Title: Cardiovascular Risk and Firefighting
1Cardiovascular Risk and Firefighting
- Dr Ian Griffiths
- Consultant Occupational Physician
- Nottingham University Hospitals
- March 2009
2Content
- Case presentation
- Cardiovascular disease in Firefighters how much
of a problem is it? - What might cause cardiovascular disease in
Firefighters? - What can we do to reduce any risks?
3Case Study
- 41 year old male FF
- Minor chest discomfort April 08
- 3 days later, severe chest pain
- In hospital 7 days
- Inferior ST elevation MI
4Risk factors
- Male (RR 3.1)
- Ex smoker aged 20
- Cholesterol 5.6mmol/L
- No family history
- Exercise 5 miles of walking or cycling 2 or 3
days a week - Not overweight
- Lundblad et al, Biomed Central, 2008
5Treatment
- Clot busted by paramedics
- Aspirin 75mg OD
- Clopidogrel 75mg OD
- Atorvastatin 40mg OD
- Ramipril 10mg OD
- Bisoprolol 2.5mg OD
- 12 sessions in cardiac rehab
6Occupational Health Involvement
- Seen July 08
- Return to Work after Cardiac illness, British
Heart Foundation 09/98 states return to full
activity including work in 4-6 weeks after MI - Well, cheerful, symptom free, returned to all
activities
7Job
- WT crew manager
- Shifts starting 0700 1900
- No LGV licence
- Likes job
8Examination findings
- Optimistic and positive
- Realistic
- Not overweight
- P 48 regular
- BP 128/76
- No signs of heart failure
9Advice to management July 08
- Fit for any work except firefighting
- Await info from specialist (asking specific
questions) - Needs careful thought on risks of returning to
- Firefighting
- Shift work
10Coronary Artery anatomy
11Reply from specialist October 08
- Angiogram May 08
- Left main disease free
- LAD modest stenosis in mid vessel, about 50
- Circumflex plaque disease
- RCA dominant, modest stenosis in mid vessel,
presumably the cause of the infarct - Small area hypokinesia inferior wall
12What constitutes significant narrowing?
- Significant flow limitation occurs when there is
a 50 reduction in diameter - Flow limitation sufficient enough to produce
effort angina does not usually occur until there
is greater than 70 reduction in luminal diameter - Medical and Occupational Evidence for Recruitment
and Retention in the Fire and Rescue Service,
ODPM, Sept 2004
13Reply from specialist October 08
- Best managed medically
- Long-term outlook good because of preserved LV
function and minor atheroma - Needs aggressive medical therapy in light of
cardiac event aged 40
14Guidance from the Bible
- In asymptomatic individuals already in service,
full post-infarction assessment, including stress
testing is required. - A negative stress test should include no
symptoms, no significant ST changes and the
individual should have completed Stage III (at
least 9 minutes) of the Bruce Protocol with no
anti-anginal therapy. Any doubt about the stress
test should lead to angiography. - Medical and Occupational Evidence for Recruitment
and Retention in the Fire and Rescue Service,
ODPM, Sept 2004
15Advice to management Oct 08
- Given reported levels of exercise, hed have no
difficulty in undertaking tasks demanded of him
as a FF - However, need to consider risks of further
cardiac event associated with FFing and/or shift
work
16Subsequent Developments
- Meeting with DCFO late Nov 08
- Risks / benefits of RTW discussed
- Limitations of research being mostly from USA
apparent
17Subsequent Developments (2)
- DCFO agrees RTW Jan 09
- Risk to colleagues the public adequately
managed - Risks to you from shift work and emergency
response are present - Asked to agree content of letter by signing
returning it
18Discussion
- Do UK FFs have an excess of CVD?
- US data showing numbers of MIs at work
- Mechanisms of CVD in FFs
- Preventative strategies
19Coronary Artery Disease
20Why might MIs occur more often in FFs?
- Does Fire fighting-
- Cause CVD to develop?
- Cause plaque rupture to occur?
- Cause arrhythmias in normal hearts?
21Deaths from Heart Disease in FFs
- Little data on extent of CVD in UK Firefighters
- No excess noted in data from Office of
Population, Censuses and Surveys - No other data that I could find showing excess
22Deaths from Heart Disease in UK FFs
- The 36 deaths (30 of total) attributed to
natural causes were generally heart attacks,
which took place either at operational incidents
or shortly afterwards, or on fire service
premises while on duty. These figures do not
include firefighters who died whilst off duty
from heart attacks. - Labour Research Dept. In the Line of Duty
Firefighter Deaths in the UK Since 1978, Nov
2008.
23Deaths from Heart Disease in US FFs
- Heart disease causes 45 of deaths of U.S. FFs
whilst on duty - Police officers 22
- Emergency Medical Service Workers 11
- All workers 15
- Kales et al, NEJM, 2007
24Deaths from Heart Disease in US Fire Fighters
cont.
