Circulating levels of liver enzymes and incidence of atrial fibrillation: the Atherosclerosis Risk in Communities cohort

New Therapeutic Approaches for the Treatment of Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and Increased Cardiovascular Risk

Metabolic dysfunction-associated steatotic liver disease (MASLD) was previously known as nonalcoholic fatty liver disease (NAFLD). The main characteristic of the disease is the process of long-term liver inflammation, which leads to hepatocyte damage followed by liver fibrosis and eventually cirrhosis. Additionally, these patients are at a greater risk for developing cardiovascular diseases (CVD). They have several pathophysiological mechanisms in common, primarily lipid metabolism disorders and lipotoxicity. Lipotoxicity is a factor that leads to the occurrence of heart disease and the occurrence and progression of atherosclerosis. Atherosclerosis, as a multifactorial disease, is one of the predominant risk factors for the development of ischemic heart disease. Therefore, CVD are one of the most significant carriers of mortality in patients with metabolic syndrome. So far, no pharmacotherapy has been established for the treatment of MASLD, but patients are advised to reduce their body weight and change their lifestyle. In recent years, several trials of different drugs, whose basic therapeutic indications include other diseases, have been conducted. Because it has been concluded that they can have beneficial effects in the treatment of these conditions as well, in this paper, the most significant results of these studies will be presented.

Potential Causal Association between Elevated Gamma-Glutamyl Transferase Level and Stroke: A Two-Sample Mendelian Randomization Study

Researchers have suggested a potential relationship between gamma-glutamyl transferase (GGT) level and stroke. We investigated a potential causal relationship between GGT level as exposures and stroke and stroke subtypes (cardioembolic, small vessel, and large artery) in a European population. We performed a two-sample Mendelian randomization (MR) study using the genome-wide association study (GWAS) data from the UK Biobank as the exposure set. For the outcome set, we used stroke in the GWAS data from the GIGASTROKE Consortium. We considered alcohol consumption, atrial fibrillation, and body mass index as confounders. We used PhenoScanner searches for removal of SNPs and multivariable MR analysis for assessing confounders. We observed significant causal associations between GGT level and stroke (odds ratio [OR] = 1.23, 95% CI = [1.05-1.44], and p = 0.012 with IVW; OR = 1.19, 95% CI= [1.02-1.39], and p = 0.031 with MR-PRESSO). These results were consistent after removing SNPs related to confounding factors. Similarly, in multivariable MR, GGT was associated with stroke after adjusting for confounding factors (OR = 1.30, 95% CI 1.07-1.60), p = 0.010). Because GGT level has a causal relationship with stroke, researchers should test its significance as a potential risk factor for stroke. Additional research is required to validate these results.

Association between the accumulation of elevated serum γ-glutamyltransferase level and risk of atrial fibrillation: a nationwide cohort study

Atrial fibrillation (AF) is the most common cardiac arrhythmia. The association between AF and γ-Glutamyltransferase (GGT) was not fully established. This study demonstrated the independent association of cumulative GGT score and AF incidence with the dose-response relationship. Using the Korean National Health Insurance Corporation database, adult subjects who had 4 consecutive annual health examinations from 2009 to 2012 were enrolled. A cumulative GGT score was calculated as the cumulative number of the highest GGT quartile amongst four examinations (0-4 times). A multivariable Cox proportional hazards regression analysis was performed. Among a total of 3,500,847 people included, AF was developed in 27,752 people (0.793%) during a median of 8.0 years of follow up. The incidence rate of AF and adjusted hazard ratio were increased by a stepwise manner in the higher quartile group and cumulative GGT score group. In subgroup analysis, this trend was more prominent in the elderly, people without hypertension, non-obese people, and people without any four comorbidities (diabetes mellitus, hypertension, dyslipidemia, and obesity). Our results suggest multiple accumulation of elevated GGT levels in health examination might be a useful marker for risk stratification of AF development, especially in the elderly and healthy population.

Evaluation of New Potential Inflammatory Markers in Patients with Nonvalvular Atrial Fibrillation

Atrial fibrillation (AF), the most common arrhythmia in clinical practice, is associated with an increase in mortality and morbidity due to its high potential to cause stroke and systemic thromboembolism. Inflammatory mechanisms may play a role in the pathogenesis of AF and its maintenance. We aimed to evaluate a range of inflammatory markers as potentially involved in the pathophysiology of individuals with nonvalvular AF (NVAF). A total of 105 subjects were enrolled and divided into two groups: patients with NVAF (n = 55, mean age 72 ± 8 years) and a control group of individuals in sinus rhythm (n = 50, mean age 71 ± 8 years). Inflammatory-related mediators were quantified in plasma samples by using Cytometric Bead Array and Multiplex immunoassay. Subjects with NVAF presented significantly elevated values of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF), interferon-gamma, growth differentiation factor-15, myeloperoxidase, as well as IL-4, interferon-gamma-induced protein (IP-10), monokine induced by interferon-gamma, neutrophil gelatinase-associated lipocalin, and serum amyloid A in comparison with controls. However, after multivariate regression analysis adjusting for confounding factors, only IL-6, IL-10, TNF, and IP-10 remained significantly associated with AF. We provided a basis for the study of inflammatory markers whose association with AF has not been addressed before, such as IP-10, in addition to supporting evidence about molecules that had previously been associated with the disease. We expect to contribute to the discovery of markers that can be implemented in clinical practice hereafter.

Further Advances in Atrial Fibrillation Research: A Metabolomic Perspective

Atrial fibrillation involves an important type of heart arrhythmia caused by a lack of control in the electrical signals that arrive in the heart, produce an irregular auricular contraction, and induce blood clotting, which finally can lead to stroke. Atrial fibrillation presents some specific characteristics, but it has been treated and prevented using conventional methods similar to those applied to other cardiovascular diseases. However, due to the influence of this pathology on the mortality caused by cerebrovascular accidents, further studies on the molecular mechanism of atrial fibrillation are required. Our aim here is provide a compressive review of the use of metabolomics on this condition, from the study of the metabolic profile of plasma to the development of animal models. In summary, most of the reported studies highlighted alterations in the energetic pathways related to the development of the condition.

Dealing with the high bleeding and thrombosis risks in critically ill patients with chronic liver disease: A dilemma in the clinical practice

No Abstract.

Non-vitamin K antagonist oral anticoagulants in atrial fibrillation patients with advanced chronic kidney and liver diseases

Advanced chronic kidney disease (CKD) or chronic liver disease (CLD) is frequent in patients with atrial fibrillation (AF) because of their common risk factors. Chronic kidney disease and CLD superimposed on AF are associated with increased risks of thrombosis and bleeding, which further complicates the use of oral anticoagulants (OACs). Because currently approved non-vitamin K antagonist oral anticoagulants (NOACs) undergo certain degrees of metabolism and clearance in the liver and kidney, increased exposure to medications and risk of bleeding are major concerns with the use of NOACs in patients with advanced CKD and CLD. Besides, these patients were mostly excluded from landmark trials of NOACs and related cohort studies are also limited. Therefore, the optimal strategy for the use of NOACs in this population remains unclear. This review would go through current evidence regarding the safety and efficacy of NOACs in AF patients with advanced CKD and CLD and provide a comprehensive discussion for clinical practices.

