Various studies have shown that fibrosis plays an essential role in cardiac arrhythmias.[33,34] Furthermore, improving myocardial fibrosis with sacubitril/valsartan may reduce the occurrence of ventricular arrhythmias.[35] On the other hand, after entering the human body, sacubitril/valsartan is decomposed into sacubitril and valsartan, which are further metabolized into LBQ657 to play a role in inhibition of neprilysin.[1] However, >50 putative peptide substrates of neprilysin have been proposed until 2016. Here, MME is linked to cardiac rhythm disease.