Heat Stress DisordersEFFoRTNCT01066923
Enhanced Firefighter Rehab Trial: The Role of Aspirin in Preventing Heat Stress Induced Platelet Activation
A study testing Daily aspirin (ASA), Active cooling and Acute aspirin (ASA) in people with Heat Stress Disorders, run by Dave Hostler at 1 site in United States.
Trial summary
The purpose of this study is to determine if aspirin taken by firefighters prevents platelets from becoming sticky when body temperature rises during work in protective clothing. Read more about this study
- Who is it for?
- Ages 18 to 49 yearsHealthy volunteers can take part
- Conditions the study is for
- Heat Stress Disorders
- What is being tested?
- Daily aspirin (ASA), Active cooling and Acute aspirin (ASA)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 124 participants
- Where
- 1 siteUnited States
- Study dates
- Feb 2010to Jun 2011
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 49 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 1. Apparently healthy males and females aged 18-49 years
Who cannot join
- History of heart disease, vascular disease, or sudden death including prior MI, coronary revascularization, congenital heart disease or history of stroke
- Hypertension during screening: SBP>139 or DBP>89
- Those who are taking medications that may be expected to blunt the physiologic response to a treadmill exercise test (e.g. beta blockers)
- Prescription medication with known side effect of impaired thermoregulation
- Positive pregnancy test at any time during the study
- Resting ECG with clinical presentation suggesting coronary heart disease (e.g. pathologic Q wave)
Show all 11Show fewer
- Known history of gastrointestinal disease or disorder i.e. diverticulitis which creates a theoretical risk of the core temperature capsule becoming lodged in the digestive tract
- Medications and supplements known to alter endothelial function (e.g. arginine, omega 3 fatty acids, NSAIDS, tobacco products. This exclusion may be disregarded for subjects willing to stop taking the supplement for the duration of the study
- At the discretion of the study physician for any other medical condition or prescription medication
- Known history of platelet dysfunction
- Aspirin allergy or intolerance
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Pittsburgh, Emergency Responder Human Performance Lab
Pittsburgh, Pennsylvania, 15213
About this study
Official title: Enhanced Firefighter Rehab Trial: Aspirin Versus Placebo
The purpose of this study is to determine if aspirin taken by firefighters prevents platelets from becoming sticky when body temperature rises during work in protective clothing.
Read the detailed description
Firefighters have the highest rate of line-of duty death (LODD) in the United States. More than half of these LODD are cardiovascular related occurring disproportionately around fire suppression activities. In addition, shift work, lifestyle factors, and the exposures associated with fire suppression (e.g. smoke, chemicals) may predispose the firefighter to earlier onset of heart disease or cause a pro-inflammatory state leading to endothelial dysfunction.
Fire suppression activities exacerbate cardiovascular strain and endothelial dysfunction and provide potential triggers for ischemic events (e.g. myocardial infarction, stroke). There is a rapid rise in heart rate following the activation of a fire company which may persist for as long as 20 minutes. Even in cases where heavy work is not being performed, the repetitive upper body exercise associated with tool use raises heart rate disproportionately to oxygen consumption.
Finally, there is a rapid rise in core body temperature from increased physical activity, environmental heat and impaired thermoregulation that has been shown to cause vasoconstriction and activate coagulation during heat stress (12, 13). This has recently been demonstrated in firefighters working in thermal protective clothing. The combination of triggers created during fire suppression may result in heart attack or stroke, especially in firefighters with risk factors for cardiovascular disease.
Interventions beyond basic fireground rehab may be required to minimize the effect of these triggers and enhance a firefighter's health and wellness. Fireground rehab typically focuses on cooling and rehydration of the firefighter following fire suppression or training with the assumption that these interventions will correct the underlying pathophysiology. Effective fireground rehab must deliver appropriate interventions and monitor the progress of the firefighter. While correcting hyperthermia and hypohydration are essential for continued performance, it is not clear if these therapies correct alterations in platelet or endothelial function or if other interventions are necessary to correct these physiological disturbances. Furthermore, the options for monitoring the firefighter beyond simply measuring heart and respiratory rate are limited. In our FEMA-funded Fireground Rehab Evaluation (FIRE) Trial, we demonstrated that five commercially available thermometers did not reliably measure or estimate core temperature following uncompensable heat stress (UHS) making it impossible to gauge the effectiveness of rehab interventions.
