Effect of preoperative vitamin D on postoperative atrial fibrillation incidence after coronary artery bypass grafting

BACKGROUND

Post-operative atrial fibrillation (POAF) is associated with adverse long-term cardiovascular events.

OBJECTIVES

This study investigated the effects of a high-dose vitamin D administered preoperatively on the postoperative atrial fibrillation (POAF) incidence in patients with vitamin D deficiency following coronary artery bypass grafting (CABG) surgery.

METHODS

This randomized controlled clinical trial was conducted on 246 CABG patients with vitamin D deficiency. All patients were randomly divided into intervention and control groups including 123 cases for each group. In the intervention group, from 3 days before surgery, they received a daily dose of 150,000 units of vitamin D orally (50,000 units of Vit D tablet three times a day) and the patients in the control group received placebo tablets before surgery. All patients in the intervention group were assessed continuously for the occurrence of POAF during the recovery period.

RESULTS

In terms of gender, age, and BMI there were no significant differences between intervention and control groups. Our findings showed that the use of vitamin D supplements did not cause a significant change in the duration of intubation and hospitalization. The ratio of POAF following CABG surgery in the control and treatment groups was 26% and 11.4%, respectively (odds ratio = 0.36; 95% CI = 0.18-0.72; P = 0.003).

CONCLUSIONS

Our findings revealed that high-dose vitamin D supplementation before CABG surgery significantly reduced the incidence of POAF. Further multicenter randomized trials with larger sample sizes are certainly warranted to confirm our results.

Vitamin D and cardiovascular diseases

Vitamin D has an established role in calcium homeostasis but its deficiency is emerging also as a new risk factor for cardiovascular disease (CVD). In particular, several epidemiological and clinical studies have reported a close association between low vitamin D levels and several cardiovascular risk factors and major CVDs, such as coronary artery disease, heart failure, and cardiac arrhythmias. In all these clinical settings, vitamin D deficiency seems to predispose to increased morbidity, mortality, and recurrent cardiovascular events. Despite this growing evidence, interventional trials with supplementation of vitamin D in patients at risk of or with established CVD are still controversial. In this chapter, we summarize the currently available evidence on the links between vitamin D deficiency and major cardiovascular risk factors and CVD, in terms of both clinical relevance and potential therapeutic implications.

Vitamin D and Cardiovascular Diseases: An Update

Vitamin D is a vital nutrient that plays a significant part in several physiological processes within the human body, including calcium metabolism, bone health, immune function, and cell growth and differentiation. It is obtained mainly through exposure to sunlight but can be acquired from certain foods and supplements as well. Vitamin D deficiency (VDD) could be the risk factor for cardiovascular diseases (CVDs), such as heart disease and stroke. In blood vitamin D low levels have been linked with an enhanced risk of developing CVDs. However, it is unclear whether vitamin D levels are the leading cause or consequence of these conditions. While some studies highlight that taking vitamin D supplements could decrease the risk of CVD; however, more research is required to better understand the association between vitamin D and cardiovascular health. In this review, we aimed to summarize the currently available evidence supporting the association between vitamin D and CVDs and anesthesia considerations.

Association of predicted body composition with occurrence of atrial fibrillation

Background

Body mass index (BMI) is insufficient evidence as a risk factor for numerous health disorders. Body composition may be more appropriate for confirming the association with cardiovascular diseases, including atrial fibrillation (AF). This study aimed to examine the association between body composition and the occurrence of AF.

Methods

A total of 2,673,108 participants (48.6% women) without AF at baseline from the Korean national health insurance data were included. Body composition including appendicular skeletal muscle mass, body fat mass, and lean body mass were indirectly measured through validated anthropometric prediction equations. The diagnosis of AF and comorbidities were defined.

Results

With a median of 9.5 (interquartile range 9.2-10.1) years' follow-up, 25,841 (0.96%) cases of incident AF were included. In multivariable analysis, higher appendicular skeletal muscle was related to low risk of AF [hazard ratio (HR) 0.829, 95% confidence interval (CI) 0.753-0.912 for men (fifth quintile) and HR 0.888, 95% CI 0.792-0.995 for women (fifth quintile)]. In contrast, a higher body fat mass [HR 1.345, 95% CI 1.221-1.483 for men (fifth quintile) and HR 1.420, 95% CI 1.274-1.591 for women (fifth quintile)] and lean body mass [HR 2.241, 95% CI 2.182-2.303 for men (fifth quintile) and HR 1.516, 95% CI 1.368-1.667 for women (fifth quintile)] were associated with the occurrence of AF.

Conclusions

In this study, body composition parameters were associated with the occurrence of AF. It should be noted that when appendicular skeletal muscle mass decreases and body fat mass and lean body mass increase, the risk of AF may be increased in general population except underweighted BMI group.

Vitamin D, vitamin D supplementation and atrial fibrillation risk in the general population: updated systematic review and meta-analysis of prospective studies

Background

Since the association of vitamin D with atrial fibrillation (AF) risk is still unclear, we conducted this updated meta-analysis of prospective studies to identify the relationship between vitamin D or vitamin D supplementation and AF in the general population.

Methods

We conducted a comprehensive search of multiple databases up to May 2023 for studies reporting vitamin D and AF. The hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled by a random-effects model.

Results

A total of seven studies were included in this meta-analysis. Vitamin D deficiency (<20 ng/ml) was associated with increased AF incidence (HR: 1.12, 95% CI: 1.005-1.25). The HR was not significant with vitamin D insufficiency (20-30 ng/ml; HR: 1.09, 95% CI: 0.98-1.21). Each 10 ng/ml increase in serum vitamin D was associated with a significantly decreased AF incidence (HR: 0.95, 95% CI: 0.93-0.97). Two studies reported the effect of vitamin D supplements on AF incidence but reached inconsistent results.

Conclusions

Vitamin D deficiency or insufficiency was associated with an increased risk of AF in the general population. The role of vitamin D supplementation in AF prevention needs further investigation.

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.

Nutritional Status as a Risk Factor for New-Onset Atrial Fibrillation in Acute Myocardial Infarction

Purpose

Our study aimed to identify new-onset atrial fibrillation (NOAF) risk factors in acute myocardial infarction (AMI) patients after treatment with percutaneous coronary intervention (PCI) and investigate whether their nutritional status can be a predicting factor of NOAF.

Patients and Methods

We analyzed 662 AMI patients after PCI for NOAF occurrence during follow-up hospitalization and divided them into an NOAF and non-NOAF group. The patients' nutritional status was assessed using the controlling nutritional status (CONUT) score and geriatric nutritional risk index (GNRI). The Kaplan‒Meier analysis was used to assess NOAF-free survival in varying degrees of malnutrition. Cox proportional hazards models were used to identify the risk factors for NOAF.

