P998Left atrial appendage closure device thrombosis is associated with systemic embolization

Abstract Introduction Atrial fibrillation, in one of its forms, is the most frequent sustained tachyarrhythmia and increases the risk of stroke more than 5 times. Cardioembolic stroke and systemic embolism (CS/SE) represents the most severe complication of this arrhythmia. Approximately 92% of intracardiac thrombosis originates from the left atrial appendage (LAA) and, although its mechanical occlusion is proved method to prevent cardioembolism, thrombosis of all types of LAA occlusion devices and their associations with CS/SE were observed. The purpose of this study is to evaluate the rate of LAA occlusion device thrombosis, its predictors and the risk for cardioembolism. Methods We analyzed a group of 359 patients (65% male, mean age 72 years) with high risk for thromboembolism (mean CHADSVASc = 4.0) after LAA catheter occlusion using any of 9 different occluder types since 2005. During clinical follow-up 819 patientyears were collected and an intracardiac thrombus was found on 22 devices. Total of 17 patients suffered CS/SE. Results Thrombosis was found in 11 men and 11 women, mean age 76 years, average CHADSVASc = 4.5 and HASBLED = 2.0. The thrombus was discovered on average 4.0 months after the LAA occlusion. In that time patients were receiving dual antiplatelet therapy (11x), acetysalicic acid (4x), or interrupted anticoagulation (6x). In 3 cases the thrombosis was associated with CS/SE which represented risk of 6.6% per year. In patients with no thrombosis annual risk of CS/SE was only 1.7% (P