- Risk of death compared to that during
nonemergency duties Time - Fire suppression 12.1 136 (1-5)
- Alarm response 2.8 14.1 (4-9)
- Alarm return 2.2 10.5 (7-15)
- Physical training 2.9 6.6 (8)
- Kales et al, NEJM, 2007
25Why should FFing cause heart disease?
- Smoke chemical exposure
- Irregular physical exertion
- Heat stress
- Shift work
- High prevalence of CVS risk factors
- Psychological stressors
26Chemical Exposures in FFing
- CO
- Oxides of nitrogen
- HCl
- Isocyanates
- Acetaldehyde
- PAHs
- Benzene
27Physiological Demands of FFing
- HR reaches 70 80 of age-predicted maximums
within 1 minute of arriving at an active fire - HR sustained at 85 100 until fire is
extinguished - Guidotti, Int Arch Occ Env Health, 1992
28Shift work CVD
- Fairly strong evidence for association
- 45-55 yr olds RR 1.6 for men, 3.0 for women
- Job strain no different in cases controls
- Mechanism unclear
- Knutsson et al, Occ Env Med 1999
29Do workers with CVD or risk factors stop shift
work?
- 7037 female nurses (5038 worked shifts, 1999 days
only) - Data collected in 2000-02, and again in 2004, on
- Known MI, angina or high BP
- High cholesterol
- Obesity
- Diabetes
30Do workers with CVD or risk factors stop shift
work? (2)
- Among shift workers, likelihood of leaving
organisation 1.83 (1.01 3.32) times higher if
had diabetes c.f. no diabetes - 2.21 (1.12 4.39) times higher if had 3-4 risk
factors c.f. no risk factors - BUT similar rates for leaving for day workers
- Hence healthy worker effect does not cause bias
- Kivimaki M et al, Scand J Work, Env health,
June 2006
31Mechanism of CVD in shift workers
- 1543 young adults examined (age 24-39) as part of
Cardiovascular Risk in Young Finns study - Measured thickness of common carotid artery
intima/media - Puttonen et al, Atherosclerosis, Jan 2009
32Mechanism of CVD in shift workers cont.
33Mechanism of CVD in shift workers cont.
- In men, shift work associated with a higher mean
thickness of common carotid artery intima/media
and 2.2 (1.2 4) fold risk of carotid plaque - Puttonen et al, Atherosclerosis, Jan 2009
34Stress and CVD
- Whitehall II
- Chronic work stress associated with CVD
- Association was stronger among participants aged
lt 50 (RR 1.68, 95 CI 1.172.42) - Chandola et al, European Heart Journal 2007
35Can we do anything about those at risk?
- In 2005, 115 FFs died on duty in USA
- 48 of fatalities were MIs
- Mean age 47
- Dept. of Homeland Security target to reduce FF
fatalities by 50 within 10 years - Gaetano et al, AAOHN Journal, Feb 2007
36Health Surveillance for US FFs
- Volunteer FFs at higher risk of MI attributed to
stress and overexertion - Virtually no standardised requirements for CV
fitness in volunteers, even as recruits - Gaetano et al, AAOHN Journal, Feb 2007
37Health Surveillance for US FFs cont.
- 1998 2003 1,458 volunteer FFs and emergency
medical services personnel had at least 1 health
surveillance examination - 45 years or over get non fasting cholesterol
HDL measured Framingham Risk Score calculated - 658 abnormal findings
- Gaetano et al, AAOHN Journal, Feb 2007
38Health Surveillance for US FFs cont.
39Cardiovascular risk
- 315 staff evaluated for CVD risk
- 52 (17) had scores of 9 (substantial risk)
- 39 of those saw GP or cardiologist
- 1 had CABG, 2 had angioplasties, 14 had
antihypertensive drugs, 9 begun lipid lowering
medication, 13 no action
40Obesity in FFs
- Fireman sacked for being 'too fat'
after failing three-month test to lose
weight Daily Mail, 15/1/09
41Obesity in FFs (2)
- 332 Massachusetts FFs BMIs compared in 1996
2001 - Mean BMI changed from 29 to 30 kg/m2
- Prevalence of obesity rose from 35 to 40 (p lt
0.0001) - Morbid obesity increased 4 fold (0.6 to 2.4, p
lt 0.0001) - Soteriades et al, Obesity Research, Oct 2005
42Obesity in FFs (3)
- Obese FFs more likely to have high BP
- (p 0.03)
- Normal weight FFs gained 1.1lb, c.f FFs with BMI
gained 1.9 lb per year - Soteriades et al, Obesity Research, Oct 2005
43Summary
- Little data on CVD in UK Firefighters
- Advice given currently has to use existing
guidance and risk assessment principles - Plenty of scope for OH and Fitness depts to
measure and address existing risk factors
undertake research
44Any questions?