Results

Eighty-four (12.7%) patients developed NOAF during hospitalization. There was a statistically significant difference in the occurrence of NOAF among different categories of nutritional status. The CONUT score and GNRI classifications were independent predictors of NOAF. NOAF occurrence was associated with older age, higher uric acid levels, higher N-terminal pro-B-type natriuretic peptide levels, greater left atrial size, and worse Killip class upon admission.

Conclusion

The nutritional status can affect NOAF occurrence in AMI patients after PCI. The CONUT score and GNRI are ideal tools for evaluating the nutritional status of AMI patients, with an excellent predictive effect on NOAF.

Associations between obesity parameters and the risk of incident atrial fibrillation and ischaemic stroke in the different age groups

Objective

Obesity and aging are important predisposing factors to atrial fibrillation (AF) and ischaemic stroke (IS). However, limited data comprehensively evaluated the relationships between obesity measurements and AF and IS in different ages.

Methods

A total of 9,432,332 adults from the Korean National Health Insurance Service Database were included. The study population was categorized into the six age subgroups by an increase every decade from the twenties. We evaluated AF and IS risk according to body mass index (BMI) and waist circumference (WC) in the different age groups.

Results

During a mean follow-up of 8.2 ± 1.0 years, BMI-AF presented a J-shaped association across ages. The highest hazard ratio (HR) of the BMI ≥ 30 kg/m² group was observed in subjects aged 30–39 years [HR 1.80, 95% CI 1.63–1.98, p < 0.001]. Underweight adults over 60 years also presented an increased AF risk. Incident IS risk increased in those with BMI over the normal range in early and midlife, but the association became obscured in adults aged > 60 years. Among the BMI ≥ 30 kg/m² groups, subjects aged 20–29 years presented the highest risk of IS [HR 3.00, 95% CI (2.34–3.84), p < 0.001]. Overall, WC-AF and WC-IS showed positive linear correlations, but the WC-IS association was weak in subjects aged ≥ 40 years.

Conclusion

The higher risks of AF and IS according to an increment of BMI and WC were most apparent among the young ages. The association between obesity measurements and IS was not significantly above the midlife. Weight management in the young and integrated risk factor management in the elderly are warranted.

Relationship between vitamin D deficiency and success of cardioversion in patients with atrial fibrillation

BACKGROUND

Inflammation plays an important role in the pathogenesis of atrial fibrillation (AF). Vitamin D deficiency has been found to increase vulnerability to AF. The authors aimed to determine the relationship between vitamin D deficiency and cardioversion success in AF patients.

METHODS

The study included 200 persistent AF patients presenting for cardioversion. Serum vitamin D level was sampled on admission. The success of cardioversion was assessed and patients divided into two groups: successful or failed (group I and II, respectively). Vitamin D level was assessed and patients were divided into three groups: deficient, insufficient, and sufficient vitamin D level. Cardioversion was performed pharmacologically or electrically. Failure of cardioversion was defined as: (1) detection of AF rhythm in 12-lead ECG recording immediately after cardioversion or within 6‑month follow-up, or (2) ECG Holter monitoring of AF lasting > 30 s at 6‑month follow-up.

RESULTS

There was a highly statistically significant difference in baseline serum vitamin D level between group I and group II (P-value < 0.01). There were no statistically significant differences between the three groups in terms of vitamin D levels regarding age, gender, body mass index, smoking, and left atrial diameter.

CONCLUSION

This study demonstrated that AF cardioversion failure was associated with vitamin D deficiency in patients without structural heart disease, while sufficient and insufficient vitamin D levels were associated with successful cardioversion. Therefore, vitamin D level assessment before cardioversion may help predict the success of cardioversion, and possible correction of deficient vitamin D levels may increase the chance of successful cardioversion.

The Relationship Between Vitamin D and Postoperative Atrial Fibrillation: A Prospective Cohort Study

Background and Aims

The relationship between postoperative atrial fibrillation (POAF) and 25-hydroxyvitamin D [25(OH)D] concentration as well as vitamin D supplementation has been discussed controversially. The relation of pre-operative vitamin D status and POAF remains unclear.

Methods and Results

We analysed the risk of POAF in a prospective, observational cohort study of n = 201 patients undergoing coronary artery bypass graft surgery (CABG) with 25(OH)D concentration. The median age was 66.6 years, 15.4% were women. The median (25th/75th percentile) vitamin D concentration at baseline was 17.7 (12.6/23.7) ng/ml. During follow-up we observed 48 cases of POAF. In age, sex, and creatinine-adjusted analyses, 25(OH)D was associated with an increased risk of POAF, though with borderline statistical significance [odds ratio (OR) 1.85, 95% confidence interval (CI) 0.87–3.92, p-value 0.107], in further risk factor-adjusted analyses the results remained stable (OR 1.99, 95% CI 0.90–4.39, p-value 0.087). The subgroup with vitamin D supplementation at baseline showed an increased risk of POAF (OR 5.03, 95% CI 1.13–22.33, p-value 0.034).

Conclusion

In our contemporary mid-European cohort, higher 25(OH)D concentration did not show a benefit for POAF in CABG patients and may even be harmful, though with borderline statistical significance. Our data are in line with a recent randomised study in community-based adults and call for further research to determine both, the clinical impact of elevated 25(OH)D concentration and vitamin D supplementation as well as the possible underlying pathophysiological mechanisms.

Vitamin D and Cardiovascular Disease: Current Evidence and Future Perspectives

Vitamin D deficiency is a prevalent condition, occurring in about 30–50% of the population, observed across all ethnicities and among all age groups. Besides the established role of vitamin D in calcium homeostasis, its deficiency is emerging as a new risk factor for cardiovascular disease (CVD). In particular, several epidemiological and clinical studies have reported a close association between low vitamin D levels and major CVDs, such as coronary artery disease, heart failure, and atrial fibrillation. Moreover, in all these clinical settings, vitamin deficiency seems to predispose to increased morbidity, mortality, and recurrent cardiovascular events. Despite this growing evidence, interventional trials with supplementation of vitamin D in patients at risk of or with established CVD are still controversial. In this review, we aimed to summarize the currently available evidence supporting the link between vitamin D deficiency and major CVDs in terms of its prevalence, clinical relevance, prognostic impact, and potential therapeutic implications.

Impact of Dietary Factors on Brugada Syndrome and Long QT Syndrome

A healthy regime is fundamental for the prevention of cardiovascular diseases (CVD). In inherited channelopathies, such as Brugada syndrome (BrS) and Long QT syndrome (LQTS), unfortunately, sudden cardiac death could be the first sign for patients affected by these syndromes. Several known factors are used to stratify the risk of developing cardiac arrhythmias, although none are determinative. The risk factors can be affected by adjusting lifestyle habits, such as a particular diet, impacting the risk of arrhythmogenic events and mortality. To date, the importance of understanding the relationship between diet and inherited channelopathies has been underrated. Therefore, we describe herein the effects of dietary factors on the development of arrhythmia in patients affected by BrS and LQTS. Modifying the diet might not be enough to fully prevent arrhythmias, but it can help lower the risk.

