Sole and combined vitamin C supplementation can prevent postoperative atrial fibrillation after cardiac surgery: A systematic review and meta-analysis of randomized controlled trials

We undertook a systematic review and meta-analysis to evaluate the effect of vitamin C supplementation (vitamin C solely or as adjunct to other therapy) on prevention of postoperative atrial fibrillation (POAF) in patients after cardiac surgery. PubMed, Embase, Web of Science, and Cochrane Library were systematically searched to identify randomized controlled trials assessing the effect of vitamin C supplementation in adult patients undergoing cardiac surgery, and the meta-analysis was performed with a random-effects model. Thirteen trials involving 1956 patients were included. Pooling estimate showed a significantly reduced incidence of POAF (relative risk [RR]: 0.68, 95% confidence interval [CI]: 0.54 to 0.87, P=0.002) both in vitamin C alone (RR: 0.75, 95% CI: 0.63 to 0.90, P=0.002) and as an adjunct to other therapy (RR: 0.32, 95% CI: 0.20 to 0.53, P<0.001). The results remain stable and robust in subgroup and sensitivity analyses, and trial sequential analysis also confirmed that the evidence was sufficient and conclusive. Additionally, vitamin C could significantly decrease intensive care unit length of stay (weighted mean difference: -0.24days, 95% CI: -0.45 to -0.03, P=0.023), hospital length of stay (weighted mean difference: -0.95days, 95% CI: -1.64 to -0.26, P=0.007), and risk of adverse events (RR: 0.45, 95% CI: 0.21 to 0.96, P=0.039). Use of vitamin C alone and as adjunct to other therapy can prevent POAF in patients undergoing cardiac surgery and should be recommended for patients receiving cardiac surgery for prevention of POAF.