney Injury
Sponsor: National Cardiovascular Center Harapan Kita Hospital Indonesia

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Non-ACT Study Protocol and Statistic Analysis Plan (SAP) 
 
Clinical Trial Gov ID. 
NCT06091982 
Protocol Number 
01.202308.101 
Title 
Renal Replacement Therapy and In-Hospital Mortality 
Incidence in Cardiac Surgery Associated Acute Kidney Injury 
Study title   
CSA AKI - RRT and Mortality Risk 
 
Date 
of 
 
last  
Version of protocol 
August 22nd, 2023 
Research question and 
objectives 
 
The purpose of this study is to evaluate the risk of 
patients with cardiac surgery associated acute kidney 
injury (CSA-AKI) with renal replacement therapy 
requirement RRT in related to in-hospital mortality 
event compared to CSA-AKI patients without the 
need of RRT. 
Primary objective 
• To analyze the association between AKI with RRT 
and intra-hospital postoperative mortality in cardiac 
surgery patients compared with AKI patients without 
RRT 
Secondary objectives 
• To analyze the risk of intra-hospital post-surgical 
mortality in cardiac surgery patients who 
complicated with CSA AKI  
• To compare the risk of intra-hospital post-surgical 
mortality in cardiac surgery patients who 
complicated with CSA AKI with requirement of 
RRT and without RRT 
• To Identify and analyze perioperative factors that 
play an important role in the incidence of mortality in 
AKI patients after cardiac surgery 

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Authors 
 
1. 
Adriane, Prieta, MD;  
2. 
Ardiyan MD; 
3. 
Dewi, Ni Luh Kusuma MD; 
4. 
Andria, Krisna MD 
Department(s) and institution(s) 
1. 
Consultant of Department of Perioperative Intensive Care and Non-Surgical 
Anaesthesia National Cardiovascular Centre Harapan Kita 
2. 
Consultant of Department of Perioperative Intensive Care and Non-Surgical 
Anaesthesia National Cardiovascular Centre Harapan Kita  
3. 
Consultant of Department of Perioperative Intensive Care and Non-Surgical 
Anaesthesia National Cardiovascular Centre Harapan Kita  
4. 
Medical Staff of Department of Perioperative Intensive Care and Non-Surgical 
Anaesthesia National Cardiovascular Centre Harapan Kita 
 
 
 
 
 
 
 
 

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1 Table of Contents 
1 
Table of Contents .................................................................................... 3 
2 
List of Abbreviations ............................................................................... 5 
3 
Responsible Parties ................................................................................. 7 
4 
Abstract ................................................................................................... 7 
5 
Rational and Background ........................................................................ 8 
6 
Research Question and Objectives .......................................................... 9 
6.1 
Primary Objective .................................................................................. 10 
6.2 
Secondary Objectives ............................................................................ 10 
7 
Research Methods .................................................................................. 10 
7.1 
Study Design ......................................................................................... 10 
7.1.1 
Design Overview ................................................................................... 10 
7.2 
Setting .................................................................................................... 11 
7.2.1 
Study Population ................................................................................... 11 
7.3 
Variables ................................................................................................ 12 
7.3.1 
Variables Operational Definition .......................................................... 13 
7.4 
Data Source ........................................................................................... 16 
7.5 
Study Size .............................................................................................. 17 
7.6 
Data Management .................................................................................. 17 
7.7 
Statistical Analysis Plan ........................................................................ 17 
7.7.1 
Analysis Sets ........................................... Error! Bookmark not defined. 
7.7.2 
Derived and Transformed Data .............................................................. 18 
7.7.3 
Statistical Methods ................................................................................. 18 
7.7.4 
Sequence of Analyses ............................................................................ 19 
7.8 
Limitations of the Research Methods .................................................... 19 
7.9 
Other Aspects ........................................................................................ 20 
8 
Protection of Human Subjects ............................................................... 20 
8.1 
Independent Ethics Committee  or Institutional Review Board ............ 20 
8.2 
Subject Information and Informed Consent ........................................... 20 
8.3 
Subject Identification and Privacy ......................................................... 20 
9 
Management and Reporting of Adverse Events .................................... 21 

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10 
Plans for Disseminating and Communicating Study Results ................. 21 
10.1 
Study Report(s) ...................................................................................... 21 
10.2 
Publication ............................................................................................. 21 
11 
References .............................................................................................. 21 
 
