Nonalcoholic Hepatic Steatosis Is a Strong Predictor of High-Risk Coronary-Artery Plaques as Determined by Multidetector CT

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.

Extrahepatic Outcomes of Nonalcoholic Fatty Liver Disease: Cardiovascular Diseases

Patients with nonalcoholic fatty liver disease (NAFLD) are at high risk of cardiovascular disease, including carotid atherosclerosis, coronary artery disease, heart failure, and arrhythmias. The risk is partially due to shared risk factors, but it may vary according to liver injury. A fatty liver may induce an atherogenic profile, the local necro-inflammatory changes of nonalcoholic steatohepatitis may enhance systemic metabolic inflammation, and fibrogenesis can run parallel in the liver and in the myocardium and precedes heart failure. The detrimental impact of a Western diet combines with polymorphisms in genes associated with atherogenic dyslipidemia. Shared clinical/diagnostic algorithms are needed to manage the cardiovascular risk in NAFLD.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

A Meta-Analysis on the Global Prevalence, Risk factors and Screening of Coronary Heart Disease in Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Cardiovascular disease remains the leading cause of death in patients with nonalcoholic fatty liver disease (NAFLD). Studies examining the association of coronary heart disease (CHD) and NAFLD are cofounded by various cardiometabolic factors, particularly diabetes and body mass index. Hence, we seek to explore such association by investigating the global prevalence, independent risk factors, and influence of steatosis grade on manifestation of CHD among patients with NAFLD.

METHODS

Two databases, Embase and Medline, were utilized to search for articles relating to NAFLD and CHD. Data including, but not limited to, continent, diagnostic methods, baseline characteristics, prevalence of CHD, CHD severity, NAFLD severity, and risk factors were extracted.

RESULTS

Of the 38 articles included, 14 reported prevalence of clinical coronary artery disease (CAD) and 24 subclinical CAD. The pooled prevalence of CHD was 44.6% (95% confidence interval [CI], 36.0%-53.6%) among 67,070 patients with NAFLD with an odds ratio of 1.33 (95% CI, 1.21%-1.45%; P < .0001). The prevalence of CHD was higher in patients with moderate to severe steatosis (37.5%; 95% CI, 15.0%-67.2%) than those with mild steatosis (29.6%; 95% CI, 13.1%-54.0%). The pooled prevalence of subclinical and clinical CAD was 38.7% (95% CI, 29.8%-48.5%) and 55.4% (95% CI, 39.6%-70.1%), respectively.

CONCLUSION

Steatosis was found to be related with CHD involvement, with moderate to severe steatosis related to clinical CAD. Early screening and prompt intervention for CHD in NAFLD are warranted for holistic care in NAFLD.

The Association of Triglyceride to High-Density Lipoprotein Cholesterol Ratio with High-Risk Coronary Plaque Characteristics Determined by CT Angiography and Its Risk of Coronary Heart Disease

The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio is an independent risk index for cardiovascular events. This study aimed to evaluate the association between TG/HDL-C ratio and coronary plaque characteristics as seen on coronary computed tomography angiography (CCTA) and the corresponding increase in the likelihood of cardiovascular events. A total of 935 patients who underwent CCTA for suspected coronary artery disease (CAD) were included. High-risk plaques (HRP) were defined based on three characteristics: positive remodeling, low-density plaques, and spotty calcification. Significant stenosis was defined as luminal narrowing of >70%. Patients with a higher TG/HDL-C ratio showed significantly greater prevalence of HRP and significant stenosis than patients with low TG/HDL-C ratios (p < 0.01). Multivariate logistic analysis demonstrated that the TG/HDL-C ratio was significantly associated with the presence of HRP (p < 0.01) but not with significant coronary stenosis (p = 0.24). During the median follow-up period of 4.1 years, 26 cardiovascular events including cardiovascular death and acute coronary syndrome occurred. The highest TG/HDL-C tertile was associated with cardiovascular events, with the lowest TG/HDL-C tertile as the reference (hazard ratio, 3.75; 95% confidence interval, 1.04−13.50). A high TG/HDL-C ratio is associated with the presence of CCTA-verified HRP, which can lead to cardiovascular events in patients with suspected CAD.

New Insights into Non-Alcoholic Fatty Liver Disease and Coronary Artery Disease: The Liver-Heart Axis

Non-alcoholic fatty liver disease (NAFLD) represents the hepatic expression of the metabolic syndrome and is the most prevalent liver disease. NAFLD is associated with liver-related and extrahepatic morbi-mortality. Among extrahepatic complications, cardiovascular disease (CVD) is the primary cause of mortality in patients with NAFLD. The most frequent clinical expression of CVD is the coronary artery disease (CAD). Epidemiological data support a link between CAD and NAFLD, underlain by pathogenic factors, such as the exacerbation of insulin resistance, genetic phenotype, oxidative stress, atherogenic dyslipidemia, pro-inflammatory mediators, and gut microbiota. A thorough assessment of cardiovascular risk and identification of all forms of CVD, especially CAD, are needed in all patients with NAFLD regardless of their metabolic status. Therefore, this narrative review aims to examine the available data on CAD seen in patients with NAFLD, to outline the main directions undertaken by the CVD risk assessment and the multiple putative underlying mechanisms implicated in the relationship between CAD and NAFLD, and to raise awareness about this underestimated association between two major, frequent and severe diseases.

Association between high oxidized high-density lipoprotein levels and increased pericoronary inflammation determined by coronary computed tomography angiography

BACKGROUND

Impaired high-density lipoprotein (HDL) function is a risk factor for cardiac mortality. We aimed to investigate the association between oxidized HDL (oxHDL) and pericoronary adipose tissue (PCAT) attenuation, a novel imaging biomarker of pericoronary inflammation, by using coronary computed tomography angiography (CTA).

