There is also a paper by Walters et al. stating that increased ACE2 plasma activity is present in patients with atrial fibrillation since they propose that elevated plasma ACE2 activity levels are connected with increased shedding of ACE2 from the tissue into the circulation and thus increase in tissue AngII is leading to structural left atrial remodeling [173]. This evidence concerns the gene ACE2 and atrial fibrillation.