587 LEFT ATRIAL APPENDAGE OCCLUSION: A REAL SOLUTION TO CARDIOEMBOLIC RISK OF ATRIAL FIBRILLATION?


 82-year-old woman comes to our clinical observation for worsening exertional dyspnea, with ECG evidence of atrial fibrillation (AF) with high ventricular response. Past medical history: previous right breast carcinoma treated in 1998 with quadrantectomy, radiotherapy and hormone therapy. Previous ischemic transitory attack. Hypertension. Dyslipidemia. The patient reports the first episode of paroxysmal AF in 2016, for which anticoagulant therapy with new oral anticoagulants NOACs was started for CHA2DS2VASc=6. During anticoagulant therapy episode of ocular haemorrhage for which the patient discontinued therapy with NOACs and used low-molecular-weight heparin LMWH "as needed" in the course of arrhythmic relapses. In July and August 2019 relapses of symptomatic paroxysmal AF. Multiple attempts to take different anticoagulants (Rivaroxaban, Edoxaban) poorly tolerated. The patient undergoes catheter ablation by isolation of the pulmonary veins (considered first line according to ESC guidelines for the control of symptoms in patients with paroxysmal AF) and percutaneous left atrial appendage occlusion (LAAO), with indication of anticoagulation therapy for at least 4 weeks after the procedure (Apixaban 2.5 mg bid, reduced dose due to the presence of age>80 years and weight<60 kg). At the entrance to our hospital, an ECG is performed with a finding of total arrhythmia from AF with a high ventricular response (HR 130 bpm), conducted with left bundle branch block (LBBB); cardiac echo-Doppler ultrasound is performed with a slight reduction in left ventricular systolic function (EF 45%), second degree diastolic dysfunction with increased filling pressures, moderate mitral valve insufficiency, severe left atrial dilatation (LAVi 125 ml/m2), moderate tricuspid valve insufficiency with moderate pulmonary arterial hypertension (PAPS 55 mmHg), right atrial dilatation, circumferential pericardial detachment, dilated inferior vena cava hyporeactive with breath acts. At blood tests: BNP 1022 pg/ml, sodium 145 mmol/l, potassium 3.5 mmol/l, creatinine 1.17 mg/dl with eGFR 43 ml/min/1.73mq. Rate control therapy with ß-blockers and Digoxin and diuretic therapy with Furosemide and Canrenone is set, with improvement of symptoms and clinical conditions. Anticoagulant therapy with LMWH is also undertaken but the patient shows poor adherence. After home discharge, the patient goes back to the emergency room for dyspnea. Further cardiac echo-Doppler ultrasound is performed with evidence of thrombotic formation in the left atrium of the size of 30×25 mm. Therapeutic dosage LMWH therapy is started with subsequent Warfarin embrication according to INR, obtaining complete resolution of the thrombotic formation.
 A systematic review of device-related thrombosis (DRT) after left atrial appendage occlusion (LAAO) proved that the overall incidence of DRT was 3.9% and the median time from procedure to diagnosis of DRT was 1.5 months. According to currently reported cases, most DRTs occur within one year after LAAO. This particular clinical case of DRT three years after LAAO underlines the importance of accurate assessment of the patient's risk profile: LAAO is a valid alternative to anticoagulant therapy in patients at high risk of bleeding but with low embolic risk profile. It's known that high CHA2DS2VASc values ​​and reduced cardiac function are recognized risk factors for thrombus formation, such as patient compliance with antithrombotic therapy. Surely additional studies are needed to determine if the current practice of antithrombotic regimens and duration after LAAO is sufficient.