Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12614000393651
Ethics application status
Approved
Date submitted
28/03/2014
Date registered
10/04/2014
Date last updated
24/05/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Paramedic-Delivered Fibrinolysis in the Treatment of STEMI: Comparison of a Physician-Assisted Versus Autonomous Paramedic Approach.
Scientific title
Autonomous paramedic delivered pre-hospital thrombolysis: A new approach in the treatment of ST-elevation myocardial infarction patients to determine if this new model may improve treatment delivery times, patient outcomes and reduce hospital admission times.
Secondary ID [1] 284355 0
Nil
Universal Trial Number (UTN)
U1111-1155-0725
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
ST-elevation myocardial infarction 291513 0
Condition category
Condition code
Cardiovascular 291882 291882 0 0
Coronary heart disease
Public Health 291953 291953 0 0
Health service research

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This proposed research will be an experimental study trialling an autonomous paramedic model for pre-hospital thrombolysis (PHT) within St John Ambulance Service, New Zealand’s largest ambulance provider, without physician oversight and authorisation. We hypothesise that adopting this approach will lead to improved patient outcomes, with reduced hospital admission times compared to the physician-authorised telemetry model. Economic benefits are also likely.

Paramedics will provide the existing treatment of PHT following the existing drug regime. The criteria for autonomous paramedic-delivered PHT will include the following:

1. DEFINITE STEMI ONLY: Paramedic and heart monitor interpretation of STEMI (>>> Acute MI <<<)

2. ST elevation greater than or equal to 1mm in two or more limbs leads (I, II, III, aVL or aVF) or

3. ST elevation greater than or equal to 2mm in two or more contiguous chest leads (V1-V6) AND

4. Symptoms consistent with myocardial ischemia of less than 12hrs duration AND

5. Transport time to hospital greater than 15 minutes

The existing PHT drug regime that will be utilised includes:

*Aspirin 300mg per oral (PO)

*Enoxaparin 30mg intravenously (IV) for patients under 75yrs of age only

*Tenecteplase IV – dose dependent based on the patient’s weight using the graduations on the syringe

*Enoxaparin 1mg/kg subcutaneous based on the patient’s weight using the graduations on the syringe

*Clopidogrel 600mg PO for patients under 75yrs of age only. For patients over 75yrs give 300 mg PO.

The overall intervention period for this study will be 20 months.
Intervention code [1] 289085 0
Diagnosis / Prognosis
Intervention code [2] 289126 0
Early detection / Screening
Comparator / control treatment
We will compare two groups of STEMI patients both of which have received PHT from paramedics but by two different models of provision. The first group, a historic retrospective cohort, will have already received PHT from paramedics under the existing physician-authorised telemetry model. In contrast, the second group, a prospective cohort, will receive PHT from paramedics who make an autonomous clinical decision under protocol that PHT is indicated, without the need for telemetry or physician-authorisation. The difference between these two groups is the ‘intervention’ – the new autonomous paramedic PHT protocol that permits this new independent model of paramedic PHT provision.

Data for the historic cohort will be collected from patient medical records within the Ambulance Service and the receiving hospital. This will be within a 36 month period from October 2008 to October 2011.
Control group
Historical

Outcomes
Primary outcome [1] 291803 0
Primary outcome 1: Time from patient symptom onset and/or call for ambulance assistance until PHT administration
Timepoint [1] 291803 0
This will be documented by ambulance paramedics at the time of PHT administration.
Primary outcome [2] 291804 0
Primary outcome 2: Patient outcomes - morbidity and all cause mortality as assessed by data linkage to medical records

Morbidity factors include:

1. Rates of Aborted Infarction, defined as ‘ST-segment resolution of less than 50% at 90 minutes from the level at presentation plus an associated rise in cardiac troponin markers of less than twice the upper limit of normal’.

2. Complications post PHT treatment in the field e.g. arrhythmias, bleeding or cardiac arrest.

3. Rates of Rescue-PCI performed post PHT.

4. In-hospital and 30-day incidence of death.

5. Infarct location.

6. Re-infarction.
Timepoint [2] 291804 0
At 30 days post PHT treatment
Primary outcome [3] 291805 0
Primary outcome 3: Patient hospital admission time (days).
Timepoint [3] 291805 0
This outcome will be assessed in each patient at time of hospital discharge.
Secondary outcome [1] 307584 0
Secondary Outcome 1: Accuracy and Safety of Autonomous Paramedic Delivered PHT Treatment.

