Determination of Risk Factors for Cardiovascular Disease in Firefighters
Grant: U.S. Department of Homeland Security, Federal Emergency Management Association, Assistance to Firefighter Grant, EMW-2007-FP-01499
Study partners
Phoenix Fire Department
Phoenix Fire Department Health Center
Tucson Fire Department
WellAmerica, LLC
Fire Protection Research Foundation (FPRF) of the National Fire Protection Association
Purpose and Objectives
Sudden cardiac deaths account for 44% of the line of duty deaths in firefighters, and generally occur in firefighters with underlying cardiovascular disease, many of whom have been previously asymptomatic. Current screening tests are therefore not adequate to identify firefighters at high risk of an on-duty cardiovascular event.
Fire suppression carries the highest risk for cardiovascular deaths, and yet we do not understand the effects of this activity, including the contribution of smoke and heat exposure, on pathways involved in the development of a myocardial infarction.
Our proposed study objectives are to evaluate the use of carotid artery intimal-medial thickness (IMT) as a medical surveillance tool in firefighters, to determine the acute effects of fire suppression on biomarkers associated with heart attacks and to evaluate a new cooling method.
Methods
Study Design and Sampling:
Goal #1: A total of 500 Phoenix and Tucson area firefighters with at least 5 years of firefighting service and without known cardiovascular disease will undergo carotid IMT to determine the extent of early atherosclerotic disease. (We reached this goal and surpassed it, ending at 597 firefighters tested)
Goal #2: Data on traditional risk factors (family history, cholesterol, HDL, LDL, triglycerides, hypertension, smoking, diabetes, exercise tolerance, BMI, and C-reactive protein (CRP)), as well as new research biomarkers will be analyzed to determine their ability to predict the presence of carotid IMT thickening in this population using statistics.
- Article
Burgess JL, Kurzius-Spencer M, Gerkin R, Fleming J, Peate W, Alison M. Risk factors for subclinical atherosclerosis in firefighters. Journal of Occupational and Environmental Medicine 2012;54:328-335.
Goal #3: The effects of fire suppression on acute measures of systemic inflammation and cardiac function will be evaluated in 50 firefighters post-exposure and at baseline. The contribution of exposure to smoke contaminants (particulates, carbon monoxide, hydrogen cyanide and aldehydes) and elevation in core body temperature (measured using an internal probe) to changes in specific lab assays from blood samples.
Goal #4: In an interventional trial, cardiac rehabilitation in 50 firefighters using a more rapid cooling method at the fire scene will be tested to determine its effectiveness in reducing core body temperature and adverse cardiovascular effects.
- Article
Burgess JL, Duncan M, Hu C, Littau SR, Caseman D, Kurzius-Spencer M, Gorman G, McDonogh P. Acute cardiovascular effects of firefighting and active cooling during rehabilitation. Journal of Occupational and Environmental Medicine 2012;54:1413-1420.
Firefighter Statin Study Reducing Atherosclerotic Disease and Risk Factors
Grant: U.S. Department of Homeland Security, Federal Emergency Management Association, Assistance to Firefighter Grant, EMW-2014-FP-00200
Study partners
Phoenix Fire Department
Phoenix Fire Department Health Center
Purpose and Objectives
Carotid Intima-Media Thickness (CIMT) is a measure of atherosclerosis, and increasing CIMT is associated with a higher risk of cardiac events. We have identified that firefighters with LDL-C > 100 mg/dl have increased CIMT. Statin therapy reduces future cardiac events and CIMT. However, firefighters without hypercholesterolemia abnormal cholesterol concentrations rarely receive statins.
We propose a randomized trial of statin therapy in Phoenix firefighters to determine its effectiveness in limiting atherosclerosis progression.
- Evaluate if rosuvastatin over a 24 month period prevents progression of CIMT.
- Measure the effect of rosuvastatin on lipids (total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides), C-reactive protein (CRP) and other biomarkers of cardiovascular risk.
- Determine if changes in lipids and other biomarkers of cardiovascular risk are associated with change in CIMT.
Methods
Study Design and Sampling:
Firefighters with LDL-C 100 to 160 mg/dl and not currently taking statins will be randomly assigned to receive rosuvastatin at 5-10 mg daily for two years or to a control group. At baseline and at 12 and 24 months, CIMT measurements of the common carotid artery, carotid bifurcation and internal carotid artery will be obtained, as will blood samples for lipids, CRP and other biomarkers of cardiovascular disease risk.