METHODS

A total of 287 outpatients with suspected coronary artery disease who had undergone both oxHDL measurement and coronary CTA were examined. PCAT attenuation values were assessed at the proximal 10-50 mm segments of the right coronary artery on coronary CTA. The presence of significant stenosis (luminal narrowing of >50 %) and high-risk plaque characteristics were also evaluated. Patients were then classified into tertiles according to their oxHDL level: low (n = 95), moderate (n = 96), and high (n = 96) groups.

RESULTS

PCAT attenuation in the high oxHDL group was significantly higher than that in other groups after adjusting for age and apolipoprotein-A-I. Multivariate linear regression analysis revealed that oxHDL was significantly associated with PCAT attenuation in the right coronary artery (β = 3.832, p < 0.001), whereas HDL cholesterol was not. Furthermore, subgroup analyses demonstrated that the association between oxHDL and PCAT attenuation remained significant in older patients (β = 6.367, p < 0.001) and in those with hypertension (β = 4.922, p < 0.011), dyslipidemia (β = 3.264, p = 0.010), diabetes mellitus (β = 4.284, p = 0.015), and significant stenosis (β = 3.075, p = 0.021).

CONCLUSIONS

High oxHDL levels were significantly associated with increased pericoronary inflammation, as assessed using coronary CTA. Our results may explain the association between impaired HDL function and the development of coronary atherosclerosis.

Association of Oxidized Low-Density Lipoprotein in Nonalcoholic Fatty Liver Disease with High-Risk Plaque on Coronary Computed Tomography Angiography: A Matched Case-Control Study

Nonalcoholic fatty liver disease (NAFLD) is a risk factor for the development of atherosclerotic cardiovascular diseases (CVDs), and oxidative stress has been proposed as a shared pathophysiological condition. This study examined whether oxidized low-density lipoprotein (LDL) is involved in the underlying mechanism that links coronary atherosclerosis and NAFLD. This study included 631 patients who underwent coronary computed tomography angiography (CTA) for suspected coronary artery disease. NAFLD was defined on CT images as a liver-to-spleen attenuation ratio of <1.0. Serum-malondialdehyde-modified LDL (MDA-LDL) and coronary CTA findings were analyzed in a propensity-score-matched cohort of patients with NAFLD (n = 150) and those without NAFLD (n = 150). This study analyzed 300 patients (median age, 65 years; 64% men). Patients with NAFLD had higher MDA-LDL levels and a greater presence of CTA-verified high-risk plaques than those without NAFLD. In the multivariate linear regression analysis, MDA-LDL was independently associated with NAFLD (β = 11.337, p = 0.005) and high-risk plaques (β = 12.487, p = 0.007). Increased MDA-LDL may be a mediator between NAFLD and high-risk coronary plaque on coronary CTA. Increased oxidative stress in NAFLD, as assessed using MDA-LDL, may be involved in the development of CVDs.

Endothelial Dysfunction in Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Individuals with nonalcoholic fatty liver disease (NAFLD) are characterized by increased cardiovascular risk. Endothelial dysfunction, a mechanism implicated in those processes, may constitute the missing link in this interaction. Therefore, this systematic review and meta-analysis aims to evaluate the association of endothelial dysfunction, assessed by flow-mediated dilation (FMD) of the brachial artery, with NAFLD. We conducted a systematic literature search for studies assessing the difference in FMD between patients with NAFLD and controls. Exclusion criteria consisted of preclinical studies, studies in children/adolescents, no FMD assessment, and the absence of an NAFLD/control group. The database search identified 96 studies. Following the application of the exclusion criteria, 22 studies were included in the meta-analysis (NAFLD: 2164 subjects; control: 3322 subjects). Compared with controls, patients with NAFLD had significantly lower FMD% values (SMD: −1.37, 95% CI −1.91 to −0.83, p < 0.001, I2: 98%). Results remained unaffected after exclusion of any single study. Subgroup analysis revealed significantly decreased FMD in NAFLD subjects diagnosed with liver ultrasound or liver biopsy compared with method combination or other methods, while no differences were observed according to the chosen cuff inflation threshold, the presence of a significant difference in obesity measures between the groups, or the type of the control group (age- and sex-matched vs. other). Funnel plot asymmetry was not observed. Finally, compared with patients with pure steatosis, individuals with nonalcoholic steatohepatitis had significantly lower FMD (SMD: −0.81, 95% CI −1.51 to −0.31, p = 0.003, I2: 81%). In conclusion, FMD of the brachial artery, indicative of endothelial dysfunction, was significantly reduced in subjects with nonalcoholic fatty liver disease. Patients with nonalcoholic steatohepatitis might be facing a more pronounced endothelial impairment.

Lipotoxicity as the Leading Cause of Non-Alcoholic Steatohepatitis

The emerging issues nowadays are non-alcoholic fatty liver disease (NAFLD) and its advanced stage non-alcoholic steatohepatitis (NASH), which further can be a predisposing factor for chronic liver complications, such as cirrhosis and/or development of hepatocellular carcinoma (HCC). Liver lipotoxicity can influence the accumulation of reactive oxygen species (ROS), so oxidative stress is also crucial for the progression of NASH. Moreover, NASH is in strong connection with metabolic disorders, and supporting evidence shows that insulin resistance (IR) is in a close relation to NAFLD, as it is involved in the progression to NASH and further progression to hepatic fibrosis. The major issue is that, at the moment, NASH treatment is based on lifestyle changes only due to the fact that no approved therapeutic options are available. The development of new therapeutic strategies should be conducted towards the potential NAFLD and NASH treatment by the modulation of IR but also by dietary antioxidants. As it seems, NASH is going to be the leading indication for liver transplantation as a consequence of increased disease prevalence and the lack of approved treatment; thus, an effective solution is needed as soon as possible.