Research status and progress of metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) is a more appropriate general predicate to describe non-alcoholic fatty liver disease. The new definition lists metabolic dysfunction as an important cause of liver disease, demonstrates the high heterogeneity of this condition, and speeds up the transformation path to new treatment. The incidence of extrahepatic complications and related diseases of MAFLD far exceed that of the liver disease itself, which seriously threatens human health. In view of the current insufficient understanding of its severity, and the imperfect understanding of the disease scope, pathogenesis, and diagnosis of extrahepatic complications, especially the lack of effective drug treatment, this paper introduces and reviews the research status and progress of extrahepatic complications of MAFLD.

The prevalence of MAFLD and its association with atrial fibrillation in a nationwide health check-up population in China

BACKGROUND AND AIMS

The epidemiological characteristics of MAFLD and its relationship with atrial fibrillation (AF) are limited in China. Therefore, we explored the epidemiological characteristics of MAFLD from adults along with the association of MAFLD and 12-ECG diagnosed AF in a nationwide population from health check-up centers.

METHODS

This observational study used cross-sectional and longitudinal studies with 2,083,984 subjects from 2009 to 2017. Age-, sex-, and regional-standardized prevalence of MAFLD was estimated. Latent class analysis (LCA) was used to identify subclusters of MAFLD. Multivariable logistic regression and mixed-effects Cox regression models were used to analyze the relationship between MAFLD and AF.

RESULTS

The prevalence of MAFLD increased from 22.75% to 35.58% during the study period, with higher rates in males and populations with high BMI or resided in northern regions. The MAFLD population was clustered into three classes with different metabolic features by LCA. Notably, a high proportion of MAFLD patients in all clusters had overweight and prediabetes or diabetes. The MAFLD was significantly associated with a higher risk of AF in the cross-sectional study and in the longitudinal study. In addition, the coexistence of prediabetes or diabetes had the largest impact on subsequent AF.

CONCLUSION

Our findings suggested a high prevalence of MAFLD and a high prevalence of other metabolic diseases in the MAFLD population, particularly overweight and glucose dysregulation. Moreover, MAFLD was associated with a significantly higher risk for existing and subsequent subclinical AF in the Chinese population.

New biomarkers from multiomics approaches: improving risk prediction of atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia leading to many adverse outcomes and increased mortality. Yet the molecular mechanisms underlying AF remain largely unknown. Recent advances in high-throughput technologies make large-scale molecular profiling possible. In the past decade, multiomics studies of AF have identified a number of potential biomarkers of AF. In this review, we focus on the studies of multiomics profiles with AF risk. We summarize recent advances in the discovery of novel biomarkers for AF through multiomics studies. We also discuss limitations and future directions in risk assessment and discovery of therapeutic targets for AF.

Nonalcoholic Fatty Liver Disease: An Emerging Driver of Cardiac Arrhythmia

Cardiac arrhythmias and the resulting sudden cardiac death are significant cardiovascular complications that continue to impose a heavy burden on patients and society. An emerging body of evidence indicates that nonalcoholic fatty liver disease (NAFLD) is closely associated with the risk of cardiac arrhythmias, independent of other conventional cardiometabolic comorbidities. Although most studies focus on the relationship between NAFLD and atrial fibrillation, associations with ventricular arrhythmias and cardiac conduction defects have also been reported. Mechanistic investigations suggest that a number of NAFLD-related pathophysiological alterations may potentially elicit structural, electrical, and autonomic remodeling in the heart, contributing to arrhythmogenic substrates in the heart. NAFLD is now the most common liver and metabolic disease in the world. However, the upsurge in the prevalence of NAFLD as an emerging risk factor for cardiac arrhythmias has received little attention. In this review, we summarize the clinical evidence and putative pathophysiological mechanisms for the emerging roles of NAFLD in cardiac arrhythmias, with the purpose of highlighting the notion that NAFLD may serve as an independent risk factor and a potential driving force in the development and progression of cardiac arrhythmias.

Risk prediction for new-onset atrial fibrillation using the Minnesota code electrocardiography classification system

Background

Few risk models are available to predict future onset of atrial fibrillation (AF) in workers. We aimed to develop risk prediction models for new-onset AF, using annual health checkup (HC) data with electrocardiogram findings.

Methods and Results

We retrospectively included 56,288 factory or office workers (mean age = 51.5 years, 33.0% women) who underwent a HC at a medical center and fulfilled the following criteria; age ≥ 40 years, no history of AF, and greater than 1 annual follow-up HC in 2013–2016. Using Cox models with the Akaike information criterion, we developed and compared prediction models for new-onset AF with and without the Minnesota code information. We externally validated the discrimination accuracy of the models in a general Japanese population cohort, the Hisayama cohort. During the median 3.0-year follow-up, 209 (0.37%) workers developed AF. Age, sex, waist circumference, blood pressure, LDL cholesterol, and γ-GTP were associated with new-onset of AF. Using the Minnesota code information, the AUC significantly improved from 0.82 to 0.84 in the derivation cohort and numerically improved from 0.78 to 0.79 in the validation cohort, and from 0.77 to 0.79 in the Hisayama cohort. The NRI and IDI significantly improved in all and male subjects in both the derivation and validation cohorts, and in female subjects in both the validation and the Hisayama cohorts.

Conclusions

We developed useful risk model with Minnesota code information for predicting new-onset AF from large worker population validated in the original and external cohorts, although study interpretation is limited by small improvement of AUC.

Nonalcoholic fatty liver disease and the risk of atrial fibrillation stratified by body mass index: a nationwide population-based study

We evaluated the association between nonalcoholic fatty liver disease (NAFLD) and incident atrial fibrillation (AF) and analyzed the impact of NAFLD on AF risk in relation to body mass index (BMI). A total of 8,048,055 subjects without significant liver disease who were available fatty liver index (FLI) values were included. Subjects were categorized into 3 groups based on FLI: < 30, 30 to < 60, and ≥ 60. During a median 8-year of follow-up, 534,442 subjects were newly diagnosed as AF (8.27 per 1000 person-years). Higher FLI was associated with an increased risk of AF (hazard ratio [HR] 1.053, 95% confidence interval [CI] 1.046–1.060 in 30 ≤ FLI < 60, and HR 1.115, 95% CI 1.106–1.125 in FLI ≥ 60). In underweight subjects (BMI < 18.5 kg/m²), higher FLI raised the risk of AF (by 1.6-fold in 30 ≤ FLI < 60 and by twofold in FLI ≥ 60). In normal- and overweight subjects, higher FLI was associated with an increased risk of AF, but the HRs were attenuated. In obese subjects, higher FLI was not associated with higher risk of AF. NAFLD as assessed by FLI was independently associated with an increased risk of AF in nonobese subjects with BMI < 25 kg/m². The impact of NAFLD on AF risk was accentuated in lean subjects with underweight.