- Conditions
- Heat Stress Disorders
- Being tested
- Daily aspirin (ASA), Active cooling, Acute aspirin (ASA), Passive cooling, Daily placebo
- Keywords
- firefighter, heat stress, platelet activation, aspirin
- Medical subject headings
- Heat Stress Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Daily aspirin (ASA)Drug
Two weeks 82 mg aspirin taken orally prior to exercise protocol
Active coolingOther
Active cooling to remediate heat stress following exercise by placing hands and forearms into cold water
Acute aspirin (ASA)Drug
325 mg chewable aspirin administered immediately following exercise
Passive coolingOther
Removing protective garments for passive cooling following exercise
Daily placeboDrug
Placebo comparator for daily aspirin therapy
Acute placeboDrug
Placebo comparator for acute aspirin therapy
| Study group | Role | What they receive |
|---|---|---|
| Daily ASA, Active cool, Acute ASA | Experimental | Two weeks of daily aspirin therapy prior to exercise, active cooling following exercise, aspirin immediately post exercise Receives: Drug: Daily aspirin (ASA); Other: Active cooling; Drug: Acute aspirin (ASA) |
| Daily ASA, Active cool, Acute placebo | Experimental | Two weeks of daily aspirin therapy prior to exercise, active cooling following exercise, placebo immediately post exercise Receives: Drug: Daily aspirin (ASA); Other: Active cooling; Drug: Acute placebo |
| Daily ASA, Passive cool, Acute ASA | Experimental | Two weeks of daily aspirin therapy prior to exercise, passive cooling following exercise, aspirin immediately post exercise Receives: Drug: Daily aspirin (ASA); Drug: Acute aspirin (ASA); Other: Passive cooling |
| Daily ASA, Passive cool, Acute placebo | Experimental | Two weeks of daily aspirin therapy prior to exercise, passive cooling following exercise, placebo immediately post exercise Receives: Drug: Daily aspirin (ASA); Other: Passive cooling; Drug: Acute placebo |
| Daily placebo, active cool, Acute ASA | Experimental | Two weeks of daily placebo prior to exercise, active cooling following exercise, aspirin immediately post exercise Receives: Other: Active cooling; Drug: Acute aspirin (ASA); Drug: Daily placebo |
| Daily placebo, active cool, Acute placebo | Experimental | Two weeks of daily placebo prior to exercise, active cooling following exercise, placebo immediately post exercise Receives: Other: Active cooling; Drug: Daily placebo; Drug: Acute placebo |
| Daily placebo, Passive cool, Acute ASA | Experimental | Two weeks of daily placebo prior to exercise, passive cooling following exercise, aspirin immediately post exercise Receives: Drug: Acute aspirin (ASA); Other: Passive cooling; Drug: Daily placebo |
| Daily placebo, Passive cool, Acute placebo | Placebo comparator | Two weeks of daily placebo prior to exercise, passive cooling following exercise, placebo immediately post exercise Receives: Other: Passive cooling; Drug: Daily placebo; Drug: Acute placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Platelet Closure Time
Measured: 0, 30, 60, and 90 minutes post exercise
Vascular Function Measured by Peripheral Arterial Tonometry
Reactive Hyperemia Index
Measured: Baseline, 30, 60, and 90 minutes post exercise
Secondary outcomes (2)
Activation of Coagulation
This measure was not collected. Equipment was not available.
Measured: 0, 30, 60, and 90 minutes post exercise
Hyperthermia and Hemoconcentration Identified by Retinal Imaging
This measure was not collected. Equipment was not available.
Measured: 0, 30, 60, and 90 minutes post exercise
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Feb 2010 (estimated)
- Study startFeb 2010
- Primary completionJun 2011
- Study completionJun 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Heat Stress DisordersStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 124 participants (actual)
Sponsor and investigators
- Lead sponsor
- Dave Hostler
- Sponsor type
- University, hospital or other
- Collaborators
- Federal Emergency Management Administration, Eyemarker Systems, Inc
- Responsible party
- Sponsor-investigator, Dave Hostler, University of Pittsburgh
- Investigators
- David Hostler, PhD, Principal investigator, University of Pittsburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01066923
- Sponsor's protocol ID
- EMW-2008-FP-01638
- Acronym
- EFFoRT
- Status last verified
- Oct 2017
- First submitted
- 5 Feb 2010
- Last updated
- 13 Nov 2017
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
Olafiranye O, Hostler D, Winger DG, Wang L, Reis SE. Effect of aspirin on acute changes in peripheral arterial stiffness and endothelial function following exertional heat stress in firefighters: The factorial group results of the Enhanced Firefighter Rehab Trial. Vasc Med. 2015 Jun;20(3):230-6. doi: 10.1177/1358863X15571447. Epub 2015 May 4.
PubMed 25939657Hostler D, Suyama J, Guyette FX, Moore CG, Pryor RR, Khorana P, McEntire SJ, Comer D, Reis SE. A randomized controlled trial of aspirin and exertional heat stress activation of platelets in firefighters during exertion in thermal protective clothing. Prehosp Emerg Care. 2014 Jul-Sep;18(3):359-67. doi: 10.3109/10903127.2013.869644. Epub 2014 Feb 18.