Vitamin D Supplementation Replaced Catheter Ablation in a Patient with Frequent Premature Ventricular Contractions

A high premature ventricular contractions (PVC) burden can disturb the patient’s condition through fatigue during exercise or palpitations. Hence, researchers started to look for treatment options that decrease PVC burden without the side effects of antiarrhythmic drugs, and vitamin D could be a valuable solution and safe alternative to drugs or catheter ablation for high-burden PVCs. We present the case of a 24-year-old patient with high-burden PVC of >25,500/24 hours referred for urgent catheter ablation. Treatment with beta-blockers and calcium blockers did not reduce PVC burden. Under propafenone, there was a slight reduction in the number of PVCs to 21,200/24 hours, therefore the patient was referred for catheter ablation. As there was a vitamin D deficiency of 10.1 ng/mL, an attempt of vitamin D supplementation was done, with increase of vitamin D to 32.1 ng/mL and decrease of PVC burden to 9,600/24 hours. Further dietary supplementation increased 25-OH vitamin D to 50.2 ng/mL and decreased the PVC burden to 119/24 hours. Consequently, catheter ablation was canceled, and the patient remained free of antiarrhythmic drugs.

Health implication of vitamin D on the cardiovascular and the renal system

Vitamin D regulates the calcium and phosphorus balance in the body. The activated form of vitamin D (1 α,25-dihydroxyvitamin D) binds to vitamin D receptor which regulates genes that control cell proliferation, differentiation and apoptosis. In the cardiovascular system, the vitamin D receptor is present in cardiomyocytes and the arterial wall. A clear correlation between vitamin D level and cardiovascular diseases is established. Vitamin D deficiency affects the renin-angiotensin system leading to ventricular hypertrophy and eventually to stroke. While clinical trials highlighted the positive effects of vitamin D supplements on cardiovascular disease these still need to be confirmed. This review outlines the association between vitamin D and cardiovascular and renal disease summarising the experimental data of selective cardiovascular disorders.

The impact of malnutrition on atrial fibrillation recurrence post ablation

BACKGROUND AND AIMS

Both malnutrition and atrial fibrillation (AF) are the major health problems in modern society. Only a few studies focused on the relationship between malnutrition and recurrence of atrial arrhythmias post AF ablation (AF recurrence), which used body mass index (BMI) as nutrition assessment tool. However, BMI can't credibly reflect body composition and has limitation in patients with water-sodium retention. In this study, we used controlling nutritional status score (CONUT score) and geriatric nutritional risk index (GNRI) to identify the malnutrition patients and explored the effect of malnutrition on AF recurrence.

METHODS AND RESULTS

This retrospective study included 246 patients who underwent AF ablation. During a median 11-month follow-up, 77 patients (31.3%) experienced AF recurrence. The recurrence group had higher CONUT score (2.3 ± 1.5 vs. 0.9 ± 1.0, P < 0.001) and lower GNRI (99.9 ± 7.6 vs. 103.9 ± 5.6, P < 0.001). After balancing the traditional risk factors, both CONUT score (OR: 2.614, 95%CI: 1.831-3.731, P < 0.001) and GNRI (OR: 0.884, 95%CI: 0.828-0.944, P < 0.001) were the independent predictors for AF recurrence. Pre-ablation CONUT score ≥1 and GNRI≥95.66 are indicative of AF recurrence. Adding CONUT score or GNRI to the base prediction model for AF recurrence significantly improved the discrimination and calibration. However, adding BMI to the base prediction model did not improve the model performance.

CONCLUSIONS

CONUT score and GNRI are ideal tools to evaluate the nutrition status of AF patients. Undernourished patients are more likely to suffer from AF recurrence. Improving nutrition status may be a potential target for reducing the postoperative recurrence rate.

Social Risk Factors and Atrial Fibrillation

Modifiable risk factor management is becoming one of the 3 treatment pillars in atrial fibrillation management along with anticoagulation as well as conventional rate and rhythm control strategies. Preventive therapies, such as reducing blood pressure and treating obstructive sleep apnea, are paramount in the strategy of preventing atrial fibrillation. Identification of new modifiable risk factors and triggers also could help in the global strategy to reduce atrial fibrillation. This article covers alcohol intake, tobacco smoking, caffeine, chocolate, cannabis use, and air pollution as social risk factors related to lifestyle habits that potentially could contribute to atrial fibrillation development.

[Atrial Fibrillation After Coronary Artery Bypass Surgery: Risk Factors, Prevention and Treatment]

This review focuses on the issue of atrial fibrillation (AF) following coronary bypass surgery in patients with ischemic heart disease. Risk factors of this complication are discussed in detail. The authors addressed the effect of diabetes mellitus on development of postoperative AF. Data on current methods for prevention and treatment of AF are provided.

Is there any Link Between Vitamin D and Recurrence of Atrial Fibrillation after Cardioversion?

Introduction

Atrial fibrillation (AF) is the most common chronic arrhythmia in the elderly population. In symptomatic patients, restoration and maintenance of sinus rhythm improve quality of life. Unfortunately, AF recurrence still occurs in a considerable number of patients after cardioversion (CV). In this study, we aimed to evaluate the association between vitamin D (VitD) and AF recurrence after electrical or medical CV.

Method

A total of 51 patients who underwent CV for symptomatic AF were included in the study. AF recurrence was defined as an AF pattern in 12-lead electrocardiography (ECG) recording after CV within 6 months or ECG Holter recording of AF lasting more than 30 seconds at 6-month follow-up.

Results

Mean vitD level was 21.4 ng/ml in our study population. VitD level was lower in the AF recurrence group than in the non-recurrence group (18 ng/ml vs. 26.3 ng/ml, respectively; P=0.001). Additionally, left atrial diameter was larger in the AF recurrence group compared to the non-recurrence group (4.4 vs. 4.1, P=0.025). Patients with AF recurrence were older than patients without AF recurrence, and, although the prevalence of hypertension is higher in the AF recurrence group, there was no statistically significant difference (P=0.107, P=0.867).

Conclusion

In our study, there is a strong association between vitD level and AF recurrence after CV. VitD deficiency might be a predictor of high risk of AF recurrence after CV and vitD supplementation during the follow-up might help the maintenance of sinus rhythm.

