An Observational Data Meta-analysis on the Differences in Prevalence and Risk Factors Between MAFLD vs NAFLD

BACKGROUND & AIMS

The shift to redefine nonalcoholic fatty liver disease (NAFLD) as metabolic associated fatty liver disease (MAFLD) can profoundly affect patient care, health care professionals, and progress within the field. To date, there remains no consensus on the characterization of NAFLD vs MAFLD. Thus, this study sought to compare the differences between the natural history of NAFLD and MAFLD.

METHODS

Medline and Embase databases were searched to include articles on prevalence, risk factors, or outcomes of patients with MAFLD or NAFLD. Meta-analysis of proportions was conducted using the generalized linear mix model. Risk factors and outcomes were evaluated in conventional pairwise meta-analysis.

RESULTS

Twenty-two articles involving 379,801 patients were included. Pooled prevalence of MAFLD was 39.22% (95% confidence interval [CI], 30.96%-48.15%) with the highest prevalence in Europe and Asia, followed by North America. The current MAFLD Definition only accounted for 81.59% (95% CI, 66.51%-90.82%) of NAFLD diagnoses. Patients had increased odds of being diagnosed with MAFLD compared with NAFLD (odds ratio, 1.37; 95% CI, 1.16-1.63; P < .001). Imaging modality resulted in a significantly higher odds of being diagnosed with MAFLD compared with NAFLD, but not biopsy. MAFLD was significantly associated with males, higher body mass index, hypertension, diabetes, lipids, transaminitis, and greater fibrosis scores compared with NAFLD.

CONCLUSIONS

There were stark differences in the prevalence and risk factors between MAFLD and NAFLD. However, in the use of the MAFLD Definition, a greater emphasis on the management of concomitant metabolic diseases and a collaborative effort is required to explore the complex pathophysiologic mechanisms underlying the disease.

Outcomes of Nonalcoholic Steatohepatitis After Liver Transplantation: An Updated Meta-Analysis and Systematic Review

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is the fastest growing indication of liver transplantation (LT) and is projected to be the leading cause of LT in the near future. The systemic pathogenesis of NASH increases risks of adverse clinical outcomes in patients with NASH receiving LT. Thus, this study aimed to conduct a time-dependent survival analysis between LT recipients with and without NASH using hazard ratios.

METHODS

A search was conducted on Medline and Embase databases for articles relating to LT outcomes for NASH recipients. A survival analysis was conducted of hazard ratios using the DerSimonian and Laird random-effects model with meta-regression. To account for censoring, survival data were reconstructed from published Kaplan-Meier curves and pooled to derive more accurate hazard estimates and all-cause mortality in NASH patients after LT. Pairwise meta-analysis was conducted to analyze secondary outcomes.

RESULTS

Fifteen studies involving 119,327 LT recipients were included in our analysis with a prevalence of NASH of 20.2% (95% CI, 12.9-30.2). The pooled 1-year, 5-year, and 10-year all-cause mortality in NASH patients after LT were 12.5%, 24.4%, and 37.9%, respectively. Overall survival was comparable between LT recipients for NASH vs non-NASH (hazard ratio, 0.910; 95% CI, 0.760 to 1.10; P = .34). Meta-regression showed that a higher model for end-stage liver disease score was associated with significantly worse overall survival in NASH compared with non-NASH after LT (95% CI, -0.0856 to -0.0181; P = .0026).

CONCLUSIONS

This study shows that patients undergoing LT for NASH cirrhosis have comparable complication rates, overall survival, and graft survival compared with non-NASH patients, although close monitoring may be indicated for those with higher model for end-stage liver disease scores.

Echocardiographic assessment of cardiovascular function and clinical outcomes in liver transplant recipients

BACKGROUND & AIMS

Cardiovascular disease contributes to a high rate of morbidity and mortality after liver transplantation (LT). However, the progression of cardiac function and cardiac remodeling in LT recipients remains poorly understood. This study sought to evaluate the progression of cardiac function and structure in LT recipients and identify independent predictors of prognosis using echocardiography.

METHODS

From 2009 to 2019, 178 adult LT recipients at a tertiary academic transplant center were retrospectively studied. Transthoracic echocardiograms 1-year pre- and post-LT were assessed. Primary outcomes were progression of systolic and diastolic function. Secondary outcomes included left ventricular remodeling, all-cause mortality, and heart failure readmission post-LT. Subgroup analyzes were performed for etiology of native liver disease. A multivariable model was constructed to examine independent predictors of outcomes.

