Vascular FunctionNCT01805063
Effect of Fire Suppression and Emergency Duties on Vascular Function
An observational study of Vascular Function and Atherothrombosis, run by University of Edinburgh at 1 site in United Kingdom.
Trial summary
Firefighters are at increased risk of death from heart attacks when compared to other emergencyy service professionals whose jobs involve similar components such as emergency call-outs and shift work. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Vascular Function, Atherothrombosis
- What is being tested?
- Forearm Vascular Study and Badimon Chamber
- Type of treatment
- Injection or infusion, Surgery or procedure
- How many people
- 30 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 9 Jan 2012to 31 Dec 2016
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Subjects will be healthy, non-smoking, whole-time firefighters working within Lothian and Borders Fire and Rescue Service
Who may be able to join
- Non-smoking healthy firefighters
Who cannot join
- Current smoker
- History of lung or ischaemic heart disease
- Malignant arrhythmia
- Systolic blood pressure >190mmHg or <100mmHg
- Renal or hepatic dysfunction
- Previous history of blood dyscrasia
Show all 10Show fewer
- Unable to tolerate the supine position
- Blood donation within the last 3 months
- Recent respiratory tract infection within the past 4 weeks
- Routine medication including aspirin and NSAIDs
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Royal Infirmary of Edinburgh Clinical Research Facility
Edinburgh, EH16 4SA
About this study
Official title: Effect of Fire Suppression and Emergency Duties on Vascular Function in Firefighters
Firefighters are at increased risk of death from heart attacks when compared to other emergencyy service professionals whose jobs involve similar components such as emergency call-outs and shift work. In the largest analysis of cause of death amongst on-duty firefighters, firefighter deaths were classified according to the duty performed during the onset of symptoms or immediately prior to any sudden death. The majority of deaths due to a cardiovascular cause (i.e. heart attack) occurred during fire suppression whilst this activity represented a relatively small amount of a firefighters professional time. There was also a risk of death associated with other duties such as emergency non-fire response and physical exertion.
The investigators hypothesize that participation in active fire-fighting duties impairs blood vessel function and increases blood clot formation when compared with non-fire-fighting activities. In this study, healthy career firefighters will be assessed after three periods of duty: fire-suppression, emergency response without fire suppression and following a sedentary shift. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess blood vessel function following these duties. By undertaking this comprehensive assessment of blood, blood vessel and heart function the investigators hope to understand the mechanisms whereby the risk of a heart attack, fatal or otherwise, is posed throughout these distinct duties that firefighters undertake on a daily basis.
- Conditions
- Vascular Function, Atherothrombosis
- Being tested
- Forearm Vascular Study, Badimon Chamber
- Keywords
- firefighters, myocardial infarction, endothelial function, thrombosis, fire suppression, non-fire emergency duty, sedentary shift
- Medical subject headings
- Thrombosis, Myocardial Infarction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Forearm Vascular StudyProcedure or surgery
Also called BK, SNP, ACh, VP
Forearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min).
Badimon ChamberProcedure or surgery
Ex-vivo assessment of thrombus formation using the Badimon Chamber
| Study group | Role | What they receive |
|---|---|---|
| Fire suppression | Firefighters will attend for vascular assessments following a night shift where they have performed fire suppression Receives: Procedure: Forearm Vascular Study; Procedure: Badimon Chamber | |
| Non-fire emergency duty | Firefighters will attend for vascular assessments following a night shift where they have had an emergency response without fire suppression eg. road traffic collision. Receives: Procedure: Forearm Vascular Study; Procedure: Badimon Chamber | |
| Sedentary shift | Firefighters will attend for vascular assessments following a night shift where they have remained sedentary throughout the shift. Receives: Procedure: Forearm Vascular Study; Procedure: Badimon Chamber |
What is being measured
The primary outcome is the main question the study is designed to answer.
