Download Heart failure: clinical features and diagnosis

March 2009
Clinical Pharmacist
Heart failure accounts for at least one in 20 admissions to hospitals in the UK. It occurs most
commonly in older people, with prevalence rates doubling for every decade of ageing
Heart failure
clinical features and diagnosis
By Mojgan Sani, DPharm, MRPharmS
eart failure is a major and growing health concern
in the UK and is still associated with a high
morbidity and mortality despite progress in its
diagnosis and treatment. The National Service Framework
for coronary heart disease (CHD) sets national standards
of care relating to CHD, including providing better care
for patients with heart failure. The National Institute for
Health and Clinical Excellence and the Scottish
Intercollegiate Guidelines Network have both issued
guidelines for the management of people with chronic
heart failure.
H
SUMMARY
Heart failure is a complex syndrome resulting from structural or
functional cardiac disorder. The syndrome is characterised by symptoms
and signs of breathlessness, fatigue and fluid retention. Many risk
factors cause heart failure, including coronary artery disease,
hypertension, congenital heart disease, arrhythmias, alcohol and some
medicines.
Heart failure is a major and growing health problem among older
people. Diagnostic and therapeutic options have advanced over the years,
together with national and international standards and guidelines focused
on improving the care of patients with heart failure.
Definition
Many definitions of heart failure have been documented
over the past 50 years. These definitions tend to include
the features of heart failure such as haemodynamics,
oxygen consumption, or exercise capacity. Guidelines
from the European Society of Cardiology (2008)1 set out
the defining features of heart failure (shown in Box 1,
p115).
Heart failure can also been defined as:
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● New-onset
● Transient
● Chronic
New-onset heart failure refers to the first presentation
of the disease. Transient heart failure refers to
symptomatic heart failure over a limited period of time
after which patients recover from the syndrome. Examples
include patients with mild myocarditis, post myocardial
infarction (heart failure resolved by diuretics administered
in a coronary care unit), or heart failure due to ischaemia
(resolved by coronary revascularisation).
Chronic heart failure is the most common type that
requires hospital admission. Treatment is based on
patients’ clinical presentation (see accompanying article,
p120).
Classification
Two classifications of the severity of heart failure are
described in the ESC guidelines, as shown in Box 2 (p115).1
The New York Heart Association functional classification
is based on symptoms and exercise capacity and is
Mojgan Sani is head of cardiac pharmacy at the
Regional Wessex Cardiac Centre. Dr Sani was also a
member of the guideline development group for the
National Institute for Health and Clinical Excellence’s
2003 clinical guideline on heart failure.
E: [email protected]
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For personal use only. Not to be reproduced without permission of the editor ([email protected])
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Epidemiology
Lack of universal agreement on the definition of heart
failure over the years has made epidemiological studies
difficult.
The Framingham heart study, which had a cohort of
5,209 subjects, has been followed up biennially since 1948.
This dataset has been used to obtain some information on
the incidence and prevalence of heart failure, defined
using clinical and radiographic criteria.2 The Framingham
Box 1: Definition of heart failure
Heart failure is a clinical syndrome in which patients
have the following features:
● Symptoms such as breathlessness at rest or with
Clinical Pharmacist
study reported that the age-adjusted prevalence of heart
failure was similar for men and women during the 1980s.
This prevalence increased significantly with increasing
age (doubling the rate of prevalence with each decade of
ageing).
Heart failure accounts for at least 5% of admissions to
hospitals in the UK.3,4 Hospital admission for heart
failure accounts for approximately 1% of the total
healthcare expenditure in the UK. Epidemiological
studies have shown that the financial burden of heart
failure on health services is increasing.3 Hospital
admissions and GP consultations occur frequently
following diagnosis and readmission rates among the
elderly range from 29% to 47% within three to six
months of the initial hospital discharge.3,4
The prevalence of heart failure is 2–3%, rising sharply
at around 75 years of age.1 In the younger population,
heart failure is more common in men, with the cause
attributed to coronary heart disease. Prevalence is similar
between older men and women. Although some patients
live for many years, overall 50% of patients will have died
four years after diagnosis.
