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Trial registered on ANZCTR


Registration number
ACTRN12615000825550
Ethics application status
Approved
Date submitted
21/07/2015
Date registered
11/08/2015
Date last updated
5/11/2019
Date data sharing statement initially provided
23/11/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Can a point of care, whole blood test, predict clotting complications after total hip and knee replacement surgery?
Scientific title
Use of preoperative rotational thromboelastography (ROTEM) assays to detect postoperative thrombotic complications following total hip and knee arthroplasty in overweight and obese patients: a pilot study.
Secondary ID [1] 286277 0
Nil
Universal Trial Number (UTN)
U1111-1167-6604
Trial acronym
RETHInK-O
Linked study record

Health condition
Health condition(s) or problem(s) studied:
DHypercoagulability 294342 0
Obesity
294343 0
Thrombotic complications of surgery 295722 0
Knee arthroplasty 295723 0
Hip arthroplasty 295724 0
Condition category
Condition code
Blood 294659 294659 0 0
Clotting disorders
Cardiovascular 294662 294662 0 0
Diseases of the vasculature and circulation including the lymphatic system
Diet and Nutrition 296003 296003 0 0
Obesity

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Preoperative and postopeartive ROTEM assays will be used detect hypercoagulability defined by the presence of rapid clot formation (evidenced by a shortened clotting time or clot formation time, increased alph angle) and/or increased clot strength (evidenced by high maximum clot firmness) in whole blood. Blood will be collected in a 3.5 mL citrated tube and 3 mL hirudin tube for ROTEM and multiplate analysis, respectively. These samples will be taken immediately prior to surgery, in the immediate post-operative period, and on days 1 and 3 post-operatively. The results of the ROTEM and multiplate investigations will not alter patient treatment. Patients will be commenced on The Prince Charles Hospital venous thromboembolic prophylactic pathway which involves TED stockings, sequential compression devices, and aspirin.
Intervention code [1] 291298 0
Not applicable
Comparator / control treatment
Nil
Control group
Uncontrolled

Outcomes
Primary outcome [1] 294416 0
Incidence of preoperative hypercoagulability as determined by ROTEM analysis.
Timepoint [1] 294416 0
This will be assessed at 4 timepoints:
1. Preopereative
2. Immediately postoperative
3. Post operative day 1
4. Post operative day 3
The patient will be deemed hypercoagulable if the ROTEM parameters are outside the normal ranges. A statistician will be employed to determine clinical thresholds using ROTEM to measure hypercoagulability, and to determine whether ROTEM can be used to predict thromboemoblic complications in overweight and obese patients.
Primary outcome [2] 294417 0
Thrombotic complications will be assessed by review of patient charts and a follow up telephone call with the patient and/or their general practitioner. The thrombotic complications of interest include cardiac death, myocardial infarction, symptomatic deep vein thrombosis, pulmonary embolism, ischaemic stroke as a composite score.
Timepoint [2] 294417 0
Any time up to 30 days post surgery
Secondary outcome [1] 313255 0
Myocardial injury (defined as elevated levels of cardiac troponin I > 0.04 ug/L on serum assay)
Timepoint [1] 313255 0
Days 1, 2 and 3 postoperatively
Secondary outcome [2] 313256 0
Number of units of blood transfused assessed by review of hospital records
Timepoint [2] 313256 0
Any time up to 30 days post surgery
Secondary outcome [3] 313257 0
Length of hospital stay measured by review of hospital records
Timepoint [3] 313257 0
From time of surgery up to 30 days post surgery
Secondary outcome [4] 313258 0
Unanticipated intensive care unit admission determined when reviewing hospital records
Timepoint [4] 313258 0
Any time up to 30 days post surgery
Secondary outcome [5] 313260 0
30 day mortality
Timepoint [5] 313260 0
Any time up to 30 days post surgery
Secondary outcome [6] 316182 0
Platelet function
Timepoint [6] 316182 0
Platelet function will be measured by Multiplate analysis pre-operatively, immediately after surgery, and on days 1 and 3 postoperatively.

Eligibility
Key inclusion criteria
All patients undergoing elective primary hip or knee replacement surgery with a BMI greater than/equal to 25 kg/m2 or waist circumference greater than/equal to 94 cm for males or 80 cm for females.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Patients will be excluded if they (1) have risk factors other than obesity for venous thromboembolism (VTE) (including previous history of VTE, malignancy, and coagulation abnormalities), (2) hypercoagulability disorders or (3) severe renal or hepatic disease.