List of Tables 
Table 7.1 Dependent Variable .................................................................................................. 13 
Table 7.2 Independent Variables .............................................................................................. 13 
List of Figures 
Figure 7.1  Study Overview ...................................................................................................... 11 
 
 
 

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2 List of Abbreviations 
 
ACE-I 
Angiotensin-converting enzyme inhibitors 
AKI 
Acute Kidney Injury 
APACHE 
Acute Physiology and Chronic Health Evaluation 
ARF 
Acute Renal Failure 
ARB 
Angiotensin Receptor Blocker 
CABG 
Coronary Artery Bypass Graft 
CI 
Confident Interval 
CKD 
Chronic Kidney Disease 
CPB 
Cardiopulmonary bypass 
CRRT 
Continuous Renal Replacement Therapy  
CSA-AKI 
Cardiac Surgery Associated- Acute Kidney Injury 
CVVH 
Continuous Veno-Venous Hemofiltration 
CVVHD 
Continuous Veno-Venous Hemodialysis 
CVVHDF 
Continuous Veno-Venous Hemodiafiltration 
DM 
Diabetes Mellitus 
EF 
Ejection Fraction 
ESRD 
End Stage Renal Disease 
EURO-SCORE II 
European System for Cardiac Operative Risk Evaluation II 
GFR 
Glomerular Filtration Rate 
HR 
Heart Rate 
HT 
Hypertension 
IABP 
Intra Aortic Balloon Pump 
ICU 
Intensive Care Unit 
IHD 
Intermittent Hemodialysis 
IRI 
Ischemic Reperfusion Injury  
KDIGO 
Kidney Disease Improving Global Outcomes 
LCOS 
Low cardiac output syndrome 
LOS 
Length Of Stay 

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LVEF 
Left Ventricle Ejection Fraction 
OR 
Odd Ratio 
RAAS 
Renin-Angiotensin-Aldosterone System 
RIFLE 
Risk Injury Failure Loss and End Stage  
ROS 
Reactive Oxygen Species 
RRT 
Renal Replacement Therapy 
RR 
Risk Ratio 
SCr 
Serum Creatinine 
UO 
Urine Output 
 
 

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3 Responsible Parties 
Principal Investigators 
Name/ Title 
Contact Details 
Adriane, Prieta, MD 
Address: Sudirman Park Apartment B 02 
CD Jl. KH Mas Mansyur kav.35, Jakarta 
Indonesia 10220 
Phone : +62 5684093 Ext: 7406 
Email : prietaadriane@gmail.com 
Contributing Investigators 
 
1. Prieta Adriane MD             Address:Department of Perioperative Intensive Care and Non-Surgical      
Anaesthesia 
Jl. S.Parman Kav.87 Jakarta Indonesia  
 
ORCID ID : 0000-0001-6950-028X  
2. Ardiyan MD.                      Address:Department of Perioperative Intensive Care and Non-Surgical      
Anaesthesia 
Jl. S.Parman Kav.87 Jakarta Indonesia  
 
ORCID ID : 0000-0002-4366-008X 
3. Ni Luh Kusuma Dewi MD Address:Department of Perioperative Intensive Care and Non-Surgical      
Anaesthesia 
Jl. S.Parman Kav.87 Jakarta Indonesia  
 
ORCID ID : 0009-0008-3756-5175 
4. Krisna Andria MD              Address:Department of Perioperative Intensive Care and Non-Surgical      
Anaesthesia 
Jl. S.Parman Kav.87 Jakarta Indonesia  
 
ORCID ID : 0009-0004-7007-9364 
 
4 Abstract 
 
The prevalence of acute kidney injury (AKI) varies up to 30% in post-cardiac surgery patients. 
Of the patients who suffer from AKI, around 1 - 10% will require renal replacement therapy 
(RRT). Cardiac surgery associated-AKI patients who require renal replacement therapy/dialysis 
have higher risk of mortality. The purpose of this study was to assess the risk of AKI-RRT on 
intrahospital mortality, and other factors that have an association with postoperative mortality. 
The method was non-experimental research design as retrospective cohort analysis. Dependent 
variable, in-hospital mortality was determined first and then the independent variables were 
examined to see the relationship between the variables. 

