Poku, E, Simpson, E, Scope, A, Evans,P.
Health Economics and Decision Science (HEDS), School of Health and Related Research (ScHARR),
University of Sheffield, UK
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia.[1] It is common in the elderly and its prevalence is steadily increasing. [2] If left
untreated, AF is a significant risk factor for stroke and other morbidities. Transthoracic echocardiography (TTE) is a procedure that allows imaging of the heart
to identify structural and functional cardiac abnormalities. Currently, TTE is not routinely recommended in all patients with AF. By undergoing TTE, significant
cardiac pathologies can be diagnosed earlier than would be anticipated in current practice.
The review investigated the clinical effectiveness of the diagnostic accuracy of TTE for clinically relevant pathologies in AF patients and the prevalence of these
pathologies within the AF population. Relevant pathologies were grouped into nine general categories based on whether the condition was present in patients
with AF; detected by TTE or resulted in change of clinical management. Pathologies of interest were, broadly grouped as structural defects; ischaemic heart
disease; pulmonary disease; endocarditis; valvular heart disease; cardiomyopathy; heart failure cardiac masses/ tumours and diseases of arteries.
Table I: Summary of review methods
Review
Table II: Summary of diagnostic accuracy and prevalence review
Diagnostic accuracy
review
AF patients. Studies
were sought from other
adult populations with
suspected cardiac
conditions if AF patients
were not included.
Prevalence review
Intervention
Conventional TTE
Not relevant
Comparators
Technique(s)
appropriate for the
diagnosis of specified
pathology
Sensitivity or specificity
Not relevant
Population
Outcomes
Study type
Literature
searching
Included studies
Data extraction
Quality
assessment
Analysis
Diagnostic accuracy
studies using TTE to
diagnose any of the
selected pathologies
March – August
2010. MEDLINE,
EMBASE, Cochrane
Library and others.
44
Standardised data
extraction form used by
one reviewer and
checked by a second.
According to hierarchy
of evidence and
QUADAS criteria [3]
Tables and narrative
review
Recently diagnosed
AF patients with
pathologies that can
be identified by TTE
Diagnostic accuracy review
Condition
Standardised data
extraction form used
by one reviewer and
checked by a
second.
According to
STROBE criteria [4]
Tables and narrative
review
Data on diagnostic accuracy and prevalence of relevant pathologies
were not available for all pre-specified pathologies. Patient
characteristics and diagnostic methods were varied in identified
studies. Diagnostic accuracy showed high specificities and high
sensitivities for selected pathologies. Prevalence data had relevance
to patients in the UK. The wide variations in prevalence rates for
selected pathologies may be explained by the degree of
heterogeneity in the included studies.
The review demonstrated that routine TTE in newly diagnosed AF
patients would identify co-existing pathologies in many patients.
However, the impact of this approach on subsequent management of
AF patients is uncertain.
This work was funded by the NIHR Health
Technology Assessment Programme.
(Project Number 08/45/01 HTA TAR).
The views and opinions expressed are those
of the authors and do not necessarily reflect
those of the UK Department of Health.
Specificity
(range)
Structural defect†
12-107
(8)‡
0.25-1.00
Valvular heart disease
37-203
(12)◊
0.22-1.00
0.66-1.00
3.3-73.8%
(13)
Ischaemic heart
disease
59-581
(9)
0.00-0.96
0.86-1.00
0.5-28.2%
(6)
Heart failure
34-621
(5)∆
0.74-1.00
0.75-1.00
14-31.1%
(2 )
Cardiomyopathy
44
(1)▫
0.77
0.77
1.2 -13%
(3)
Endocarditis
36-75
(3)
0.44-0.87
0.62-0.98
No data
Pulmonary disease
86-152
(2)
0.52-1.00
0.87-1.00
No data
Diseases of arteries
35-660
(4)
0.59-0.95
0.51-0.98
No data
Cardiac
masses/tumours
77
(1)
0.88
0.95
No data
Prevalence of
specific pathology
Epidemiological
studies
March – August
2010. MEDLINE,
EMBASE, Cochrane
Library and others.
16
Sample size Sensitivity
(number of (range)
studies)
Prevalence
review
(number of
studies)
0.9-1.00
0.9%
(atrial septal
Not calculable defect- 1 )
in 5 studies
‡TTE
was considered the gold standard in one study.
◊Four studies used TTE as the gold standard test.
∆Two studies used TTE as the gold standard test.
▫TTE was used as the gold standard in 2 studies to distinguish between ischaemic and
non-ischaemic cardiomyopathy.
For the diagnostic and prevalence reviews, a number of studies investigated more than
one clinically significant pathology.
1. The National Collaborating Centre for Chronic Conditions. Atrial fibrillation:
national clinical guideline for management in primary and secondary care. 2006.
2. Fuster, V., Ryden, L.E., Cannom, D.S., Crijns, H.J., Curtis, A.B., Ellenbogen,
K.A. et al. 2011 ACCF/AHA/HRS Focused Updates Incorporated Into the
ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial
Fibrillation. Circulation 2011; 123(10):e269-e367.
3. Elm, E.v., Altman, D.G., Egger, M., Pocock, S.J., Gotzsche, P.C.,
Vandenbroucke, J.P. et al. Strengthening the reporting of observational studies in
epidemiology (STROBE) statement: guidelines for reporting observational
studies. BMJ 2007; 335(7624):806-808.
4. Whiting, P., Rutjes, A., Reitsma, J., Bossuyt, P., Kleijnen, J. The development of
QUADAS: a tool for the quality assessment of studies of diagnostic accuracy
included in systematic reviews. BMC Medical Research Methodology 2003;
3(1):25.
Note: References of included studies are available from the presenter on request.
Contact: Edith Poku, Research Associate, Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, U.K.
Email: e.poku@sheffield.ac.uk, Tel: +44 (0)1142220692, Fax: +44 (0)1142724095