Non-alcoholic Fatty Liver Disease and the Risk of Incident Atrial Fibrillation in Young Adults: A Nationwide Population-Based Cohort Study

Metabolic Dysfunction-Associated Steatotic Liver Disease as a Cardiovascular Risk Factor: Focus on Atrial Fibrillation

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease, is increasingly recognized as a multisystem disorder with significant cardiovascular implications, particularly in its association with atrial fibrillation (AF). As the most common sustained cardiac arrhythmia, AF contributes to substantial morbidity and mortality, making it essential to explore its links with MASLD. The relationship between these conditions is underpinned by shared pathophysiological mechanisms, including systemic inflammation, insulin resistance, oxidative stress, and activation of the renin-angiotensin-aldosterone system. These processes drive atrial remodeling and electrical instability, predisposing individuals with MASLD to AF. Epidemiological studies further support this connection, showing an independent association between MASLD and an increased risk of AF, particularly in those with metabolic comorbidities such as obesity and type 2 diabetes. Beyond increasing AF susceptibility, MASLD may also influence disease progression and response to treatment, affecting anticoagulation safety, rhythm-control strategies, and the success of catheter ablation. Given these clinical implications, therapies targeting metabolic dysfunction-such as statins, renin-angiotensin-aldosterone system inhibitors, and structured lifestyle modifications-may offer dual benefits in mitigating both MASLD and AF risk. However, significant knowledge gaps remain regarding the causal direction of this association, the impact of MASLD severity on AF burden, and the most effective management strategies for patients with both conditions. Future research should prioritize longitudinal studies, mechanistic investigations, and randomized controlled trials to deepen our understanding of this relationship, ultimately guiding more personalized and integrated treatment approaches. Incorporating MASLD screening into cardiovascular risk assessment may enhance early detection and improve outcomes for at-risk populations.

Impact of steatotic liver disease categories on atrial fibrillation in type 2 diabetes: a nationwide study

This study aims to investigate the incidence of new-onset atrial fibrillation (AF) in individuals with type 2 diabetes mellitus (T2DM) across different categories of steatotic liver disease (SLD). Using a health examination database between 2009 and 2012, this study included 2,480,880 patients. Participants were categorized into five groups based on hepatic steatosis (fatty liver index ≥ 60), cardiometabolic risk factors, and alcohol consumption. Cox regression analyses were performed. The metabolic dysfunction-associated steatotic liver disease (MASLD) group showed an increased risk of new-onset AF (adjusted hazard ratio (aHR), 1.10; 95% confidence interval (CI), 1.08-1.11). The MASLD with other combined group demonstrated increased AF development (aHR, 1.22; 95% CI, 1.18-1.26). In metabolic dysfunction and alcohol-related steatotic liver disease (MetALD) and alcohol-related liver disease (ALD) with metabolic groups, heavy to excessive alcohol consumption increased the risk of AF incidence, with the highest aHR associated with greater alcohol intake (aHR, 1.26; 95% CI, 1.22-1.29, 1.48; 95% CI, 1.41-1.55). MASLD increased the risk of AF in patients with T2DM, with a higher risk observed when accompanied by other liver diseases. Alcohol consumption was associated with proportional increase in the risk of AF, with excessive alcohol consumption associated with the highest risk of AF.

A Mendelian randomization study reveals a causal association between NASH and the risk of atrial fibrillation

Background

Epidemiological evidence suggests that non-alcoholic fatty liver disease (NAFLD) may increase the risk of atrial fibrillation (AF). However, the findings are inconsistent, and the causality remains to be established.

Methods

We conducted two-step, two-sample Mendelian randomization (MR) analysis to assess the association between genetically predicted NAFLD (i.e. chronically elevated serum alanine aminotransferase levels [cALT], imaging-based and biopsy-confirmed NAFLD) and AF. Subsequently, we further performed Mendelian randomization to investigate the causal relationship between non-alcoholic steatohepatitis (NASH), a subtype of NAFLD, and AF. The inverse variance weighted (IVW) method was used as the primary approach to reveal the potential causation between the exposure and outcome.

