The boundaries for pre-implant LVEF were < @ % ( n = @ ; @ + / - @ % ; T ( low ) ) , @ % to @ % ( n = @ ; @ + / - @ % ; T ( middle ) ) and > @ % ( n = @ ; @ + / - @ % ; T ( high ) ) for each tertile.Two-year post-implant LVEF was @ + / - @ % ( T ( low ) ) , @ + / - @ % ( T ( middle ) ) and @ + / - @ % ( T ( high ) ) .