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

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Enhanced Firefighter Rehab Trial: Aspirin Versus Placebo

Brief 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.

Detailed Summary:

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. Effe
Sponsor: University of Pittsburgh

Current 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

Original Primary Outcome: Platelet Closure Time [ Time Frame: 0, 30, 60, and 90 minutes post exercise ]

Current Secondary Outcome:

• Activation of Coagulation [ Time Frame: 0, 30, 60, and 90 minutes post exercise ]
  This measure was not collected. Equipment was not available.
• Hyperthermia and Hemoconcentration Identified by Retinal Imaging [ Time Frame: 0, 30, 60, and 90 minutes post exercise ]
  This measure was not collected. Equipment was not available.

Original Secondary Outcome:

• Vascular function measured by peripheral arterial tonometry [ Time Frame: 0, 30, 60, and 90 minutes post exercise ]
• 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 ]

Information By: University of Pittsburgh

Dates:
Date Received: February 5, 2010
Date Started: February 2010
Date Completion:
Last Updated: July 5, 2016
Last Verified: July 2016