Amiodarone With or Without N-Acetylcysteine for Post-Surgery Atrial Fibrillation

In an article published in Anesthesiology, researchers evaluated whether N-acetylcysteine could reduce the incidence of postoperative atrial fibrillation. According to the primary investigator, David Amar, and colleagues from the Memorial Sloan Kettering Cancer Center in New York, NY “dual therapy comprising N-acetylcysteine plus amiodarone did not reduce the incidence of postoperative atrial fibrillation or markers of inflammation and oxidative stress early after major thoracic surgery, compared with amiodarone alone.”

The article also reported that recurrent atrial fibrillation episodes are common in patients with postoperative atrial fibrillation within one year of thoracic surgery.

The randomized trial included 154 patients at high risk for postoperative atrial fibrillation who were scheduled to undergo major thoracic surgery. Participants received either N-acetylcysteine plus amiodarone or a placebo plus amiodarone in the post-anesthesia care unit. The primary measures of the trial were incidence of sustained atrial fibrillation longer than 30 seconds by telemetry within 72 hours of surgery, or “symptoms requiring intervention and confirmed by electrocardiography within seven days of surgery.”

The results showed that postoperative atrial fibrillation occurred in 15 of 78 patients who received N-acetylcysteine (19%) compared to 13 of 76 patients who received placebo (17%; odds ratio = 1.24; 95% confidence interval, 0.53–2.88; p = 0.615). Inflammatory and oxidative stress markers were similar between groups.

Ultimately, the trial was stopped at the interim analysis date due to “futility.” The authors did add that “regardless of treatment at 1 year, 7 of 28 patients with postoperative atrial fibrillation (25%) had recurrent episodes of atrial fibrillation.”