IJCS | Volume 32, Nº5, September/October 2019

466 Cont. Table 1 - Distribution of patients by hemodynamic and structural variables, according to CHA 2 DS 2 -VASc values CHA 2 DS 2 VASc Total 0 to 1 2 to 3 ≥ 4 N % N % N % N % ᵪ 2 (2, N = 247) = 16.82 - p < 0.001 LAA group 150 75 22 247 100.0% Thrombogenic 69 46.0% 46 61.3% 16 72.7% 131 53.0% Non-thrombogenic 81 54.0% 29 38.7% 6 27.3% 116 47.0% ᵪ 2 (2, N = 247) = 8.48 - p = 0.014 Non-thrombogenic: chicken wing; Thrombogenic: windsock, cauliflower and cactus; TIA: transient ischemic attack; ICO: coronary insufficiency; EF: ejection fraction; LAA: left atrial appendage. Linhares et al. Transesophageal echocardiography and CHA2DS2-Vasc score Int J Cardiovasc Sci. 2019;32(5):460-470 Original Article vitamin K antagonists (such as warfarin, with a target INR of 2.0-3.0), or with factor XAblocking anticoagulants, such as rivaroxaban or apixaban, or the direct thrombin inhibitor dabigatran. 7 Risk scores and stroke in patients with AF The risk of stroke increased with the CHA 2 DS 2 -VASc score, ranging from 0.84% (0 point), 1.75% (1 point), 2.69 (2 points) and 3.2% (3 points). 2,8 Patients are classified as low risk (CHA 2 DS 2 -VASc score = 0 to 1), moderate (CHA 2 DS 2 -VASc score = 1 to 2) and high risk (CHA 2 DS 2 - VASc score ≥ 3) for cerebrovascular ischemic events. In patients without risk factors, antithrombotic therapy is not recommended (Class I level of evidence A). 8 On the other hand, in patients considered to be at high risk, antithrombotic therapy is recommended through oral anticoagulation. 9 The benefits of antithrombotic therapy are not yet evident in patients considered to be at moderate risk. According to the latest European guideline on the management of AF (2016), oral anticoagulation is recommended for patients considered to be at moderate risk, but the risk of bleeding complications and the patients’ preference should be assessed first (Class IIa level of evidence A), as also proposed by the latest guidelines of the American Heart Association/ American College of Cardiology Foundation (2011), which recommends considering the use of aspirin or oral anticoagulation (Class IIa). 1,2 Inclinical practice forpatientspresentingCHA 2 DS 2 VASc ≤ 2 score, the risk of bleedingwould outweigh any benefits of anticoagulation, thus reducing its net benefit, since patients at low risk for thromboembolic complications are considered. However, there are reports that these patients have some risk and that anticoagulation should be considered. Some other type of information would be needed to characterize this individual and make anticoagulation effective. A probable explanation for the risk of some low-risk patients with stroke may be based on left atrial appendage morphology. Association between TEE data and the risk of systemic thromboembolism TEE has a greater sensitivity in the detection of intracardiac thrombi, especially those located in the atria compared to the transthoracic scan. Besides, it provides a better left atrial appendage evaluation, as it evaluates its shape and determine important hemodynamic parameters such as blood flow velocity, which is an important predictor of thrombus formation, which is not possible using transthoracic echocardiography. TEE also has greater accessibility and lower investigative cost compared to magnetic resonance imaging and computed tomography. The r e l a t i onsh ip be tween the f i ndi ngs of transesophageal echocardiography and the CHA 2 DS 2 - VASc score has not yet been established in our country, since most studies looks into the association in the presence of thrombus with the score. 10,11 As patients with a higher CHA 2 DS 2 -VASc score have more comorbidities, they are expected to have more abnormalities in echocardiographic parameters, predisposing to thrombus formation and increased risk of stroke/TIA. 12-14