Hepatosteatosis and Atherosclerotic Plaque at Coronary CT Angiography

Purpose

To assess the association between nonalcoholic fatty liver disease (NAFLD) and quantitative atherosclerotic plaque at CT.

Materials and Methods

In this post hoc analysis of the prospective Scottish Computed Tomography of the HEART trial (November 2010 to September 2014), hepatosteatosis and coronary artery calcium score were measured at noncontrast CT. Presence of stenoses, visually assessed high-risk plaque, and quantitative plaque burden were assessed at coronary CT angiography. Multivariable models were constructed to assess the impact of hepatosteatosis and cardiovascular risk factors on coronary artery disease.

Results

Images from 1726 participants (mean age, 58 years ± 9 [SD]; 974 men) were included. Participants with hepatosteatosis (155 of 1726, 9%) had a higher body mass index, more hypertension and diabetes mellitus, and higher cardiovascular risk scores (P < .001 for all) compared with those without hepatosteatosis. They had increased coronary artery calcium scores (median, 43 Agatston units [AU] [interquartile range, 0-273] vs 19 AU [0-225], P = .046), more nonobstructive disease (48% vs 37%, P = .02), and higher low-attenuation plaque burden (5.11% [0-7.16] vs 4.07% [0-6.84], P = .04). However, these associations were not independent of cardiovascular risk factors. Over a median of 4.7 years, there was no evidence of a difference in myocardial infarction between those with and without hepatosteatosis (1.9% vs 2.4%, P = .92).

Conclusion

Hepatosteatosis at CT was associated with an increased prevalence of coronary artery disease at CT, but this was not independent of the presence of cardiovascular risk factors.Keywords: CT, Cardiac, Nonalcoholic Fatty Liver Disease, Coronary Artery Disease, Hepatosteatosis, Plaque QuantificationClinical trial registration no. NCT01149590 Supplemental material is available for this article. © RSNA, 2022See also commentary by Abohashem and Blankstein in this issue.

Association of NAFLD with cardiovascular disease and all-cause mortality: a large-scale prospective cohort study based on UK Biobank

Objective

Nonalcoholic fatty liver disease (NAFLD) is considered as the hepatic manifestation of metabolic syndrome, sharing the similar cardiometabolic risk factors with cardiovascular disease (CVD). Whether NAFLD by itself is associated with increased cardiovascular events and death remain an issue to debate. This study aimed to further investigate the association between NAFLD and adverse CVD outcomes.

Methods

Participants were followed up until the end of 2020 in current analysis. NAFLD is defined using fatty liver index (FLI). Cox proportional hazard model was used to analyze the association between NAFLD and all-cause mortality, major adverse cardiovascular events (MACEs), CVD mortality, fatal/nonfatal acute myocardial infarction (AMI), and fatal/nonfatal stroke. C-index was calculated to evaluate the model enhancement when adding NAFLD factor.

Results

After screening the data of 502,492 participants in the original cohort, 215,245 eligible participants were included in this study for MACEs outcome. Compared with non-NAFLD participants, the multivariable adjusted hazard ratios of NAFLD group was 1.25 (1.14-1.36) for MACEs; 1.14 (1.08-1.20) for all-cause mortality; 1.61(1.42-1.82) for CVD mortality; 1.58(1.19-2.11) for AMI mortality; and 1.18 (0.85-1.64) for stroke mortality. When adding FLI, C-index of NAFLD model improved for all-cause mortality, MACEs, and CVD mortality compared with that in the traditional CVD risk factor model.

Conclusion

NAFLD is an independent risk factor for all-cause mortality and adverse CVD outcomes. Based on the traditional CVD risk factor model, additionally screening NAFLD could improve the prediction efficiency for adverse CVD outcomes.

Association between higher pericoronary adipose tissue attenuation measured by coronary computed tomography angiography and nonalcoholic fatty liver disease: A matched case-control study

Non-alcoholic fatty liver disease (NAFLD) is a risk factor for cardiac mortality. Pericoronary adipose tissue (PCAT) attenuation, expressed by the fat attenuation index on coronary computed tomography angiography, reflects pericoronary inflammation. We aimed to investigate the association between PCAT attenuation and NAFLD.This is a single-center cohort study comprising of patients who underwent coronary computed tomography angiography for suspected stable coronary artery disease between January and December 2020. Patient characteristics and coronary computed tomography angiography findings were analyzed between patients with NAFLD (n = 78) and a propensity score-matched cohort of patients without NAFLD (n = 78). PCAT attenuation was assessed in Hounsfield units (HU) of proximal 40-mm segments of the left anterior descending artery (LAD) and right coronary artery.The mean PCAT attenuation in LAD and right coronary artery were significantly higher in patients with NAFLD than those without NAFLD. When patients were divided into 2 groups using the median LAD-PCAT attenuation of -72.5 HU, the high PCAT attenuation group had more males (82% vs 67%, P = .028) and NAFLD patients (63% vs 37%, P = .001) compared to the low PCAT attenuation group. No differences in age, body mass index, conventional cardiovascular risk factors, or the presence of high-risk plaque were observed between the 2 groups. In the multivariate logistic analysis, NAFLD was independently associated with high PCAT attenuation (odds ratio 2.912, 95% confidence interval 1.386 to 6.118, P = .005).NAFLD is associated with high PCAT attenuation on coronary computed tomography angiography. This finding suggests that pericoronary inflammation is involved in the increased cardiac mortality in NAFLD patients.