Non-alcoholic fatty liver disease and heart failure with preserved ejection fraction: from pathophysiology to practical issues

The prevalence of non‐alcoholic fatty liver disease (NAFLD) in heart failure (HF) preserved left ventricular ejection fraction (HFpEF) patients could reach 50%. Therefore, NAFLD is considered an emerging risk factor. In 20% of NAFLD patients, the condition progresses to non‐alcoholic steatohepatitis (NASH), the aggressive form of NAFLD characterized by the development of fibrosis in the liver, leading to cirrhosis. The purpose of this review is to provide an overview of the relationships between NAFLD and HFpEF and to discuss its impact in clinical setting. Based on international reports published during the past decade, there is growing evidence that NAFLD is associated with an increased incidence of cardiovascular diseases, including impaired cardiac structure and function, arterial hypertension, endothelial dysfunction, and early carotid atherosclerosis. NAFLD and HFpEF share common risk factors, co‐morbidities, and cardiac outcomes, in favour of a pathophysiological continuum. Currently, NAFLD and NASH are principally managed with non‐specific therapies targeting insulin resistance like sodium‐glucose co‐transporter‐2 inhibitors and liraglutide, which can effectively treat hepatic and cardiac issues. Studies including HFpEF patients are ongoing. Several specific NAFLD‐oriented therapies are currently being developed either alone or as combinations. NAFLD diagnosis is based on a chronic elevation of liver enzymes in a context of metabolic syndrome and insulin resistance, with fibrosis scores being available for clinical practice. In conclusion, identifying HF patients at risk of NAFLD is a critically important issue. As soon as NAFLD is confirmed and its severity determined, patients should be proposed a management focused on symptoms and co‐morbidities.

Association between routine biomarkers and atrial fibrillation in patients undergoing implantation of a dual-chamber pacemaker

BACKGROUND

Elderly patients having a permanent pacemaker frequently have atrial remodeling. We examined the association between routine biomarkers and atrial fibrillation (AF) in patients receiving a dual-chamber pacemaker for sinus node disease (SND) or second-/third-degree atrioventricular block.

METHODS

We recorded clinical, laboratory, and electrocardiographic parameters as well as pacemaker lead parameters at implantation. The final analysis included 217 patients with SND and 393 patients with atrioventricular block. Notably, 102/217 (47%) of the SND patients (median age: 77 years, 54% men) and 54/393 (14%) of the atrioventricular block patients (median age: 79 years, 54% men) had AF history (paroxysmal or persistent).

RESULTS

Multivariable analysis showed that red blood cell distribution width (RDW) (OR: 1.17; 95% CI: 1.05-1.36; P = .05) and serum γ-glutamyl transferase (γGT) levels (OR: 1.15; 95% CI: 1.03-1.28; P = .04) were independently associated with AF history in patients with SND. In ROC curve analysis, the area under the curve (AUC) was 0.648; P < .01 for RDW, and 0.753; P < .01 for γGT. A RDW cut-off point of 14 was associated with AF with a sensitivity of 67% and a specificity of 68%, while a γGT cut-off point of 21 was associated with AF with a sensitivity of 80% and a specificity of 65%. In patients with second-/third-degree atrioventricular block, there were no significant independent correlations between AF and the parameters studied.

CONCLUSIONS

In elderly patients with SND, RDW and γGT have an independent association with AF history. Our study failed to show any corresponding associations in patients with advanced disorders of atrioventricular conduction.

Serum Gamma-Glutamyltransferase Levels Predict the Development of Cerebral Infarction in the Korean Population

PURPOSE

This study examined the relationship between serum gamma-glutamyltransferase concentration and the risk of cerebral infarction in the Koreans.

MATERIALS AND METHODS

A total of 209,481 out of 223,551 participants in the National Health Information Database who received medical checkups in 2009 were included in the final analysis. The diagnosis code ICD I63 was used for identifying cerebral infarction cases and tracked the development of cerebral infarction by 2013. Cox proportional hazards model was used to calculate hazard ratios (HRs) for cerebral infarction and their confidence interval (CI).

RESULTS

During a follow-up period of 915,387.5 person-years, 2403 incident cases of cerebral infarction developed between 2009 and 2013. After adjusting for multiple covariates, the hazard ratios (95% confidence interval) for incident cerebral infarction, comparing the second, third, and fourth quartile of serum gamma-glutamyltransferase levels with the first quartile, were 1.11 (0.98-1.27), 1.39 (1.22-1.58), and 1.49 (1.29-1.71), respectively (P for trend <0.001).

CONCLUSION

Elevated serum gamma-glutamyltransferase levels were independently associated with the future development of cerebral infarction in Koreans.

Low Liver Enzymes and Risk of Dementia: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Low levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the low physiologic range, surrogate markers for reduced liver metabolic function, are associated with cerebral hypometabolism, impairment in neurotransmitter production and synaptic maintenance, and a higher prevalence of dementia. It is unknown whether a prospective association exists between low liver enzyme levels and incident dementia.

OBJECTIVE

To determine whether low levels of ALT and AST are associated with higher risk of incident dementia.

METHODS

Plasma ALT and AST were measured on 10,100 study participants (mean age 63.2 years, 55% female, 22% black) in 1996-1998. Dementia was ascertained from comprehensive neuropsychological assessments, annual contact, and medical record surveillance. Cox proportional hazards regression was used to estimate the association.

RESULTS

During a median follow-up of 18.3 years (maximum 21.9 years), 1,857 individuals developed dementia. Adjusted for demographic factors, incidence rates of dementia were higher at the lower levels of ALT and AST. Compared to the second quintile, ALT values <10th percentile were associated with a higher risk of dementia (hazard ratio [HR] 1.34, 95% CI 1.08-1.65). The corresponding HR was 1.22 (0.99-1.51) for AST.

CONCLUSION

Plasma aminotransferases <10th percentile of the physiologic range at mid-life, particularly ALT, were associated with greater long-term risk of dementia, advocating for attention to the putative role of hepatic function in the pathogenesis of dementia.

Association between Atrial Fibrillation and Advanced Liver Fibrosis in Patients with Non-Alcoholic Fatty Liver Disease

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is independently associated with the development of atrial fibrillation (AF). However, the association of AF with advanced liver fibrosis, which is related to all-cause, cardiovascular, and liver-related mortality, has not been established in NAFLD patients. We aimed to investigate the association between AF and advanced liver fibrosis in NAFLD patients.