RESULTS

Systolic function significantly worsened, with reduction in stroke volume (45-37 ml/m² , p < .001), left ventricular ejection fraction (LVEF) (65%-62%, p < .001) and cardiac index (3.00-2.60 L/min/m² , p < .001). Conversely, there were significant improvements in diastolic indices, including tricuspid regurgitation V_max (228-215 cm/s, p = .017), left atrial volume index (LAVI) (32-26 ml/m² , p < .001) and right ventricular systolic pressure (RVSP) (31-28 mmHg, p = .001). Additionally, patients had increased relative wall thickness (RWT) (p < .001) and decreased left ventricular end-diastolic dimension/body surface area (p < .001) post-LT. The independent predictors for all-cause mortality and heart failure were increased pre-LT mitral annular early diastolic velocity (HR 1.11, CI 1.02-1.22, p = .018), LAVI (HR 1.06, CI 1.02-1.11, p = .007) and decreased LVEF (HR .89, CI .82-.97, p = .006). The effect of non-alcoholic steatohepatitis on cardiovascular outcomes post-LT was largely comparable to that of Hepatitis B.

CONCLUSION

This study showed reduced systolic and improved diastolic function in LT recipients and highlighted the utility of pre-LT echocardiogram in the prognostication and risk stratification of LT candidates.

A systematic review and meta-analysis on the impact of pre-existing and new-onset atrial fibrillation on outcomes before and after liver transplantation

BACKGROUND AND AIMS

Atrial Fibrillation (AF) is the most commonly diagnosed cardiac arrhythmia. It is associated with significant morbidity and mortality, as it is a major risk factor for cerebral vascular accidents (CVA). Our aim was to determine the prevalence of pre-existing and new-onset AF among patients undergoing liver transplantation (LT) and its impact on post-transplant outcomes.

METHODS

Medline and Embase were searched. Single-arm analysis was conducted using the generalized linear mixed model to determine the prevalence of pre-existing and new-onset AF. Logistic regression was performed to analyze risk factors. Comparative meta-analysis in odds ratio was conducted for binary outcomes.

RESULTS

Twenty articles were included, with 17 studies on pre-existing AF, and 7 including data on new-onset AF post-LT. The prevalence of pre-existing AF was 3.3% (CI 2.3-4.7) (14 studies, 45,070 patients) in pooled analysis. Significantly higher prevalence of pre-existing AF patients from North America was noted when compared to Europe (4.5%, CI 3.4-5.8 vs 1.5%, CI 0.8-2.7; p = 0.001). Body mass index (BMI), history of hypertension, diabetes, coronary artery disease (CAD), and cerebrovascular accidents (CVA) were risk factors for pre-existing AF. Pre-existing AF was significantly associated with major adverse cardiac or cerebrovascular events (MACCE) postoperatively (OR 8.02, 95%CI 5.40-11.90, p < 0.001). New-onset AF post-LT had an incidence of 6.8% (CI 4.9-9.3), and was associated with increased risk of mortality (OR 2.31, 95% CI 1.76-3.02, p < 0.001) and graft failure (OR 2.98, CI 1.99-4.47, p < 0.001).

CONCLUSION

AF is relatively more common among patients undergoing LT compared to the general non-transplant population. Additionally, it is associated with adverse outcomes including MACCE, thus warranting clinical attention. Thorough cardiac assessment, and close surveillance of post-operative AF may be clinically prudent.

A Diagnostic Test Meta-Analysis Evaluating Imaging-Based and Blood Biomarker-Based Assessment Tools for Fibrosis After Liver Transplantation

