Background: Atrial fibrillation is associated with inflammation and oxidative stress. Hypothesis: Carvedilol and N-acetyl cysteine (NAC) combination decreases inflammation, oxidative stress, and postoperative atrial fibrillation (POAF) rates more than metoprolol or carvedilol. Methods: Preoperative and postoperative total oxidative stress (TOS), total antioxidant capacity (TAC), and white blood cells (WBC) were measured in metoprolol, carvedilol, or carvedilol plus NAC groups, and association with POAF was evaluated. Results: Preoperative TAC, TOS, and WBC levels were similar among the groups. Postoperative TAC levels were lower in the metoprolol group compared with the carvedilol group (1.0 vs 1.4) or the carvedilol plus NAC group (1.0 vs 1.9) and were also lower in the carvedilol group compared with the carvedilol plus NAC group (all P < 0.0001). Postoperative TOS levels were higher in the metoprolol group as compared with the carvedilol (29.6 vs 24.2; P < 0.0001) or the carvedilol plus NAC groups (P < 0.0001), and were also higher in the carvedilol group as compared with the carvedilol plus NAC group (24.2 vs 19.3; P < 0.0001). Postoperative WBC counts were lower in the carvedilol plus NAC group compared with the metoprolol group (12.9 vs 14.8; P = 0.004), were similar between the carvedilol and the metoprolol groups (13 vs 14.8) and between the carvedilol plus NAC group and the carvedilol group (both P > 0.05). Postoperative TAC, TOS, and WBC were associated with POAF. Conclusions: Carvedilol plus NAC reduced oxidative stress and inflammation compared with metoprolol and decreased oxidative stress compared with carvedilol. Postoperative TAC, TOS, and WBC were associated with POAF.
IntroductionCardiopulmonary bypass may cause oxidative stress and inflammation 1 processes that have been shown to be associated with atrial fibrillation.2 -5 Carvedilol is a nonselective β-blocker and N-acetyl cysteine (NAC) is a mucolytic agent. These agents have anti-inflammatory and antioxidant properties, 6 -16 and they decreased postoperative atrial fibrillation (POAF) rates in previous studies.2,17 -22 In a randomized study, we have shown that carvedilol plus NAC decreased POAF incidence compared with metoprolol or carvedilol.23 However, it is not known whether the effect of carvedilol and NAC is associated with changes in the levels of oxidative markers or whether there is a correlation between these markers and the development of POAF.