A Randomized Controlled Trial of Aspirin and Exertional Heat Stress Activation of Platelets in Firefighters during Exertion in Thermal Protective Clothing

Abstract

Daily aspirin therapy blunts platelet activation during exertional heat stress and single-dose aspirin therapy following exertional heat stress reduces platelet activation within 60 minutes.

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

“…Physiologic responses to exertional heat stress have been reported in the main trial. 15 Of note, physiologic responses to exertional heat stress were not significantly different among AA, PP, AP and PA groups. 15 …”

“…There are multiple pathophysiological processes associated with exertional heat stress and firefighting that may be expected to exert vascular effects. 4,5,15 Platelet activation, a rapid rise in core body temperature (approximately 1.0-1.5°C in 20 minutes), hypohydration, and maximal exertion are known to affect the cardiovascular system during fire suppression. 4,5,15 Furthermore, AI and pulse wave velocity have been observed to increase with firefighting activities.…”

“…4,5,15 Platelet activation, a rapid rise in core body temperature (approximately 1.0-1.5°C in 20 minutes), hypohydration, and maximal exertion are known to affect the cardiovascular system during fire suppression. 4,5,15 Furthermore, AI and pulse wave velocity have been observed to increase with firefighting activities. 6 Increased AI, indicating enhanced arterial wave reflections and peripheral arterial stiffness, leads to increased left ventricular (LV) afterload and mechanical strain of the LV, 19 and is an early manifestation of vascular disease.…”

“…15 In that study, active cooling was delivered after exertion by 20 minutes of hand and forearm immersion into cold-water immersion. Only subjects randomized to receive passive cooling are included in this analysis.…”

Electrocardiographic Responses During Fire Suppression and Recovery Among Experienced Firefighters

“…2,8 In addition, fire suppression activities and exertion in thermal protective clothing result in significant cardiovascular strain and heat stress that could provide triggers for acute myocardial infarction in the setting of coronary artery disease. 9,10 Nevertheless, an examination of autopsy data from firefighter line-of-duty death cases reported a high prevalence of enlarged hearts in firefighters suffering heart attack when compared with traumatic deaths, leading to the possibility that some proportion of these cardiac line-of-duty deaths might be arrhythmogenic related to structural heart disease. 11 This is especially important given that cardiac autonomic modulation plays a significant role in the pathogenesis of arrhythmic death.…”