Atrial fibrillation (AF) is a common complication after cardiac surgery, affecting up to 30% of patients. Since oxidative stress is associated with AF, several studies in recent years have investigated the effects of post-surgery treatment with Vitamin C, an antioxidant. Hemilä and Suonsyrjä have just published a systematic review of 15 trials, ranging from 2003 to 2016. Of those, 14 trials measured the incidence of AF after cardiac surgery in a total of 2006 high-risk patients. Vitamin C was administered orally or intravenously.
Vitamin C administration in the five trials taking place in the US did not prevent AF, whereas the nine trials in the rest of the world (Greece, Slovenia, Iran, and Russia) showed a significant reduction of 44% (95% CI: 0.47-0.67) in the incidence of AF. Whether vitamin C was administered orally or intravenously made a difference in trials outside the US: intravenous vitamin C was found to reduce the length of hospital stay (1.47 days), but it was oral vitamin C that had the best results for AF (a 73% decrease).
The causes for such a great difference between US and non-US trials are not clear, but this strong evidence from other countries merits at least further investigation.
Vitamin C for preventing atrial fibrillation in high risk patients: a systematic review and meta-analysis.
CONCLUSIONS: Our meta-analysis indicates that vitamin C may prevent post-operative atrial fibrillation in some countries outside of the USA, and it may also shorten the duration of hospital stay and ICU stay of cardiac surgery patients. Vitamin C is an essential nutrient that is safe and inexpensive. Further research is needed to determine the optimal dosage protocol and to identify the patient groups that benefit the most.
PMID: 28143406 PMCID: PMC5286679 DOI: 10.1186/s12872-017-0478-5