Early detection of liver graft fibrosis is crucial for risk stratification to identify patients for liver biopsy and timely treatment. However, diagnostic accuracy of noninvasive tests (NITs) remains unclear. Thus, this study sought to evaluate diagnostic accuracy of NITs in assessing liver allograft fibrosis and compare the differences in specificities and sensitivities among NITs. Medline and Embase databases were searched to include articles on diagnostic tests in liver transplantation (LT) patients with fibrosis. A meta-analysis on diagnostic test accuracy was conducted in a random-effects model. Sensitivities and specificities among the diagnostic tests were compared, and threshold values were calculated where applicable. A total of 25 articles were included. Vibration-controlled transient elastography (VCTE) met the minimum diagnostic accuracy requirements, yielding sensitivity, specificity, and diagnostic odds ratios of 0.9 (CI, 0.8-1.0), 0.9 (CI, 0.8-1.0), and 379.6 (CI, 45.8-1728.7), respectively. In the threshold assessment, the optimal cutoff was 9.30 kPa with a sensitivity, specificity, and area under the curve of 0.7 (CI, 0.5-0.9), 0.9 (CI, 0.8-0.9), and 0.9 (CI, 0.8-0.9), respectively. For significant fibrosis, acoustic radiation force impulse (ARFI) was superior to FibroTest (LabCorp [Burlington, NC]) and magnetic resonance elastography (MRE) in sensitivity. VCTE was superior to FibroTest in specificity. For advanced fibrosis, ARFI was superior to the Fibrosis-4 Index (FIB-4) in sensitivity. VCTE was superior to the AST to Platelet Ratio Index (APRI), MRE, and FIB-4 in specificity. In cirrhosis, VCTE was superior to APRI in specificity (P = 0.004) with comparable sensitivity. This study demonstrates the potential of VCTE and ARFI as diagnostic tools for fibrosis in LT recipients compared with blood-based NITs, which were shown to be less optimal.

A Meta-Analysis and Systematic Review on the Global Prevalence, Risk Factors, and Outcomes of Coronary Artery Disease in Liver Transplantation Recipients

The shift in the changing etiology of cirrhosis requiring liver transplantation (LT) has resulted in an increasing prevalence of coronary artery disease (CAD) that can potentially impact post-LT outcomes. This systematic review and meta-analysis evaluates the prevalence of CAD, risk factors, and outcomes of patients diagnosed with CAD before LT. MEDLINE and EMBASE were searched for articles describing CAD in pre-LT patients. Meta-analysis of proportions using the generalized linear mix model was conducted to analyze the pooled prevalence of CAD in pre-LT patients. Associated risk factors for CAD in pre-LT patients and outcomes were evaluated in conventional pairwise meta-analysis. A total of 39 studies were included. The pooled prevalence of patients diagnosed with CAD before LT was 15.9% (95% CI, 9.8%-24.7%). Age, male sex, diabetes mellitus, hypertension, hyperlipidemia, smoking, nonalcoholic steatohepatitis, hepatitis B virus, and hepatocellular carcinoma were significantly associated with CAD. Patients from high-income countries especially North America, Europe, and South America, with the associated risk factors were at increased risk for CAD before LT. CAD before LT was associated with an increased odds of overall mortality (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.4-1.4; P = 0.01) and cardiac-related mortality (OR, 1.2; 95% CI, 1.1-1.3; P = 0.03). A total of 48.7% of included articles considered the presence of cardiovascular risk factors for CAD screening. However, 10.3% of the studies screened for CAD in pre-LT patients via invasive coronary angiography only, without stress testing or risk stratification. This study demonstrates the high prevalence of CAD in pre-LT patients, associated risk factors, and outcomes. There is heterogeneity among guidelines and practice in screening for pre-LT CAD, and more studies are needed to establish consensus.

A meta-analysis on the prevalence of chronic kidney disease in liver transplant candidates and its associated risk factors and outcomes

Pre-liver transplant (LT) chronic kidney disease (CKD) has emerged as a leading cause of post-operative morbidity. We aimed to report the prevalence, associated risk factors, and clinical outcomes in patients with pre-LT CKD. Meta-analysis and systematic review were conducted for included cohort and cross-sectional studies. Studies comparing healthy and patients with s pre-LT CKD were included. Outcomes were assessed with pooled hazard ratios. 15 studies were included, consisting of 82,432 LT patients and 26,754 with pre-LT CKD. Pooled prevalence of pre-LT CKD was 22.35% (CI: 15.30%-32.71%). Diabetes mellitus, hypertension, viral hepatitis, and non-alcoholic fatty liver disease, and older age were associated with increased risk of pre-LT CKD: (OR 1.72 CI: 1.15-2.56, P = 0.01), (OR 2.23 CI: 1.76-2.83, P < 0.01), (OR 1.09; CI: 1.05-1.13, P < 0.01), (OR 1.73; CI: 1.10-2.71 P = 0.03), and (MD: 2.92 years; CI: 1.29-4.55years; P < 0.01) respectively. Pre-LT CKD was significantly associated with increased mortality (HR 1.38; CI: 1.2-1.59; P < 0.01), post-LT end-stage renal disease and post-LT CKD. Almost a quarter of pre-LT patients have CKD and it is significantly associated with post-operative morbidity and mortality. However, long-term outcomes remain unclear due to a lack of studies reporting such outcomes.

