Effect of Real-fire Training on Vascular Function

NCT01812317 | Completed DMC

• 2 other identifiers: 11-SS-0086PG/11/27/28842
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

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.

Conditions

Vascular Function; Atherothrombosis

Keywords

firefighters; fire-simulation training; myocardial infarction; endothelial function; thrombosis

Outcome Measures

Primary Outcomes (1)

• Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators

  3-6 hours post exposure

Secondary Outcomes (2)

• Ex-vivo thrombus formation using the Badimon chamber

  2 hours post exposure

• Plasma t-PA and PAI concentrations following infusion of bradykinin

  During forearm study, 3-6 hours post exposure

Study Arms (2)

Real-fire training exercise

ACTIVE COMPARATOR

Subjects will undergo a 20 minute standardised training exercise in a fire simulation facility.

Procedure: Forearm Vascular Study; Procedure: Badimon Chamber Study

Sedentary training session

SHAM COMPARATOR

Subjects will undergo a training exercise where they will remain sedentary for 20 mins in an ambient temperature.

Procedure: Forearm Vascular Study; Procedure: Badimon Chamber Study

Interventions

Forearm Vascular Study PROCEDURE

Forearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min).

Also known as: BK, SNP, ACh, VP

Real-fire training exercise; Sedentary training session

Badimon Chamber Study PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Real-fire training exercise; Sedentary training session

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Non-smoking healthy firefighters

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Edinburgh: lead

Study Sites (1)

Royal Infirmary of Edinburgh Clinical Research Facility

Edinburgh, EH16 4SA, United Kingdom

Location

Related Publications (1)

• 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.

  PMID: 28373523 RESULT

MeSH Terms

Conditions

Thrombosis; Myocardial Infarction

Condition Hierarchy (Ancestors)

Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases; Myocardial Ischemia; Heart Diseases; Infarction; Ischemia; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Necrosis

Study Officials

• David E Newby, MD PhD

  University of Edinburgh

  STUDY CHAIR

• Nicholas L Mills, MBChB PhD

  University of Edinburgh

  STUDY DIRECTOR

• Amanda L Hunter, MBChB

  University of Edinburgh

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 4, 2013
• First Posted: March 18, 2013
• Study Start: April 1, 2012
• Primary Completion: September 1, 2016
• Study Completion: September 1, 2016
• Last Updated: June 21, 2021

Record last verified: 2021-06

Locations

GB (1)