PubMed 24548114
Study at a glance
From the registry record, last updated by the sponsor on 13 Nov 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Enhanced Firefighter Rehab Trial: Aspirin Versus Placebo
- ClinicalTrials.gov ID
- NCT01066923
- Acronym / sponsor ID
- EFFoRT / EMW-2008-FP-01638
- Conditions
- Heat Stress Disorders
- Keywords
- firefighter, heat stress, platelet activation, aspirin
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 124 participants (actual)
- Lead sponsor
- Dave HostlerUniversity, hospital or other
- Collaborators
- Federal Emergency Management Administration, Eyemarker Systems, Inc
- Study start
- Feb 2010
- Primary completion
- Jun 2011 (actual)
- Study completion
- Jun 2011 (actual)
- First posted
- 10 Feb 2010 (estimated)
- Results
- Posted 17 Aug 2016
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to determine if aspirin taken by firefighters prevents platelets from becoming sticky when body temperature rises during work in protective clothing.
Detailed description
Firefighters have the highest rate of line-of duty death (LODD) in the United States. More than half of these LODD are cardiovascular related occurring disproportionately around fire suppression activities. In addition, shift work, lifestyle factors, and the exposures associated with fire suppression (e.g. smoke, chemicals) may predispose the firefighter to earlier onset of heart disease or cause a pro-inflammatory state leading to endothelial dysfunction.
Fire suppression activities exacerbate cardiovascular strain and endothelial dysfunction and provide potential triggers for ischemic events (e.g. myocardial infarction, stroke). There is a rapid rise in heart rate following the activation of a fire company which may persist for as long as 20 minutes. Even in cases where heavy work is not being performed, the repetitive upper body exercise associated with tool use raises heart rate disproportionately to oxygen consumption.
Finally, there is a rapid rise in core body temperature from increased physical activity, environmental heat and impaired thermoregulation that has been shown to cause vasoconstriction and activate coagulation during heat stress (12, 13). This has recently been demonstrated in firefighters working in thermal protective clothing. The combination of triggers created during fire suppression may result in heart attack or stroke, especially in firefighters with risk factors for cardiovascular disease.
Interventions beyond basic fireground rehab may be required to minimize the effect of these triggers and enhance a firefighter's health and wellness. Fireground rehab typically focuses on cooling and rehydration of the firefighter following fire suppression or training with the assumption that these interventions will correct the underlying pathophysiology. Effective fireground rehab must deliver appropriate interventions and monitor the progress of the firefighter. While correcting hyperthermia and hypohydration are essential for continued performance, it is not clear if these therapies correct alterations in platelet or endothelial function or if other interventions are necessary to correct these physiological disturbances. Furthermore, the options for monitoring the firefighter beyond simply measuring heart and respiratory rate are limited. In our FEMA-funded Fireground Rehab Evaluation (FIRE) Trial, we demonstrated that five commercially available thermometers did not reliably measure or estimate core temperature following uncompensable heat stress (UHS) making it impossible to gauge the effectiveness of rehab interventions.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 8
| Arm | Type | Receives |
|---|---|---|
| Daily ASA, Active cool, Acute ASA | Experimental | Drug: Daily aspirin (ASA), Other: Active cooling, Drug: Acute aspirin (ASA)Two weeks of daily aspirin therapy prior to exercise, active cooling following exercise, aspirin immediately post exercise |
| Daily ASA, Active cool, Acute placebo | Experimental | Drug: Daily aspirin (ASA), Other: Active cooling, Drug: Acute placeboTwo weeks of daily aspirin therapy prior to exercise, active cooling following exercise, placebo immediately post exercise |
| Daily ASA, Passive cool, Acute ASA | Experimental | Drug: Daily aspirin (ASA), Drug: Acute aspirin (ASA), Other: Passive coolingTwo weeks of daily aspirin therapy prior to exercise, passive cooling following exercise, aspirin immediately post exercise |
| Daily ASA, Passive cool, Acute placebo | Experimental | Drug: Daily aspirin (ASA), Other: Passive cooling, Drug: Acute placeboTwo weeks of daily aspirin therapy prior to exercise, passive cooling following exercise, placebo immediately post exercise |
| Daily placebo, active cool, Acute ASA | Experimental | Other: Active cooling, Drug: Acute aspirin (ASA), Drug: Daily placeboTwo weeks of daily placebo prior to exercise, active cooling following exercise, aspirin immediately post exercise |
| Daily placebo, active cool, Acute placebo | Experimental | Other: Active cooling, Drug: Daily placebo, Drug: Acute placeboTwo weeks of daily placebo prior to exercise, active cooling following exercise, placebo immediately post exercise |
