O papel da ecocardiografia transtorácica na avaliação do acidente vascular cerebral isquêmico e do ataque isquêmico transitório

Abstract

Defining the mechanism of ischemic stroke or transient ischemic attack (TIA) and instituting adequate secondary prophylaxis are essential to prevent recurrence of the event. Despite being commonly used, the routine use of echocardiography in this scenario has been questioned. Prospective cohort study, conducted between April/2020 and April/2021, in a tertiary public hospital, which aimed to evaluate the transthoracic echocardiogram (TTE) as a modifier of clinical conduct, with emphasis on the determination of secondary drug prophylaxis - indication of anticoagulation in detriment of antiaggregation in patients with ischemic stroke and TIA. The secondary objectives were to determine the frequency of clinical conditions and echocardiographic alterations and their associations with the mechanisms related to stroke. The variables were compared using the chi-squared and Fisher's exact tests, in addition to the Kruskal-Wallis test and the ROC curve. The significant p value was < 5%. Were analyzed 330 cases (93%) of ischemic stroke and 25 (7%) of TIA, 75 (21,1%) of which were cardioembolic. In 12 patients (3,4%) anticoagulation was indicated by echocardiographic criteria. In another 44 patients (12,4%), the TTE identified alterations that resulted in therapy optimization or redirection. Of the categorical variables, only the history of heart disease, 51 (14,4%), was associated with a specific mechanism - cardioembolism (p<0.01). Regarding quantitative variables, the cardioembolism group had older age, higher mass index, left ventricular systolic and diastolic diameters, left atrial volumes and diameters, and lower ejection fractions (p<0.01). Compared to the cardioembolism and large artery atherosclerosis groups, the stroke scale (NIHSS) was lower in the small artery occlusion group (p<0.01). The other comparisons did not result in significant differences. When testing echocardiographic variables and Atrial Fibrilation/Atrial Flutter outcome using the ROC curve, left atrial volume (AUC: 0.807) and diameter (AUC: 0.805) performed the best. The TTE identified significant alterations in 15,8% of the patients and was fundamental in the definition of anticoagulation in a proportion of 3,4% of the cases. The clinical-demographic variables were not related to specific mechanisms, with the exc-eption of the history of heart disease, which, like the echocardiographic variables studied, was shown to be related to cardioembolism. Of the echocardiographic variables, only the volume and the diameter of the left atrium had a good ability to predict Atrial Fibrillation/Atrial Flutter.