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Trial registered on ANZCTR


Registration number
ACTRN12617001366347
Ethics application status
Approved
Date submitted
31/08/2017
Date registered
27/09/2017
Date last updated
31/08/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Different measurements of stress hyperglycaemia and their relationship with post-cardiac surgery outcomes.
Scientific title
Post-CABG outcomes and the association with absolute glucose levels versus the relative change in glucose as determined by the Stress Hyperglycaemia Ratio.
Secondary ID [1] 289772 0
None
Universal Trial Number (UTN)
Trial acronym
SHR-CABG
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Coronary artery bypass surgery 299648 0
Post-operative glucose management 299649 0
Condition category
Condition code
Metabolic and Endocrine 299599 299599 0 0
Diabetes
Surgery 299600 299600 0 0
Other surgery
Cardiovascular 303941 303941 0 0
Coronary heart disease

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Patients undergoing elective or semi-urgent Coronary Artery Bypass Graft surgery at Flinders Medical Centre will be identified through the ANZ Cardiac Surgery Registry. The association of stress hyperglycaemia with adverse outcomes will be determined using absolute glucose levels, and the relative change in glucose as determined by the Stress Hyperglycaemia Ratio.
The Stress Hyperglycaemia Ratio is defined by the time-weighted glucose during ICU stay divided by the estimated average glucose level of the prior 3 months ( as calculated from the HbA1c using the formula developed by Nathan et al. Diab Care 2008;31:1473–14788). The study is retrospective - patients will have undergone routine post-op intensive care. Pathology results used in the analysis will be those already available through routine care.
Intervention code [1] 295427 0
Not applicable
Comparator / control treatment
Patients at Flinders Medical Centre undergoing elective or semi-urgent Coronary Artery Bypass Graft surgery over the period 8/2/2010 to 20/12/2016 will be identified through the ANZ Cardiac Surgery Registry. The association of adverse post-op outcomes will be compared using time-weighted mean glucose levels post-operatively during critical care, and the time-weighted mean Stress Hyperglycaemia Ratio. The association of outcomes with time-weighted mean glucose levels will act as the conventional control group.
The study is retrospective - patients will have undergone routine post-op intensive care. Pathology results used in the analysis will be those already available through routine care.
Control group
Historical

Outcomes
Primary outcome [1] 299071 0
Combined endpoint for adverse outcomes - mortality, infection (deep and superficial sternal wound infection, bacteraemia, pneumonia), respiratory failure (need for ventilator assistance for longer than 48 h), acute kidney injury (increase in creatinine level 40% from baseline), new MI, new CCF, new arrhythmias, stroke,hospital readmissions related to the procedure. The ANZ Cardiac Surgery Registry contains extensive patient demographic data and outcome data, which will be linked to local pathology data.
Timepoint [1] 299071 0
30 days post-discharge
Secondary outcome [1] 326058 0
Mortality
Timepoint [1] 326058 0
30 days post-discharge as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [2] 326099 0
Post-operative infection
Timepoint [2] 326099 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [3] 326100 0
Myocardial infarction
Timepoint [3] 326100 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [4] 338530 0
Hospital length of stay as identified in the ANZ Cardiac Surgery Registry.
Timepoint [4] 338530 0
Duration of primary admission
Secondary outcome [5] 338531 0
Length of stay in Intensive Care Unit as identified in the ANZ Cardiac Surgery Registry.
Timepoint [5] 338531 0
Duration of primary admission
Secondary outcome [6] 338610 0
New onset arrhythmia
Timepoint [6] 338610 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [7] 339021 0
Stroke
Timepoint [7] 339021 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [8] 339023 0
Respiratory failure (>48 hours of ventilator assistance)
Timepoint [8] 339023 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [9] 339024 0
Acute kidney injury
Timepoint [9] 339024 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [10] 339025 0
New onset of exacerbation of heart failure
Timepoint [10] 339025 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.
Secondary outcome [11] 339026 0
Readmission within 30 days of discharge
Timepoint [11] 339026 0
Up to 30 days post-discharge, as identified in the ANZ Cardiac Surgery Registry.

Eligibility
Key inclusion criteria
Undergoing elective or semi-urgent Coronary Artery Bypass Graft surgery with or without concurrent cardiac surgery.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
<18 years age, pregnant, emergency surgery, GFR<30ml/min/sq.m., hepatic failure, history of hyperglycaemic crisis.

