Low plasma renin activity is associated with 'Apparently' idiopathic atrial fibrillation

Background: Previous studies have reported the direct or indirect relationship between the renin-angiotensin-aldosterone system (RAAS) and atrial fibrillation (AF). However, in patients with “apparently” idiopathic AF without possible external influence, whether RAAS is dysregulated at an early stage of AF and its relationship with the recurrence of AF after ablation have not been studied. Methods: This single-center, prospective, case-control study included apparently healthy individuals with AF (the case group) or paroxysmal supraventricular tachycardia (PSVT, the control group) referred for catheter ablation at the same period. The primary outcome was RAAS activation in these two groups. The secondary outcome was the 1-year recurrence of AF after ablation. Results: This study included 51 “apparently” idiopathic AF and 91 patients with PSVT. A greater proportion of patients in the case group had plasma renin activity (PRA) levels