The sensitivity and specificity along with PPV and NPV of the paramedics’ clinical diagnoses will be determined from their identification of patients suitable for PHT or not. This will occur in the prospective cohort. Three independent cardiology consultants (experts) will review all cases to determine actual field diagnosis. Accuracy of paramedic protocol application will be measured against this ‘gold standard’. In addition, the rate of True Positive and True Negative cases, along with False Positive and False Negative cases will be determined in the prospective cohort. Each of these cases will be described as proportions of the total number of clinical decisions made. Causes of False Positives and False Negatives will also be investigated.
Timepoint [1] 307584 0
Following completion of study at 20 months.

Eligibility
Key inclusion criteria
a) The retrospective cohort (n = 54) will include patients at/or greater than 18 years of age who have received paramedic-delivered PHT under physician authorisation in the Northland and Hawkes Bay regions since this historic PHT model was established in 2008.

b) The prospective cohort (n = 54) will include; patients at/or greater than 18 years of age who receive autonomous paramedic-delivered PHT; or those who have been considered for the treatment over a 20 month period; in the Northland and Hawkes Bay regions; and in line with protocol criteria. In addition, during this 20-month prospective period, the study will also investigate all patients at/or greater than 18 years of age transported by paramedics without PHT treatment in the same regions, but who went on to receive in-hospital thrombolysis following an in-hospital diagnosis of STEMI.
Minimum age
18 Years
Maximum age
85 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Key patient exclusion criteria is essentially those that do not meet our inclusion criteria for either the historic or prospective cohort.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Patients will be enrolled in the study if they recieve paramedic-delivered PHT following either the physician-authorised telemetry model, or autonomous paramedic model. Patients in the two observed cohorts will also need to meet the inclusion criteria as previously discussed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
n/a
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
This proposed study has a prospective analysis of differences design. Data from two separate groups of STEMI patients (an historic retrospective cohort and a prospective cohort) will be collected and analysed and a post-intervention comparison made. The Prospective data analysis enables standardisation of measures used in the study and provides stronger confidence in the design. A true experimental design with randomisation was considered neither ethical nor pragmatic due to the impossibility of blinding the protocol application, as well as the lengthy time frame required to reach statistically significant levels of patient numbers. Therefore, our selected design provides a reasonable alternative with efficient use of available patient data. Data will be collected from patient medical records within the Ambulance Service and the receiving hospital. Medical records provide an abundance of information that can be evaluated in context. However, inconsistencies may exist and information may be incomplete. For these reasons we intend to primarily draw on data in the records that are part of gold standard routine assessments conducted on all patients in context with the study.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Based on a previous New Zealand paramedic PHT study involving 100 patients and an a priori power analysis using their data, 108 patients are required, being 54 patients within each of the two observed groups. This was assuming a statistical significance level of alpha = 0.05, denoting a 95% confidence interval, a power of 0.80 and an expected effect size of 0.30.

The current version of SPSS statistical software will be used for statistical analysis and the significance level will be set at 0.05. Initial analysis will be primarily descriptive, producing frequencies, mean and standard deviations, or medians and interquartile ranges where relevant and testing for normal distributions of continuous measures e.g. time between events. If normality is not achieved, transformations such as the log of measure will be examined.
To test Hypothesis One, the rates of True Positive and True Negative, along with False Positive and False Negative cases will be identified. The sensitivity, specificity, PPV and NPV of paramedic protocol application will then be calculated. This will be achieved by use of a frequency score and subsequent presentation of results utilising a frequency distribution table, with comparison of scores to the standard (a dummy variable) as determined by three independent cardiologists (experts).
In order to test Hypotheses Two and Three, both observed groups will initially be compared using Chi-squared tests and comparisons of medians will be made using Mann-Whitney U tests. Primary analyses will compare the two groups using logistic regression for dichotomous outcome measures such as mortality, and general linear models for continuous measures such as length of hospital stay. Confounders such as time to PHT, time to hospital, patient demographics, time of day and severity of condition will also be examined. Presentation characteristics of patients before and after initiation of the intervention will be compared (e.g. demographics, distance from hospital, presentation symptoms). If significant differences are present, those characteristics will be added as covariates to the model after examination for potential correlations.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/06/2015
Actual
28/05/2015
Date of last participant enrolment
Anticipated
10/09/2017
Actual
25/05/2017
Date of last data collection
Anticipated
Actual
1/12/2017
Sample size
Target
108
Accrual to date
Final
174
Recruitment outside Australia
Country [1] 5941 0
New Zealand
State/province [1] 5941 0
Northland Region
Country [2] 5962 0
New Zealand
State/province [2] 5962 0
Hawkes Bay Region

