Management of Anticoagulant Therapy Monitored by an Implantable Device With Telecardiology in Patients With Acute Coronary Syndrome Associated With de Novo Atrial Fibrillation Arrhythmia

Inclusion Criteria: * Atrial fibrillation diagnosed before hospitalization for acute coronary syndrome, whether treated or not. * Atrial fibrillation still present at inclusion time. * Transient atrial fibrillation due to a reversible disorder (thyrotoxycosis, pulmonary embolism, recent surgery). * Acute coronary syndrome that has not been revascularized. * Acute coronary syndrome surgically treated (bypass). * Patient already on anticoagulant therapy. * Scheduled aortocoronary bypass. * Creatinine clearance \< 30 ml per minute. Exclusion Criteria: Pathologic criteria : * Atrial fibrillation diagnosed before hospitalization for acute coronary syndrome, whether treated or not. * Atrial fibrillation still present at inclusion time. * Transient atrial fibrillation due to a reversible disorder (thyrotoxycosis, pulmonary embolism, recent surgery). * Acute coronary syndrome that has not been revascularized. * Acute coronary syndrome surgically treated (bypass). * Patient already on anticoagulant therapy. * Scheduled aortocoronary bypass. * Creatinine clearance \< 30 ml per minute. Bleeding risks : * Contraindications to anticoagulant therapy. * Active internal hemorrhage, clinically significant bleeding, bleeding non accessible to compression or bleeding diathesis within 30 days prior to selection visit. * Platelet count \< 90000/µL at the selection visit. * Bleeding event in the twelve months prior to inclusion. * Bleeding events detected either clinically or biologically (hemoglobinemia \< 10g/dl). * Elective surgery. Comorbidities : * Cardiogenic shock. * Hyperthyroidism. * Prior history of significant liver disease (acute hepatitis, active chronic hepatitis, cirrhosis) or liver function disorder detected at selection visit. * Significant mitral valvular heart disease. General : * Patient under 18. * Non menopausal woman or without contraception. * Patient whose physical and / or mental health may have an impact on the compliance to the study. * Participation in another biomedical research study (interventional or noninterventional) or participation in a research study within the 30 days prior to inclusion. * Protected adults (under judicial protection, guardianship, or supervision).