exercise, fatigue, tiredness, ankle swelling
● Signs such as tachycardia, tachypnoea,
Causes
pulmonary rales, pleural effusion, raised jugular
venous pressure, peripheral oedema,
hepatomegaly
● Objective evidence of structural or functional
abnormality of the heart at rest — cardiomegaly,
third heart sound, cardiac murmurs, abnormality
on echocardiogram, raised natriuretic peptide
concentration
ESC guidelines state that the most common reasons for
functional deterioration of the heart are damage or loss of
heart muscle, acute or chronic ischaemia, increased
vascular resistance with hypertension, or the development
of a tachyarrhythmia such as atrial fibrillation.
Causes of heart failure therefore include:
Box 2: Heart failure classification
ACC/AHA STAGES OF HEART FAILURE
NYHA FUNCTIONAL CLASSIFICATION
(STAGES OF HEART FAILURE BASED ON
STRUCTURE AND DAMAGE TO HEART MUSCLE)
(SEVERITY BASED ON SYMPTOMS AND PHYSICAL
ACTIVITY)
Stage A
At high risk for developing heart failure.
No identified structural or functional
abnormality; no signs or symptoms
Class I
No limitation of physical activity.
Ordinary physical activity does not
cause undue fatigue, palpitation or
dyspnoea
Stage B
Developed structural heart disease that
is strongly associated with the
development of heart failure, but
without signs and symptoms
Class II
Slight limitation of physical activity.
Comfortable at rest but ordinary
physical activity results in fatigue,
palpitation or dyspnoea
Stage C
Class III
Symptomatic heart failure associated
Marked limitation of physical activity.
with underlying structural heart disease Comfortable at rest but less than
ordinary physical activity results in
fatigue, palpitation or dyspnoea
Stage D
Advanced structural heart disease and
marked symptoms of heart failure at
rest despite maximal medical therapy
Class IV
Unable to carry out any physical
activity without discomfort. Symptoms
at rest. If any physical activity is
undertaken discomfort is increased
ACC/AHA = American College of Cardiology and American Heart Association
NYHA = New York Heart Association
● Coronary artery disease (myocardial infarction,
ischaemia)
● Hypertension
● Cardiomyopathy
● Congenital heart disease
● Arrhythmias (tachycardia and bradycardia)
● Alcohol
● Medicines (calcium antagonists, antiarrhythmics,
cytotoxic drugs)
Pathophysiology
Heart failure is a multisystem disorder associated with
systolic and diastolic dysfunction of the myocardial tissue.
It is characterised by abnormalities of cardiac, skeletal
muscle and renal function; stimulation of the sympathetic
nervous system; and a complex pattern of neurohormonal
changes.
Myocardial systolic dysfunction Myocardial systolic
dysfunction is described by impairment of left ventricular
function, which leads to a fall in cardiac output. This in
turn leads to activation of neurohormonal compensatory
mechanisms aiming to improve the mechanical capacity of
the heart, as shown in Figure 1 (p116). It has been
estimated that 30–40% of patients with heart failure have
normal ventricular systolic contraction.5
Myocardial diastolic dysfunction Myocardial diastolic
dysfunction occurs because myocardial relaxation is
compromised, causing stiffness in the ventricular wall and
impairment of diastolic ventricular filling.5
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routinely used in clinical trials. The American College of
Cardiology and American Heart Association classification
describes stages of heart failure based on structural
changes and symptoms.
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Figure 1: Neurohormonal mechanism and compensatory mechanism in heart failure
Left ventricular dysfunction
Heart failure
value for heart failure, a completely normal ECG would
mean that systolic dysfunction is unlikely.
Common ECG abnormalities in patients with heart
failure can include: sinus tachycardia; sinus bradycardia;
atrial tachycardia, flutter or fibrillation; ventricular
arrhythmias; ischaemia; left ventricular hypertrophy; and
atrioventricular block.