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Retrospective
Statistical methods / analysis
Statistical power: Assuming a Type I error rate of 5%, an outcome event rate of 30%, and the proportion of variance explained by the other covariates in the model is no more than 55%, a sample size of 2500 subjects provides 80% power to detect an independent association between SHR and outcome with an estimated odds ratio of 1.20 per 0.1 SHR increment at the two-tailed 0.05 significance level.
Variables of interest (glucose, SHR, APACHE IIIj, type of surgery, lactate), will be subject to multivariable regression analysis to determine the association with adverse outcomes.
Locally Weighted Scatterplot Smoothing will be used to explore the relationship between patients with (HbA1c>=6.5%) or without (HbA1c<6.5%) pre-existing chronic background hyperglycaemia.
Subgroup analysis of patients with mean glucose <10mmol/L will be made to determine existence of clinically significant stress hyperglycaemia at glucose levels conventionally considered clinically insignificant.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA
Recruitment hospital [1] 6269 0
Flinders Medical Centre - Bedford Park
Recruitment postcode(s) [1] 13803 0
5042 - Bedford Park

Funding & Sponsors
Funding source category [1] 294152 0
Hospital
Name [1] 294152 0
Flinders Medical Centre
Address [1] 294152 0
Flinders Drive, Bedford Park SA 5042
Country [1] 294152 0
Australia
Primary sponsor type
Hospital
Name
Flinders Medical Centre
Address
Flinders Drive, Bedford Park SA 5042
Country
Australia
Secondary sponsor category [1] 292983 0
None
Name [1] 292983 0
Address [1] 292983 0
Country [1] 292983 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 295571 0
Southern Adelaide Clinical Human Research Ethics Committee
Ethics committee address [1] 295571 0
The Flats G5 – Rooms 3 and 4
Flinders Drive
Flinders Medical Centre, Bedford Park SA 5042
Ethics committee country [1] 295571 0
Australia
Date submitted for ethics approval [1] 295571 0
15/09/2016
Approval date [1] 295571 0
19/10/2016
Ethics approval number [1] 295571 0
OFR # 373.16 - HREC/16/SAC/346

Summary
Brief summary
Hyperglycaemia in hospitalised patients is independently associated with increased morbidity and mortality in a wide range of patient groups, including post-operative outcomes. The association between hyperglycaemia and poor post-operative outcomes is strong in patients without diabetes, but a weaker predictor in patients with diabetes.
This discrepancy is in part driven by the difficulty in distinguishing genuine stress hyperglycaemia from chronic high levels seen in diabetic patients. A high plasma glucose concentration in a hospitalised patient can occur because of chronic poor diabetes control and be “normal” for that patient, represent a transient physiologic response to an inter¬current illness (stress hyperglycaemia), or be a combination of the above.
A metric for stress hyperglycaemia has been developed at FMC - the Stress Hyperglycaemia Ratio is defined as glucose concentration divided by the Estimated Average Glucose concentration, which is calculated from HbA1c. This enables quantification of the relative change in hyperglycaemia eg a patient with a SHR of 1.4 has an glucose concentration 40% higher than their average glucose over the prior 3 months.
Our previous work indicated that the relative change in glucose was a better indicator of stress hyperglycaemia and more strongly associated with adverse patient outcomes than glucose.
This initial work was in a broad general hospital population. This study aims to determine the clinical applicability of the Stress Hyperglycaemia Ratio to post-op outcomes for patients undergoing CABG surgery. This group requires mandatory post-op observation in the ICU setting, and commonly require intervention for glucose management. We aim to determine if the Stress Hyperglycaemia Ratio is more strongly associated with adverse post-op outcomes in this group than glucose alone.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 67774 0
Mr Greg Roberts
Address 67774 0
Pharmacy Department
Flinders Medical Centre
Flinders Drive, Bedford Park, SA 5042
Country 67774 0
Australia
Phone 67774 0
+61 8 82046936
Fax 67774 0
+61 8 82046245
Email 67774 0
greg.roberts2@sa.gov.au
Contact person for public queries
Name 67775 0
Mr Greg Roberts
Address 67775 0
Pharmacy Department
Flinders Medical Centre
Flinders Drive, Bedford Park, SA 5042
Country 67775 0
Australia
Phone 67775 0
+61 8 82046936
Fax 67775 0
+61 8 82046245
Email 67775 0
greg.roberts2@sa.gov.au
Contact person for scientific queries
Name 67776 0
Mr Greg Roberts
Address 67776 0
Pharmacy Department
Flinders Medical Centre
Flinders Drive, Bedford Park, SA 5042
Country 67776 0
Australia
Phone 67776 0
+61 8 82046936
Fax 67776 0
+61 8 82046245
Email 67776 0
greg.roberts2@sa.gov.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary