Does postoperative corticosteroid management prevent atrial fibrillation after mitral valve surgery?

INTERVENTION: Trade Name: Solu‐Cortef 100mg inj kuiva‐aine ja liuotin liuosta varten Product Name: Solu‐Cortef Product Code: 420596 Pharmaceutical Form: Concentrate and solvent for solution for infusion Other descriptive name: HYDROCORTISONE SODIUM SUCCINATE Pharmaceutical form of the placebo: Solution for infusion Route of administration of the placebo: Intravenous use CONDITION: new onset atrial fibrallation and paroxysmal atrial fibrillation Therapeutic area: Diseases [C] ‐ Cardiovascular Diseases [C14] PRIMARY OUTCOME: Main Objective: The main objective of the trial is to investigate wether postopetavine corticosteroid management prevents new‐onset atrial fibrillation or activation of paroxysmal atrial fibrallation immediately after mitral valve surgery. Primary end point(s): patient stays in sinus rhytm for 3 days post mitral valve surgery or patient gets atrial fibrillation during first three postoperative days after mitral valve surgery Secondary Objective: Not applicable Timepoint(s) of evaluation of this end point: 3 postoperative days SECONDARY OUTCOME: Secondary end point(s): none Timepoint(s) of evaluation of this end point: none INCLUSION CRITERIA: mitral valve surgery (plasty or prostesis), adult, willing to participate, not in chronic atrial fibrillation preoperatively Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐64 years) yes F.1.2.1 Number of subjects for this age range 120 F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range 120