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Keywords: Acute Kidney Injury (AKI), Renal Replacement Therapy (RRT), cardiac surgery, 
intrahospital mortality 
 
5 Rational and Background 
 
The overall incidence of mortality post-cardiac surgery in some literatures varies between 2-
8%. Cardiac surgery associated - acute kidney injury (CSA-AKI), a common postoperative 
complication, has increased risk for post-operative mortality. The incidence of mortality in 
patients complicated with CSA-AKI is up to 60%. The most severe stage of CSA-AKI, which 
requires dialysis therapy, is an independent risk factor. The prevalence of acute kidney injury is 
ranged up to 28% in cardiac surgery patients, of which around 1 – 10% of those patients required 
renal replacement therapy (RRT). 1-5 
The term of Acute Kidney Injury was developed by the Kidney Disease Improving Global 
Outcomes (KDIGO) organization in 2012, which is defined it as a sudden decrease (< 24 hours) 
in renal function characterized by an increase in serum creatinine (≥0.3 mg/dL or ≥ 50% [1.5 
times baseline]), or reduction in urine output <0.5 mL/kg/hour for >6 consecutive hours. Based 
on these criteria, AKI stage 3 is categorized as acute renal failure or ARF.1, 6, 7 
In a study conducted by Bove et al. in 2018, AKI is a serious complication after cardiac surgery 
that increases the incidence of morbidity and mortality. Renal replacement therapy (RRT) has 
been used as one of the important therapies in patients with severe AKI. Although the incidence 
of CSA-AKI requiring RRT is reported in about 1-10% of all AKI events after cardiac surgery, 
it is also shown that patients with severe AKI who require RRT therapy suffer a higher post-
operative mortality rate. Previous studies reported intra-hospital mortality up to 43.5% in 
patients with AKI-RRT. Recent research found that from 412 CSA AKI-RRT patients, 174 
patients (42.2%) died intra-hospital, with a EuroScore > 7, intraoperative bleeding > 1 liter and 
mechanical ventilation time > 70 hours as other independent risk factors. Meanwhile, post-
operative use of furosemide was considered as protective factor in this study (OR 0.48). This 
information is similar with the results of our previous study regarding the use of diuretics for 
CSA-AKI patients. 8-11  

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Considering the significant impact of AKI on the outcomes of patients’ post-cardiac surgery, 
this study aimed to conduct an analysis of the risk factors that contribute to the incidence of 
post-operative mortality in patients with CSA-AKI, particularly regarding those cases in stages 
which required RRT. Based on the above background, this study’s primary purposes was to 
analyze association between patients with CSA-AKI with RRT and in-hospital postoperative 
mortality risk compared to patients with CSA-AKI without RRT. 
 
Study Rationale 
Acute reduction in kidney function post cardiac surgery is the initial mechanism for acute 
kidney injury. Reduced blood flow, ischemia and reperfusion, hemolysis, activation of the 
inflammatory response, vascular redistribution and embolism are some of the etiologies that 
play an important role. The prevalence of acute kidney injury in the patient population with 
valve cardiac surgery is approximately 28%, with 1 – 10% requiring renal replacement therapy. 
Acute Kidney Injury/AKI is a strong independent predictor of post-operative mortality, 
particularly in patients with the requirement of renal replacement therapy. Postoperative AKI is 
not only increasing mortality, but also reduces long-term survival, extends the length of stay 
(LOS) in the intensive care unit, increases the risk of chronic kidney disease (CKD), and 
increases the financial burden on health facilities. Although cardiac surgery associated AKI is 
not a rare postoperative complication, when it reaches a severe stage that requires renal 
replacement therapy/RRT, the risk of postoperative mortality will increase several-fold. Apart 
from that, there are also other factors that increase the risk of mortality. Based on the explanation 
above, the formulation of the problem in this study is what is the relationship between AKI post-
cardiac surgery patients with RRT on the incidence of intra-hospital mortality compared with 
AKI patients without RRT. 
6 Research Question and Objectives 
The purpose of this study is to evaluate the risk of patients with cardiac surgery associated acute 
kidney injury (CSA-AKI) with renal replacement therapy requirement RRT in related to in-
hospital mortality event compared to CSA-AKI patients without the need of RRT. 
 