An Epidemiological Meta-Analysis on the Worldwide Prevalence, Resistance, and Outcomes of Spontaneous Bacterial Peritonitis in Cirrhosis

Background and Aims: Spontaneous bacterial peritonitis (SBP) is a common and potentially fatal complication of liver cirrhosis. This study aims to analyze the prevalence of SBP among liver cirrhotic patients according to geographical location and income level, and risk factors and outcomes of SBP. Methods: A systematic search for articles describing prevalence, risk factors and outcomes of SBP was conducted. A single-arm meta-analysis was performed using generalized linear mix model (GLMM) with Clopper-Pearson intervals. Results: Ninety-Nine articles, comprising a total of 5,861,142 individuals with cirrhosis were included. Pooled prevalence of SBP was found to be 17.12% globally (CI: 13.63-21.30%), highest in Africa (68.20%; CI: 12.17-97.08%), and lowest in North America (10.81%; CI: 5.32-20.73%). Prevalence of community-acquired SBP was 6.05% (CI: 4.32-8.40%), and 11.11% (CI: 5.84-20.11%,) for healthcare-associated SBP. Antibiotic-resistant microorganisms were found in 11.77% (CI: 7.63-17.73%) of SBP patients. Of which, methicillin-resistant Staphylococcus aureus was most common (6.23%; CI: 3.83-9.97%), followed by extended-spectrum beta-lactamase producing organisms (6.19%; CI: 3.32-11.26%), and lastly vancomycin-resistant enterococci (1.91%; CI: 0.41-8.46%). Subgroup analysis comparing prevalence, antibiotic resistance, and outcomes between income groups was conducted to explore a link between socioeconomic status and SBP, which revealed decreased risk of SBP and negative outcomes in high-income countries. Conclusion: SBP remains a frequent complication of liver cirrhosis worldwide. The drawn link between income level and SBP in liver cirrhosis may enable further insight on actions necessary to tackle the disease on a global scale.

A network meta-analysis of direct oral anticoagulants for portal vein thrombosis in cirrhosis

BACKGROUND

Current guidelines have limited consensus on the approach to portal venous thrombosis (PVT) in cirrhotic patients. While there is rising interest in direct oral anticoagulants (DOACs) use for PVT, current evidence is limited by small sample size and lack of comparisons to traditional anticoagulants. Thus, a network meta-analysis was conducted to compare the use of DOACs with traditional anticoagulants.

METHODS

Medline and Embase were searched for articles about anticoagulation use in cirrhotic patients with nontumorous PVT for articles on DOACs, warfarin, low-molecular weight heparin (LMWH) or antithrombin III. A network analysis was conducted using risk ratios (RR) with surface under the cumulative ranking curve (SUCRA). A single-arm meta-analysis was used to summarize the outcomes of DOAC treatment.

RESULTS

A total of 10 articles were included in the study. 79.5% (CI 38.8-95.9) of DOACs patients achieved complete or partial recanalization and 9.80% (CI 4.50-20.0) experienced a bleeding event. DOACs were superior to LMWH (RR 2.299, CI 1.037-5.093, p = 0.040), warfarin (RR 1.762, CI 1.017-3.053, p = 0.043) and no treatment (RR 3.489, CI 1.394-8.733, p = 0.008) in complete recanalization. For partial recanalization, while DOACs were not superior to any treatment, they had the highest probability in achieving partial recanalization in SUCRA analysis. Bleeding risk and mortality were similar compared to other treatments.

CONCLUSION

The network analysis supports the use of DOACs in cirrhotic patients, with significant rates of complete recanalization compared to other treatments without increasing bleeding risk. DOACs can potentially be considered for nontumorous PVT in cirrhosis.

A Meta-Analysis on the Incidence of Donor Related Depression after Liver Transplant

AIM

Living donor liver transplantation (LDLT) is increasing, yet gaps exist in the understanding of psychological wellbeing of donors after liver transplant. This meta-analysis seeks to evaluate the incidence and risk factors for donor-related depression after liver transplantation.

