The Myocardial Micro-injury and Cardiac Remodeling Extension Study in the Sodium Lowering In Dialysate Trial ( Mac-SoLID study ) aims to determine whether lower dialysate [ Na + ] results in ( i ) increased levels of high-sensitivity Troponin T ( hsTnT ) , a well-established marker of intra-dialytic myocardial micro-injury in HD populations , and ( ii ) increased fixed LV segmental wall motion abnormalities , a marker of recurrent myocardial stunning and micro-injury , and ( iii ) detrimental changes in LV geometry due to maladaptive homeostatic mechanisms .