Incremental prognostic value of non-alcoholic fatty liver disease over coronary computed tomography angiography findings in patients with suspected coronary artery disease

AIMS

This study aimed to investigate additional risk stratification benefits of hepatic steatosis (HS) concurrently assessed during coronary computed tomography angiography (CTA) in a large patient cohort with suspected stable coronary artery disease (CAD).

METHODS AND RESULTS

In this prospective study, 1148 Japanese outpatients without a history of CAD who underwent coronary CTA for suspected stable CAD (mean age 64 ± 14 years) were included. HS, defined on CT as a hepatic-to-spleen attenuation ratio of <1.0, was examined just before the evaluation of adverse CTA findings, defined as obstructive and/or high-risk plaque. The major adverse cardiac events (MACE) were the composite of cardiac death, acute coronary syndrome, and late revascularization. The incremental predictive value of HS was evaluated using the global χ2 test and C-statistic. HS was identified in 247 (22%) patients. During a median follow-up of 3.9 years, MACE was observed in 40 (3.5%) patients. HS was significantly associated with MACE in a model that included adverse CTA findings (hazard ratio 4.01, 95% confidence interval 2.12-7.59, P < 0.001). By adding HS to the Framingham risk score and adverse CTA findings, the global χ2 score and C-statistic significantly increased from 29.0 to 49.5 (P < 0.001) and 0.74 to 0.81 (P = 0.026), respectively. In subgroup analyses in patients with diabetes mellitus and metabolic syndrome, HS had significant additive predictive value for MACE over the Framingham risk score and adverse CTA findings.

CONCLUSION

In patients with suspected stable CAD, concurrent evaluation of HS during coronary CTA enables more accurate detection of patients at higher risk of MACE.

The correlation between hepatic fat fraction evaluated by dual-energy computed tomography and high-risk coronary plaques in patients with non-alcoholic fatty liver disease

PURPOSE

To determine the relationship between non-alcoholic fatty liver disease (NAFLD) evaluated by a hepatic fat fraction (HFF) using dual-energy computed tomography (DECT) and high-risk coronary plaques (HRP) in NAFLD patients.

METHODS

We conducted a matched case-control study involving 172 NAFLD individuals recruited from August 2019 to September 2020. They underwent dual-energy coronary computed tomographic angiography and were classified as no-plaque, HRP negative and HRP positive groups. HFF values were measured using multimaterial decomposition algorithm of DECT, and the differences among three groups were compared. Multiple logistic regression analysis was performed to determine the independent correlation between HFF and HRP. Spearman rank correlation was used to assess the correlations between HFF and multiple variables.

RESULTS

HRP positive group (15.3%) had higher HFF values than no-plaque (6.9%) and HRP negative groups (8.9%) (P < 0.001). After adjusting for confounding variables, the results indicated that HFF was an independent risk factor for HRP (OR 1.93, P < 0.001). Additionally, HFF significantly correlated with coronary artery calcium score, hepatic CT attenuation, epicardial and pericoronary adipose tissue volume, and CT attenuation (all P < 0.001).

CONCLUSIONS

As a new imaging marker for the quantification of liver fat, HFF was independently associated with HRP.

Increased Circulating Malondialdehyde-Modified Low-Density Lipoprotein Level Is Associated with High-Risk Plaque in Coronary Computed Tomography Angiography in Patients Receiving Statin Therapy

Objective: To evaluate the association of serum malondialdehyde low-density lipoprotein (MDA-LDL), an oxidatively modified LDL, with the prevalence of high-risk plaques (HRP) determined with coronary computed tomography angiography (CTA) in statin-treated patients. Methods: This study was a single-center retrospective cohort comprising 268 patients (mean age 67 years, 58% men) with statin therapy and who underwent coronary CTA for suspected stable coronary artery disease. Patients were classified into two groups according to median MDA-LDL level or median LDL-C level. Coronary CTA-verified HRP was defined when two or more characteristics, including positive remodeling, low-density plaques, and spotty calcification, were present. Results: Patients with HRP had higher MDA-LDL (p = 0.011), but not LDL-C (p = 0.867) than those without HRP. High MDA-LDL was independently associated with HRP (odds ratio 1.883, 95% confidential interval 1.082–3.279) after adjustment for traditional risk factors. Regarding incremental value of MDA-LDL for predicting CTA-verified HRP, addition of serum MDA-LDL levels to the baseline model significantly increased global chi-square score from 26.1 to 32.8 (p = 0.010). Conclusions: A high serum MDA-LDL level is an independent predictor of CTA-verified HRP, which can lead to cardiovascular events in statin-treated patients.

Hepatocellular carcinoma and other complications of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in Japan: A structured review of published works

AIMS

Hepatocellular carcinoma (HCC) is a significant cause of morbidity and mortality in Japan. As the treatment of viral hepatitis improves, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are rapidly becoming leading causes of HCC in Japan. This structured review aims to characterize the morbidity and mortality of HCC and other malignant and non-malignant complications among Japanese NAFLD and NASH patients.

METHODS

An English and Japanese structured search of published works was undertaken in PubMed, Embase, and Ichushi Web databases, identifying 6553 studies, 34 of which met predefined inclusion criteria.