Relationship Between 25-Hydroxyvitamin D, Renin, and Collagen Remodeling Biomarkers in Atrial Fibrillation

The interplay between vitamin D, the renin-angiotensin system (RAS), and collagen remodeling has been implicated in the pathogenesis of various cardiovascular diseases. This study sought to explore this relationship in atrial fibrillation (AF) by profiling plasma levels of 25-hydroxyvitamin D, RAS biomarkers, and collagen remodeling biomarkers using the enzyme-linked immunosorbent assay method. We hypothesized that 25-hydroxyvitamin D levels would inversely correlate with RAS biomarkers and that levels of RAS and collagen remodeling biomarkers would positively correlate with each other. Although our AF cohort (n = 37) did not exhibit decreased 25-hydroxyvitamin D levels compared to normal controls (n = 26), these levels inversely correlated with renin (Spearman r = -0.57, P = 0.005). Renin levels were elevated in patients with AF compared to normal controls (1233 ± 238 ng/mL vs 401 ± 27 ng/mL, P = 0.0002) and positively correlated with levels of matrix metalloproteinase 1 (MMP-1; Spearman r = 0.89, P = 0.01) and MMP-2 (Spearman r = 0.82, P = 0.03). These data suggest that 25-hydroxyvitamin D may influence RAS activation, and renin may help mediate the collagen remodeling process in AF. Understanding mediators of RAS dysregulation in AF may elucidate targets for therapeutic intervention to prevent collagen remodeling.

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

Background

In this meta-analysis, we aimed to investigate the possible relationship between atrial fibrillation development after cardiac surgery and preoperative vitamin D levels.

Methods

Literature review was carried out in the PubMed, ScienceDirect and Ovid electronic databases without any limitation of time frame. Published studies which recorded the preoperative levels of vitamin D and atrial fibrillation after cardiac surgery in the English language were included. The results of the studies were evaluated based on either random or fixed effect model according to the presence of heterogeneity (I²>25%).

Results

A total of 1,865 articles were screened. After the article titles and abstracts were analyzed, six articles involving 769 patients which met the inclusion criteria were included. The results indicated that there was a relationship between preoperative vitamin D levels and postoperative atrial fibrillation (SMD: -0.46, 95% CI: -0.79 to -0.12; p<0.007). Heterogeneity was observed for studies conducted (I² =76.1%).

Conclusion

We concluded that low preoperative vitamin D levels were associated with the development of atrial fibrillation after cardiac surgery. However, there is a need for large-scale, randomized-controlled trials for preventing the heterogeneity of the results.

[Vitamin D deficiency study in railway drivers.]

Heart rhythm disturbances are significant pathology and one of the reason of sudden cardiac arrest. Locomotive crew drivers are at high risk for cardiovascular diseases, including heart rhythm disturbances. Multiple factors as a professional stress, frequent night shifts, lack of insolation, diet disbalance, low physical activity, exposure to vibration and noise, and an unfavorable industrial climate. In this study it was found that railway-men are predisposed to vitamin D deficiency. This condition reduces resistance to stress and increases risk of unfavorable heart rhythm disturbances.

The Status and Research Progress on Vitamin D Deficiency and Atrial Fibrillation

Atrial fibrillation is a common type of arrhythmia and is an important cause of stroke and heart failure. vitamin D is an emerging risk factor of AF, and is implicated in the pathophysiology of atrial fibrillation. It has been established that this vitamin is extensively involved in the regulation of both the renin angiotensin aldosterone system and the immune system. Epidemiological studies have not yet reached a consensus on the possible association between vitamin D deficiency and atrial fibrillation. Better research designs and methods can further clarify the relationship between the two.

The relationship between vitamin D and risk of atrial fibrillation: a dose-response analysis of observational studies

Background

The relationship between serum vitamin D and atrial fibrillation (AF) or postoperative atrial fibrillation (POAF) in patients undergoing coronary artery bypass graft (CABG) is still debated. It is also unclear whether there is a dose-response relationship between circulating vitamin D and the risk of AF or POAF.

Methods

The Cochrane Library, PubMed, and Embase databases were searched for relevant studies. We used a “one-stage approach” with a restricted cubic spline model to summarize the dose-specific relationships between serum vitamin D and AF. Relative risk (RR) was used to measure the effects in this meta-analysis.

Results

In total, 13 studies were included with a total of 6519 cases of AF among 74,885 participants. Vitamin D deficiency (< 20 ng/ml) was associated with increased risks of AF (RR: 1.23, 95% CI: 1.05–1.43). In the dose-response analysis, the summary RR for a 10 ng/ml increased in vitamin D was 0.88 (95% CI: 0.78–0.98) and there was no evidence of a non-linear association, P_{non-linearity} = 0.86. In the age subgroup, high vitamin D (per 10 ng/ml increase) reduced the risk of AF in the older group (> 65 years) (RR = 0.68, 95% CI = 0.52–0.89) but not among young individuals (< 65 years) (RR = 0.87, 95% CI = 0.72–1.06). In addition, a strong association was found between a 10 ng/ml increased in vitamin D and POAF incident in the patient after CABG (RR: 0.44, 95% CI: 0.24–0.82).

Conclusion

Our dose-response meta-analysis suggested serum vitamin D deficiency was associated with an increased risk of AF in the general population and POAF in patients after CABG. Further studies are needed to explore the age difference in the association between serum vitamin D level and the risk of AF and whether vitamin D supplements will prevent AF.

Trial registration

This study has been registered with PROSPERO (International prospective register of systematic reviews)-registration number-CRD42019119258.

Effects of high-dose vitamin D supplementation on the occurrence of post-operative atrial fibrillation after coronary artery bypass grafting: randomized controlled trial

OBJECTIVE

This study aimed to investigate the preventive effects of a high-dose vitamin D administered preoperatively on the post-operative atrial fibrillation (POAF) occurrence in patients with insufficient or deficient serum vitamin D levels who underwent coronary artery bypass grafting (CABG) surgery.

METHODS

The study was a randomized controlled, blinded and parallel-arm trial conducted on 116 who had vitamin D deficiency or insufficiency during the pre-operative evaluation were included in the study conducted between January 2018 and January 2019. Patients were divided into those who received oral vitamin D (treatment group; n = 58) and those who did not (control group; n = 58) 48 h before CABG surgery. In the treatment group, patients with vitamin D deficiency were administered 300.000 IU vitamin D orally and those with vitamin D insufficiency 150.000 IU 48 h preoperatively. Patients were followed up during hospitalisation process with respect to POAF.

RESULTS

Both groups showed no significant differences with regard to age, gender, body mass index, creatine level, left atrial diameter, pre-operative drug use, calcium level, ejection fraction, diabetes mellitus and hypertension. The ratio of POAF occurrence found in the treatment and control groups were 12.07% and 27.59%, respectively. Vitamin D treatment was found to reduce the risk of POAF development by 0.24 times (p = 0.034).

CONCLUSION

In this study with sufficient sample size, preoperative short-term high-dose vitamin D supplementation was found to be significantly preventive to the occurrence of POAF in patients with vitamin D insufficiency and deficiency who underwent CABG surgery.

Vitamin D with calcium supplementation and risk of atrial fibrillation in postmenopausal women

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in adults. Although vitamin D deficiency is associated with AF risk factors, retrospective studies of association with AF have shown mixed results. We sought to determine the efficacy of calcium and vitamin D (CaD) supplementation for AF prevention in a randomized trial.

METHODS

We performed a secondary analysis of the Women's Health Initiative trial on CaD supplementation versus placebo. We linked participants to their Medicare claims to ascertain incident AF.