Reduced stroke volume and cardiac output
Chest X-ray Chest X-ray is an important diagnostic tool
Neurohormonal response
Activation of sympathetic
nervous system
Activation of renin-angiotensinaldosterone system
Vasoconstriction
(increased catecholamines)
Vasoconstriction
(increased angiotensin)
Raised heart rate and
contractility
Increased blood volume, salt
and water retention (aldosterone)
Ventricular wall dilatation (remodelling)
and further heart failure
Symptoms
The most common symptoms of chronic heart failure
include dyspnoea, fatigue, lethargy and oedema.
Breathlessness on exertion is particularly common in
heart failure, particularly in patients with comorbid
pulmonary disease.
Orthopnoea is thought to be a more specific symptom,
and paroxysmal nocturnal dyspnoea has a greater
predictive value for heart failure as it results from
increased left ventricular filling pressure. Fatigue and
lethargy are related to skeletal muscle abnormalities and
impaired muscle blood flow. Swelling of ankles and feet
(oedema) is also commonly seen when patients present
with heart failure.
Although there seems to be a poor relationship
between symptoms and the severity of cardiac
dysfunction, symptoms tend to correlate well with
prognosis. Symptom control can be used effectively for
monitoring the effects of therapy.
for patients with suspected heart failure and it can also be
used to monitor the response to therapy. Chest X-ray may
show cardiac enlargement (including cardiomegaly),
pulmonary venous congestion, pleural effusion, and
pulmonary infection or infiltration.
Natriuretic peptides The heart secretes natriuretic
peptides as a homeostatic signal to maintain stable blood
pressure and prevent excess salt and water retention.
Atrial natriuretic peptide (ANP) has been identified in the
atrial myocardium. B-type natriuretic peptide (BNP) is
primarily secreted by the ventricles in the heart as a
response to ventricular stretching or wall tension.6
BNP levels can be used to assess cardiac function, to
help diagnose heart failure, including diastolic
dysfunction, and to monitor the success of treatment.
However, the use of BNP testing has been controversial
because of its cost and also because BNP levels can be
increased in pulmonary or renal diseases. Nevertheless,
BNP concentrations are thought to correlate well with
severity of heart failure and prognosis.
Troponins Troponin I or T levels are mainly used to
determine myocyte necrosis in acute coronary syndrome
and hence can identify potential candidates for coronary
revascularisation. Troponin levels are also raised in acute
myocarditis and in severe heart failure or during a period
of acute fluid overload (ie, decompensation, for example
due to ischaemia or sepsis).
The combination of increased troponin levels and an
increased BNP level is a strong marker for the presence of
heart failure.
Echocardiography Echocardiography is the most useful
non-invasive tool for the assessment of left ventricular
dysfunction and, ideally, should be used for all patients
with suspected heart failure.
Diagnosis
There are several diagnostic techniques that can be used
to determine heart failure. NICE’s diagnostic algorithm is
reproduced in Figure 2 (p119).
Clinical examination The symptoms and signs of heart
failure are crucially important for early identification of
heart failure. The ESC guidelines recommend the clinical
assessments described in Box 3, including observation,
palpation and auscultation.
Electrocardiogram An electrocardiogram (ECG) is
taken routinely for all patients with suspected heart
failure. Although an abnormal ECG has little predictive
Box 3: Clinical examination
Appearance
Alertness, nutritional state, weight
Pulse
Rate, rhythm and character
Blood pressure
Systolic, diastolic and pulse pressure
Fluid overload
Jugular venous pressure, peripheral
oedema (ankles and sacrum),
hepatomegaly, ascites
Lungs
Respiratory rate, rales, pleural effusion
Heart
Apex displacement, gallop rhythm,
third heart sound and murmurs
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Prognosis
Cardiac catheterisation Cardiac catheterisation is not
3
used routinely for the diagnosis or management of heart
failure. It is considered useful for heart failure patients
with a history of angina or ischaemic left ventricular
dysfunction. It may also be used for patients with
refractory heart failure of unknown cause.