RESULTS

Hepatocellular carcinoma was the most common incident malignancy among NAFLD/NASH patients, with higher incidence in patients with advanced/severe fibrosis (F3/F4) of 10.5%-20.0%. Although NASH results in a lower HCC cumulative incidence than hepatitis C virus (HCV) (11.3% vs. 30.5%), they have similar impacts on health outcomes, including overall mortality. Among Japanese NASH patients, HCC was found to be the main driver of mortality (40.0% in 2.7 years in NASH-HCC). With longer follow-up, higher mortality rates are observed in F3/4 patients: 25.0% in NASH F3/F4 versus 0.0% in NASH F0/2 over 7.7 years. The NASH-HCC patients also have a higher post-operative mortality than HCV-HCC patients. Additionally, NAFLD/NASH patients had higher rates of cardiovascular disease than non-NAFLD/NASH controls, and slightly higher rates of gastric cancer than HCV patients.

CONCLUSION

Hepatocellular carcinoma is the most common malignancy and cause of death among NAFLD/NASH patients in Japan, with higher mortality observed among those with advanced disease and complications. Early identification and effective treatments are needed.

Higher oxidized high-density lipoprotein to apolipoprotein A-I ratio is associated with high-risk coronary plaque characteristics determined by CT angiography

BACKGROUND

Oxidized high-density lipoprotein (oxHDL), unlike native HDL, is characterized by reduced cholesterol efflux capability and anti-inflammatory properties. The ratio of oxHDL to apolipoprotein A-I (oxHDL/apoAI) is a possible marker of dysfunctional HDL. The aim of this study was to evaluate the association between oxHDL/apoAI and coronary plaque characteristics that increase the likelihood of cardiovascular events as determined by coronary computed tomography (CT) angiography.

METHODS

A total of 297 patients (mean age; 67 years, men; 63%) who underwent coronary CT angiography for suspected stable coronary artery disease (CAD) were included. High-risk plaques (HRP) were defined by three characteristics: positive remodeling; low-density plaques; and spotty calcification. Significant stenosis was defined as a luminal narrowing of >70%. Serum concentrations of oxHDL were measured using an enzyme-linked immunosorbent assay.

RESULTS

Patients with higher oxHDL/ApoAI showed significantly greater prevalence of HRP (p = 0.03) and significant stenosis (p < 0.01) compared with patients with low oxHDL/ ApoAI. The multivariate logistic analysis demonstrated that oxHDL/ApoAI significantly associated with the presence of HRP and significant coronary stenosis (p = 0.01 and < 0.01). In the follow-up study including 243 patients for a median period of 1.8 years, univariate cox regression analysis showed that oxHDL/ApoAI, HRP and significant stenosis were significant predictors of cardiovascular events.

CONCLUSIONS

A high oxHDL/apoAI was associated with the presence of HRP and significant stenosis determined by coronary CT angiography, which can lead to cardiovascular events in patients with suspected stable CAD.

Using machine learning algorithms to review computed tomography scans and assess risk for cardiovascular disease: Retrospective analysis from the National Lung Screening Trial (NLST)

BACKGROUND

The National Lung Screening Trial (NLST) demonstrated that annual screening with low dose CT in high-risk population was associated with reduction in lung cancer mortality. Nonetheless, the leading cause of mortality in the study was from cardiovascular diseases.

PURPOSE

To determine whether the used machine learning automatic algorithms assessing coronary calcium score (CCS), level of liver steatosis and emphysema percentage in the lungs are good predictors of cardiovascular disease (CVD) mortality and incidence when applied on low dose CT scans.

MATERIALS AND METHODS

Three fully automated machine learning algorithms were used to assess CCS, level of liver steatosis and emphysema percentage in the lung. The algorithms were used on low-dose computed tomography scans acquired from 12,332 participants in NLST.

RESULTS

In a multivariate analysis, association between the three algorithm scores and CVD mortality have shown an OR of 1.72 (p = 0.003), 2.62 (p < 0.0001) for CCS scores of 101-400 and above 400 respectively, and an OR of 1.12 (p = 0.044) for level of liver steatosis. Similar results were shown for the incidence of CVD, OR of 1.96 (p < 0.0001), 4.94 (p < 0.0001) for CCS scores of 101-400 and above 400 respectively. Also, emphysema percentage demonstrated an OR of 0.89 (p < 0.0001). Similar results are shown for univariate analyses of the algorithms.

CONCLUSION

The three automated machine learning algorithms could help physicians to assess the incidence and risk of CVD mortality in this specific population. Application of these algorithms to existing LDCT scans can provide valuable health care information and assist in future research.

NAFLD and cardiovascular diseases: a clinical review

Non-alcoholic fatty liver DISEASE (NAFLD) is the most common chronic liver disease in Western countries and affects approximately 25% of the adult population. Since NAFLD is frequently associated with further metabolic comorbidities such as obesity, type 2 diabetes mellitus, or dyslipidemia, it is generally considered as the hepatic manifestation of the metabolic syndrome. In addition to its potential to cause liver-related morbidity and mortality, NAFLD is also associated with subclinical and clinical cardiovascular disease (CVD). Growing evidence indicates that patients with NAFLD are at substantial risk for the development of hypertension, coronary heart disease, cardiomyopathy, and cardiac arrhythmias, which clinically result in increased cardiovascular morbidity and mortality. The natural history of NAFLD is variable and the vast majority of patients will not progress from simple steatosis to fibrosis and end stage liver disease. However, patients with progressive forms of NAFLD, including non-alcoholic steatohepatitis (NASH) and/or advanced fibrosis, as well as NAFLD patients with concomitant types 2 diabetes are at highest risk for CVD. This review describes the underlying pathophysiological mechanisms linking NAFLD and CVD, discusses the role of NAFLD as a metabolic dysfunction associated cardiovascular risk factor, and focuses on common cardiovascular manifestations in NAFLD patients.

