Epidemiology of heart failure by zy636H

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									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                                  Point value[*]
                                                                    Boston Criteria for
Category I: history
Rest dyspnea                                                4       diagnosing Heart Failure
Orthopnea                                                   4
Paroxysmal nocturnal dyspnea                                3
Dyspnea while walking on level area                         2
Dyspnea while climbing                                      1
                                                                    from Marantz et al
                                                                    Circulation 1988;77:607-12.
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                                    4
Interstitial pulmonary edema                                3
Bilateral pleural effusion                                  3
Cardiothoracic ratio greater than 0.50                      3
Upper zone flow redistribution                              2

8 to 12 points = definite HF
5 to 7 points = possible HF
<4 points = unlikely HF
       “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?
  Prevalence of Congestive Heart
  Failure by Age and Sex
  NHANES: 1999-2002

                                                                                           9.8 10.9
                           10
   Percent of Population




                           8
                                                                  5.8          6.2
                           6
                                                                                     4.1
                           4
                                                      1.8                2.3
                                                            1.5
                           2    0.3 0.3   0.5   0.4
                           0
                                20-34      35-44       45-54          55-64    65-74        75+
                                                               Ages

                                                      Men    Women

Source: CDC/NCHS and NHLBI.
Prevalence of heart failure, adults aged between 45 and 84, UK studies compared
                                                                                                                  MEN                            WOMEN

Source                        Study                                         Year       Place           45-54 55-64 65-74 75-84          45-54 55-64 65-74 75-84
                                                                                                          %     %     %     %              %     %     %     %


                              4th National Study of Morbidity
RCGP                          Statistics from General Practice              1991/92 Engl & Wales                0.5*    3.2     8.0             0.4*    2.3      7.1

McDonagh et al, 1997          MONICA                                        1992       Glasgow                   2.5    3.2                      2.0    3.6

Mair et al, 1996              Two general practices in Liverpool            1994       Liverpool                 2.7    5.3   10.4 **            1.2    5.1     13.3 **

                                2000
Office for National Statistics,Key Health Statistics from General Practice 1998        Engl & Wales       0.3    1.4    4.5   10.9        0.2    0.9    3.6      9.9

Davies et al, 2001             Heart of England Screening Study             1995/99 W Midlands            0.3    2.7    4.2     7.3         0    0.9    1.7      6.6


Notes:             * 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
                                              Most deprived (Q5)
                                              Least deprived (Q1)
  Prevalence per 1,000 population




                                    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


Men

Q1 (least deprived)                             1.7             10.0            39.7           102.7            213.2            25.9
Q2                                              2.8             12.7            43.2           120.5            193.2            28.8
Q3                                              2.7             13.1            41.8           101.6            184.8            26.8
Q4                                              2.6             14.4            48.0           109.6            195.4            29.3
Q5 (most deprived)                              3.5             18.3            50.6           107.5            169.5            30.5


Women

Q1 (least deprived)                             1.4              5.4            27.0            83.0            195.7            19.8
Q2                                              1.3              7.8            35.4            99.7            199.2            23.6
Q3                                              1.5              8.5            32.5           101.6            183.0            23.0
Q4                                              2.0              9.6            37.7           106.8            184.9            25.1
Q5 (most deprived)                              2.6             14.0            43.9            93.6            186.1            26.8


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…
                          Congestive Heart Failure Episodes by Sex
                          United States: 1970-2002

                           600
Discharges in Thousands




                           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
           20                                      Heart Failure

                                                   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

                                                      Ca
                                               Breast cancer
           60
Survival
                                               MI
  %
           40                                  Ovarian Ca
                                               Bowel Ca
           20                                  Heart Failure

                                               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…

								
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