RESULTS

Among 16,801 included participants, there were 1,453 (8.6%) cases of incident AF over an average of 4.5 years, at an average rate of 19.9 events per 1,000 person-years. We found no significant difference in incident AF rates between the CaD and placebo arms (hazard ratio 1.02 for CaD vs placebo, 95% CI 0.92-1.13). After multivariate adjustment, there was no significant association between baseline 25-hydroxyvitamin D serum levels and incident AF (hazard ratio 0.92 for lowest subgroup vs highest subgroup, 95% CI 0.66-1.28).

CONCLUSIONS

We present the first analysis of a large randomized trial of daily vitamin D supplementation for AF prevention. We found that CaD had no effect on incidence of AF in Women's Health Initiative CaD trial participants. We also found that baseline serum 25-hydroxyvitamin D level was not predictive of long-term incident AF risk.

Association of vitamin D deficiency with electrocardiographic markers of left atrial abnormalities

OBJECTIVE

Electrocardiographic markers of left atrial (LA) abnormalities are linked to increased risk of cardiovascular disease (CVD). We examined the relationship of vitamin D deficiency with prolonged P wave duration and PR interval as markers of LA abnormalities.

METHODS

This analysis included 5,894 participants (58.12 ± 12.9 years; 54.7% women; 49.8% non-Hispanic Whites) without clinical CVD from NHANES III. A multivariable logistic regression model was used to examine the association of vitamin D categories (<20 ng/ml, 20-29 ng/ml and >30 ng/ml (reference) with prolonged P wave duration (≥120 ms) and PR interval (≥200 ms).

RESULTS

There was an incremental increase in the prevalence of prolonged P wave duration and PR interval across vitamin D categories with the highest prevalence in study participants with vitamin D levels <20 ng/ml, followed by 20-29 ng/ml and then >30 ng/ml (trend p-value < 0.0001). Vitamin D deficiency (<20 ng/ml) was associated with prolonged P wave duration (OR [95% CI]: 1.22 [1.03-1.45], p = 0.02) and prolonged PR interval (OR [95% CI]: 1.48 [1.12-1.97], p = 0.006) in multivariable logistic regression models adjusted for demographics, CVD risk factors, and other potential confounders. These associations were consistent across subgroups stratified by age, sex, and race.

CONCLUSIONS

Vitamin D deficiency is associated with an increased risk of LA abnormalities. This association elucidates an alternate pathway through which vitamin D deficiency may increase CVD risk. Whether vitamin D supplementation would improve LA abnormalities requires further investigation.

Effect of Plasma Level of Vitamin D on Postoperative Atrial Fibrillation in Patients Undergoing Isolated Coronary Artery Bypass Grafting

Objective

Postoperative atrial fibrillation (PoAF) is a common complication after coronary artery bypass grafting (CABG). The aim of the present study was to evaluate the association between development of PoAF and vitamin D levels in patients undergoing isolated CABG.

Methods

This prospective randomized clinical trial was conducted on the patients with isolated CABG. The study was terminated when 50 patients in both PoAF(+) group and PoAF(-) group were reached. Development of AF until discharge period was assessed. Vitamin D level was measured immediately after AF; it was measured on the discharge day for the patients without PoAF. Predictive values of the independent variables were measured for the development of PoAF.

Results

The groups were separated as PoAF(-) group (66% male, mean age 58.18±10.98 years) and PoAF(+) group (74% male, mean age 61.94±10.88 years). 25(OH) vitamin D level (OR=0.855, 95% CI: 0.780-0.938, P=0.001) and > 65 years (OR=3.525, 95% CI: 1.310-9.483, P=0.013) were identified as an independent predictor of postoperative AF after CABG surgery in multivariate analysis. The cut-off level for 25(OH) vitamin D level in receiver-operating characteristic curve analysis was determined as 7.65 with sensitivity of 60% and specificity of 64% for predicting PoAF (area under the curve: 0.679, P=0.002).

Conclusion

Vitamin D level is considered an independent predictor for development of PoAF. Lower vitamin D levels may be one of the reasons for PoAF.

Preventive Effect of Preoperative Vitamin D Supplementation on Postoperative Atrial Fibrillation

Objective

To assess the relationship between preoperative vitamin D (vitD) supplementation and the development of postoperative atrial fibrillation (POAF).

Methods

The study group consisted of 328 consecutive patients. The ınfluence of preoperative vitD supplementation on POAF was reviewed in 136 patients who underwent coronary artery bypass graft surgery with vitD insufficiency (n=80) and vitD deficiency (n=56). Patients were assigned to receive either oral vitD (50.000 U) (treatment group, n=68) or not (control group, n=68) 48 hours before surgery. Patients were followed up during hospitalisation process with respect to POAF.

Results

There was no significant difference between treatment and control groups with regards to age, gender, diabetes mellitus, smoking history, chronic obstructive pulmonary disease, left atrial diameter, and biochemical parameters. Also, there was no significant difference between these groups with regards to mean vitD level on both insufficiency and deficiency patients (24.6±3.7 vs. 24.9±3.9 ng/ml P=0.837, 11.4±4.9 vs. 10.9±5.2 ng/ml P=0.681, respectively). Although the occurrence of POAF was not significantly different among treatment and control groups in patients with vitD insufficiency (31% vs. 33% P=0.538), there was a significant difference between the two groups regarding to POAF in patients with vitD deficiency (18% vs. 29% P=0.02).

Conclusion

Although preoperative vitD supplementation was not found to be associated with prevention of POAF in patients with vitD insufficiency, it was found to be strongly associated with prevention of POAF in those with vitD deficiency.

Dietary Supplements and Cardiovascular Diseases

The market of nutritional supplements is expected to expand over 6%/year through 2018 due to growing interest in personal health, aging population, and promising personalized care products. The most used dietary supplements are fish oil, multivitamins, Vitamin D, and coenzyme Q10 (CoQ10) in this order, while probiotics is the fastest growing supplement. In the U.S., over 68% of the population use dietary supplements regularly. On the other hand, in the developed countries, cardiovascular diseases (CVDs) are the main cause of death and morbidity from the 1900s. The effects of most dietary supplements on cardiovascular risk and CVD have been studied for a long time. However, despite several studies explored the association of the various supplements to the cardiovascular risk, there is still a lack of consensus. Multivitamin supplementation has been advocated to reduce cardiovascular events; Vitamin D levels have been associated with the occurrence of coronary artery disease, heart failure, and atrial fibrillation; CoQ10 deficiency has been associated with myocardial dysfunction and with statin myopathy; probiotoics has been suggested to lower both blood pressure and circulating lipids. However, the study of the effects of dietary supplementations is not straightforward, since people assuming dietary supplements generally have a healthier diet and lifestyle, and randomized studies are rarely performed. In this review, we will summarize the findings linking dietary supplements to CVD with a special focus on novel insights.