MATERIALS AND METHODS

Out of 53704 adults who participated in the health check-up program, 6293 subjects aged 35 years and older were diagnosed as NAFLD using ultrasound. The stage of liver fibrosis was assessed based on the newly adjusted NAFLD fibrosis score (NFS) and Fibrosis-4 (Fib-4) Index, which were used to determine the low and high cut-off values (COVs).

RESULTS

Of 6293 patients with NAFLD, 59 (0.9%) were diagnosed with AF. Patients with AF were older (52.0 vs. 64.6 years, p<0.001), had higher body mass index (25.2 vs. 26.6 kg/m², p<0.001), and had bigger waist circumference (84.0 vs. 89.9 cm, p<0.001) than those without AF. In NAFLD patients, AF was independently associated with advanced liver fibrosis, assessed using both COVs of NFS [low-COV group: final adjusted odds ratios (aORs)=2.85, p=0.004; high-COV group: ORs=12.29, p<0.001). AF was independently associated with advanced liver fibrosis, assessed using both COVs of Fib-4 (low-COV group: aORs=2.49, p<0.001; high-COV group: aORs=3.84, p=0.016).

CONCLUSION

AF is independently associated with advanced liver fibrosis in patients with NAFLD.

Extra-hepatic manifestations and complications of nonalcoholic fatty liver disease

This review article aims to synthesize the evidence regarding nonalcoholic fatty liver disease (NAFLD) as a systemic disorder. We critically discuss the metabolic syndrome and its components; the cardiovascular and the endocrine system; chronic respiratory disorders; the musculoskeletal system; the skin; and extra-hepatic tumors. We conclude that, while some of these extra-hepatic conditions clearly predispose to the development of secondary forms of NAFLD (typically hypothyroidism-induced NAFLD), others result from pre-existent NAFLD (e.g., certain extra-hepatic tumors) and others (such as Type 2 Diabetes) have, with NAFLD, mutual and bidirectional associations. Analyzed data imply that NAFLD is not merely a hepatic disease. It is also and possibly more importantly, a systemic disorder requiring a special awareness, a multidisciplinary approach and a multidimensional vision.

Effect of serum γ-glutamyltranferase and albumin levels on the response to cardiac resynchronization therapy in the elderly

BACKGROUND

Several liver function tests have been identified as predictors of hospitalization for heart failure (HF) and death in patients with chronic HF. The relationship between serum γ-glutamyltranferase (GGT) and albumin (SA) levels with the response to cardiac resynchronization therapy (CRT) has not been reliably determined. The aim of the study was to evaluate the impact of liver function tests on the results of CRT in the elderly.

METHODS

Baseline GGT and SA were assessed before CRT device implantation in the elderly (> 70-year-old) patients. The endpoints were: (1) CRT response defined as > 5% left ventricular ejection fraction improvement and no hospitalization for HF or cardiovascular death; (2) hospitalizations; and (3) mortality.

RESULTS

Eighty of 138 (58%) included patients were responders at nine months. Compared to responders, the SA levels were not significantly different (35.1 ± 5.4 vs. 33.6 ± 5.5 g/L, P = 0.103); but the GGT levels, higher (81.6 ± 69.3 vs. 54.7 ± 49.6 U/L, P = 0.013) in non-responders to CRT. GGT level was independently associated with non-response to CRT (P < 0.001, OR = 0.17; 95% CI: 0.08-0.38, P < 0.001). GGT cut-off value ≥ 55 U/L was highly predictive of non-response [AUC = 0.65, 64% Sensitivity, 69% Specificity (95% CI: 0.56-0.74)]. GGT ≥ 55 U/L was also associated with higher risk of hospitalization for atrial fibrillation (AF) (95% vs. 83%, P = 0.024). Both SA and GGT had no impact on overall (P = 0.220, P = 0.723) mortality.

CONCLUSIONS

Higher level of GGT is an independent predictor of non-response to CRT in patients over age 70 years and is associated with higher risk of hospitalization for AF. Baseline serum levels of albumin and GGT and have no impact on mortality in elderly patients undergoing CRT.

Liver enzyme variability and risk of heart disease and mortality: A nationwide population-based study

BACKGROUND & AIMS

Liver enzymes, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyltransferase (GGT), have been suggested as surrogate markers of various cardiovascular diseases. However, previous studies assessed liver enzymes only once at baseline. We investigated the association between liver enzyme variability and the risk of mortality and cardiovascular outcomes in general population.

METHODS

A total of 6 496 271 subjects participating in ≥3 health examinations within the previous 5 years including the index year (2009-2010) were included. Variability was measured using variability independent of the mean. Cox proportional hazard models adjusting demographic factors, comorbidities, blood pressure, total cholesterol, glomerular filtration rate and baseline liver enzyme level were used.

RESULTS

During a median follow-up of 6 years, there were 106 413 deaths (1.6%), 53 385 myocardial infarctions (MI, 0.8%), 65 143 atrial fibrillations (AF, 1.0%) and 50 139 congestive heart failures (CHF, 0.7%). High variability in AST, ALT and GGT was associated with a higher risk for all-cause mortality, MI, AF and CHF. The degree of association was largest for GGT variability. For the highest quartile of GGT variability relative to the lowest quartile, the hazard ratios (95% confidence intervals) were 1.32 (1.28-1.35) for all-cause mortality, 1.16 (1.11-1.20) for MI, 1.28 (1.18-1.38) for AF and 1.25 (1.20-1.30) for CHF. These findings were consistent regardless of alcohol consumption, body mass index and degree of fatty liver. Sensitivity analysis also revealed similar results.

CONCLUSIONS

Higher visit-to-visit variability of liver enzymes was an independent predictor of all-cause mortality and cardiovascular events.

Association between aminotransferase/alanine aminotransferase ratio and cardiovascular disease mortality in patients on peritoneal dialysis: a multi-center retrospective study

Background

Elevated aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio is an independent risk factor for cardiovascular disease (CVD) among the general population. However, an association between AST/ALT ratio and CVD mortality in patients on peritoneal dialysis (PD) has received little attention.

Methods

A total of 2224 incident PD patients from multi-centers were enrolled from November 1, 2005, to June 30, 2017, in this retrospective cohort study. The primary endpoint was CVD mortality. Eligible patients were divided into high and normal groups according to the AST/ALT ratio cut-off for CVD mortality with the receiver operating characteristic (ROC) curve. The associations between the AST/ALT ratio and CVD mortality were evaluated by the Cox regression model.

Results

Of eligible 1579 patients with a mean age of 49.3 ± 14.6 years, 55.4% of patients were male, 18.1% of patients had diabetes, and 64.2% of patients had hypertension. The prevalence of a high AST/ALT ratio was 76.6% in the cohort population. During a follow-up period with 4659.6 patient-years, 316 patients died, of which 193 (61.1%) deaths were caused by CVD episodes. The incidence of CVD mortality in the high group was significantly higher than that in the normal group (13.1% versus 9.2%, P = 0.024). Cumulative CVD mortality rates were significantly different between the two groups by Kaplan-Meier analysis [hazards ratio (HR) = 1.50, 95% confidence index (CI) 1.09–2.07, P = 0.014]. After adjusting for confounding factors, a higher AST/ALT ratio was independently associated with an increased risk of CVD mortality compared with their counterparts (HR = 1.43, 95%CI 1.08–2.41, P = 0.002).