4
Pulmonary function testing Spirometry is useful
7
for excluding respiratory causes of breathlessness and
to evaluate the severity of concomitant pulmonary
disease.
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Clinical Pharmacist
Determining an individual heart failure patient’s
prognosis is difficult, with many factors complicating the
picture. These factors include: advanced age; ischaemia;
arrhythmias; marked elevation of BNP; low LVEF; and
presence of other diseases such as diabetes, renal
dysfunction, anaemia, chronic obstructive pulmonary
disease and depression.
References
1
2
5
6
Task force for diagnosis and treatment of acute and chronic heart failure
2008 of the European Society of Cardiology. ESC guidelines for the
diagnosis and treatment of chronic heart failure 2008. European Heart
Journal 2008;29:2388–442.
Ho KK, Pinsky JL, Kannel WB, et al. The epidemiology of heart failure:
Framingham study. Journal of the American College of Cardiology
1993;22:6–13A.
Cowie MR, Mosterd A, Wood DA, et al. The epidemiology of heart failure.
European Heart Journal 1997;18:208–25.
Cowie MR, Wood DA, Coats AJS, et al. Incidence and aetiology of heart
failure: a population-based study. European Heart Journal 1999;20:421–8.
Grossman W. Diastolic dysfunction in congestive heart failure. New
England Journal of Medicine 1991;325:1557–64.
Yasue H, Yoshimura M, Surhida H, et al. Localisation and mechanism of
secretion of B-type natriuretic peptide in comparison with those of Atype natriuretic peptide in normal subjects and patients with heart
failure. Circulation 1994;90:195–203.
Cheesman MG, Leech G, Chambers J, et al. Central role of
echocardiography in the diagnosis and assessment of heart failure. Heart
1998;80(s1):S1–5.
National Institute for Health and Clinical Excellence. Management of
chronic heart failure in adults in primary and secondary care.
www.nice.org.uk (accessed 17 February 2009).
Figure 2: Diagnostic algorithm for heart failure
This algorithm, which summarises recommendations for
the diagnosis of heart failure, forms part of a clinical
guideline published by the National Institute for Health
and Clinical Excellence in 2003.8 The guideline is being
reviewed by NICE and a partial update is expected in 2010
KEY
BNP = B-type natriuretic peptide
ECG = Electrocardiogram
FBC = Full blood count
LFTs = Liver function tests
TFTs = Thyroid function tests
U&Es = Urea and electrolytes
Suspected heart failure
?
How can
you fit
diploma
tutoring into your
busy workload
(history, signs and symptoms)
Seek to exclude heart failure
through
● 12-lead echocardiogram
● and/or natriuretic peptide (eg, BNP)
where available
Other recommended tests to
exclude other conditions
● Chest X-ray
● Blood tests: U&Es, creatinine, FBC,
TFTs, LFTs, glucose and lipids
● Urinalysis and peak flow/spirometry
CAREER DEVELOPMENT
Both normal
Heart failure unlikely,
consider alternative diagnosis
No abnormality detected
Heart failure unlikely, but if diagnostic
doubt persists consider diastolic
dysfunction and consider referral for
specialist assessment
One of more abnormal
Imaging by echocardiography
Abnormal
Assess heart failure severity, cause,
precipitating and exacerbating factors
and type of cardiac dysfunction.
Correctable causes must be identified.
Consider referral
(p141)
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Echocardiography allows a quantitative measurement
of the left ventricular ejection fraction (LVEF normal
>45%), which in turn is well correlated with the
outcome and survival of patients with heart failure.7
Advances in echocardiography using contrast agents have
allowed for observation of left ventricular walls in more
detail.
Common echocardiographic abnormalities observed
in heart failure include: reduced left ventricular ejection
fraction, increased left atrial size, left ventricular
thickness, and valvular stenosis or regurgitation.
Greater availability of echocardiography services for
heart failure patients in primary care has the potential to
improve patient’s prognosis through speedier diagnosis.
March 2009