Results

There was no significant causal association between NAFLD diagnosed based on cALT, confirmed by imaging, or verified by biopsy, and an increased risk of atrial fibrillation. Furthermore, the results of the IVW method revealed a positive causal effect of NASH on AF (OR=1.113, 95% CI=1.025-1.209, P = 0.011). In the reverse analysis, however, no evidence supported a significant genetic association between AF and NASH (OR=0.974, 95% CI=0.934-1.016, P = 0.214).

Conclusion

A causal relationship existed between NASH and the risk of AF. However, no significant genetic association has been observed between NAFLD and AF risk. This suggests that managing the progression of NAFLD may hold potential value in preventing the onset of AF.

Exploring Anti-Inflammatory Treatment as Upstream Therapy in the Management of Atrial Fibrillation

Inflammation has been widely recognized as one of the major pathophysiological drivers of the development of atrial fibrillation (AF), which works in tandem with other risk factors of AF including obesity, diabetes, hypertension, and heart failure (HF). Our current understanding of the role of inflammation in the natural history of AF remains elusive; however, several key players, including the NLRP3 (NLR family pyrin domain containing 3) inflammasome, have been acknowledged to be heavily influential on chronic inflammation in the atrial myocardium, which leads to fibrosis and eventual degradation of its electrical function. Nevertheless, our current methods of pharmacological modalities with reported immunomodulatory properties, including well-established classes of drugs e.g., drugs targeting the renin-angiotensin-aldosterone system (RAAS), statins, and vitamin D, have proven effective in reducing the overall risk of developing AF, the onset of postoperative atrial fibrillation (POAF), and reducing overall mortality among patients with AF. This might bring hope for further progress in developing new treatment modalities targeting cellular checkpoints of the NLRP3 inflammasome pathway, or revisiting other well-known anti-inflammatory drugs e.g., colchicine, vitamin C, nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticosteroids, and antimalarial drugs. In our review, we aim to find relevant upstream anti-inflammatory treatment methods for the management of AF and present the most current real-world evidence of their clinical utility.

MASLD Is Associated With an Increased Long-Term Risk of Atrial Fibrillation: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Studies have reported an association between metabolic dysfunction-associated steatotic liver disease (MASLD) and an increased risk of developing atrial fibrillation (AF). However, the magnitude of the risk and whether this risk varies with the severity of MASLD remains uncertain.

METHODS

In this systematic review and meta-analysis, we searched three large electronic databases using predefined keywords to identify cohort studies (published up to 30 September 2024) in which MASLD was diagnosed by liver biopsy, imaging methods, International Classification of Diseases (ICD) codes, or blood-based scores. The primary outcome was the occurrence of AF based on ICD codes, medical records, or electrocardiograms. Meta-analysis was performed using random-effects modelling.

RESULTS

We identified 16 retrospective cohort studies with aggregate data on ~19.5 million individuals followed for a median of 7.2 years. MASLD was significantly associated with an increased risk of developing incident AF (random-effects hazard ratio 1.20, 95% CI 1.10-1.32; I2 = 92%). This risk did not appear to further increase with the severity of liver fibrosis (n = 3 studies; random-effects hazard ratio 1.22, 95% CI 1.18-1.26; I2 = 10%). The risk of AF remained significant even after adjusting for age, sex, body mass index, hypertension, Type 2 diabetes or other cardiometabolic risk factors. Sensitivity analyses did not modify these findings. The funnel plot and Egger's test showed no significant publication bias.

CONCLUSIONS

This updated and comprehensive meta-analysis provides evidence that MASLD is significantly associated with an increased long-term risk of developing incident AF. Further research is required to better decipher the link between MASLD and increased AF incidence.

Association of nonalcoholic fatty liver disease with new-onset atrial fibrillation stratified by age groups

BACKGROUND

The association between nonalcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) has been inconsistent, and the impact of hepatic fibrosis on this relationship remains uncertain. We investigated the association between NAFLD and the risk of new-onset AF across different age groups.

METHODS

A total of 3,179,582 participants from the 2009 Korean National Health Screening Program were divided into five groups based on NAFLD status: no NAFLD (fatty liver index [FLI] < 30); grade 1 NAFLD without advanced fibrosis (FLI 30-59 & BARD < 2); grade 1 NAFLD with advanced fibrosis (FLI 30-59 & BARD ≥ 2); grade 2 NAFLD without advanced fibrosis (FLI ≥ 60 & BARD < 2); and grade 2 NAFLD with advanced fibrosis (FLI ≥ 60 & BARD ≥ 2). The primary outcome was incident AF.