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6.1 Primary Objective 
• To analyze the association between AKI with RRT and intra-hospital postoperative 
mortality in cardiac surgery patients compared with AKI patients without RRT 
6.2 Secondary Objectives 
• To analyze the risk of intra-hospital post-surgical mortality in cardiac surgery patients 
who complicated with CSA AKI  
• To compare the risk of intra-hospital post-surgical mortality in cardiac surgery patients 
who complicated with CSA AKI with requirement of RRT and without RRT 
• To Identify and analyze perioperative factors that play an important role in the 
incidence of mortality in AKI patients after cardiac surgery 
 
7 Research Methods 
 
7.1 Study Design 
This research is a non-experimental study with a retrospective cohort analysis design. Data 
were secondary collected from patient’s registry.  
The dependent variable is intra-hospital post-surgical mortality, while the independent 
variables are cardiac surgery patients with complication of Acute Kidney Injury (AKI) and 
Renal Replacement Therapy (RRT).  
Analysis was carried out to determine the relationship between these variables. 
 
7.1.1 Design Overview 
This retrospective study was conducted at a tertiary hospital after obtaining approval from 
the hospital's institutional review board. Data were secondary collected from patient’s 
registry. There is no direct observation or prospective observation to patients. 
The need for informed consent was waived since the data analysis was performed 
retrospectively using hospital electronic medical records (EMR). The diagram below 
summarizes the study plan (see Figure 7.1). 

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Figure 7.1  Study Overview 
 
 
7.2 Setting 
This study will be conducted in tertiary cardiac center in Jakarta, Indonesia. Study began 
after approval from the ethics committee of Hospital until data collection was completed. 
7.2.1 Study Population 
Target population for this study is patient aged at least 18 years, who experienced cardiac 
surgery at adult cardiac surgical unit at tertiary cardiac center from January 2020 to December 
2022.  
The study population will be identified according to the below inclusion and exclusion criteria. 
 
Inclusion Criteria: 
The patient can be included in the study when: 
• Data on patients who are at least 18 years old, who experienced cardiac surgery at our 
tertiary cardiac center from January 2020 to December 2022. 

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• Data on post-cardiac surgery patients who complicated with Acute Kidney Injury 
(AKI) which was characterized by an increase in serum creatinine > 0.3 mg/dL or 
>150% of the pre-operative serum creatinine level, which was checked within 12 
hours post-surgery. 
• Data is available in the medical records unit of the Harapan Kita National Heart 
Center. 
 
Exclusion Criteria: 
The patient cannot be included when the patient 
• Patients with a previous history of dialysis. 
•  Data on patients who underwent surgery outside the specified period 
 
7.3 Variables 
 
The data collected from EMR included demographic data (age, weight, height, sex), type of 
surgery, comorbidities (history of diabetes, hypertension, stroke, smoking, renal disease), 
creatinine level, duration of mechanical ventilation, and ICU length of stay.  Clinical variables 
are obtained that included mechanical ventilation time, ICU length of stay, postoperative 
diuretic, inotropes, vasopressor therapy, postoperative use of intra-aortic balloon pump (IABP), 
postoperative RRT, and in-hospital mortality. For the study’s purpose, several continuous 
variables are categorized qualitatively such as mechanical ventilation (>48 hours as a cutoff 
point), ICU (≥5 days), postoperative diuretic therapy (yes/no), inotropes and vasopressor 
therapy ≥2 drugs (yes/no), and postoperative use of IABP (yes/no). 
 
 
 
 
 

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7.3.1 Variables Operational Definition 
 
Table 7.1 Dependent Variable 
No. 
Variable 
Definition 
Measured 
with 
Scoring 
Scale 
1 
In-hospital 
mortality 
Patient dies in hospital during 
treatment after cardiac surgery 
(patient has never gone home or 
been discharged from hospital) 
Medical 
record 
0 = Not Died 
1 = Died  
Categorical 
 
