Factors, associated with the outcomes of the thyrotoxic atrial fibrillation

BACKGROUND: Thyrotoxic atrial fibrillation (TAF) is associated with an increase in total and cardiovascular mortality, mainly due to the thromboembolic events. Therefore, thromboembolism prevention is an important TAF treatment component. Thus, it seems interesting to identify TAF thromboembolic complications predictors.TAF is a potentially reversible state. However, the spontaneous reversion to sinus rhythm after the euthyroidism achievement does not occur in all patients. In patients with a history of thyrotoxicosis the hospitalization rate due to cardiovascular pathology, and due to atrial fibrillation (AF), in particular, is higher than in the general population, even after the radical treatment of thyrotoxicosis.The development of prediction tools for mentioned above TAF complications and adverse outcomes, would make it possible to create more detailed and high-quality guidelines for the management of patients with thyrotoxicosis-induced AF. At the same time, the predictors of TAF thromboembolic complications and TAF maintenance after the euthyroid state is achieved, are not well currently understood.AIM: The purpose of this study was to identify risk factors for TAF adverse outcomes: thromboembolic events and the lack of spontaneous reversion to sinus rhythm after the euthyroidism was achieved.MATERIALS AND METHODS: This is a retrospective study of 70 patients aged 24 to 70 years with a history of overt thyrotoxicosis and TAF. The following parameters were analyzed in all participants: thromboembolic events due to TAF, the presence of the spontaneous reversion to sinus rhythm after the euthyroidism was achieved and potentially associated with TAF adverse outcomes factors: a number of clinical and demographic factors, echocardiography data and characteristics of the TAF course. Regression analysis was performed to study the effect of these potential predictors on the risk of the thromboembolism and TAF maintenance. The cut-off points for the identified risk factors were determined by receiver operating characteristic (ROC) curves creating.RESULTS: The analysis showed that the only independent TAF thromboembolic complications predictor among studied parameters was the large left atrium diameter (>4.3 cm), and the predictors of TAF maintenance after the euthyroid state is achieved included the large left ventricle end-diastolic size (>4.5 cm) and the presence of left atrium dilation.CONCLUSION: In this study, echocardiographic parameters associated with TAF thromboembolic complications and TAF persistence after euthyroid state is achieved, were identified. This may be useful for the TAF adverse outcomes risk assessment tools development in the future.