Interactions Among Vitamin D, Atrial Fibrillation, and the Renin-Angiotensin-Aldosterone System

Blockade of the renin-angiotensin-aldosterone system (RAAS) with angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARB) has been shown to decrease incident atrial fibrillation (AF). Vitamin D deficiency has been implicated but associations between vitamin D and AF are inconsistent. However, vitamin D deficiency results in renin and angiotensin upregulation. This study seeks to determine the relation between vitamin D deficiency and incident AF and characterize this relation in the setting of RAAS inhibition. A total of 47,062 patients with 25-hydroxyvitamin D [25(OH)D] laboratory testing were retrospectively identified. Clinical information was extracted from the medical record. The primary outcome was incidence of AF. Given significant patient variation, propensity score matching was used to select comparable groups of those who initiated ACEI/ARB ("AI") versus those who did not ("NAI"). Odds ratios (ORs) for incident AF associated with ACEI/ARB initiation and 25(OH)D level were estimated using generalized linear mixed models. AI patients had less incident AF than NAI patients (OR 0.36, 95% confidence interval [CI] 0.32 to 0.39) consistent with previous studies, but 25(OH)D deficiency was not associated with incident AF (OR 1.08, 95% CI 0.95 to 1.22). When stratified by 25(OH)D, there was a statistically significant decreased rate of AF in AI patients. Interestingly, this benefit was attenuated in 25(OH)D deficiency (deficient: OR 0.48, 95% CI 0.38 to 0.60 vs normal: OR 0.34, 95% CI 0.30 to 0.37). In conclusion, 25(OH)D deficiency was not associated with incident AF, and the benefit of ACE/ARB use was attenuated in 25(OH)D deficiency; this suggests that 25(OH)D may act as a cofactor in the mitigation of AF by RAAS inhibition.

Vitamin D deficiency and risk of cardiovascular diseases: a narrative review

Vitamin D, a fat-soluble prohormone, has wide-ranging roles in the regulation of many physiological processes through their interactions with the vitamin D receptors (VDR). It plays a major role in bones and calcium metabolism. Vitamin D deficiency is not uncommon and it has been associated with many health-related issues, including skeletal and non-skeletal complications. The association of low vitamin D and cardiovascular diseases and risk factors has been explored in both animal and human studies. However, studies and trials on the effect of vitamin D supplementation on cardiovascular risk factors and hypertension are conflicting with inconsistent results. Therefore, large, well-powered randomized controlled trials are warranted. If successful, supplementation with easy and low-cost vitamin D can impact our health positively. Here, we summarized the evidence for the association of vitamin D, cardiovascular diseases and risk factors, including coronary artery diseases, stroke, and hypertension, and mortality, with special consideration to resistant hypertension.

Vitamin D and new-onset atrial fibrillation: A meta-analysis of randomized controlled trials

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, which affects 1.5% to 2% of the general population. More than six million Europeans suffer from AF. To research vitamin D levels in the prevention of new-onset atrial fibrillation (AF), we conducted a systematic review of randomized controlled trials (RCTs). We focused on the vitamin D levels in the prevention of new-onset AF. The outcomes assessed were vitamin D levels, left ventricular ejection fraction (LVEF), and left atrium diameter. Six RCTs ultimately met the inclusion criteria in the meta-analysis. The outcomes of Vitamin D levels (MD = -4.27, 95% CI = -5.20 to-3.34, P = 0.30) in the new-onset AF showed no significant difference. The left atrium diameter (MD = 1.96, 95% CI = 1.48 to 2.60, P < 0.01) between new-onset AF and LVEF (MD = -0.92, 95% CI = -1.59 to -0.26, P < 0.01) showed significant difference. Our study shows that circulating vitamin D levels may not play a major role in the development of new-onset AF.

Effect of vitamin D deficiency on the development of postoperative atrial fibrillation in coronary artery bypass patients

Introduction: Various factors may be responsible for the development of postoperative atrial fibrillation (POAF) in coronary artery bypass graft (CABG) patients. In our study, we demonstrated the effect of vitamin D deficiency on the development of POAF. Methods: In this prospective case control study, patients undergoing elective, isolated CABG were considered. A total of 15 patients (16.6%) who developed POAF during the first five days after surgery made up the POAF group. Seventy-five patients that had a sinus rhythm in the same period were the non-POAF group. The two groups were compared statistically in terms of laboratory, clinical, echocardiographic, operative, and postoperative parameters. Results: All patients were in sinus rhythm at discharge. The baseline characteristics of the study groups were comparable. The POAF group had a lower vitamin D level than the non-POAF group (9.0 ± 5.0 and 15.0 ± 8.4 ng/mL, respectively; P=0.007). In the POAF group, the patients' left atrium diameter and incidence of hypertension (HT) were higher than those of the non-POAF group. Conclusion: Incidence of POAF was significantly higher in patients with vitamin D deficiency or insufficiency than the patients with vitamin D level in normal range. Therefore vitamin D deficiency or insufficiency may be a predictor of POAF in patients with CABG.

Vitamin D and its effects on cardiovascular diseases: a comprehensive review

Vitamin D is a molecule that is actively involved in multiple metabolic pathways. It is mostly known for its implications related to calcium metabolism. It has also been determined that it actively participates in the cardiovascular system, influencing blood pressure, coronary artery disease and other vascular diseases, such as heart failure and atrial fibrillation. Furthermore, it has been established that this vitamin is extensively involved in the regulation of both the renin angiotensin aldosterone system and the immune system. In this review, we present the different vitamin D metabolic pathways associated with the cardiovascular pathophysiology, and we include studies in animal and human models, as well as some of the controversies found in the literature. This review also incorporates an overview of the implications in the molecular biology and public health fields.

Relationship between plasma level of vitamin D and post operative atrial fibrillation in patients undergoing CABG

Objective:

Atrial fibrillation is the most common arrhythmia after cardiac surgery. Several studies have shown the impact of vitamin D on heart disease; however, there have been few studies for the incidence of AF and its relationship with vitamin D levels. According to the different results of these studies, we decided to evaluate the relation of plasma levels of vitamin D and postoperative atrial fibrillation in patients undergoing coronary artery bypass surgery (CABG).

Methods:

This cross-sectional study was performed on 50 patients after CABG surgery. Simple random sampling was done. Twenty five patients who developed AF within 48 hours after CABG with Cardiopulmonary bypass (CPB) were enrolled in the case group and 25 patients who did not develop AF within 48 hours after CABG with CPB were enrolled in the control group. Plasma levels of vitamin D in both groups of patients were recorded. Collected data were analyzed by the SPSS software version 17.

Results:

There was no significant difference in terms of demographic characteristics, comorbidities, lipid profile and kidney function between two groups. The mean plasma level of vitamin D was 27.4 ± 2.22 ng/ml in the case group and was 28.2 ± 1.18 ng/ml in the control group it (p= 0.803).