Table 7.2 Independent Variables 
No. 
Variable 
Definition 
Measured 
with 
Scoring 
Scale 
 1 
Acute 
Kidney 
Injury 
Patients with an increase in 
serum creatinine more than 
1.5 times or > 0.3 mg/dL with 
urine output < 0.5 cc/kg/hour 
for 6 consecutive hours. 
Medical 
record 
0 = No AKI 
1 = With AKI 
Categorical 
 2 
 Renal 
Replacement 
Therapy 
Use of a renal replacement 
therapy 
machine, 
either 
continuous 
(CVVH) 
or 
intermittent (HD), during the 
period the patient is treated 
post-operatively 
until 
discharge from the hospital. 
Medical 
record 
0=Not required 
1=Required 
Categorical 
 3 
Age 
calculated from the day of 
birth to the day the surgery 
was performed in years 
Medical 
record 
0 = <60 years 
1 = >60 years 
Categorical 

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 4 
Type 
of 
surgery 
These are surgical procedures 
undertaken 
by 
patients, 
divided into 5 categories: 
1. Coronary Artery Bypass 
Graft (CABG) is a coronary 
heart bypass surgery 
2. Valves or heart valve 
surgery is surgery performed 
on heart valves 
3. Mixed valves are heart 
valve 
surgery 
performed 
simultaneously with other 
heart surgical procedures (for 
example 
coronary 
or 
vascular) 
4. Congenital is surgery for 
congenital 
heart 
defects 
suffered by the patient 
5. Other is for surgery that is 
not 
included 
in 
the 
4 
categories 
above 
(for 
example Vascular) 
Medical 
record 
1 = CABG 
2 = Valves 
3=Mixed 
Valves 
4= Congenital 
5 = Others 
Categorical 
 5 
Diabetes 
Mellitus 
Obtained from the history of 
the disease suffered and blood 
sugar laboratory results. 
Medical 
record 
0= No 
1= Yes 
Categorical 
 6 
Hypertension 
Obtained from the history of 
the disease suffered by the 
patient/which was diagnosed 
Medical 
record 
0= No 
1= Yes 
Categorical 

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before undergoing surgery, 
where the increase in systolic 
blood pressure is above the 
normal limit, namely more 
than 140 mmHg and diastolic 
blood pressure is more than 
90 mmHg. 
 7 
Serum 
Creatinine 
Serum creatinine value > 3.0 
obtained last before surgery, 
in mg/dL 
Medical 
record 
0= No 
1= Yes 
Categorical 
 8 
History 
of 
Stroke 
History of stroke diagnoses 
that 
the 
patient 
has 
experienced, either with or 
without sequelae 
Medical 
record 
0= No 
1= Yes 
Categorical 
 9 
Smoking 
History 
Smoking history obtained 
from the patient's history in 
the medical record 
Medical 
record 
0= No 
1= Yes 
Categorical 
 10 
History of 
Renal 
Disease  
History of kidney disease in 
the patient before surgery. 
Medical 
record 
0= No 
1= Yes 
Categorical 
 11 
Prolonged 
Ventilation 
Use of a ventilator > 48 hours 
after surgery 
Medical 
record 
0= No 
1= Yes 
Categorical 
 12 
Prolonged 
ICU stay 
Length of stay in ICU > 5 
days after surgery 
Medical 
record 
0= No 
1= Yes 
Categorical 
 13 
Post 
operative 
IABP 
Use of the IABP machine 
post-surgery 
Medical 
record 
0= No 
1= Yes 
Categorical 
14 
Use of more Use of more than 2 types of Medical 
0=No or less Categorical 

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than 2 types 
of inotropic 
and 
vasoactive 
drugs 
inotropic 
(Adrenaline, 
Dobutamine, 
Dopamine, 
Milrinon) 
or 
vasoactive 
(noradrenaline, vasopressin) 
drugs in post-surgical care 
record 
than 2 types 
1=Use 2 or more  
15 
Postoperative 
diuretic 
therapy 
 
Use of diuretic therapy in the 
form of furosemide in the 
form of continuous infusion 
at a dose of 5 – 40 mg/hour 
post-surgery 
Medical 
record 
0=Not require 
1=Required 
Categorical 
 
7.4 Data Source 
The data to be collected in the study will be obtained from patients’ registry, from electronic 
medical records and manual medical records.  Data collection processes consist of this 
following process:  
1. Data checking (editing)  
This is an activity to check the research data form sheet for data completeness so that 
if there are any discrepancies it can be completed immediately by the researcher. 
2. Giving code (coding)  
The activity of changing data into numbers/numbers. 
3. Entering data into a computer program (data entry)  
This is an activity of processing data obtained from research data forms and then 
analyzing it by entering the data into a computer program. 
4. Cleaning data (cleaning)  
Data cleaning activities were carried out to check again before further analysis was 
carried out. 
All data collected during this study must be documented on an ongoing basis in a complete, 
accurate, eligible, and timely fashion. The data in the eCRF should be consistent with the 
relevant source documents.  