Conclusions

PD patients with high baseline AST/ALT ratio levels may be at a significant risk of CVD mortality.

Edoxaban Versus Warfarin in Patients With Atrial Fibrillation and History of Liver Disease

BACKGROUND

Patients with liver disease have increased risk of thrombosis and bleeding but are typically excluded from trials of direct oral anticoagulant agents.

OBJECTIVES

This study evaluated the pharmacokinetics (PK), pharmacodynamics (PD), clinical efficacy and safety of edoxaban versus warfarin in patients with atrial fibrillation (AF) and history of liver disease.

METHODS

ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis In Myocardial Infarction Study 48) was a randomized, double-blind trial comparing edoxaban with warfarin in patients with AF followed for 2.8 years. History of liver disease was defined as investigator-reported liver disease or >2-fold transaminase elevation at randomization. The primary efficacy and safety endpoints of stroke or systemic embolic event (SSEE) and major bleeding were assessed stratified by history of liver disease. PK/PD assessments of edoxaban included endogenous and extrinsic factor Xa activity and edoxaban concentration.

RESULTS

Among 21,105 patients, 1,083 (5.1%) had a history of liver disease; they had a higher prevalence of many comorbidities. The adjusted risks of SSEE were similar (adjusted hazard ratio [HR_adj]: 0.90; 95% confidence interval [CI]: 0.67 to 1.22; p = 0.50), but major bleeding was more common in patients with liver disease (HR_adj: 1.38; 95% CI: 1.10 to 1.74; p = 0.005). There were no significant differences in PK/PD assessment of edoxaban in patients with versus without liver disease. The HRs for higher-dose edoxaban versus warfarin for SSEE were 0.86 (95% CI: 0.73 to 1.01) in patients without and 1.11 (95% CI: 0.54 to 2.30) with liver disease (p for interaction [p_int] = 0.47), major bleeding 0.80 (95% CI: 0.70 to 0.91) in patients without and 0.91 (95% CI: 0.56 to 1.47) with liver disease (p_int = 0.63). There were no significant differences in hepatic adverse events between the 2 treatment groups.

CONCLUSIONS

Among patients with AF receiving oral anticoagulation, bleeding, but not thromboembolic events, was increased in patients with liver disease. A history of liver disease did not alter the relative efficacy and safety of edoxaban compared with warfarin. Hepatic adverse events were similar between edoxaban and warfarin.

AST/ALT ratio predicts the functional severity of chronic heart failure with reduced left ventricular ejection fraction

Objective

Despite previous research that focused on liver transaminases as predictors of cardiovascular disease, there has been limited research evaluating the predictive value of AST/ALT ratio in patients with heart failure. We aimed to investigate AST/ALT ratio as an indicator of the functional severity in chronic heart failure with reduced left ventricular ejection fraction.

Results

Overall, 105 patients previously diagnosed with HFrEF from Buraidah-Al Qassim province, Saudi Arabia were included in this retrospective cross-sectional study. Data on study variables, including demographic data, left ventricular ejection fraction, NYHA class, and AST/ALT ratio, were collected from patients’ records. The patients were divided into two groups, namely group-1 (AST/ALT ratio < 1) and group-2 (AST/ALT ratio ≥ 1), to identify any differences in their cardiac function profiles. NYHA class and NT-proBNP were higher and LVEF was lower in group-2 than in group-1. We found a mild significant correlation between AST/ALT ratio and APRI, FIB-4 score, NYHA-class, and LVEF (r = 0.2, 0.25, 0.26, and − 0.24, respectively; P < 0.05). Multivariate linear regression analysis model and ROC curve showed that AST/ALT ratio could independently predict HFrEF functional severity with a best cut-off value of 0.9, sensitivity of 43.6%, and specificity of 81.4%.

Atrial fibrillation in hospitalized patients with end-stage liver disease: temporal trends in prevalence and outcomes

BACKGROUND & AIMS

End-stage liver disease (ESLD) happens due to the development and progression of chronic liver disease. This study aims to investigate the temporal trend, patient characteristics and outcomes of atrial fibrillation (AF) in hospitalized ESLD patients across the United States.

METHODS

Nationwide Inpatient Sample from 2003 to 2014 was utilized to retrospectively study the weighted prevalence of AF in hospitalized ESLD patients. Multivariable regression models were used to assess the association between AF with clinical factors, in-hospital mortality, length of stay (LOS) and cost.

RESULTS

639 345 hospitalizations associated with ESLD were identified, of which 47 710 (7.48%) were diagnosed with AF. The prevalence of AF increased from 5.73% in 2003 to 9.75% in 2014 in ESLD and varied by age, race, income, insurance type and hospital characteristics. Factors associated with AF included advancing age, male, white race, high income and urban teaching hospital. AF presence was associated with significant higher in-hospital mortality (odds ratio, 1.40; 95% confidence interval, 1.35-1.45), 21% longer LOS and 22% higher cost. In addition, a significant decreasing trend in in-hospital mortality was observed (from 16.70% to 10.63% in patients with AF and from 10.74% to 7.50% in patients without AF).

CONCLUSIONS

The prevalence of AF in hospitalized ESLD patients has continued to increase from 2003 through 2014. AF is associated with poor prognosis and higher health resource utilization. Innovative anticoagulation strategies through improved collaboration between cardiologists and hepatologists are required for better management of hospitalized ESLD patients comorbid with AF.

Nonalcoholic Fatty Liver Disease Pandemic Fuels the Upsurge in Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain a leading cause of death worldwide. Among the major risk factors for CVD, obesity and diabetes mellitus have received considerable attention in terms of public policy and awareness. However, the emerging prevalence of nonalcoholic fatty liver disease (NAFLD), as the most common liver and metabolic disease and a cause of CVD, has been largely overlooked. Currently, the number of individuals with NAFLD is greater than the total number of individuals with diabetes mellitus and obesity. Epidemiological studies have established a strong correlation between NAFLD and an increased risk of CVD and CVD-associated events. Although debate continues over the causal relationship between NAFLD and CVD, many mechanistic and longitudinal studies have indicated that NAFLD is one of the major driving forces for CVD and should be recognized as an independent risk factor for CVD apart from other metabolic disorders. In this review, we summarize the clinical evidence that supports NAFLD as a risk factor for CVD epidemics and discuss major mechanistic insights regarding the acceleration of CVD in the setting of NAFLD. Finally, we address the potential treatments for NAFLD and their potential impact on CVD.

