Thirteen RCTs (n=1,338) were included in meta-analyses. Sample sizes varied from 20 to 295. Only blinding was reported for the quality assessment; two studies had inadequate blinding. The follow-up duration of included RCTs was not reported.
When the studies were combined, N-acetylcysteine was significantly associated with a reduction in post-surgery atrial fibrillation compared with controls (relative risk 0.64, 95% CI: 0.42 to 0.98, p=0.048; six RCTs), with a pooled risk difference of 8% (95% CI: 1% to 15%). There were no statistically significant differences in other outcomes between the two groups.
No statistically significant heterogeneity was observed in the outcomes. Sensitivity analyses did not materially affect the results. Funnel plots (not shown in the report) suggested the possibility of publication bias, but Egger's weighted regression statistics suggested that publication bias was unlikely.