Epidemiology of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in Japan: A focused literature review

Non‐alcoholic fatty liver disease (NAFLD) and non‐alcoholic steatohepatitis (NASH) represent a growing unmet medical need and an increasingly prevalent cause of cirrhosis, hepatocellular carcinoma (HCC), and death in Japan. The aim of this review was to characterize the epidemiology of NAFLD and NASH in Japan. An English and Japanese literature search was conducted in PubMed, Embase, and ICHUSHI Web, identifying 6553 studies, 67 of which were included. Prevalence of NAFLD in the Japanese population rose from the early 1990s (12.6–12.9%) to the early 2000s (24.6–34.7% of the population). Japanese NASH prevalence is estimated to be 1.9–2.7%. NAFLD and NASH are more common among males than females; however, females experience more severe disease than males. While obese patients had higher prevalence of NAFLD/NASH, nonobese individuals (body mass index [BMI] <25 kg/m²) consistently comprised 20% to >35% of NAFLD and NASH patients. The evidence shows that, despite obesity being linked with worse disease stages, “lean‐NASH” also plays an important role in NASH epidemiology. Besides obesity, diabetes and metabolic syndrome appeared to be reliably associated with disease severity. The prevalence of advanced fibrosis or cirrhotic disease was the highest in patients with NASH‐HCC (44–80% with stage F3/F4 disease), while 21–50% of patients with NASH had F3/F4 disease. NAFLD/NASH is common in the Japanese population, and the prevalence of these conditions has tripled in the last two decades. Furthermore, these NAFLD/NASH patients have a high comorbidity burden. Early and efficient identification of safe and effective treatments for NAFLD/NASH patients is urgently needed.

Clinical significance of hepatic steatosis according to coronary plaque morphology: assessment using controlled attenuation parameter

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) plays a significant role in coronary atherosclerosis, independent of shared metabolic risk factors. The measurement of the controlled attenuation parameter (CAP) has shown to allow early and noninvasive detection of NAFLD at subclinical stage. We evaluated the significance of CAP-defined NAFLD in association with the presence of any type of coronary plaques and different plaque compositions.

METHODS

We conducted a retrospective cohort of apparently healthy subjects who had liver Fibroscan and coronary computed tomography during health screening exams.

RESULTS

A greater number of subjects with CAP-defined NAFLD was found in group with coronary plaques (61.3% vs. 73.5%, p = 0.005 without vs. with any type of plaque). From multivariate regression model, CAP ≥ 222 dB/m was an independent and significant parameter associated with the presence of coronary plaques, after adjusting possible confounders (OR 1.624, 95% 1.047-2.518, p = 0.030). Interestingly, CAP ≥ 222 dB/m was significantly associated with non-calcified plaque (adjusted OR 3.528, 95% CI 1.463-8.511, p = 0.005), whereas it was not significant in calcified plaques (p = 0.171).

CONCLUSION

CAP-defined NAFLD is independently associated with coronary plaques, especially non-calcified plaques. The association between NAFLD and non-calcified plaques suggests that particular attention should be given to the subjects with NAFLD for primary prevention.

Non-alcoholic fatty liver disease is a strong predictor of coronary artery calcification in metabolically healthy subjects: A cross-sectional, population-based study in middle-aged subjects

Objectives

This study aims to estimate the relationship between non-alcoholic fatty liver disease (NAFLD) and measures of atherosclerotic cardiovascular disease (ASCVD), and to determine to what extent such relationships are modified by metabolic risk factors.

Methods

The study was conducted in the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) pilot cohort (n = 1015, age 50–64 years, 51.2% women). NAFLD was defined as computed tomography liver attenuation ≤40 Hounsfield Units, excluding other causes of liver fat. Coronary artery calcification score (CACS) was assessed using the Agatston method. Carotid plaques and intima media thickness (IMT) were measured by ultrasound. Metabolic status was based on assessments of glucose homeostasis, serum lipids, blood pressure and inflammation. A propensity score model was used to balance NAFLD and non NAFLD groups with regards to potential confounders and associations between NAFLD status and ASCVD variables in relation to metabolic status were examined by logistic and generalized linear regression models.

Results

NAFLD was present in 106 (10.4%) of the subjects and strongly associated with obesity-related traits. NAFLD was significantly associated with CACS after adjustment for confounders and metabolic risk factors (OR 1.77, 95% CI 1.07–2.94), but not with carotid plaques and IMT. The strongest association between NAFLD and CACS was observed in subjects with few metabolic risk factors (n = 612 [60% of all] subjects with 0–1 out of 7 predefined metabolic risk factors; OR 5.94, 95% CI 2.13–16.6).

Conclusions

NAFLD was independently associated with coronary artery calcification but not with measures of carotid atherosclerosis in this cohort. The association between NAFLD and CACS was most prominent in the metabolically healthy subjects.

Correlations between the abdominal fat-related parameters and severity of coronary artery disease assessed by computed tomography

Background

Obesity is considered a challenging public problem, which has been proven to be closely associated with coronary artery disease (CAD). Each risk factor of CAD has been separately studied many times in the past, but very few have comprehensively and quantitatively evaluated the relationship between the abdominal fat-related parameters and severity of CAD. The aim of this study was to analyze whether the abdominal fat-related parameters were associated with severity of CAD using abdominal non-enhanced computed tomography (NECT).

Methods

Patients who went through both abdominal NECT and invasive coronary angiography (ICA) were included and retrospectively analyzed. The abdominal fat-related parameters [the ratio of visceral adipose tissue to subcutaneous adipose tissue (VAT/SAT ratio)] and traditional cardiovascular risk factors were evaluated in the participants with or without obstructive CAD. The correlations between the abdominal fat-related parameters and severity of CAD were assessed, and the multivariable logistic regression analysis was performed to investigate the parameters that could be used to predict the severity of CAD.