METHODS

A search was conducted on Medline and Embase database. Articles assessing incidence of depression in LDLT donors were included. Incidence was pooled after Freeman-Tukey double-arcsine transformation. For risk factors, dichotomous variables were analyzed with generalized linear model while a conventional meta regression with logit transformation was conducted for continuous variables.

RESULTS

Of 1,069 abstracts, 40 articles underwent full-text review. 17 articles were included. The pooled incidence of depression among 1,888 LT donors was 7.66% (CI: 4.47% - 12.80%). Depression rates were significantly higher in Asian compared to Western studies (RR: 1.73, CI: 1.19 - 2.52, p=0.0039). Female gender (p<0.001), Caucasian ethnicity (p=0.047), employment status (p<0.001) and lower education levels (p=0.044) were significantly associated with depression. Donor relationship with recipients was not a significant risk factor.

CONCLUSIONS

LDLT remains a core aspect of the treatment of end-stage liver disease. However, the high depression rates after LT suggest that there remains room for improvement in the care of donors' mental health post-transplant.

Is Fatty Liver Associated With Depression? A Meta-Analysis and Systematic Review on the Prevalence, Risk Factors, and Outcomes of Depression and Non-alcoholic Fatty Liver Disease

Background and Aims: Both non-alcoholic fatty liver disease (NAFLD) and depression have a high global prevalence which is projected to increase further. While studies exploring the association have been done, there are conflicting data. This study aims to assess the prevalence and association between depression and NAFLD.

Methods: Medline and Embase were searched from inception to March 3, 2020. Meta-analysis of proportions using the generalized linear mix model was conducted to analyze the pooled prevalence of depression in NAFLD patients. Risk factors for depression in NAFLD patients were evaluated in conventional pairwise meta-analysis.

Results: Ten studies involving 2,041,752 NAFLD patients were included. Pooled prevalence of depression was 18.21% (CI: 11.12–28.38%) in patients with NAFLD and 40.68% (CI: 25.11–58.37%) in patients with non-alcoholic steatohepatitis (NASH). NAFLD resulted in significantly higher risk of development of depression (OR: 1.29, CI: 1.02–1.64, p = 0.03). NASH patients had a significantly higher risk of depression compared with NAFLD patients (RR: 2.83, CI: 2.41–3.32, p < 0.001). Diabetes, body mass index (BMI), female sex, smoking, and history of pulmonary disease were significant risk factors for depression in NAFLD patients.

Conclusion: This study demonstrated a high prevalence of depression in NAFLD patients and a significant association between both conditions. Furthermore, patients with NASH had a significantly higher risk of depression compared with those with NAFLD. Diabetes, BMI, history of lung disease or smoking, and female gender were significant risk factors. Further studies investigating the pathophysiological mechanism underlying depression and NAFLD are needed.

A systematic review and meta-analysis on the incidence of osteoporosis and fractures after liver transplant

Following liver transplant (LT), osteoporosis is a severe complication that causes morbidity. However, the incidence and risk factors of osteoporosis and fractures have not been well described. Single-arm meta-analysis of studies reporting osteopenia, osteoporosis, and fractures post-LT was performed with meta-regression for study period. Dichotomous variables, continuous variables and time-to-event variables were pooled in odds ratio, weighted mean difference and hazard ratio, respectively. For risk factors with limited data, a systematic review of literature was conducted. There was a significant increase in both osteoporosis and fractures compared to non-LT patients. Osteopenia, osteoporosis and incident fractures were newly diagnosed in 34.53% (CI: 0.17-0.56, n = 301), 11.68% (CI: 0.05-0.24, n = 1251) and 20.40% (CI: 0.13-0.30, n = 4322) of LT patients, respectively. Female gender (P = 0.017) increased risks of osteoporosis but not older age and BMI. Older age, lower pre-LT bone mineral density (BMD), presence of bone disease pre-LT were significant risk factors for fractures but not female gender, post-menopausal state, BMI, smoking and alcohol. There is a high incidence of skeletal complications post-LT. Older age, lower pre-LT BMD and presence of bone disease pre-LT are significant risk factors that are associated with incident fractures physicians should be cognisant of in liver transplant recipients.