RESULTS

During the median follow-up of 9.3 years, 62,542 patients were diagnosed with new-onset AF. In the age- and sex-adjusted model, the risk of new-onset AF increased across NAFLD grades and fibrosis categories: grade 1 NAFLD without advanced fibrosis (hazard ratio [HR] 1.120, 95% confidence interval [CI]: 1.081-1.161); grade 1 NAFLD with advanced fibrosis (HR 1.275, 95% CI 1.251-1.300); grade 2 NAFLD without advanced fibrosis (HR 1.305, 95% CI: 1.252-1.360); and grade 2 NAFLD with advanced fibrosis (HR 1.627, 95% CI: 1.586-1.670). In the multivariate model, the excess risk of AF in patients with NAFLD and advanced fibrosis remained significant, even in participants aged 20-39 years.

CONCLUSION

Patients with NAFLD had a higher risk of new-onset AF, which increased progressively with NAFLD severity, particularly in those aged 20-29 years.

Correlation between serum uric acid to high-density lipoprotein cholesterol ratio and atrial fibrillation in patients with NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is independently associated with atrial fibrillation (AF) risk. The uric acid (UA) to high-density lipoprotein cholesterol (HDL-C) ratio (UHR) has been shown to be closely associated with cardiovascular disease (CVD) and NAFLD. The aim of this study is to clarify whether elevated UHR is associated with the occurrence of AF in patients with NAFLD and to determine whether UHR predicted AF.

METHODS

Patients diagnosed with NAFLD in the Department of Cardiovascular Medicine of the Second Hospital of Shanxi Medical University from January 1, 2020, to December 31, 2021, were retrospectively enrolled in this study. The study subjects were categorized into AF group and non-AF group based on the presence or absence of combined AF. Logistic regression was performed to evaluate the correlation between UHR and AF. Sensitivity analysis and subgroup interaction analysis were performed to verify the robustness of the study results. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff value for UHR to predict the development of AF in patients with NAFLD.

RESULTS

A total of 421 patients with NAFLD were included, including 171 in the AF group and 250 in the non-AF group. In the univariate regression analysis, NAFLD patients with higher UHR were more likely to experience AF, and the risk of AF persisted after confounding factors were adjusted for (OR: 1.010, 95%CI: 1.007-1.013, P<0.001). AF risk increased with increasing UHR quartile (P for trend < 0.001). Despite normal serum UA and HDL-C, UHR was still connected with AF in patients with NAFLD. All subgroup variables did not interact significantly with UHR in the subgroup analysis. The ROC curve analysis showed that the areas under the curve for UA, HDL-C, and UHR were 0.702, 0.606, and 0.720, respectively, suggesting that UHR has a higher predictive value for AF occurrence in NAFLD patients compared to HDL-C or UA alone.

CONCLUSION

Increased UHR level was independently correlated with a high risk of AF in NAFLD patients.

Non-alcoholic fatty liver disease increases the risk of cardiovascular disease in young adults and children: a systematic review and meta-analysis of cohort studies

Background and aims

It is uncertain if there is a link between non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVD) in young adults and children. To evaluate the potential link between these two conditions, we conducted a systematic review and meta-analysis of cohort studies.

Methods

A comprehensive search was conducted in PubMed, Web of Science and Embase in order to locate all relevant cohort studies published until August 2023. Random effects meta-analyses were conducted using the generic inverse variance method, with additional subgroup and sensitivity analyses. The Newcastle-Ottawa Scale was employed to evaluate the methodological quality.

Results

Four cohort studies (eleven datasets) involving 10,668,189 participants were included in this meta-analysis. This meta-analysis demonstrated that NAFLD increases the risk of CVD in young adults and children (HR = 1.63, 95% CI: 1.46-1.82, P < 0.00001). Further subgroup analyses showed that individuals with NAFLD were at a heightened risk of coronary heart disease (CHD) (HR = 3.10, 95% CI: 2.01-4.77, P < 0.00001), myocardial infarction (MI) (HR = 1.69, 95% CI: 1.61-1.78, P < 0.00001), atrial fibrillation (AF) (HR = 2.00, 95% CI: 1.12-3.57, P = 0.02), congestive heart failure (CHF) (HR = 3.89, 95% CI: 1.20-12.61, P = 0.02), and stroke (HR = 1.47, 95% CI: 1.39-1.55, P < 0.00001). The results of subgroup analyses based on the study location, NAFLD definition, and follow-up time also showed consistency with the overall results. Sensitivity analyses showed that our results were robust. All of the included studies were judged to be of medium to high quality.