Results

A total of 223 consecutive subjects (obstructive CAD group, n=117; non-obstructive CAD group, n=106) were analyzed. The VAT/SAT ratio was significantly higher (0.95±0.33 vs. 0.70±0.25, P<0.001) in obstructive CAD (O-CAD) patients than that in non-obstructive CAD (NO-CAD) patients. There was a trend to having nonalcoholic fatty liver disease (NAFLD) in the O-CAD patients than that of NO-CAD (P=0.002); the abdominal aortic calcification (AAC) score in O-CAD patients were higher than that in NO-CAD patients (P<0.001). The multivariable logistic regression analysis demonstrated that VAT/SAT ratio, NAFLD, and AAC score were independent predictors of O-CAD after adjusting the traditional cardiovascular risk factors. The area under the curve (AUC) of the combination of the above risk factors is 0.85, which leads to an increase in AUC than each risk factor alone in differentiating patients with or without O-CAD.

Conclusions

VAT/SAT ratio, NAFLD, and AAC score are correlated with the severity of CAD, indicating their characteristics of being independent risk factors for O-CAD, irrespective of the traditional cardiovascular risk factors. Those CT-derived parameters may make positive contributions to the differentiation of the patients with increased risk of O-CAD.

Managing the Burden of Non-NASH NAFLD

Purpose of Review

The purpose of this review article is to raise awareness of the significance of steatosis that exist within the spectrum of nonalcoholic fatty liver disease (NAFLD). While the impact of nonalcoholic steatohepatitis (NASH), and its potential for histologic progression to cirrhosis and hepatocellular carcinoma is widely appreciated, the impact of non-NASH NAFLD (steatosis) on morbidity and mortality is less well recognized.

Recent Findings

NAFLD is a spectrum of hepatic pathology with a rising prevalence worldwide. Steatosis without fibrosis carries a low risk of progression to cirrhosis but likely confers an increased risk of diabetes mellitus and cardiovascular disease.

Summary

About a quarter of the world population is affected by NAFLD. NAFLD represents a burden to affected individuals, economics of the health care system and contributes significantly to morbidity and mortality worldwide. An increased level of awareness and knowledge about risk factors and diagnostic strategies is needed to identify patients affected with disease.

Arterial Calcification in Diabetes Mellitus: Preclinical Models and Translational Implications

Diabetes mellitus increasingly afflicts our aging and dysmetabolic population. Type 2 diabetes mellitus and the antecedent metabolic syndrome represent the vast majority of the disease burden-increasingly prevalent in children and older adults. However, type 1 diabetes mellitus is also advancing in preadolescent children. As such, a crushing wave of cardiometabolic disease burden now faces our society. Arteriosclerotic calcification is increased in metabolic syndrome, type 2 diabetes mellitus, and type 1 diabetes mellitus-impairing conduit vessel compliance and function, thereby increasing the risk for dementia, stroke, heart attack, limb ischemia, renal insufficiency, and lower extremity amputation. Preclinical models of these dysmetabolic settings have provided insights into the pathobiology of arterial calcification. Osteochondrogenic morphogens in the BMP-Wnt signaling relay and transcriptional regulatory programs driven by Msx and Runx gene families are entrained to innate immune responses-responses activated by the dysmetabolic state-to direct arterial matrix deposition and mineralization. Recent studies implicate the endothelial-mesenchymal transition in contributing to the phenotypic drift of mineralizing vascular progenitors. In this brief overview, we discuss preclinical disease models that provide mechanistic insights-and point to challenges and opportunities to translate these insights into new therapeutic strategies for our patients afflicted with diabetes mellitus and its arteriosclerotic complications.

Evaluation of Echocardiographic Epicardial Fat Thickness as a Sign of Cardiovascular Risk in Positive Exercise Test Patients

BACKGROUND

The association between epicardial fat thickness (EFT) and positive exercise test results for the diagnosis of coronary artery diseases (CAD) has yet to be evaluated. This study assessed the predictive value of EFT for CAD on the angiographs of patients with positive exercise tests.

METHODS

A total of 91 subjects were chosen consecutively from stable angina pectoris patients who were referred for coronary angiography due to a positive exercise test result. The EFT measures were obtained by echocardiographic parasternal long-axis views on the free wall of the right ventricle at end-systole of three cardiac cycles. Gensini scores were calculated by a conventional coronary angiography technique using a calculation method previously defined.

RESULTS

Receiver operator characteristic (ROC) curve analysis revealed a 0.65 cm (95% confidence interval: 0.628, 0.832, p < 0.001) area under the curve with 74.3% sensitivity and 62.3% specificity at the cut-off value of EFT for the prediction of critical coronary artery stenosis. Following ROC curve analysis, two groups were defined according to EFT cut-off value (groups 1 and 2). The severe coronary stenosis ratio was significantly higher in group 2 compared to group 1 (31.9 % vs. 11%, p < 0.001) and Gensini scores were significantly higher in group 2 (6.3 ± 13.3 vs. 16.5 ± 17.9; p < 0.001). There was no significant correlation between Gensini scores and EFT in group 1 (r = 0.093, p = 0.549), but there was a strong significant correlation in group 2 (r = 0.730, p < 0.001). Linear multivariate regression analysis revealed that EFT (> 0.65 cm) was the only independent risk factor for critical coronary artery stenosis (β = 0.451, p < 0.001).

CONCLUSIONS

EFT was significantly correlated with the severity and prevalence of coronary artery disease in positive exercise test patients.