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7.5 Study Size 
The sample size was determined based on time, namely all data on adult heart surgery patients 
between January 1, 2020 - December 31, 2022, who were selected based on acceptance 
criteria. 
 
7.6 Data Management 
The main purpose of the eCRF is to obtain data required by the non-experimental study 
protocol in a complete, accurate, legible, and timely manner. The data in the eCRF should be 
consistent with the relevant source documents. 
Data protection and privacy regulations will be implemented in capturing, forwarding, 
processing, and storing subject data.
7.7 Statistical Analysis Plan 
All analyses will be performed on patients who underwent cardiac surgery in period between 1 
January 2020 until 31 December 2022, with complication of acute kidney injury (AKI) 
postoperative. All data were retrieved from patient medical record retrospectively. There were 
no active observation or data retrieved directly from patients. 
Data analysis will be carried out by the statistical team after the research samples have been 
taken and the data has been completed. The analysis was carried out using SPSS Version 29. 
and all statistical analysis plans have been completely documented in this statistical analysis 
plan.  
Data that has been processed correctly is then analyzed by: 
a. 
Univariate analysis 
This univariate analysis was carried out to obtain an overview of the frequency distribution of 
research subjects and the distribution of the proportion of cases and controls according to each 
independent variable (risk factor) studied. 
b. 
Bivariate analysis 

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Bivariate analysis was used to determine the relationship between the main risk factors and the 
incidence of death in hospital while also testing the research hypothesis using the chi square 
test. 
c. 
Multivariate analysis  
Multivariate analysis is carried out with the aim of describing the relationship between the 
dependent variable and the independent variable simultaneously in the population. Multivariate 
analysis was carried out by connecting several independent variables with one dependent 
variable simultaneously. Because the independent variables are categorical, logistic regression 
was used for the analysis. 
 
7.7.1 Derived and Transformed Data 
Missing data on each variable will be recorded in the table and not considered in data analysis. 
 
7.7.2 Statistical Methods 
The statistical analyses described in this section will be performed as further outlined in the 
SAP, which will be finalized prior to database lock and will be included in the clinical study 
report for this protocol. The final SAP will take into account any amendment to the protocol. 
General Statistical Methodology: 
Descriptive statistics (mean, SD, median, interquartile range) will be provided for continuous 
variables according to the results of data normality tests. Frequencies and percentages will be 
presented for categorical and ordinal variables.  
All analyzes will consider the security of the dataset. 
 
Primary Outcome Analysis:  
The primary outcome in this study is to look at the incidence of death in the treatment of patients 
who have kidney problems with CRRT or not.  
Bivariate analysis was carried out using the chi square/fisher's exact test to see whether there 
was a difference in the incidence of death in treatment between groups (CRRT vs Non-CRRT) 

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which was then continued to the multivariate analysis stage if it had a p value <0.25, multivariate 
analysis was carried out using regression multiple logistics with a significance level of 0.05 
which shows that it is a variable that influences the incidence of death in care. 
 
Secondary Endpoint Analysis: 
The secondary outcome in this study is to look at the factors causing CRRT in patients 
undergoing cardiac surgery with AKI.  
Bivariate analysis was carried out using the chi square/ Fisher's exact test to see whether there 
were differences in patient characteristics between patients who were given CRRT and those 
who were not, which was then continued to the multivariate analysis stage if it had a p value 
<0.25. Multivariate analysis was carried out using multiple logistic regression with The 
significance level is 0.05 which shows that it is a variable that influences the incidence of CRRT 
use.  
7.7.3 Sequence of Analyses 
Analysis was carried out after the research data was complete, in this study no interim analysis 
was carried out. 
 
 
7.8 Limitations of the Research Methods 
There are some limitations that should be considered in this study. First, due to the retrospective 
design used, there were some predictors of CSA-AKI that could not be included. Second, there 
were limitations in the capacity to do crosschecking due to inability to access patients directly, 
which may lead to confusion and heterogeneity of the dataset. Finally, data only included a 
single center, which may not reflect the actual demographics of patients and cardiac disease as 
distinguished from other centers. 
However, the difference from real-life observational data, which is more essential to assess and 
improve clinical practice worldwide and complement randomized controlled trials by 
providing clinically relevant, real-world data and provide considerable health economic 
information. 

