Atrial fibrillation after cardiac surgery and preoperative vitamin D levels: A systematic review and meta-analysis

The Possible Influence of Vitamin D Levels on the Development of Atrial Fibrillation-An Update

Atrial fibrillation (AF) is a severe and most common supraventricular arrhythmia in humans, which, if left untreated or treated ineffectively, can lead to ischemic stroke or heart failure. It has been suggested that serum vitamin D (VitD) deficiency may be one of the critical factors influencing the onset of AF, especially in the period after cardiac surgery, such as coronary artery bypass grafting. Several papers have indicated that VitD supplementation reduces the risk of AF, significantly reducing the proportion of patients between the control and study groups in both the pre- and postoperative periods. Factors that increase the risk of AF from VitD deficiency are also further indicated, and these are age, gender, weight, season or comorbidities. In addition, the cardiodepressive mechanism of VitD is not fully understood; however, it is suggested that it acts through at least two pathways. The first indicates a direct effect of VitD on atrial muscle degradation, while the second is related to the modulation of cardiovascular depression factors. Despite many reports showing correlations between no VitD concentrations on the development of AF, this topic is still widely debated and the results from these papers are still subject to doubt. Therefore, this review aims at describing in detail the problem of correlation between VitD deficiency and the development of AF associated mainly with the postoperative period, i.e., after cardiac surgery, especially pathogenesis, and results of this correlation, taking into account recent studies, limitations and future perspectives. Due to the fact that this is still a topical problem, we believe that the collection of the latest reports and a detailed description of the problem is most appropriate in this case.

Effect of vitamin D on postoperative atrial fibrillation in patients who underwent coronary artery bypass grafting: A systematic review and Meta-analysis

BACKGROUND

Vitamin D insufficiency/deficiency has been identified as a risk factor for postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG). This is associated with significantly increased morbidity and mortality leading to not only prolonged hospital and intensive care unit (ICU) stay, but increased risk of stroke, heart failure, dementia, and long-term atrial fibrillation. This analysis aims to evaluate the efficacy of vitamin D supplementation in preventing POAF in patients undergoing CABG.

METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials and SCOPUS from inception to June 2022 for randomized controlled trials (RCTs). The outcome of interest was the incidence of POAF. Secondarily, we analyzed the length of ICU stay, length of hospital stay, cardiac arrest, cardiac tamponade, and blood transfusion. Results were pooled using a random-effect model. Three RCTs consisting of 448 patients were included.

RESULTS

Our results suggest that vitamin D significantly reduced the incidence of POAF (RR: 0.60; 95 % CI: 0.40, 0.90; p = 0.01; I² = 8 %). It was also observed that vitamin D significantly reduced the duration of ICU stay (WMD: -1.639; 95 % CI: -1.857, -1.420; p < 0.00001). Furthermore, the length of hospital stay (WMD: -0.85; 95 % CI: -2.14, 0.43; p = 0.19; I² = 87 %) was also reduced, however, the result was not significant.

CONCLUSION

Our pooled analysis suggests that vitamin D prevents POAF. Future large-scale randomized trials are needed to confirm our results.

The effects of vitamin D supplementation on postoperative atrial fibrillation after coronary artery bypass grafting in patients with vitamin D deficiency

INTRODUCTION

Postoperative atrial fibrillation (POAF) as a common complication of coronary artery bypass grafting (CABG) surgery is associated with increased mortality and morbidity rates. Vitamin D deficiency increases the prevalence of POAF; however, the effects of vitamin D supplementation on the incidence of POAF have not yet been completely elucidated.

METHODS

In this prospective, open-label, randomized clinical trial the level of 25-hydroxy vitamin D (25(OH) D) was measured in patients undergoing CABG surgery. Patients with vitamin D insufficiency (defined as 25(OH) D level < 30 ng/ml) were included and randomly assigned to control group to receive either the general standard of care (Group A) or to study group to receive the general standard of care plus oral vitamin D₃ , 600,000 IU 5 days before surgery (Group B). The primary outcome of our study was the occurrence of POAF during the first 5 days after CABG surgery.

RESULTS

Totally, 93 patients in group B and 103 patients in group A completed the study. The occurrence of POAF was significantly lower in group B as compared to group A (9.68% vs. 20.39%, p = .038). The length of intensive care unit (ICU) stay and hospital stay were reduced in group B patients (2.21 vs. 3.86 days, p < .001 and 7.40 vs. 9.58 days, p = .022, respectively).