Conclusions:

Plasma levels of vitamin D were almost the same in both groups and there was no statistically significant difference between the groups with and without atrial fibrillation following CABG.

Meta-analysis of Vitamin D Deficiency and Risk of Atrial Fibrillation

BACKGROUND

There are accumulating studies investigating the association between vitamin D status and the risk of atrial fibrillation (AF). However, the results in these studies were inconsistent in regard to the role of vitamin D deficiency in predicting the development of AF.

HYPOTHESIS

Vitamin D deficiency is associated increased risk of AF.

METHODS

Using PubMed and Embase databases, we searched for records published before March 2016. Additionally, a manual search was conducted using all review articles on this topic. Of the 587 initially identified records, 8 studies with a total of 27 307 patients were finally analyzed.

RESULTS

In the categorical variable analysis, vitamin D deficiency was associated with the occurrence of AF (odds ratio: 1.31, 95% confidence interval: 1.06-1.62, P = 0.01). In the continuous variable analysis, higher vitamin D levels appear to protect against the development of AF (odds ratio: 0.92, 95% confidence interval: 0.87-0.97, P = 0.002). However, the association is weak on the pooled analysis of prospective cohort studies focused on new-onset AF (P = 0.07 and 0.04), whereas the pooled analysis of case-control studies mainly assessing for chronic AF strongly support such an association (both P < 0.0001).

CONCLUSIONS

Vitamin D deficiency modestly increases the risk of AF. Further studies are needed to determine the if there is a direct causal relationship between vitamin D levels and AF and whether vitamin D supplements will prevent new-onset AF.

Relationship between vitamin D level and left atrial fibrosis in patients with lone paroxysmal atrial fibrillation undergoing cryoballoon-based catheter ablation

BACKGROUND

Left atrial (LA) fibrosis is known as the hallmark for arrhythmogenic substrate in atrial fibrillation (AF). Quantification of LA fibrosis by using delayed-enhanced magnetic resonance imaging (DE-MRI) in AF patients is a pioneering noninvasive technique. Vitamin D (vitD) negatively regulates the renin-angiotensin system, binds to vitD receptors on cardiac myocytes, and has antioxidant properties that may ameliorate the inflammation and proarrhythmic substrate formation. However, its role in LA fibrosis is unclear. We aimed to investigate the association of serum 25(OH)D level with the extent of LA fibrosis by using DE-MRI and also predictors for AF recurrence after cryoablation was assessed in patients with paroxysmal AF.

METHODS

A total of 48 patients with lone paroxysmal AF (41.7% female; age: 48.5±8.4 years) who underwent DE-MRI at 1.5T and initial cryoballoon-based catheter ablation along with 48 healthy control subjects were enrolled. Fibrosis degree was categorized according to Utah class defined in the DECAAF study.

RESULTS

Serum 25(OH)D levels were significantly lower in AF group compared to control group (25.8±7.6ng/ml vs. 31.0±9.5ng/ml, p=0.004). Serum 25(OH)D levels were associated with moderate-severe LA fibrosis independent of other measures (OR: 0.72, 95% CI: 0.54-0.97, p=0.028). At a mean 16.5±2.6 months follow-up, late recurrence was observed in 10 (20.8%) patients. In multivariable Cox regression analysis, LA volume index (HR: 1.42, 95% CI: 1.01-2.01, p=0.045) and the extent of LA fibrosis (HR: 1.14, 95% CI: 1.01-1.28, p=0.034) were found as independently associated with late AF recurrence during follow-up.

CONCLUSION

Lower levels of serum 25(OH)D are significantly associated with more extensive LA fibrosis in patients with lone paroxysmal AF and may be implicated in the pathophysiology of AF recurrence after cryoablation. Further large-scale studies are needed to elucidate the exact role of vitD deficiency and replacement on LA fibrosis.

Relationship between Vitamin D and the development of atrial fibrillation after on-pump coronary artery bypass graft surgery

Background:

Vitamin D deficiency is associated with many diverse cardiovascular disorders, such as hypertension, heart failure, stroke, coronary artery disease and atrial fibrillation. The relationship between Vitamin D and the development of atrial fibrillation after coronary artery bypass surgery (CABG) has not been studied. Therefore, we assessed the relationship between Vitamin D and the development of postoperative atrial fibrillation (POAF) after CABG.

Methods:

Medical records of consecutive patients who underwent CABG surgery were retrospectively reviewed for the development of atrial fibrillation in the postoperative period. Vitamin D, other biochemical parameters, and clinical and echocardiographic parameters were evaluated in all patients. The independent variables for the development of postoperative atrial fibrillation were defined and their predictive values were measured.

Results:

The study group consisted of 128 patients, of whom 41 (32%) developed POAF. Age, diabetes mellitus, chronic obstructive pulmonary disease, history of transient ischaemic attack/stroke, heart failure, left atrial diameter, platelet:largecell ratio, and creatinine, urea, uric acid, calcium and potassium levels were identified as important variables for the development of POAF. However, with logistic regression analysis, chronic obstructive pulmonary disease (OR: 28.737, 95% CI: 0.836–16.118, p < 0.001), heart failure (OR: 15.430, 95% CI: 0.989–7.649, p = 0.006), diabetes mellitus (OR: 11.486, 95% CI: 0.734–11.060, p = 0.001) and left atrial diameter (OR: 1.245, 95% CI: 0.086–6.431, p = 0.011) appeared as independent variables predicting the development of POAF.

Conclusion:

In our study, although there was a significant negative correlation between Vitamin D and left atrial diameter, Vitamin D level was not an independent predictor for POAF.

Underweight is a risk factor for atrial fibrillation: A nationwide population-based study

BACKGROUND

Obesity is a well-known risk factor for development of atrial fibrillation (AF). However, the impact of underweight on AF has not been previously recognized. We sought to determine the risk of AF in subjects with underweight in this study.

METHODS

We analyzed clinical data from a total of 132,063 individuals with the age of 40years or older who received health care checkups arranged by the national insurance program between 2003 and 2004. Newly diagnosed nonvalvular AF was identified using claim data during a median follow-up duration of 9.0years.

RESULTS

The mean body mass index (BMI) of patients was 23.9kg/m(2), and 3,323 individuals (2.5%) were classified as being underweight (BMI <18.5kg/m(2)). During the study period, 3,237 individuals (2.5%) developed AF. There was a U-shaped relationship between BMI and AF occurrence: Each 1.0kg/m(2) increase of BMI above 20kg/m(2) was associated with a 6% increased risk of AF (p<0.001), while each 1.0kg/m(2) lower BMI below 20kg/m(2) was associated with a 13% increased risk of AF (p<0.001) after multivariable adjustment. Underweight was significantly associated with 23% increased risk of AF, while obesity classes I and II were with 26% and 120% increased risk of AF, respectively. Excess risk of AF in the underweight was independent of thyroid disease, chronic lung disease, or history of malignancy, and was not attributable to cigarette smoking, low socioeconomic status, excessive physical activity, or heavy alcohol consumption.