Anti-inflammatory Effects of Deuterium-Depleted Water Plus Rosa Damascena Mill. Essential Oil Via Cyclooxygenase-2 Pathway in Rats

Objectives

Natural medicine has been proposed for treating sepsis worldwide. Therefore, in this study, the effect of deuterium-depleted water (DDW) alone and adjuvant with Rosa damascena Mill. (RD) essential oils was considered through the evaluation of oxidative stress-antioxidant parameters and the expression of cyclooxygenase-2 (COX-2) inflammatory gene in liver damage caused by sepsis.

Materials and Methods

The rats were randomly divided into 5 groups: 1) laparotomy group; 2) cecal ligation and puncture (CLP) group; 3) DDW (15 ppm and 30 ppm doses) group; 4) DDW (15 ppm and 30 ppm doses) plus RD essential oil (100 mg/kg.bw); 5) indomethacin (2 mg/kg.bw) as a positive control. The treatments were daily administrated for 2 weeks and the CLP model was created on the day 15. Then, the animals were killed and their liver tissue was separated for histopathologic and biochemical assessment.

Results

Our results demonstrated that the treatment of animals with DDW and DDW plus RD essential oil was effective due to the regulation of the oxidative stress-antioxidant parameters including lipid peroxidation, glutathione (GSH), GSH s-transferases, myeloperoxidase, ferric reducing ability of plasma and inflammatory parameters such as prostaglandin E2 and COX-2. Pathological studies also showed that sepsis led to the liver tissue injuries, which can be reduced by treatments.

Conclusion

Sepsis caused oxidative stress in the liver tissue, but the administration of DDW and DDW plus RD essential oil can be useful to prevent and heal these injuries.

Association between non-alcoholic fatty liver disease and risk of new-onset atrial fibrillation in healthy adults

BACKGROUND & AIMS

Previous studies demonstrated conflicting results regarding the association between non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF). The statistical power was not sufficient because of modest sample sizes of these studies. We analysed a large population-based cohort to evaluate the association between NAFLD and AF.

METHODS

We evaluated 334 280 healthy individuals without comorbidities who underwent National Health check-ups in South Korea from 2009 to 2014. NAFLD was defined by a surrogate marker, the fatty liver index (FLI). The association between FLI and AF incidence was analysed using multivariate Cox proportional hazards regression models.

RESULTS

During a median follow-up of 5.3 years, 1415 subjects (0.4%) were newly diagnosed with AF. Subjects were categorized into quartile groups according to FLI (range: Q1, 0-4.9; Q2, 5.0-12.5; Q3, 12.6-31.0; Q4, >31.0). The cumulative incidence of AF was significantly higher in subjects with higher FLIs than in those with lower FLIs (Q1, 167 [0.2%]; Q2, 281 [0.3%]; Q3, 470 [0.6%]; Q4, 497 [0.6%]; P < .001). Adjusted hazard ratios (HRs) indicated that a higher FLI was independently associated with an increased risk for AF (HR between Q4 and Q1, 1.35; 95% confidence interval [CI], 1.11-1.63; P = .002). After further adjustment for the interim events (diabetes, hypertension, heart failure and myocardial infarction), this association remained statistically significant (HR between Q4 and Q1, 1.55; 95% CI, 1.19-2.03; P = .001).

CONCLUSIONS

NAFLD, assessed by FLI, was independently associated with increased risk for AF in healthy Korean population. Moreover, NAFLD itself predisposes to AF independently of the interim events.

Effects of Gamma-Glutamyl Transferase on Stroke Occurrence Mediated by Atrial Fibrillation

Background and Purpose

Gamma-glutamyl transferase (GGT) is reported to be associated with stroke independently of the conventional risk factors. However, the underlying mechanism remains to be identified. This study focused on atrial fibrillation (AF), which also reportedly has a close association with GGT.

Methods

Acute ischemic stroke patients who were admitted to the Seoul National University Hospital within 7 days of stroke onset were analyzed. Multinomial logistic regression was performed to assess the relationship between GGT and cardioembolic stroke. Mediation analysis based on binary logistic regression was used to determine whether AF mediates the relationship between GGT and cardioembolic stroke.

Results

AF was found in 132 (15.0%) of 880 eligible patients with acute ischemic stroke, and 270 (30.7%) patients were categorized as cardioembolic stroke. High GGT levels in acute ischemic stroke patients was associated with cardioembolic stroke [odds ratio (OR)=3.42, 95% CI=1.59–7.37], but not with large-artery atherosclerosis stroke (OR=1.10, 95% CI=0.54–2.23). Approximately half (53.9%) of the total effect of GGT levels on cardioembolic stroke was mediated by AF.

Conclusions

The GGT level was significantly associated with cardioembolic stroke via AF. The results obtained in the present study may explain why GGT is associated with stroke.

Cardiac abnormalities in patients with nonalcoholic fatty liver disease : Insights from auxiliary examinations

Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease in developed countries and is associated with type 2 diabetes mellitus, obesity, hypertension, dyslipidemia, and metabolic syndrome. It is defined as steatosis in over 5% of hepatocytes. The disease spectrum of NAFLD ranges from simple fatty liver to nonalcoholic steatohepatitis, liver fibrosis, even hepatic cirrhosis. The disease affects various extra-hepatic systems such as the cardiovascular system and urinary system. Heart-related disease is identified as the leading cause of mortality in NAFLD patients rather than liver-related disease. In this review, we summarize the cardiac abnormalities (structural, functional, arrhythmic cardiac complications etc.) seen in NAFLD patients with the assistance of auxiliary examinations, such as electrocardiography, echocardiography, computed tomography, magnetic resonance imaging etc. In addition, the epidemiology of NAFLD and how NAFLD affects the myocardium are also discussed.

NAFLD and Extra-Hepatic Comorbidities: Current Evidence on a Multi-Organ Metabolic Syndrome

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its incidence is definitely increasing. NAFLD is a metabolic disease with extensive multi-organ involvement, whose extra-hepatic manifestations include type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, chronic kidney disease, osteoporosis, and polycystic ovarian syndrome. Recently, further evidence has given attention to pathological correlations not strictly related to metabolic disease, also incorporating in this broad spectrum of systemic involvement hypothyroidism, psoriasis, male sexual dysfunction, periodontitis, and urolithiasis. The most common cause of mortality in NAFLD is represented by cardiovascular disease, followed by liver-related complications. Therefore, clinicians should learn to screen and initiate treatment for these extra-hepatic manifestations, in order to provide appropriate multidisciplinary assessments and rigorous surveillance. This review evaluates the current evidence regarding extra-hepatic associations of NAFLD, focusing on the pathogenic hypothesis and the clinical implications.