| Daily placebo, Passive cool, Acute ASA | Experimental | Drug: Acute aspirin (ASA), Other: Passive cooling, Drug: Daily placeboTwo weeks of daily placebo prior to exercise, passive cooling following exercise, aspirin immediately post exercise |
| Daily placebo, Passive cool, Acute placebo | Placebo comparator | Other: Passive cooling, Drug: Daily placebo, Drug: Acute placeboTwo weeks of daily placebo prior to exercise, passive cooling following exercise, placebo immediately post exercise |
Who may qualify
- Ages
- 18 to 49 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- 1. Apparently healthy males and females aged 18-49 years
Key exclusion criteria (11 listed)
- History of heart disease, vascular disease, or sudden death including prior MI, coronary revascularization, congenital heart disease or history of stroke
- Hypertension during screening: SBP>139 or DBP>89
- Those who are taking medications that may be expected to blunt the physiologic response to a treadmill exercise test (e.g. beta blockers)
- Prescription medication with known side effect of impaired thermoregulation
- Positive pregnancy test at any time during the study
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 |
|---|---|---|
| Daily aspirin (ASA)Two weeks 82 mg aspirin taken orally prior to exercise protocol | Drug | Daily ASA, Active cool, Acute ASA, Daily ASA, Active cool, Acute placebo, Daily ASA, Passive cool, Acute ASA, Daily ASA, Passive cool, Acute placebo |
| Active coolingActive cooling to remediate heat stress following exercise by placing hands and forearms into cold water | Other | Daily ASA, Active cool, Acute ASA, Daily ASA, Active cool, Acute placebo, Daily placebo, active cool, Acute ASA, Daily placebo, active cool, Acute placebo |
| Acute aspirin (ASA)325 mg chewable aspirin administered immediately following exercise | Drug | Daily ASA, Active cool, Acute ASA, Daily ASA, Passive cool, Acute ASA, Daily placebo, Passive cool, Acute ASA, Daily placebo, active cool, Acute ASA |
| Passive coolingRemoving protective garments for passive cooling following exercise | Other | Daily ASA, Passive cool, Acute ASA, Daily ASA, Passive cool, Acute placebo, Daily placebo, Passive cool, Acute ASA, Daily placebo, Passive cool, Acute placebo |
| Daily placeboPlacebo comparator for daily aspirin therapy | Drug | Daily placebo, Passive cool, Acute ASA, Daily placebo, Passive cool, Acute placebo, Daily placebo, active cool, Acute ASA, Daily placebo, active cool, Acute placebo |
| Acute placeboPlacebo comparator for acute aspirin therapy | Drug | Daily ASA, Active cool, Acute placebo, Daily ASA, Passive cool, Acute placebo, Daily placebo, Passive cool, Acute placebo, Daily placebo, active cool, Acute placebo |
Primary outcome
Platelet Closure Time
Time frame: 0, 30, 60, and 90 minutes post exercise
Vascular Function Measured by Peripheral Arterial Tonometry
Time frame: Baseline, 30, 60, and 90 minutes post exercise
Reactive Hyperemia Index
2 secondary outcomes
Activation of Coagulation
Time frame: 0, 30, 60, and 90 minutes post exercise
Hyperthermia and Hemoconcentration Identified by Retinal Imaging
Time frame: 0, 30, 60, and 90 minutes post exercise
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Nov 2017.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 25939657Olafiranye O, Hostler D, Winger DG, Wang L, Reis SE. Effect of aspirin on acute changes in peripheral arterial stiffness and endothelial function following exertional heat stress in firefighters: The factorial group results of the Enhanced Firefighter Rehab Trial. Vasc Med. 2015 Jun;20(3):230-6. doi: 10.1177/1358863X15571447. Epub 2015 May 4.
- Results publication: PubMed 24548114Hostler D, Suyama J, Guyette FX, Moore CG, Pryor RR, Khorana P, McEntire SJ, Comer D, Reis SE. A randomized controlled trial of aspirin and exertional heat stress activation of platelets in firefighters during exertion in thermal protective clothing. Prehosp Emerg Care. 2014 Jul-Sep;18(3):359-67. doi: 10.3109/10903127.2013.869644. Epub 2014 Feb 18.
- Individual participant dataSharing planned: No
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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 Hostler, PhD principal investigator
University of Pittsburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Daily aspirin (ASA), Active cooling and Acute aspirin (ASA) in people with Heat Stress Disorders, run by Dave Hostler at 1 site in United States.
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 11 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 13 Nov 2017. 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 States. 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. Some participants in this study may receive a placebo. 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?
Yes. Results are posted in the registry (first posted 17 Aug 2016). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Platelet Closure Time (time frame: 0, 30, 60, and 90 minutes post exercise). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01066923, which also lists 2 linked publications.
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 13 Nov 2017; AzTrials last refreshed its copy on 8 Nov 2026.