IJCS | Volume 32, Nº5, September/October 2019

464 Chart 1 - Distribution of patients by CHA 2 DS 2 -VASc values and atrial fibrillation. Atrial fibrillation CHAD CHAD-0 to 1 CHAD-2 to 3 CHAD-4 and more Presence of AF Absence of AF Linhares et al. Transesophageal echocardiography and CHA2DS2-Vasc score Int J Cardiovasc Sci. 2019;32(5):460-470 Original Article thrombus (6.7%) and LAA mean velocity < 0.4 m/s (22.7%) compared to other groups. Besides this, it presented the second highest percentage of AF (26.7%), moderate left atrial dilation degree (16.0%), stroke/TIA (38.7%), ICO (10.7%), and ejection fraction smaller than 55% (13.3%), compared to other groups (Table 1). Finally, patients in group 3 (CHA 2 DS 2 -VASc ≥ 4) presented the highest AF percentages (31.8%), moderate left atrial dilation (22.7%), stroke/TIA (77.3%), ICO (13.6%), with an ejection fraction of smaller than 55% (18.2%). The LAAmorphology of the thrombogenic type was present in 72.7% of these patients (Table 1). Table 1 shows an association between the CHA 2 DS 2 - VASc values and hemodynamic and structural variables, except for the presence of thrombus (p = 0.079). Table 2 shows the association of AF with spontaneous contrast (p < 0.001), left atrial dilation degree (p < 0.001), presence of thrombus (p = 0.001), decreased ejection fraction (p = 0.007) and lowLAA flowvelocity (p < 0.001). There were no associations of the other variables with AF. In the group of patients with AF, there was a higher occurrence of spontaneous contrast (67.5%vs. 3.4% in the group without AF), mild, moderate and severe degrees of left atrial dilation (35.0%, 32.5% and 10.0% versus 9.7%, 3.4% and 0.5%, respectively, in the non-AF group), presence of thrombus (17.5%), ejection fraction smaller than 55% (20.0% versus 5.8% in the group without AF) and mean LAA velocity smaller than 0.4 m/s (60.0% vs. 1.4% in the group without atrial fibrillation). The association of LAA morphology with a history of stroke/TIA is shown in table 3. There is a higher occurrence of stroke/TIA in patients with thrombogenic LAA (25.2%) compared to the non-thrombogenic group (11.2%), (p = 0.005), regardless of the CHA 2 DS 2 -Vasc score (Table 3). Discussion Atrial fibrillation is the most common type of supraventricular tachyarrhythmia in the adult population. Its prevalence ranges from 1.5 to 2% in the age group of 60 to 70 years, increasing to more than 15% in the population aged over 80. 1 This arrhythmia is associated with a 5-fold increase in stroke risk and a 3-fold increase in the incidence of congestive heart disease in addition to evolving with high mortality. 2 The main international guidelines guide the implementation of a risk stratification for cerebrovascular events in patients with AF, in order to identify patients with greater and lower risk for this complication. From this point on, the preventive drug treatment begins, and the best therapeutic choice can be established, such as