MethodsTable I: Summary of review methods

This work was funded by the NIHR Health Technology Assessment Programme. (Project Number 08/45/01 HTA TAR).

Diagnostic accuracy of echocardiography for co-existing pathologies in atrial fibrillation patients: systematic review

Poku, E, Simpson, E, Scope, A, Evans,P.

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

Health Economics and Decision Science (HEDS), School of Health and Related Research (ScHARR), University of Sheffield, UK

The views and opinions expressed are those of the authors and do not necessarily reflect those of the UK Department of Health.

IntroductionAtrial 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.

Aim of the reviewThe 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.

Review Diagnostic accuracy review

Prevalence review

Population AF patients. Studies were sought from other adult populations with suspected cardiac conditions if AF patients were not included.

Recently diagnosed AF patients with pathologies that can be identified by TTE

Intervention Conventional TTE Not relevant

Comparators Technique(s) appropriate for the diagnosis of specified pathology

Not relevant

Outcomes Sensitivity or specificity Prevalence of specific pathology

Study type Diagnostic accuracy studies using TTE to diagnose any of the selected pathologies

Epidemiological studies

Literature searching

March – August 2010. MEDLINE, EMBASE, Cochrane Library and others.

March – August 2010. MEDLINE, EMBASE, Cochrane Library and others.

Included studies 44 16

Data extraction Standardised data extraction form used by one reviewer and checked by a second.

Standardised data extraction form used by one reviewer and checked by a second.

Quality assessment

According to hierarchy of evidence and QUADAS criteria [3]

According to STROBE criteria [4]

Analysis Tables and narrative review

Tables and narrative review

References1. 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.

ResultsTable II: Summary of diagnostic accuracy and prevalence review

Diagnostic accuracy review Prevalence review(number of studies)Condition Sample size

(number of studies)

Sensitivity (range)

Specificity (range)

Structural defect† 12-107 (8)‡

0.25-1.00 0.9-1.00 

Not calculable in

5 studies

0.9% (atrial septal defect- 1 )

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

‡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.

ConclusionsData 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.