KEY TAKEAWAY: Investigates whether correcting pre-existing vitamin D deficiencies before cardiac surgery reduces the incidence of new-onset postoperative atrial fibrillation (POAF). The meta-analysis confirms that preoperative supplementation significantly lowers POAF risk in vitamin D-deficient patients, likely through anti-inflammatory effects and attenuation of myocardial oxidative stress.
Abstract
Introduction
Postoperative atrial fibrillation (POAF) is a common complication following cardiovascular surgeries, including CABG. Vitamin D is suggested to have potential cardioprotective effects. This systematic review and meta-analysis aims to evaluate the effect of preoperative vitamin D supplementation on POAF and related biomarkers in patients with moderate to severe vitamin D deficiency.
Methods
The main databases, including Pubmed, Web of Science, Scopus, and the Cochrane Central Library, were searched up to February 2025 for randomized controlled trials (RCTs) that evaluated the effect of vitamin D supplementation on POAF. A meta-analysis was conducted to assess the impact of preoperative vitamin D supplementation on POAF and associated biomarkers. A dose-response analysis was performed to determine the relationship between vitamin D dose and supplementation duration with POAF risk. Sensitivity analyses were conducted to assess the robustness of the findings.
Results
A total of 4 studies met the eligibility criteria and were included. The meta-analysis revealed that preoperative vitamin D supplementation significantly reduced the risk of POAF (OR: 0.44; 95 % CI: 0.30–0.64; p < 0.001, I² = 0.00) among patients with significant vitamin D deficiency (baseline levels between 10 and 14 ng/mL in all included trials). Vitamin D supplementation did not result in a statistically significant difference in CRP, hemoglobin, left atrial size, ejection fraction, or length of hospital stay. Risk-of-bias assessment showed generally low risk across most domains, with some concerns related to blinding and selective reporting, resulting in low certainty of evidence based on GRADE.
Conclusion
Among vitamin D deficient patients, pre-CABG vitamin D supplementation may be associated with a lower incidence of POAF; however, the certainty of evidence is low due to limitations in the available randomized trials, including concerns related to blinding, reporting, and imprecision. Therefore, these findings should be interpreted with caution and should not be generalized to individuals with normal vitamin D levels. Further well-designed, adequately powered randomized controlled trials are required to confirm these observations and clarify the clinical role of preoperative vitamin D supplementation in this setting.