Phd in ANGIO-CARDIO-THORACIC PATHOPHYSIOLOGY AND IMAGING

Thesis title: Parametri clinici ed ecocardiografici nella predizione del rischio tromboembolico in pazienti affetti da fibrillazione atriale non valvolare in trattamento con nuovi anticoagulanti orali (NAO): studio prospettico osservazionale

Background: International guidelines recommend anticoagulation therapy in high risk stroke patients suffering from nonvalvular atrial fibrillation (NVAF) and with a CHA2DS2-VASc score ≥ 2, while for low risk patients oral anticoagulant therapy is not always required. Indeed, the predicting value of CHA2DS2-VASc score in moderate risk stroke patients could be modest. The aim of this study is to evaluate the utility of simple echocardiographic parameters to predict stroke in NVAF patients treated with Non-vitamin K Oral Anticoagulants (NOACs), the current anticoagulant best treatment. Methods: An observational study was conducted over a population of patients affected by NVAF treated with NOACs therapy. Echocardiographic data were collected. A 12-month follow up was performed evaluating the incidence of stroke, transient ischemic attack (TIA), arterial embolism and a composite endpoint of all 3 events. Furthermore a descriptive study was conducted in order to define cohort’s features. Predictive analysis of CHA2DS2-VASc and echocardiographic parameters was performed using logistic regression. ROC curves have also been elaborated. Results: An overall cohort of 725 patients was enrolled. After a 12-month follow-up, thromboembolic events occurred in 21 (2,9%) patients: 12 of these were treated with Apixaban (3.7% of Apixaban population), 5 with Dabigatran (2,5 % of Dabigatran population), 3 with Rivaroxaban (1,69 % of Rivaroxaban population) and 1 with Edoxaban (3,33% of Edoxaban population). Stroke events were 13 (1,8%), TIA episodes were 7 (0,9 %), systemic embolisms were 2 (0,5%). Ejection fraction (EF), indexed left ventricular end-diastolic diameter (LVEDD) and indexed left atrial volume (LAVI) showed increased risk of stroke and thromboembolic events (composite endpoint and stroke) at univariate analysis. Multivariate analysis showed correlation only between LAVI and thromboembolic events. Only LAVI was associated with an increased risk of TIA. No correlation between CHA2DS2-VASc and events was found. Conclusions: This study suggests that clinical parameters and echocardiographic measures, such as EF, LVEDD and principally LAVI, can help to identify patients at greater risk of thromboembolic complications, leading to clinical decision for the most suitable NOAC.