Funding & Sponsors
Funding source category [1] 288996 0
Commercial sector/Industry
Name [1] 288996 0
Clinical Audit and Research Group

St John Ambulance Service

New Zealand
Country [1] 288996 0
New Zealand
Primary sponsor type
University
Name
Auckland University of Technology (AUT)
Address
Auckland University of Technology (AUT)

Research and Innovation Office
Private Bag 92006
Auckland 1142
New Zealand
Country
New Zealand
Secondary sponsor category [1] 287676 0
Commercial sector/Industry
Name [1] 287676 0
Clinical Audit and Research Group
St John Ambulance Service
New Zealand
Address [1] 287676 0
c/o

Dr Craig Ellis

Deputy Medical Director

Department: Clinical Development

Mailing address:

St John
62 Tait Drive
Napier 4112
New Zealand
Country [1] 287676 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290804 0
Health and Disability Ethics Committee (HDEC)
Ethics committee address [1] 290804 0
Health and Disability Ethics Committee (HDEC)

Ministry of Health
C/- MEDSAFE, Level 6, Deloitte House
10 Brandon Street
PO Box 5013
Wellington
6011
Ethics committee country [1] 290804 0
New Zealand
Date submitted for ethics approval [1] 290804 0
01/05/2014
Approval date [1] 290804 0
02/12/2014
Ethics approval number [1] 290804 0
14/NTA/112
Ethics committee name [2] 290805 0
Auckland University of Technology Ethics Committee (AUTEC)
Ethics committee address [2] 290805 0
C/O

Kate O'Connor
Executive Manager
AUTEC

Room WA505E, Level 5, WA Building
55 Wellesley Street East
Private Bag 92006
Auckland 1010
Ethics committee country [2] 290805 0
New Zealand
Date submitted for ethics approval [2] 290805 0
01/06/2014
Approval date [2] 290805 0
10/02/2015
Ethics approval number [2] 290805 0
15/03

Summary
Brief summary
Heart disease is the second leading cause of death in New Zealand, after cancer. At the acute end of the spectrum of this disease is ST-elevation myocardial Infarction (STEMI), a common type of heart attack and the most severe. However, specific treatments are available for STEMI patients, which have high rates of success, especially if they are performed early, within the first hours of symptom onset. One such treatment is ‘thrombolysis’ which involves the administration of certain drugs. This treatment is time-dependent, with early provision conferring the greatest clinical benefits and results. Paramedics are able to play a key strategic role in achieving this objective, as they are often the first healthcare professionals to encounter the STEMI patient.

Internationally, autonomous paramedic-delivered pre-hospital thrombolysis (PHT) has proven to be the most effective strategy in facilitating expedited delivery of this treatment modality. However, within New Zealand ambulance services have been slow to adopt and/or refine such paramedic-based approaches. Current New Zealand models rely on physician authorised telemetry-based systems which have proved problematic, particularly due to technological failings.

This proposed research will be an experimental study trialling an autonomous paramedic model for PHT within St John Ambulance Service, New Zealand’s largest ambulance provider, without physician oversight and authorisation. We hypothesise that adopting this approach will lead to improved patient outcomes, with reduced hospital admission times compared to the physician-authorised telemetry model. Economic benefits are also likely.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 46726 0
Mr Paul Davis
Address 46726 0
c/o St John Ambulance
43 Western Hills Drive
Kensington 0112
WHANGAREI
Country 46726 0
New Zealand
Phone 46726 0
+64 09 437 2199
Fax 46726 0
Email 46726 0
[email protected]
Contact person for public queries
Name 46727 0
Mr Paul Davis
Address 46727 0
St John Ambulance Service

43 Western Hills Drive
Kensington 0112
Whangarei
Country 46727 0
New Zealand
Phone 46727 0
+64 09 437 2199
Fax 46727 0
Email 46727 0
[email protected]
Contact person for scientific queries
Name 46728 0
Mr Paul Davis
Address 46728 0
St John Ambulance Service

43 Western Hills Drive
Kensington 0112
Whangarei
Country 46728 0
New Zealand
Phone 46728 0
+64 09 437 2199
Fax 46728 0
Email 46728 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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