Impact of New Biomarkers on Maintenance of Sinus Rhythm After Cardioversion or Ablation of Atrial Fibrillation

Inclusion Criteria: * Patients with paroxystic or persistent atrial fibrillation for whom a decision to perform ablation is made. * Patients with persistent atrial fibrillation for whom a decision to perform cardioversion is made. * Patients with social security coverage, or beneficiary thereof. * Patients who provide written informed consent. Exclusion Criteria: * Age \<18 years or \>80 years * Patients with significant valvular heart disease defined as symptomatic aortic valve disease, severe aortic or mitral stenosis or tricuspid or mitral insufficiency grade 3/4 or 4/4 * Patients with pulmonary arterial hypertension \>45 mmHg on echocardiography * Patients with chronic respiratory disease, chronic obstructive pulmonary disease stage II, III or IV. * Patients with a left ventricular ejection fraction \<45% * Patients with recent (\<1 month) acute decompensation of heart failure * Patients with recent (\<1 month) acute coronary syndrome * Anemia (hemoglobin \<10 g/dL) * Pregnant or lactating women * Patients with anticipated poor compliance, as assessed by the study investigator * Patients within the exclusion period of another clinical study * Patients under legal guardianship