CONCLUSION

Our study demonstrated that vitamin D supplementation reduces the incidence of POAF, duration of ICU, and hospital stay following CABG surgery.

Association Between the Circulating Level of 25-Hydroxyvitamin D and Clinical Results After Cardiac Surgery: A Meta-Analysis and Systematic Review

Background: Vitamin D (VitD) is an important pleiotropic hormone for organ systems. Studies have focused on the level of VitD, especially that of 25-hydroxyvitamin D (25-(OH)-VitD), in patients after cardiac surgery and the relationship between VitD deficiency and adverse outcomes, but the results have been inconsistent. We carried out a meta-analysis to evaluate differences in the 25-(OH)-VitD level before and after cardiac surgery, and evaluated the predictive value of 25-(OH)-VitD level in the clinical outcomes of patients undergoing cardiac surgery.

Methods: Studies related to VitD level and cardiac surgery were searched from PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases from inception to October 2020. We applied the Newcastle–Ottawa Scale to assess the risk of a bias in individual studies. We examined the heterogeneity and publication bias and performed subgroup analyses and sensitivity analyses.

Results: Fifteen studies were included in our analysis. The 25-(OH)-VitD level was significantly lower immediately after surgery [stand mean difference (SMD), 0.69; 95%CI (0.1, 1.28), P = 0.023] and 24-h after surgery [0.84; (0.47, 1.21), 0.000] compared with that before surgery. A higher prevalence of 25-(OH)-VitD deficiency was recorded 24 h after surgery [RR, 0.59; 95%CI (0.47, 0.73), P = 0.00]. Pooled results demonstrated a significant relationship between the preoperative 25-(OH)-VitD level and vasoactive-inotropic score (VIS) [SMD, −3.71; 95%CI (−6.32, −1.10); P = 0.005], and patients with 25-(OH)-VitD deficiency revealed a comparatively poor prognosis and severe condition after cardiac surgery [−0.80; (−1.41, −0.19), 0.01]. However, 25-(OH)-VitD deficiency was not associated with the duration of stay in the intensive care unit.

Conclusions: Cardiac surgery would leads to deficiency of 25-(OH)-VitD. And the preoperative and postoperative levels of 25-(OH)-VitD are associated with adverse events, which is eligible to work as an indicator to demonstrate clinical outcomes.

The Relationship Between Vitamin D Status and Cardiovascular Diseases

With cardiovascular conditions being a leading cause of mortality and morbidity globally, several studies have identified that there is an important correlation between the level of Vitamin D and cardiovascular diseases, including an increased risk of hypertension, heart failure, and coronary artery diseases. Current published studies are in the form of both in vivo and in vitro studies and they primarily showed the evidence of how Vitamin D can downregulate Renin-Angiotensin-Aldosterone system activity and therefore providing a cardioprotective role. Nevertheless, most of these studies are observational, and there yet to be large-scale randomized controlled trials which would increase the evidence of the findings.This review aims to capture the current evidence of Vitamin D as a metabolite which is critical in reducing cardiovascular conditions and the possible physiological pathways that it works via.

The relationship between preoperative serum vitamin D deficiency and postoperative atrial fibrillation: A systematic review and meta-analysis

Postoperative atrial fibrillation (POAF) is the most common arrhythmia seen in the first days following cardiac surgeries. Recently, there is a growing discussion regarding the link between vitamin D deficiency and POAF development. This systematic review and meta-analysis of the observational studies aimed at evaluating the association between preoperative vitamin D deficiency and Postoperative atrial fibrillation. In this study, using PubMed, Scopus, Google Scholar, EMBASE, Web of Science, and Cochrane Libraries, we searched for records published before July 2020. Two reviewers screened for studies that examined the relationship between preoperative vitamin D levels and the generation of POAF. Data regarding study design, patient characteristics, definition of atrial fibrillation (AF), type of surgery, vitamin D levels, and measurement methods were extracted. Five studies were included in the meta-analysis. Our primary analysis showed a significant relationship between preoperative levels of vitamin D and POAF development (mean differences (MD) = -2.851, 95% confidence interval (CI) =-5.506 to -0.195; P value 0.035). Our meta-analysis suggested serum vitamin D deficiency is associated with an increased risk of POAF development. Further large scale interventional studies are needed to explore whether vitamin D supplementation will prevent POAF.