Nonalcoholic fatty liver disease is associated with coronary artery calcification: A systematic review and meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is associated increased cardiovascular events and mortality. Coronary artery calcium scanning (CAC) is the robust predictor of coronary events in the asymptomatic individuals. Several recent studies have investigated the association between NAFLD and this surrogate marker. Thus, we conducted a systematic review and meta-analysis to better characterize the association between NAFLD and CAC.

METHODS

MEDLINE and EMBASE were searched through May 2016. Primary outcome was the association between NAFLD and CAC. Pooled odds ratio (OR) and 95% confidence interval (CI) from multivariable-adjusted estimates were calculated using a random-effects model. The between-study heterogeneity of effect-size was quantified using the Q statistic and I².

RESULTS

Data were extracted from 16 studies (all cross-sectional studies) involving 16,433 NAFLD patients and 41,717 controls. NAFLD is significantly associated with CAC score >0 and CAC score >100 with pooled OR of 1.41 (95%CI 1.26-1.57, P_{heterogeneity}=0.07, I²=66%) and 1.24 (95%CI 1.02-1.52, P_{heterogeneity}=0.10, I²=42%).

CONCLUSIONS

NAFLD is associated with increased coronary artery calcification independent of traditional risk factors. The assessment of coronary artery calcium may be useful in identifying NAFLD patients at risk of future cardiovascular events.

Nonalcoholic fatty liver disease, association with cardiovascular disease and treatment. (I). Nonalcoholic fatty liver disease and its association with cardiovascular disease

Non-alcoholic fatty liver disease (NAFLD) comprises a series of histologically lesions similar to those induced by alcohol consumption in people with very little or no liver damage. The importance of NAFLD is its high prevalence in the Western world and, from the point of view of the liver, in its gradual progression from steatosis to steatohepatitis, cirrhosis, and liver cancer. During the last decade it has been observed that NAFLD leads to an increased cardiovascular risk with acceleration of arteriosclerosis and events related to it, being the main cause of its morbidity and mortality. This review, updated to January 2016, consists of two parts, with the first part analysing the association of NAFLD with cardiovascular disease.

Understanding the association between developing a fatty liver and subsequent cardio-metabolic complications

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries and is also predicted to become the most frequent indication for liver transplantation by 2030. In the last decade, it has become evident that the clinical burden of NAFLD is not restricted to liver-related morbidity or mortality, but there is now compelling evidence that NAFLD is a multisystem disease, affecting many extra-hepatic organs. In this article, we discuss the evidence linking NAFLD with important cardiometabolic complications (mainly Type 2 diabetes and cardiovascular disease) and the putative underlying mechanisms by which NAFLD may contribute to the development of these complications.

Cardiovascular Disease and Myocardial Abnormalities in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in many developed countries, affecting an estimated 30 % of the adult population. In this updated clinical review, we summarize the current knowledge regarding the strong association between NAFLD and the risk of coronary heart disease (CHD) and other functional, structural, and arrhythmic cardiac complications (e.g., left ventricular dysfunction, heart valve diseases and atrial fibrillation). We also briefly discuss the putative biological mechanisms linking NAFLD with these important extra-hepatic complications. To date, a large body of evidence has suggested that NAFLD is not simply a marker of CHD and other functional, structural, and arrhythmic cardiac complications, but also may play a part in the development and progression of these cardiac complications. The clinical implication of these findings is that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions aimed at decreasing the risk of CHD and other cardiac and arrhythmic complications.

Gut Microbiota and Lifestyle Interventions in NAFLD

The human digestive system harbors a diverse and complex community of microorganisms that work in a symbiotic fashion with the host, contributing to metabolism, immune response and intestinal architecture. However, disruption of a stable and diverse community, termed "dysbiosis", has been shown to have a profound impact upon health and disease. Emerging data demonstrate dysbiosis of the gut microbiota to be linked with non-alcoholic fatty liver disease (NAFLD). Although the exact mechanism(s) remain unknown, inflammation, damage to the intestinal membrane, and translocation of bacteria have all been suggested. Lifestyle intervention is undoubtedly effective at improving NAFLD, however, not all patients respond to these in the same manner. Furthermore, studies investigating the effects of lifestyle interventions on the gut microbiota in NAFLD patients are lacking. A deeper understanding of how different aspects of lifestyle (diet/nutrition/exercise) affect the host-microbiome interaction may allow for a more tailored approach to lifestyle intervention. With gut microbiota representing a key element of personalized medicine and nutrition, we review the effects of lifestyle interventions (diet and physical activity/exercise) on gut microbiota and how this impacts upon NAFLD prognosis.

Correlations between quantitative fat-water magnetic resonance imaging and computed tomography in human subcutaneous white adipose tissue

Beyond estimation of depot volumes, quantitative analysis of adipose tissue properties could improve understanding of how adipose tissue correlates with metabolic risk factors. We investigated whether the fat signal fraction (FSF) derived from quantitative fat-water magnetic resonance imaging (MRI) scans at 3.0 T correlates to CT Hounsfield units (HU) of the same tissue. These measures were acquired in the subcutaneous white adipose tissue (WAT) at the umbilical level of 21 healthy adult subjects. A moderate correlation exists between MRI- and CT-derived WAT values for all subjects, [Formula: see text], [Formula: see text], with a slope of [Formula: see text], (95% CI [Formula: see text]), indicating that a decrease of 1 HU equals a mean increase of 0.38% FSF. We demonstrate that FSF estimates obtained using quantitative fat-water MRI techniques correlate with CT HU values in subcutaneous WAT, and therefore, MRI-based FSF could be used as an alternative to CT HU for assessing metabolic risk factors.