Oral Anticoagulation in Patients With Liver Disease

Patients with liver disease are at increased risks of both thrombotic and bleeding complications. Many have atrial fibrillation (AF) or venous thromboembolism (VTE) necessitating oral anticoagulant agents (OACs). Recent evidence has contradicted the assumption that patients with liver disease are "auto-anticoagulated" and thus protected from thrombotic events. Warfarin and non-vitamin K-antagonist OACs have been shown to reduce thrombotic events safely in patients with either AF or VTE. However, patients with liver disease have largely been excluded from trials of OACs. Because all currently approved OACs undergo metabolism in the liver, hepatic dysfunction may cause increased bleeding. Thus, the optimal anticoagulation strategy for patients with AF or VTE who have liver disease remains unclear. This review discusses pharmacokinetic and clinical studies evaluating the efficacy and safety of OACs in patients with liver disease and provides a practical, clinically oriented approach to the management of OAC therapy in this population.

Cardio-Metabolic Disorders in Non-Alcoholic Fatty Liver Disease

With the progressive epidemics of obesity, non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in adults and children. The increasing prevalence and incidence of NAFLD with advanced fibrosis is concerning because patients appear to experience higher non-liver-related morbidity and mortality than the general population. Recent clinical evidence suggests that NAFLD is directly associated with an increased risk of cardio-metabolic disorders. This mini review describes briefly the current understanding of the pathogenesis of NAFLD, summarizing the link between NAFLD and cardio-metabolic complications, focusing mainly upon ischemic stroke, type 2 diabetes mellitus (DM), hypertension, chronic kidney disease (CKD) and cardiac arrhythmias. In addition, it describes briefly the current understanding of the pathogenesis of NAFLD.

Atrial fibrillation is highly prevalent yet undertreated in patients with biopsy-proven nonalcoholic steatohepatitis

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is associated with increased cardiovascular disease. Atrial fibrillation is a prominent risk marker for underlying cardiovascular disease with a prevalence of 2% in patients <65 years old. Atrial fibrillation prevalence in NASH is unknown. We sought to assess the prevalence and impact of atrial fibrillation on healthcare utilization in NASH.

METHODS

Patients were identified from a tertiary care centre Electronic Database from 2002 to 2015. International Classification of Diseases 9 (ICD9) codes identified comorbidities and atrial fibrillation. Descriptive statistics were used to compare characteristics between patients with NASH with and without atrial fibrillation.

RESULTS

Of 9108 patients with ICD9 diagnosis of NASH, 215 (2.3%, mean age 57 years, 32% male) had biopsy-proven NASH. Atrial fibrillation prevalence was 4.6%. Patients with NASH and atrial fibrillation had a higher prevalence of heart failure (54.5% vs 8.8%, P < 0.001) and cerebrovascular (27.3% vs 2.0%, P < 0.001) or vascular disease (54.5% vs 13.2%, P = 0.002), compared to NASH without atrial fibrillation. All patients with NASH and atrial fibrillation had a CHA2DS2VASc score ≥2 indicating high stroke risk and need for anticoagulation. Eight of 10 patients were eligible for anticoagulation and 5 of 8 (62.5%) received appropriate therapy.

CONCLUSION

Atrial fibrillation prevalence is two-fold higher in patients with NASH compared to the general population. Patients with NASH have a high risk of stroke; however, many do not receive appropriate guideline-directed therapy. Future studies are needed to identify whether guideline-based management of atrial fibrillation in NASH reduces cardiovascular morbidity and mortality.

Association between non-alcoholic fatty liver disease and risk of atrial fibrillation in adult individuals: An updated meta-analysis

BACKGROUND & AIMS

Recent studies examined the association between non-alcoholic fatty liver disease (NAFLD) and risk of atrial fibrillation (AF) in adults, but the findings have been inconsistent. We provided a quantitative estimate of the magnitude of the association between NAFLD and risk of AF.

METHODS

We searched publication databases using predefined keywords to identify observational studies (published up to December 14, 2018), in which NAFLD was diagnosed by biopsy, imaging or biochemistry and AF was diagnosed by medical history and electrocardiograms. Data from selected studies were extracted and meta-analysis was performed using random-effects modelling.

RESULTS

Nine cross-sectional and longitudinal studies were included in the final analysis (n = 364 919 individuals). Meta-analysis of data from 5 cross-sectional studies showed that NAFLD was associated with an increased risk of prevalent AF (random-effects odds ratio 2.07, 95% CI 1.38-3.10; I²  = 54.7%), independent of age, sex, body mass index, hypertension and other common AF risk factors. This risk was particularly high among patients with established diabetes (n = 1 study; random-effects odds ratio 5.17, 95% CI 2.05-13.02). Meta-analysis of data from 4 longitudinal studies showed that NAFLD was independently associated with a 10-year increased risk of incident AF only in type 2 diabetic patients (n = 1 study; random-effects hazard ratio 4.96, 95% CI 1.42-17.28). Sensitivity analyses did not modify these findings. Funnel plots did not reveal significant publication bias.

CONCLUSIONS

NAFLD is associated with an increased risk of AF in middle-aged and elderly individuals (especially in those with type 2 diabetes). However, the observational design of the eligible studies does not allow for proving causality.

Nonalcoholic fatty liver disease: current concepts, epidemiology and management strategies

Nonalcoholic fatty liver disease (NAFLD) is now the most prevalent liver disease in the world. It involves a spectrum of conditions from hepatic steatosis to nonalcoholic steatohepatitis and liver fibrosis, and is a major cause of cirrhosis and hepatocellular carcinoma. It is defined by presence of steatosis in 5% of hepatocytes or more in the absence of other causes of fatty liver. The metabolic syndrome is the major known risk factor for NAFLD. Dietary contributors such as high fructose intake and coffee consumption appear to increase and decrease the risk of disease respectively, but these links are unclear. Genetic associations have also been identified. The estimated prevalence of the disease varies according to diagnostic method and population demographics. It appears to be a major issue in Europe with population studies showing up to 50% of the individuals are affected while in the USA one in three adults are estimated to have NAFLD. Laboratory investigations and ultrasound are typically first-line investigations. Fibrosis may be assessed noninvasively through transient elastography and biomarkers but liver biopsy remains the gold standard to quantify hepatic damage. Associated comorbidities include cardiovascular disease and chronic kidney disease. Weight loss, dietary changes and exercise are recommended in management. Medications should be considered to manage underlying risk factors including insulin resistance. Surgical options include bariatric procedures and liver transplantation. The combination of rising prevalence and significant potential complications warrant further research into NAFLD, particularly in areas with research gaps including Eastern Europe.

Oxidative stress and atrial fibrillation: an update

Atrial remodelling involves electrophysiological and structural abnormalities that promote the development and perpetuation of atrial fibrillation. Experimental and clinical data indicate that oxidative stress is implicated in the pathophysiology of atrial remodelling. The mechanistic links between atrial remodelling and oxidative stress are complex with several underlying diseases and conditions may affect these pathways. Therefore, the development of antioxidant interventions in this setting remains difficult. Besides classical antioxidant compounds, several agents with pleiotropic effects, including anti-inflammatory and antioxidant, have been tested in experimental and clinical settings with variable results. Strategies applying conventional antioxidants in specific situations such as postoperative atrial fibrillation show beneficial effects, especially the two-step regimen of antioxidants combination. Of note, there are limited data on the development of strategies that target specific sources of reactive oxygen species implicated in atrial remodelling. Lifestyle, diet, and risk factors modification is a complementary promising approach. This updated review provides a concise and critical overview of all available data regarding oxidative stress and its modulation in atrial fibrillation. Future directions on this exciting field are also discussed.

