Download Epidemiology of heart failure

Epidemiology of
heart failure
Darrel Francis
Clinical Senior Lecturer in Cardiology
Imperial College School of Medicine
• Difficulties of case definition
• Aetiology
• Prevalence and Incidence
• Temporal trends
• Global burden
Case definition
The greatest challenge in the
epidemiology of heart failure:
difficulty defining cases
• Symptoms are protean
• Signs are commonly found in subjects
without heart failure
– Tachycardia, crepitations, leg oedema(!)
• Tests: what is normal?
why is this a challenge?
Why are normal ranges
so important here?
After all, we can study blood
pressure without predeciding
normal range…
BP is easier because there is
only one way to measure it
(or at least experts have
developed conventions)
There is more than one “test”
for heart failure!
• No tests, just symptoms + signs
Criterion
Category I: history
Rest dyspnea
Orthopnea
Paroxysmal nocturnal dyspnea
Dyspnea while walking on level area
Dyspnea while climbing
Point value[*]
4
4
3
2
1
Category II: physical examination
Heart rate abnormality (1 point if 91 to 110 beats per
1 or 2
minute; 2 points if more than 110 beats per minute)
Jugular venous elevation (2 points if greater than
2 or 3
6 cm H2O; 3 points if greater than 6 cm H2O plus
hepatomegaly or edema)
Lung crackles (1 point if basilar; 2 points if more than 1 or 2
basilar)
Wheezing
3
Third heart sound
3
Category III: chest radiography
Alveolar pulmonary edema
Interstitial pulmonary edema
Bilateral pleural effusion
Cardiothoracic ratio greater than 0.50
Upper zone flow redistribution
8 to 12 points = definite HF
5 to 7 points = possible HF
<4 points = unlikely HF
4
3
3
3
2
Boston Criteria for
diagnosing Heart Failure
from Marantz et al
Circulation 1988;77:607-12.
“No tests” gives
very poor validity
• Less than half of those identified
by clinical judgement alone are
confirmed by subsequent tests
• Even more unreliable for women
than for men
ESC gives guidelines
for definition of HF
Eur Heart J 2005; 26: 1115–1140 .
There is more than one “test”
for heart failure!
• No tests, just symptoms + signs
• Brain Natriuretic Peptide
(blood test)
• Radionucleide ventriculography
(MUGA) or contrast ventriculography
• 2d Echocardiography
• Magnetic Resonance Imaging
• Tissue Doppler Imaging
Impact of difficult case
definition?
• Difficult to safely compare
absolute rates beyond study
– may be due to ascertainment
method, not a true difference in the
population
• Reasonably safe to look for
relationships (e.g. with age)
within any one study
Aetiology
Aetiology of heart failure
in a UK population
Coronary Artery Disease 52%
Idiopathic 13%
Valve Disease 10%
Cardiomyopathy 10%
Hypertension 4%
Alcohol 4%
Atrial Fibrillation 3%
(Wood, 2002)
A more honest breakdown?
Cowie, Hillingdon heart failure study, Eur Heart J 1999; 20: 421–428
Aetiology does change
• In the 1950’s, Hypertension was the
commonest aetiology
– Garrison GE, McDonough JR, Hames CG, Stulb
SC. Prevalence of chronic congestive heart
failure in the population of Evans County,
Georgia. Am J Epidemiol 1966;83:338-344.
• Since then, primary prevention
(antihypertensive therapy) has
dramatically reduced this proportion
– Kannel WB, Ho K, Thorn T. Changing
epidemiological features of cardiac failure. Br
Heart J 1994;72:S3-S9
Prevalence
Case study: Heart of England Screening study
Invited random sample (n=1617)
of all men and women aged over 45 years
registered at GP practices in the West Midlands.
All patients who agreed to participate were assessed in their own
general practice by
clinical history (including prescribed drugs),
determination of New York Heart Association functional class,
clinical examination,
resting 12 lead electrocardiography, and
echocardiography including Doppler studies.
Defined heart failure according to ESC criteria:
appropriate symptoms (NYHA II or worse)
plus objective evidence of cardiac dysfunction.
EF<40%: "definitely impaired“
40-50%: "borderline" (40-50%)
Did not attempt to diagnose diastolic dysfunction.
Davis et al, BMJ 2002;325:1156-60.
Heart of England Screening study
Over 2% of patients (3% of men and 1.7% of women) screened had definite
heart failure.
Probable heart failure was seen in around a further 1% of patients.
From these prevalence rates they estimate:
about 369,000 men aged >45 in the UK with definite heart failure,
and 300,000 women,
giving a total of around 669,000.
If probable cases of heart failure are included, there are an estimated 497,500
men and 404,000 women, a total of 901,500 people aged 45 and over who
have heart failure in the UK today.
Prevalence of heart failure increases steeply with age, so that while around
1% of men and women aged under 65 have heart failure, this increases to
about 7% of those aged 75-84 years and 15% of those aged 85 and above.
Potentially complex contributory factors
Does the “2%” prevalence
cover all types of patient?
Percent of Population
Prevalence of Congestive Heart
Failure by Age and Sex
NHANES: 1999-2002
9.8 10.9
10
8
6
4.1
4
1.8
2
6.2
5.8
0.3 0.3
0.5
2.3
1.5
0.4
0
20-34
35-44
45-54
55-64
Ages
Men
Source: CDC/NCHS and NHLBI.
