Clinical trial NCT01812317: Effect of Real-fire Training on Vascular Function
Official title: Effect of Real-fire Training on Vascular Function
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vascular Function
Atherothrombosis
Keywords: firefighters
fire-simulation training
myocardial infarction
endothelial function
thrombosis
Lead sponsor: University of Edinburgh
Sponsor class: OTHER
First posted: 2013-03-18
Enrollment: 19
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Fire-fighters are at increased risk of death from heart attacks when compared to other emergency service professionals whose jobs involve similar components such as emergency call-outs and shift work. The unique risk to fire-fighters is likely to reflect a combination of factors including extreme physical exertion, mental stress, heat and pollutant exposure.

In the largest analysis of cause of death amongst on-duty fire-fighters, fire-fighter 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 fire-fighters professional time. Fire simulation training centers offer a unique opportunity to assess the heart, blood and blood vessel response to fire suppression in a controlled environment.

In this study the investigators will assess healthy career fire-fighters on two occasions: following a fire-suppression training exercise in a purpose built real-fire training center, and following a sedentary period as a control. 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 fire suppression. By undertaking this comprehensive assessment of blood, blood vessel and heart function we hope to understand the mechanisms whereby the risk of a heart attack is influenced by fire suppression. The investigators hypothesize that following the fire-suppression exercise firefighters blood will clot more readily and their blood vessels will not relax properly which are two of the main processes in the development of a heart attack.


Eligibility criteria: Inclusion Criteria:

* Non-smoking healthy firefighters

Exclusion Criteria:

* 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
* 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

Primary outcomes:
measure: Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
timeFrame: 3-6 hours post exposure
Secondary outcomes:
measure: Ex-vivo thrombus formation using the Badimon chamber
timeFrame: 2 hours post exposure
measure: Plasma t-PA and PAI concentrations following infusion of bradykinin
timeFrame: During forearm study, 3-6 hours post exposure
Other outcomes:
Locations:
city: Edinburgh
country: United Kingdom
facility: Royal Infirmary of Edinburgh Clinical Research Facility
Study officials:
affiliation: University of Edinburgh
name: David E Newby, MD PhD
role: STUDY_CHAIR
affiliation: University of Edinburgh
name: Nicholas L Mills, MBChB PhD
role: STUDY_DIRECTOR
affiliation: University of Edinburgh
name: Amanda L Hunter, MBChB
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hunter AL, Shah AS, Langrish JP, Raftis JB, Lucking AJ, Brittan M, Venkatasubramanian S, Stables CL, Stelzle D, Marshall J, Graveling R, Flapan AD, Newby DE, Mills NL. Fire Simulation and Cardiovascular Health in Firefighters. Circulation. 2017 Apr 4;135(14):1284-1295. doi: 10.1161/CIRCULATIONAHA.116.025711.