Enhanced Firefighter Rehab Trial: The Role of Aspirin in Preventing Heat Stress Induced Platelet Activation (EFFoRT)

This study has been completed.
Sponsor:
Collaborators:
Federal Emergency Management Administration
Eyemarker Systems, Inc
Information provided by (Responsible Party):
University of Pittsburgh
ClinicalTrials.gov Identifier:
NCT01066923
First received: February 5, 2010
Last updated: October 6, 2011
Last verified: October 2011
  Purpose

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.


Condition Intervention Phase
Heat Stress Disorders
Drug: Daily aspirin (ASA)
Other: Active cooling
Drug: Acute aspirin (ASA)
Other: Passive cooling
Drug: Daily placebo
Drug: Acute placebo
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
Official Title: Enhanced Firefighter Rehab Trial

Resource links provided by NLM:


Further study details as provided by University of Pittsburgh:

Primary Outcome Measures:
  • Platelet closure time [ Time Frame: 0, 30, 60, and 90 minutes post exercise ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Vascular function measured by peripheral arterial tonometry [ Time Frame: 0, 30, 60, and 90 minutes post exercise ] [ Designated as safety issue: No ]
  • Activation of coagulation [ Time Frame: 0, 30, 60, and 90 minutes post exercise ] [ Designated as safety issue: No ]
  • Hyperthermia and hemoconcentration identified by retinal imaging [ Time Frame: 0, 30, 60, and 90 minutes post exercise ] [ Designated as safety issue: No ]

Estimated Enrollment: 160
Study Start Date: February 2010
Study Completion Date: June 2011
Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Daily ASA, Active cool, Acute ASA
Two weeks of daily aspirin therapy prior to exercise, active cooling following exercise, aspirin immediately post exercise
Drug: Daily aspirin (ASA)
Two weeks 82 mg aspirin taken orally prior to exercise protocol
Other: Active cooling
Active cooling to remediate heat stress following exercise by placing hands and forearms into cold water
Drug: Acute aspirin (ASA)
325 mg chewable aspirin administered immediately following exercise
Experimental: Daily ASA, Active cool, Acute placebo
Two weeks of daily aspirin therapy prior to exercise, active cooling following exercise, placebo immediately post exercise
Drug: Daily aspirin (ASA)
Two weeks 82 mg aspirin taken orally prior to exercise protocol
Other: Active cooling
Active cooling to remediate heat stress following exercise by placing hands and forearms into cold water
Drug: Acute placebo
Placebo comparator for acute aspirin therapy
Experimental: Daily ASA, Passive cool, Acute ASA
Two weeks of daily aspirin therapy prior to exercise, passive cooling following exercise, aspirin immediately post exercise
Drug: Daily aspirin (ASA)
Two weeks 82 mg aspirin taken orally prior to exercise protocol
Drug: Acute aspirin (ASA)
325 mg chewable aspirin administered immediately following exercise
Other: Passive cooling
Removing protective garments for passive cooling following exercise
Experimental: Daily ASA, Passive cool, Acute placebo
Two weeks of daily aspirin therapy prior to exercise, passive cooling following exercise, placebo immediately post exercise
Drug: Daily aspirin (ASA)
Two weeks 82 mg aspirin taken orally prior to exercise protocol
Other: Passive cooling
Removing protective garments for passive cooling following exercise
Drug: Acute placebo
Placebo comparator for acute aspirin therapy
Experimental: Daily placebo, active cool, Acute ASA
Two weeks of daily placebo prior to exercise, active cooling following exercise, aspirin immediately post exercise
Other: Active cooling
Active cooling to remediate heat stress following exercise by placing hands and forearms into cold water
Drug: Acute aspirin (ASA)
325 mg chewable aspirin administered immediately following exercise
Drug: Daily placebo
Placebo comparator for daily aspirin therapy
Experimental: Daily placebo, active cool, Acute placebo
Two weeks of daily placebo prior to exercise, active cooling following exercise, placebo immediately post exercise
Other: Active cooling
Active cooling to remediate heat stress following exercise by placing hands and forearms into cold water
Drug: Daily placebo
Placebo comparator for daily aspirin therapy
Drug: Acute placebo
Placebo comparator for acute aspirin therapy
Experimental: Daily placebo, Passive cool, Acute ASA
Two weeks of daily placebo prior to exercise, passive cooling following exercise, aspirin immediately post exercise
Drug: Acute aspirin (ASA)
325 mg chewable aspirin administered immediately following exercise
Other: Passive cooling
Removing protective garments for passive cooling following exercise
Drug: Daily placebo
Placebo comparator for daily aspirin therapy
Placebo Comparator: Daily placebo, Passive cool, Acute placebo
Two weeks of daily placebo prior to exercise, passive cooling following exercise, placebo immediately post exercise
Other: Passive cooling
Removing protective garments for passive cooling following exercise
Drug: Daily placebo
Placebo comparator for daily aspirin therapy
Drug: Acute placebo
Placebo comparator for acute aspirin therapy

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.

  Eligibility

Ages Eligible for Study:   18 Years to 49 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

1. Apparently healthy males and females aged 18-49 years

Exclusion Criteria:

  1. History of heart disease, vascular disease, or sudden death including prior MI, coronary revascularization, congenital heart disease or history of stroke
  2. Hypertension during screening: SBP>139 or DBP>89
  3. Those who are taking medications that may be expected to blunt the physiologic response to a treadmill exercise test (e.g. beta blockers)
  4. Prescription medication with known side effect of impaired thermoregulation
  5. Positive pregnancy test at any time during the study
  6. Resting ECG with clinical presentation suggesting coronary heart disease (e.g. pathologic Q wave)
  7. 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
  8. 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
  9. At the discretion of the study physician for any other medical condition or prescription medication
  10. Known history of platelet dysfunction
  11. Aspirin allergy or intolerance
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01066923

Locations
United States, Pennsylvania
University of Pittsburgh, Emergency Responder Human Performance Lab
Pittsburgh, Pennsylvania, United States, 15213
Sponsors and Collaborators
University of Pittsburgh
Federal Emergency Management Administration
Eyemarker Systems, Inc
Investigators
Principal Investigator: David Hostler, PhD University of Pittsburgh
  More Information

No publications provided

Responsible Party: University of Pittsburgh
ClinicalTrials.gov Identifier: NCT01066923     History of Changes
Other Study ID Numbers: EMW-2008-FP-01638
Study First Received: February 5, 2010
Last Updated: October 6, 2011
Health Authority: United States: Institutional Review Board

Keywords provided by University of Pittsburgh:
firefighter
heat stress
platelet activation
aspirin

Additional relevant MeSH terms:
Stress Disorders, Traumatic
Heat Stress Disorders
Anxiety Disorders
Mental Disorders
Wounds and Injuries
Aspirin
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Analgesics
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Pharmacologic Actions
Anti-Inflammatory Agents
Therapeutic Uses
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Cardiovascular Agents
Hematologic Agents
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Antipyretics
Central Nervous System Agents

ClinicalTrials.gov processed this record on September 16, 2014