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7.9 Other Aspects 
None 
8 Protection of Human Subjects 
8.1 Independent Ethics Committee or Institutional Review Board 
Prior to commencement of the study at a given site, the protocol will be submitted together to 
the responsible IEC/IRB for its favorable opinion/approval. The written favorable 
opinion/approval of the IEC/IRB will be filed by the Investigator. 
The IEC/IRB will be asked to provide documentation of the date of the meeting at which the 
favorable opinion/approval was given, and of the members and voting members present at the 
meeting. Written evidence of favorable opinion/approval that clearly identifies the study, the 
protocol version, and the subject information and consent form version reviewed should be 
provided.  
8.2 Subject Information and Informed Consent 
Since the data analysis was performed retrospectively derived from hospital electronic medical 
records (EMRs), the need for informed consent was waived.   
Whenever important new information becomes available that may be relevant to the subject’s 
consent, the written subject information sheet and any other written information provided to 
subjects will be revised by the Sponsor and be submitted again to the IEC/IRB for review and 
favorable opinion. The agreed, revised information will be forwarded to each subject in the 
study. The Investigator will explain the changes to the previous version. 
 
8.3 Subject Identification and Privacy 
 
A unique subject number will be assigned to each subject at inclusion. This number will serve 
as the subject’s identifier in the study as well in the study database. The Investigator must ensure 
that the subjects’ anonymity is maintained.  

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The Investigator should keep a separate log of subjects’ identification numbers, names, 
addresses, telephone numbers and hospital numbers (if applicable). Only authorized persons 
will have access to identifiable personal details, if required for data verification. The 
Investigator is responsible for retrieving information from personal medical records. Data 
protection and privacy regulations will be observed in capturing, forwarding, processing, and 
storing subject data.  
9 Management and Reporting of Adverse Events 
This study design is retrospective study. All the events and incidences were already happened 
in the past period. This study does not interact directly to patients, there are no adverse events 
were caused directly by the study.  
10 Plans for Disseminating and Communicating Study Results 
After completion of the study, we shall prepare a final report of study results, in close 
collaboration with the coordinating Investigator. All publications and presentations should be 
based on the final study report. 
10.1 Study Report(s) 
The completed study will be summarized in a final report that accurately and completely 
presents the study objectives, methods, results, limitations of the study, and interpretation of 
the findings. 
10.2 Publication 
The publication will be a publication of the results of the analysis of the Primary Endpoint that 
will include data from study
 
11 References 
 
1. 
Yi Q, Li K, Jian Z, Xiao YB, Chen L, Zhang Y, et al. Risk Factors for Acute Kidney 
Injury after Cardiovascular Surgery: Evidence from 2,157 Cases and 49,777 Controls - A 
Meta-Analysis. Cardiorenal Med. 2016;6(3):237-50. 

 
 
2. 
Thakar CV, Arrigain S, Worley S, Yared JP, Paganini EP. A clinical score to predict acute 
renal failure after cardiac surgery. J Am Soc Nephrol. 2005;16(1):162-8. 
3. 
Vives M, Hernandez A, Parramon F, Estanyol N, Pardina B, Munoz A, et al. Acute kidney 
injury after cardiac surgery: prevalence, impact and management challenges. Int J Nephrol 
Renovasc Dis. 2019;12:153-66. 
4. 
Olivero JJ, Olivero JJ, Nguyen PT, Kagan A. Acute kidney injury after cardiovascular 
surgery: an overview. Methodist Debakey Cardiovasc J. 2012;8(3):31-6. 
5. 
Carrascal Y, Laguna G, Blanco M, Paneda L, Segura B. Acute Kidney Injury after Heart 
Valve Surgery in Elderly Patients: any Risk Factors to Modify? Braz J Cardiovasc Surg. 
2021;36(1):1-9. 
6. 
Kellum JA, Lameire N, Group KAGW. Diagnosis, evaluation, and management of acute 
kidney injury: a KDIGO summary (Part 1). Crit Care. 2013;17(1):204. 
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