The clinical benefits of perioperative antioxidant vitamin therapy in cardiac patients remain controversial. Here, we conducted a meta-analysis to determine the strength of the evidence supporting the perioperative use of antioxidant vitamins in patients undergoing cardiac surgery. We searched 4 databases (PubMed, EMBASE, Science Citation Index and Cochrane Library) for randomized controlled trials that reported the effects of antioxidant vitamin therapy on patients undergoing cardiac surgery until 6 June 2016. Risk ratio (RR) or mean difference (MD) and its 95% confidence interval (95% CI) served as the summarized results. Heterogeneity among included studies was evaluated using the I2 statistic, which help determine which effect model to apply. We constructed a funnel plot to assess the existence of publication bias. Sensitivity analyses were also conducted to evaluate the robustness of the outcomes. Twelve trials with 1584 cardiac patients were included. Compared with placebo or no antioxidant vitamin therapy, administration of antioxidant vitamin therapy resulted in a reduction in postoperative atrial fibrillation (POAF) (RR 0.55, 95% CI 0.42, 0.73, P < 0.0001), duration of hospital stay (MD -0.68, 95% CI -0.98, -0.39, P < 0.00001), intensive care unit length of stay (MD -0.21, 95% CI -0.30, -0.12, P < 0.00001) and intubation time (MD -2.41, 95% CI -3.83, -0.98, P = 0.001). Our results also showed a trend towards a decrease in postoperative complications (RR 0.72, 95% CI 0.48, 1.08, P = 0.11) and duration of POAF (MD -1.950, 95% CI -3.28, 0.29, P = 0.10). This meta-analysis demonstrated that perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery can reduce the incidence of POAF, duration of hospital stay, intensive care unit length of stay and intubation time.