Study design
Purpose
Screening
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Sample size calculation: according to previous studies, the proportion of subjects to experience post-operative complications is 4.2% and they are more likely to have a maximum clot firmness of at least 3 units than those who do not develop complications. In order to detect this with 80% power at 5% significance level with an estimated 5% incidence of complications, a sample size of approximately 300 particpants would be required. The current pilot study would be performed on 50 patients to assess feasibility.

Analysis plan: for the primary aim, logistic regression will be used to assess the ability of the ROTEM assay measures to predict postoperative thrombotic complications in obese and overweight patients. Classification of body mass index and weight circumference will be according to WHO guidelines. Sensitivity and specificity analysis will be performed to determine best thresholds for identifying those patients at high risk of postoperative complications; where necessary, models will be adjusted for additional confounders such as age and other comorbidities. A paried t-test of pre and post surgery will be used to compare the multiplate and ROTEM measure changes. FInally, the predictive capability of the ROTEM assay will be assessed, stratified by overweight/obese category. A p value of 0.05 will be considered significant. Analysis wil be perfomed with input from QIMR/RBWH statistics unit.

Recruitment
Recruitment status
Recruiting
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)
QLD
Recruitment hospital [1] 3695 0
The Prince Charles Hospital - Chermside
Recruitment postcode(s) [1] 9527 0
4032 - Chermside

Funding & Sponsors
Funding source category [1] 291094 0
Charities/Societies/Foundations
Name [1] 291094 0
The Common Good: The Prince Charles Hospital foundation
Address [1] 291094 0
Rode Road
Chermside
QLD 4032
Country [1] 291094 0
Australia
Primary sponsor type
Hospital
Name
The Prince Charles Hospital
Address
Rode Road
Chermside
QLD 4032
Country
Australia
Secondary sponsor category [1] 289771 0
None
Name [1] 289771 0
Address [1] 289771 0
Country [1] 289771 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292675 0
The Prince Charles hospital human research ethics committee
Ethics committee address [1] 292675 0
627 Rode Road
Chermside
QLD 4032
Ethics committee country [1] 292675 0
Australia
Date submitted for ethics approval [1] 292675 0
15/05/2015
Approval date [1] 292675 0
24/06/2015
Ethics approval number [1] 292675 0
HREC/15/QPCH/123

Summary
Brief summary
This primary aim of this study is to determine if preoperative hypercoagulability, identified by ROTEM analysis, can predict postoperative thrombotic complications in overweight and obese patients undergoing elective lower limb joint replacements.

Secondary aims:
1. To develop clinical threshold with ROTEM parameters to identify high risk patients with increased body mass index and/or waist circumference.
2. To monitor coagulation changes with ROTEM assays and platelet function with Multiplate analyser, preoperatively and postoperatively, in this cohort of patients.
3. To assess the sensitivity of the ROTEM assay to predict high-risk patients stratified according to body mass index and waist circumference.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 55366 0
Dr Lisa Stanton
Address 55366 0
Department of Anaesthetics and Perfusion
Level 1
The Prince Charles Hospital
Rode Road
Chermside
QLD 4032
Country 55366 0
Australia
Phone 55366 0
+ 61 7 3139 4648
Fax 55366 0
Email 55366 0
lisa.stanton@health.qld.gov.au
Contact person for public queries
Name 55367 0
Dr Lisa Stanton
Address 55367 0
Department of Anaesthetics and Perfusion
Level 1
The Prince Charles Hospital
Rode Road
Chermside
QLD 4032
Country 55367 0
Australia
Phone 55367 0
+ 61 7 3139 4648
Fax 55367 0
Email 55367 0
lisa.stanton@health.qld.gov.au
Contact person for scientific queries
Name 55368 0
Dr Lisa Stanton
Address 55368 0
Department of Anaesthetics and Perfusion
Level 1
The Prince Charles Hospital
Rode Road
Chermside
QLD 4032
Country 55368 0
Australia
Phone 55368 0
+ 61 7 3139 4648
Fax 55368 0
Email 55368 0
lisa.stanton@health.qld.gov.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Currently there is no plan to make this data publicly available
What supporting documents are/will be available?
No other documents available
Summary results
No Results