Conclusion

Current evidence reveals that NAFLD is linked to an increased risk of major CVD (including CHD, MI, AF, CHF and stroke) in young adults and children. Further research is needed to strengthen this association and provide stronger evidence for primary prevention of CVD in young adults and children with NAFLD.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, PROSPERO registration number: CRD42023457817.

Fatty Liver Index and the Risk of Atrial Fibrillation in a General Japanese Population - The Suita Study

BACKGROUND

Atrial fibrillation (AF) is the most diagnosed arrhythmia in clinical settings. The fatty liver index (FLI) is a marker of liver steatosis with potential cardiovascular implications. This study investigated whether FLI could predict the risk of AF.

METHODS AND RESULTS

We used data from the Suita Study, a Japanese population-based prospective cohort study. A total of 2,346 men and 3,543 women, aged 30-84 years, without prevalent AF were included and followed up. The diagnosis of AF was established during follow-up using electrocardiograms, hospital records, and death certificates. FLI was assessed during a baseline health checkup. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for incident AF per FLI quintile and log-transformed FLI. Within a median 14.5 years of follow-up, 142 men and 105 women developed AF. Compared with women in the third (middle) FLI quintile, women in the first (lowest), fourth, and fifth (highest) quintiles showed a higher risk of AF, with multivariable-adjusted HRs of 2.37 (95% CI 1.06-5.31), 2.60 (95% CI 1.30-5.17), and 2.04 (95% CI 1.00-4.18), respectively. No corresponding associations were observed in men. The change in log-transformed FLI was not associated with the risk of AF in either sex.

CONCLUSIONS

A U-shaped association between FLI and AF risk was detected in Japanese women. FLI could be a screening tool to detect women at high risk of developing AF.

Association between nonalcoholic fatty liver disease and atrial fibrillation and other clinical outcomes: a meta-analysis

The association between nonalcoholic fatty liver disease (NAFLD) with cardiovascular and cerebrovascular outcomes, as well as their clinical impact, has yet to be established in the literature. This meta-analysis aims to evaluate the association between the NAFLD patients and the risk of atrial fibrillation (AF), heart failure (HF), stroke, cardiovascular mortality (CVM), and revascularization incidence. We performed a systematic literature search using PubMed, Embase, Scopus, and Cochrane libraries for relevant articles from inception until August 2022. A total of 12 cohort studies with 18,055,072 patients (2,938,753 NAFLD vs 15,116,319 non-NAFLD) were included in our analysis. The mean age of the NAFLD patients group and the non-NAFLD group was comparable (55.68 vs 55.87). The most common comorbidities among the NAFLD patients group included hypertension (38% vs 24%) and diabetes mellitus (14% vs 8%). The mean follow-up duration was 6.26 years. The likelihood of AF (risk ratio (RR), 1.42 (95% CI 1.19, 1.68), p < 0.001), HF (RR, 1.43(95% CI 1.03, 2.00), p < 0.001), stroke (RR, 1.26(95% CI 1.16, 1.36), p < 0.001), revascularization (RR, 4.06(95% CI 1.44, 11.46), p = 0.01), and CVM (RR, 3.10(95% CI 1.43, 6.73), p < 0.001) was significantly higher in the NAFLD patients group compared to that of the non-NAFLD group. However, all-cause mortality was comparable between both the groups of patients (RR, 1.30 (95% CI 0.63, 2.67), p = 0.48). In conclusion, the patients with NAFLD are at increased risk of AF, HF, and CVM.

A systematic review and meta-analysis of cohort studies on the potential association between NAFLD/MAFLD and risk of incident atrial fibrillation

Background and objective

The association between atrial fibrillation (AF) and non-alcoholic fatty liver disease (NAFLD) or metabolic-associated fatty liver disease (MAFLD) has been explored in recent cohort studies, however, the results have been controversial and inconclusive. This meta-analysis aimed to explore this potential association.

