Postoperative day 3 , day 5 , and peak creatinine levels were lower in the carvedilol plus NAC group ( 1.11 [ 1.0-1 .23 ] , 1.14 [ 1.0-1 .25 ] and 1.15 [ 1.0-1 .25 ] ) as compared with the metoprolol ( 1.4 [ 1.3-1 .49 ] , 1.3 [ 1.0-1 .54 ] and 1.3 [ 1.0-1 .54 ] ) or carvedilol groups ( 1.2 [ 1.0-1 .52 ] , 1.25 [ 1.0-1 .52 ] and 1.25 [ 1.0-1 .55 ] mg/dL ; all P values < 0.05 ) , but were similar between the metoprolol and carvedilol groups ( all P values > 0.05 ) .