CONCLUSION

BMI has a U-shaped relationship with the risk of AF. Underweight was an independent risk factor for AF independent of confounding factors such as chronic lung disease and malignancy. These findings suggest that underweight is associated with biological effects that contribute to the development of AF.

Plasma 25-hydroxyvitamin D2 and D3 levels and incidence of postoperative atrial fibrillation

Low circulating levels of total 25-hydroxyvitamin D (25(OH)D) have been associated with an increased risk of adverse effects after cardiac surgery. The metabolites, 25(OH)D₂ and 25(OH)D₃, provide a good index of vitamin D status. In this study, we examined the association between preoperative plasma levels of total 25(OH)D, 25(OH)D₂ and 25(OH)D₃ and the risk of postoperative atrial fibrillation (POAF) following open heart surgery. The levels of plasma 25(OH)D₂ and 25(OH)D₃ in 118 patients, who underwent coronary artery bypass grafting and/or valvular surgery, were measured immediately prior to surgery and on postoperative day 3 by liquid chromatography–tandem mass spectrometry. Patients who developed POAF had higher median plasma levels of 25(OH)D₂ than those who remained in sinus rhythm (SR) (P = 0·003), but no significant difference was noted in levels of 25(OH)D₃ or total 25(OH)D between the two groups (P > 0·05). By univariate analysis, patients with total 25(OH)D and 25(OH)D₂ levels above the median had higher frequency of POAF (P < 0·05) and the incidence of POAF increased significantly with each higher quartile of preoperative plasma levels of 25(OH)D₂ (P = 0·001), an association that was independent of confounding factors. In both the SR and POAF groups, the median plasma levels of 25(OH)D₂, 25(OH)D₃ and total 25(OH)D were lower (P < 0·05) on the third postoperative day compared with preoperatively. Our findings demonstrate that higher plasma levels of 25(OH)D₂ are associated with increased risk of POAF, while this is not the case for 25(OH)D₃ or total 25(OH)D. The reason for these discrepant results is not clear but warrants further study.

Serum 25-hydroxyvitamin D and the incidence of atrial fibrillation: the Atherosclerosis Risk in Communities (ARIC) study

AIMS

To assess the prospective association between circulating 25-hydroxyvitamin D [25(OH)D] and atrial fibrillation (AF) risk.

METHODS AND RESULTS

We studied 12 303 participants from the Atherosclerosis Risk in Communities study without baseline AF (1990-92). Baseline serum total 25(OH)D was measured using mass spectrometry. Incident AF cases were identified from electrocardiograms, hospital discharge codes, and death certificates through 2012. We estimated hazard ratios (HRs) and 95% confidence intervals (95% CIs) of AF across clinical categories of serum 25(OH)D concentrations with multivariable Cox models, and tested interactions by age, race, and sex. We meta-analysed our results with those from published prospective studies that reported associations between 25(OH)D and AF risk. During a median follow-up of 21 years, we identified 1866 AF events. In multivariable models, deficient 25(OH)D status (<20 ng/mL), compared with optimal levels (≥30 ng/mL), was not associated with AF risk (HR, 95% CI: 1.10, 0.96-1.26). A significant interaction of 25(OH)D concentrations with age (P = 0.01), but not with race or sex (P > 0.40), was identified, with higher risk of AF among those with deficient 25(OH)D status in younger (HR, 95% CI: 1.35, 1.05-1.73) but not older individuals (HR, 95% CI: 1.02, 0.86-1.21). A meta-analysis of these results and four prospective studies did not support a clinically relevant association of circulating 25(OH)D with AF risk [pooled HR, 95%CI: 1.04, 1.00-1.08, per 1 SD lower 25(OH)D].

CONCLUSION

Low serum 25(OH)D was not associated with incident AF in a community-based cohort and in a meta-analysis of prospective studies. A possible association in younger individuals warrants further investigation.

Vitamin D Attenuates Left Atrial Volume Changes in African American Males with Obesity and Prediabetes

Vitamin D deficiency is common among African Americans in the United States and is associated with increased cardiovascular disease risk. In this study, prediabetic African American males who were found to be vitamin D-deficient were randomized to vitamin D supplementation and assessed for changes in left atrial (LA) volume. Prediabetic African American males who were vitamin D-deficient (25(OH)D: 5.0-29 ng/mL) were randomized to high-dose ergocalciferol or placebo. Echocardiography was performed at baseline and at 1 year. Ejection fraction (EF), septal and posterior wall thickness, LA area, LA length, LA volume, E, A, septal and lateral e' and a', deceleration time, and isovolumetric relaxation time were collected. Eighty-one of 158 (51%) subjects received vitamin D2 . Baseline characteristics were similar among both groups. In the placebo group, left atrial volume significantly increased on follow-up (LA volume increased 6.3 mL, P = 0.0025). Compared with placebo group, the treatment group with ergocalciferol had attenuated increases in left atrial volume (LA volume increased 2.6 mL, P = 0.29). Changes in left atrial volume persisted when indexed to body surface area. There was no significant difference in other diastolic parameters and blood pressure between groups. In conclusion, vitamin D-deficient prediabetic African American males who were treated with high-dose vitamin D2 were found to have attenuated increases in left atrial volume compared with controls over 12-month follow-up.

Optimal Vitamin D Supplementation Levels for Cardiovascular Disease Protection

First described in relation to musculoskeletal disease, there is accumulating data to suggest that vitamin D may play an important role in cardiovascular disease (CVD). In this review we aim to provide an overview of the role of vitamin D status as both a marker of and potentially causative agent of hypertension, coronary artery disease, heart failure, atrial fibrillation, stroke, and peripheral vascular disease. The role of vitamin D levels as a disease marker for all-cause mortality is also discussed. We review the current knowledge gathered from experimental studies, observational studies, randomised controlled trials, and subsequent systematic reviews in order to suggest the optimal vitamin D level for CVD protection.

Vitamin D cell signalling in health and disease

Vitamin D deficiency has been linked to many human diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), hypertension and cardiovascular disease. A Vitamin D phenotypic stability hypothesis, which is developed in this review, attempts to describe how this vital hormone acts to maintain healthy cellular functions. This role of Vitamin D as a guardian of phenotypic stability seems to depend on its ability to maintain the redox and Ca(2+) signalling systems. It is argued that its primary action is to maintain the expression of those signalling components responsible for stabilizing the low resting state of these two signalling pathways. This phenotypic stability role is facilitated through the ability of vitamin D to increase the expression of both Nrf2 and the anti-ageing protein Klotho, which are also major regulators of Ca(2+) and redox signalling. A decline in Vitamin D levels will lead to a decline in the stability of this regulatory signalling network and may account for why so many of the major diseases in man, which have been linked to vitamin D deficiency, are associated with a dysregulation in both ROS and Ca(2+) signalling.