Women
65-74
75+
Prevalence of heart failure, adults aged between 45 and 84, UK studies compared
Source
Study
Year
RCGP
4th National Study of Morbidity
Statistics from General Practice
1991/92 Engl & Wales
McDonagh et al, 1997
MONICA
1992
Mair et al, 1996
Two general practices in Liverpool
1994
Office for National Statistics,Key
2000
Health Statistics from General Practice 1998
Davies et al, 2001
Notes:
Heart of England Screening Study
Place
MEN
WOMEN
45-54 55-64 65-74 75-84
%
%
%
%
45-54 55-64 65-74 75-84
%
%
%
%
0.5*
3.2
Glasgow
2.5
3.2
Liverpool
2.7
5.3
10.4 **
0.3
1.4
4.5
10.9
0.3
2.7
4.2
7.3
Engl & Wales
1995/99 W Midlands
8.0
0.4*
2.3
7.1
2.0
3.6
1.2
5.1
13.3 **
0.2
0.9
3.6
9.9
0
0.9
1.7
6.6
* for those aged 45-64 years
** for those aged 75 & over
Sources:
Royal College of General Practitioners, the Office of Population Censuses and Surveys and the Department of Health (1995) Morbidity Statistics
from General Practice, Fourth National Study 1991-1992. HMSO: London;
Mair FS, Crowley T and Bundred P (1996) Prevalence, aetiology and management of heart failure in general practice. British Journal of General Practic
McDonagh TA, Morrison CE, Lawrence A, Ford I, Tunstall-Pedoe H, McMurray JJV (1997) Syptomatic and asymptomatic left ventricular systolic dysfun
Office for National Statistics (2000) Key Health Statistics from General Practice. The Stationery Office: London.
Davies MK, Hobbs FDR, Davis RC, Kenkre JE, Roalfe AK, Hare R, Wosornu D, Lancashire RJ (2001) Prevalence of left-ventricular systolic
dysfunction and heart failure in the Echocardiographic Heart of England Screening study: a population based study. The Lancet 358:439-444.
Prevalence of heart failure by deprivation, 1998, England and Wales
250
Prevalence per 1,000 population
Most deprived (Q5)
Least deprived (Q1)
200
150
100
50
0
45-54
55-64
65-74
75-84
85 and over
Total
Age group
Ellis C et al (2001) Health Statistics Quarterly 11: 17-24
www.heartstats.org
Prevalence of treated heart failure by age, sex and deprivation category, 1998,
England and Wales
45-54
55-64
65-74
75-84
85 & over
Total
1.7
2.8
2.7
2.6
3.5
10.0
12.7
13.1
14.4
18.3
39.7
43.2
41.8
48.0
50.6
102.7
120.5
101.6
109.6
107.5
213.2
193.2
184.8
195.4
169.5
25.9
28.8
26.8
29.3
30.5
1.4
1.3
1.5
2.0
2.6
5.4
7.8
8.5
9.6
14.0
27.0
35.4
32.5
37.7
43.9
83.0
99.7
101.6
106.8
93.6
195.7
199.2
183.0
184.9
186.1
19.8
23.6
23.0
25.1
26.8
Men
Q1 (least deprived)
Q2
Q3
Q4
Q5 (most deprived)
Women
Q1 (least deprived)
Q2
Q3
Q4
Q5 (most deprived)
Notes:
Data from the General Practice Research Database.
Deprivation categories were derived using the Townsend Material Deprivation Score at ward level. The category Q1 contains
the 20% least deprived wards in England and Wales and category Q5 contains the 20% most deprived wards.
Source:
Ellis C, Gnani S and Majeed A (2001) Prevalence and management of heart failure in General Practice in England and Wales,
1994-1998. Health Statistics Quarterly 11: 17-24.
Temporal trends
Prevalence is rising…
Discharges in Thousands
Congestive Heart Failure Episodes by Sex
United States: 1970-2002
600
500
400
300
200
100
0
70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 00 02
Years
Source: CDC/NCHS.
Males
Females
Why is prevalence rising?
Levy, NEJM 2002; 347:1397-1402
Survival
Levy, NEJM 2002; 347:1397-1402
Levy, NEJM 2002; 347:1397-1402
Levy, NEJM 2002; 347:1397-1402
Levy, NEJM 2002; 347:1397-1402
Survival after diagnosis of
cancer or heart disease
100
Men:
80
Survival
%
60
MI
Bladder Ca
40
Prostate Ca
Bowel Ca
Heart Failure
20
Lung Ca
0
0
12
24
36
48
60
Months from diagnosis
Stewart S, EJHF 2001; 3:315-322
Survival after diagnosis of
cancer or heart disease
in women:
Where does breast cancer lie?
100
80
Survival
%
Breast cancer
Ca
60
MI
40
Ovarian Ca
Bowel Ca
Heart Failure
20
Lung Ca
0
0
12
24
36
48
60
Months from diagnosis
Epidemiology of
Heart failure
•Numbers heavily depend on methods
– clinical assessment is unreliable
•Marked increase in prevalence with age
•Risk factors are similar to those of
coronary artery disease
•Mortality worse than most cancers
•Increasing survival with modern
therapy leads to increasing prevalence
Today a problem of the
developed world, but…