Preoperative and postoperative day @ creatinine levels were similar among the metoprolol ( @ -LSB- @-@ @ -RSB- and @ -LSB- @-@ @ -RSB- ) the carvedilol ( @ -LSB- @-@ @ -RSB- and @ -LSB- @-@ @ -RSB- ) and the carvedilol plus NAC groups ( @ -LSB- @-@ @ -RSB- and @ -LSB- @-@ @ -RSB- mg/dL ; all P values > @ ) .