Methods

We systematically searched PubMed, Embase, and Web of Science databases to identify all relevant cohort studies investigating the association between NAFLD/MAFLD and AF published from database inception to October 30, 2022. Random-effects models were utilized to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for summary purposes. Additionally, subgroup and sensitivity analyses were performed.

Results

A total of 13 cohort studies with 14 272 735 participants were included. Among these, 12 cohort studies with 14 213 289 participants (median follow-up of 7.8 years) showed a significant association between NAFLD and an increased risk of incident AF (HR = 1.18, 95% CI: 1.12-1.23, P < 0.00001). Our subgroup analyses mostly yielded similar results, and the results of sensitivity analyses remained unchanged. However, meta-analysis of data from 2 cohort studies with 59 896 participants (median follow-up of 2.15 years) showed that MAFLD was not linked to incident AF (HR = 1.36, 95% CI: 0.63-2.92, P = 0.44).

Conclusion

Current evidence shows that NAFLD may be linked to a slightly higher risk of developing AF, particularly among Asian populations and those diagnosed with NAFLD using FLI criteria. Nevertheless, there is not enough evidence to support the proposed association between MAFLD and an increased risk of AF. To better understand this relationship, future studies should consider factors such as specific population, the severity of NAFLD/MAFLD, diagnostic methods of NAFLD and AF, and cardiometabolic risk factors.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero, identifier CRD42022371503.

High liver fibrosis scores in metabolic dysfunction-associated fatty liver disease patients are associated with adverse atrial remodeling and atrial fibrillation recurrence following catheter ablation

BACKGROUND

A number of epidemiological studies have suggested an association between metabolic dysfunction-associated fatty liver disease (MAFLD) and the incidence of atrial fibrillation (AF). However, the pathogenesis leading to AF in the context of MAFLD remains unclear. We therefore aimed at assessing the impact of MAFLD and liver fibrosis status on left atrium (LA) structure and function.

METHODS

Patients with a Fatty Liver Index (FLI) >60 and the presence of metabolic comorbidities were classified as MAFLD+. In MAFLD+ patients, liver fibrosis severity was defined using the non-alcoholic fatty liver disease (NAFLD) Fibrosis Score (NFS), as follows: MAFLD w/o fibrosis (NFS ≦ -1.455), MAFLD w/indeterminate fibrosis (-1.455 < NFS < 0.675), and MAFLD w/fibrosis (NFS ≧ 0.675). In the first cohort of patients undergoing AF ablation, the structural and functional impact on LA of MAFLD was assessed by LA strain analysis and endocardial voltage mapping. Histopathological assessment of atrial fibrosis was performed in the second cohort of patients undergoing cardiac surgery. Finally, the impact of MAFLD on AF recurrence following catheter ablation was assessed.

RESULTS

In the AF ablation cohort (NoMAFLD n = 123; MAFLD w/o fibrosis n = 37; MAFLD indeterm. fibrosis n = 75; MAFLD w/severe fibrosis n = 10), MAFLD patients with high risk of F3-F4 liver fibrosis presented more LA low-voltage areas as compared to patients without MAFLD (16.5 [10.25; 28] vs 5.0 [1; 11] low-voltage areas p = 0.0115), impaired LA reservoir function assessed by peak left atrial longitudinal strain (19.7% ± 8% vs 8.9% ± 0.89% p = 0.0268), and increased LA volume (52.9 ± 11.7 vs 43.5 ± 18.0 ml/m² p = 0.0168). Accordingly, among the MAFLD patients, those with a high risk of F3-F4 liver fibrosis presented a higher rate of AF recurrence during follow-up (p = 0.0179). In the cardiac surgery cohort (NoMAFLD n = 12; MAFLD w/o fibrosis n = 5; MAFLD w/fibrosis n = 3), an increase in histopathological atrial fibrosis was observed in MAFLD patients with a high risk of F3-F4 liver fibrosis (p = 0.0206 vs NoMAFLD; p = 0.0595 vs MAFLD w/o fibrosis).

CONCLUSION

In conclusion, we found that liver fibrosis scoring in MAFLD patients is associated with adverse atrial remodeling and AF recurrences following catheter ablation. The impact of the management of MAFLD on LA remodeling and AF ablation outcomes should be assessed in dedicated studies.