Can we assess the risk of embolic complications of cardioversion?
Polish Archives of Internal Medicine
EDITORIAL Can we assess the risk of embolic complications of cardioversion? 5 et al 4 attempted to identify additional predictors allowing to evaluate embolic risk in this setting. Transthoracic echocardiography (TTE) has a very low sensitivity in identifying LAAT but provides information on cardiac structure and function, which helps assess the embolic risk. 3-8 Nevertheless, TTE-derived parameters (ie, ejection fraction [EF] <40%) play only a minor role in the current risk classification
... classification scheme. The presented study identifies left ventricular (LV) and left atrial size (LV end-diastolic dimension [LVEDd] >52 mm; left atrial diameter >51mm) as independent predictors of the LAA thrombogenic milieu. The calculated cut-off value for the LVEDd is puzzling, as 52 mm is within the normal range. 9 The chamber size and volume indexation to the body surface area may better predict LAAT, but this was not analyzed in the study group. 10 A reduced EF (being also a part of the CHA 2 DS 2 -VASc score) was associated with LAAT in a univariate but not in a multivariate analysis. It should be mentioned, however, that the Teicholz's formula used in the study is currently not recommended, and a more precise Simpson's method should be used instead. 5,8 The authors did not analyze the LV mass index or LV diastolic function, although some studies suggested a discriminative capability of such parameters in the prediction of LAAT. 11 TEE is a very useful tool for excluding LAAT before cardioversion. 3 In the Stroke Prevention in Atrial Fibrillation (SPAF) substudy, the presence of LAAT, LAA peak flow velocity of less than 27 cm/s, and aortic plaque were all independently associated with thromboembolic events. 12 In the current era, when left atrial occluders have become available, more focus has been placed on LAA imaging, and important limitations of LAA evaluation on TEE were documented compared with computed tomography, magnetic resonance imaging, and contrast angiography. In less experienced hands, TEE may provide both false-positive Atrial fibrillation (AF) is the most common sustained arrhythmia. It occurrs in up to 2% of the general population, particularly in elderly patients, and remains the major challenge in cardiology. 1 AF is associated with increased risk of thromboembolic events, frequently leading to large strokes. 1-3 Decision making for thromboprophylaxis needs to balance the risk of stroke against the risk of major bleeding. 2 Stroke risk is a continuum but current guidelines recommend focusing on the identification of "truly low-risk" patients with AF, in whom anticoagulation could be safely avoided. 2,4,5 The CHA 2 DS 2 -VASc score is related to long-term risk of ischemic stroke in patients with nonvalvular AF and not receiving anticoagulation. The score is based on simple clinical parameters, not taking into account anatomic data available from cardiac imaging studies. Nevertheless, the CHA 2 DS 2 -VASc score has been well validated and became the most common tool used for the assessment of long-term stroke risk in clinical practice. 4 AF predisposes to blood stasis and may lead to atrial thrombus formation. 3 In up to 90% of cases, it is located in the left atrial appendage (LAA) and can be mobilized when the sinus rhythm is restored. However, there is no validated scoring system assessing the risk of thromboembolic complications of cardioversion. The recommended way to avoid stroke is not to perform cardioversion if AF persists for more than 48 hours and if there had been no previous anticoagulant treatment lasting at least 3 to 4 weeks. 1,6 The number of such patients is substantial, and in clinical practice, they are either discharged home with an anticoagulant prescribed or require transesophageal echocardiography (TEE) to exclude LAA thrombus (LAAT). It is clear that such an approach causes delays and generates costs and logistic problems, and a delay in cardioversion may decrease the number of successful cardioversion procedures. This is why, Jaroch