The association of non-alcoholic fatty liver disease and atrial fibrillation: a review

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent and causes an enormous burden to human health and health-care systems all over the world. A great proportion of this burden results from increased risk of cardiovascular diseases. Atrial fibrillation (AF) is the most common chronic heart arrhythmia globally and it increases the risk of embolic stroke and heart failure. Recent studies have explored the association between NAFLD and AF with somewhat conflicting results. However, ultrasound-verified prospective studies concur that NAFLD is associated with the incidence of AF. According to epidemiological evidence, the greater the prevalence of NALFD in a population, the stronger the association with AF incidence and prevalence. Specifically, diabetic individuals with NAFLD are at the greatest risk of AF. Additionally, the risk of AF may concentrate most in individuals with advanced NAFLD, particularly those with liver fibrosis. The possible mechanistic factors between NAFLD and AF, particularly obesity and systemic inflammation, are diverse and form a complex interplaying network. However, further studies are needed to elucidate whether NAFLD has a causative role in the development of AF. The purpose of this article is to review and discuss the epidemiologic evidence and possible mechanistic links between these two conditions. KEY MESSAGES Although epidemiologic studies have provided conflicting results on the association of NAFLD and AF, prospective studies with ultrasound-verified NAFLD concur that NAFLD is associated with about 2-fold greater incidence of AF among general population and about 6-fold greater incidence among subjects with type 2 diabetes. The risk of AF among individuals with NAFLD is increased by other cardiovascular risk factors, especially type 2 diabetes and advanced age. The possible mechanistic links between NALFD and AF are diverse, with obesity and systemic inflammation having a significant role, but further studies are needed until NAFLD can be established as a causal factor in the incidence of AF.

Risk of cardiomyopathy and cardiac arrhythmias in patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common, progressive liver disease that affects up to one-quarter of the adult population worldwide. The clinical and economic burden of NAFLD is mainly due to liver-related morbidity and mortality (nonalcoholic steatohepatitis, cirrhosis or hepatocellular carcinoma) and an increased risk of developing fatal and nonfatal cardiovascular disease, chronic kidney disease and certain types of extrahepatic cancers (for example, colorectal cancer and breast cancer). Additionally, there is now accumulating evidence that NAFLD adversely affects not only the coronary arteries (promoting accelerated coronary atherosclerosis) but also all other anatomical structures of the heart, conferring an increased risk of cardiomyopathy (mainly left ventricular diastolic dysfunction and hypertrophy, leading to the development of congestive heart failure), cardiac valvular calcification (mainly aortic-valve sclerosis), cardiac arrhythmias (mainly atrial fibrillation) and some cardiac conduction defects. This Review focuses on the association between NAFLD and non-ischaemia-related cardiac disease, discusses the putative pathophysiological mechanisms and briefly summarizes current treatment options for NAFLD that might also beneficially affect cardiac disease.

NAFLD/NASH in patients with type 2 diabetes and related treatment options

Type 2 diabetes may reduce life expectancy and patients' quality of life due to its micro- and macro-vascular complications and to the higher risk of several types of cancer. An emerging important factor is represented by the hepatic involvement; it is recognized that excessive hepatic fat accumulation represents a typical feature of diabetic patients and that it also plays an important pathogenic role. It is now evident that non-alcoholic fatty liver disease (NAFLD), generally perceived as a benign condition, may have on the contrary an important deleterious impact for diabetic patients increasing the risk to develop cardiovascular complications but also serious hepatic diseases, in particular non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Lifestyle intervention, bariatric surgery and several drug therapies have now accumulated evidence of efficacy in treating NASH. On the other hand, their durability and safety in the long-term is yet to be proven and their use may be sometimes associated with side effects or higher risk of adverse events limiting the regular administration or contraindicating it. Professional health care providers, building awareness about the importance of these hepatic complications, should put more efforts in primary prevention using a behavioral therapy needing a multidisciplinary approach, in secondary prevention applying on a regular basis in the clinical setting available predictive algorithms to identify the patients at higher cardiovascular and hepatologic risk, and in tertiary prevention treating, when not contraindicated, the diabetic patients preferentially with drugs with proven benefit on NAFLD/NASH.

Liver enzymes are not directly involved in atrial fibrillation: a prospective cohort study

BACKGROUND

Epidemiological evidence proposes the direct involvement of the liver enzymes in atrial fibrillation. These relationships are controversial and mechanistically unclear. As part of the British Regional Heart Study, we investigated whether change in liver enzymes over time associates with atrial fibrillation in men initially free of this heart condition.

MATERIALS AND METHODS

We prospectively investigated change (delta) in liver enzymes and new-onset atrial fibrillation in a representative sample of 1428 men aged 60-79 years.

RESULTS

Mean follow-up was 12·3 years, after which 108 new atrial fibrillation cases were identified. The liver enzymes did not differ at baseline or follow-up, except for gamma-glutamyl transferase which was higher at follow-up in men who developed atrial fibrillation compared to those who did not (P < 0·0001). Change in GGT was greater in men who developed AF than those who did not (+6·12 vs. -2·60 U/L, P = 0·036). N-terminal pro-brain natriuretic peptide (baseline and follow-up, P < 0·0001) and total bilirubin (follow-up only, P < 0·0001) were also higher in men who developed atrial fibrillation while serum haemoglobin was similar at baseline and follow-up (P ≥ 0·74). Atrial fibrillation was associated with change in gamma-glutamyl transferase (OR, 1·18; 95% CI, 1·01-1·37) after multiple adjustments and exclusions. However, after adjusting for baseline (P = 0·088) or change (P = 0·40) in N-terminal pro-brain natriuretic peptide, the association between atrial fibrillation and change in gamma-glutamyl transferase was lost.

CONCLUSION

The direct relationship between atrial fibrillation and liver enzymes is absent and depends, at least in part, on the progression of heart failure as captured by N-terminal pro-brain natriuretic peptide.

Linking atrial fibrillation with non-alcoholic fatty liver disease: potential common therapeutic targets

Non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) are common chronic non-infectious diseases with rising incidences. NAFLD is an independent risk factor for the onset of AF, after adjusting potentially related factors. The pathogenesis of these diseases share several mechanisms including reduced adiponectin level, insulin resistance, and renin angiotensin aldosterone system (RAAS) activation, in addition to activation of common disease pathways that promote inflammation, oxidative stress, and fibrosis. Furthermore, statins and RAAS blockers exert therapeutic effects concurrently on NAFLD and AF. The common pathogenesis of NAFLD and AF may serve as a potential therapeutic target in the future.