Decision problem
The purpose of the assessment was to address the question ‘What is the clinical effectiveness and cost-effectiveness of performing a routine echocardiogram in all newly diagnosed patients with AF in preventing complications arising from AF, in comparison with current practice of selective testing?’
The population was newly diagnosed patients with AF.
Potential subgroups identified prior to the review were those patients in whom AF was diagnosed when they presented with associated medical conditions (heart failure, stroke or thromboembolism), as opposed to patients in whom AF was the primary diagnosis, whether asymptomatic or based on symptoms not requiring hospital visit, or patients receiving diagnoses of paroxysmal, persistent or permanent AF. Lack of data made analyses of these subgroups impractical.
The technology investigated was TTE.
Conventional TTE was the intervention. Included modes were M-mode, 2D/cross-sectional and the Doppler modes (colour flow mapping, continuous wave, pulsed wave).
Complex or invasive modes of TTE were excluded, such as stress/exercise echocardiography, contrast echocardiography, three-dimensional echocardiography and intraoperative echocardiography. These would not form the routine TTE. Invasive modes, such as contrast TTE requiring application of dobutamine or adenosine, would have a different impact on patients and may have adverse effects, unlike routine TTE, as well as differences in time taken and cost.
We excluded diagnostic assessments that used a combination of tests including TTE.
The intervention was defined as TTE in all newly diagnosed patients with AF. This included patients for whom TTE is not currently recommended, such as patients with AF for whom the need to initiate anticoagulation therapy has already been decided on clinical criteria.
The comparator was current practice, that is only selected subgroups of patients with AF undergoing TTE. These comprise:
younger patients for whom a baseline echocardiogram is important for long-term management
patients for whom cardioversion (electrical or pharmacological) is being considered
patients in whom there is a high risk or a suspicion of underlying structural/functional heart disease (such as heart failure or heart murmur) that influences their subsequent management
patients in need of clinical risk stratification for antithrombotic therapy.
The decision problem was essentially reduced to the cost-effectiveness of TTE in those patients where there would initially be a decision not to provide anticoagulation treatment (that is those patients with a CHADS2 or CHA2 DS2-VASC score of 0). In such a group the use of TTE could detect underlying conditions that are associated with a high risk of stroke and for which the use of anticoagulant treatment would be recommended.
Outcomes sought related to selected pathologies in patients with AF identifiable by TTE. Clinical outcome measures were diagnostic accuracy of TTE in identifying pathologies as measured in terms of sensitivity [proportion of true-positives (TPs)] and specificity [proportion of true-negatives (TNs)] and prognosis of AF populations based on diagnosis of pathology by TTE, and prevalence of these pathologies in AF.