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
Measured: up to 12 hours after exposure
Secondary outcomes (2)
Ex-vivo thrombus formation using the Badimon chamber
Measured: up to 12 hours after exposure
Plasma t-PA and PAI concentrations following infusion of bradykinin
Measured: During forearm study, up to 12 hours after exposure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Mar 2013 (estimated)
- Study start9 Jan 2012
- Primary completion31 Dec 2016
- Study completion31 Dec 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Vascular FunctionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case crossover
- Time perspective
- Prospective
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- David E Newby, MD PhD, Study chair, University of EdinburghNicholas L Mills, MBChB PhD, Study director, University of EdinburghAmanda L Hunter, MBChB, Principal investigator, University of Edinburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01805063
- Sponsor's protocol ID
- 11-SS-0049
- Other IDs
- PG/11/27/28842
- Status last verified
- Mar 2013
- First submitted
- 4 Mar 2013
- Last updated
- 1 May 2024
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 1 May 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Fire Suppression and Emergency Duties on Vascular Function in Firefighters
- ClinicalTrials.gov ID
- NCT01805063
- Acronym / sponsor ID
- 11-SS-0049
- Conditions
- Vascular Function, Atherothrombosis
- Keywords
- firefighters, myocardial infarction, endothelial function, thrombosis, fire suppression, non-fire emergency duty, sedentary shift
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Study start
- 9 Jan 2012 (actual)
- Primary completion
- 31 Dec 2016 (actual)
- Study completion
- 31 Dec 2016 (actual)
- First posted
- 5 Mar 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Firefighters are at increased risk of death from heart attacks when compared to other emergencyy service professionals whose jobs involve similar components such as emergency call-outs and shift work. In the largest analysis of cause of death amongst on-duty firefighters, firefighter deaths were classified according to the duty performed during the onset of symptoms or immediately prior to any sudden death. The majority of deaths due to a cardiovascular cause (i.e. heart attack) occurred during fire suppression whilst this activity represented a relatively small amount of a firefighters professional time. There was also a risk of death associated with other duties such as emergency non-fire response and physical exertion.
The investigators hypothesize that participation in active fire-fighting duties impairs blood vessel function and increases blood clot formation when compared with non-fire-fighting activities. In this study, healthy career firefighters will be assessed after three periods of duty: fire-suppression, emergency response without fire suppression and following a sedentary shift. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess blood vessel function following these duties. By undertaking this comprehensive assessment of blood, blood vessel and heart function the investigators hope to understand the mechanisms whereby the risk of a heart attack, fatal or otherwise, is posed throughout these distinct duties that firefighters undertake on a daily basis.
Study design
- Observational model
- Case crossover
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Fire suppression | – | Procedure: Forearm Vascular Study, Procedure: Badimon ChamberFirefighters will attend for vascular assessments following a night shift where they have performed fire suppression |
| Non-fire emergency duty | – | Procedure: Forearm Vascular Study, Procedure: Badimon ChamberFirefighters will attend for vascular assessments following a night shift where they have had an emergency response without fire suppression eg. road traffic collision. |
| Sedentary shift | – | Procedure: Forearm Vascular Study, Procedure: Badimon ChamberFirefighters will attend for vascular assessments following a night shift where they have remained sedentary throughout the shift. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Subjects will be healthy, non-smoking, whole-time firefighters working within Lothian and Borders Fire and Rescue Service
Key inclusion criteria (1 listed)
- Non-smoking healthy firefighters
Key exclusion criteria (10 listed)
- Current smoker
- History of lung or ischaemic heart disease
- Malignant arrhythmia
- Systolic blood pressure >190mmHg or <100mmHg
- Renal or hepatic dysfunction
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Forearm Vascular StudyAlso: BK, SNP, ACh, VPForearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min). | Procedure or surgery | Fire suppression, Non-fire emergency duty, Sedentary shift |
| Badimon ChamberEx-vivo assessment of thrombus formation using the Badimon Chamber | Procedure or surgery | Fire suppression, Non-fire emergency duty, Sedentary shift |
Primary outcome
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
Time frame: up to 12 hours after exposure
2 secondary outcomes
Ex-vivo thrombus formation using the Badimon chamber
Time frame: up to 12 hours after exposure
Plasma t-PA and PAI concentrations following infusion of bradykinin
Time frame: During forearm study, up to 12 hours after exposure
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 May 2024.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
David E Newby, MD PhD study chair
University of Edinburgh
Nicholas L Mills, MBChB PhD study director
University of Edinburgh
Amanda L Hunter, MBChB principal investigator
University of Edinburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Vascular Function and Atherothrombosis, run by University of Edinburgh at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 May 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators (time frame: up to 12 hours after exposure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 May 2024; AzTrials last refreshed its copy on 1 Nov 2026.