Noninvasive assessment of liver fibrosis and portal hypertension.

PURPOSE OF REVIEW: The result of ongoing liver injury - and disease, regardless of cause - is fibrosis, and fibrosis appears to be a critically important result of ongoing injury. Further, in a number of different liver diseases, the presence of fibrosis has prognostic value. Therefore, the assessment of fibrosis is of critical clinical importance. Given the importance of fibrosis, there has been a rapid evolution in the use of noninvasive liver tests. This review highlights a number of the core principles surrounding. RECENT FINDINGS: The use of noninvasive test has progressed rapidly over the last decade and data are rapidly accumulating. New terminology has been adapted by the American Association for the Study of Liver Disease (AASLD) for noninvasive assessment of liver disease and termed 'NILDA' (Non-Invasive Liver Disease Assessment). Blood based such as APRI and or FIB-4 and imaging tests such as liver stiffness measurement (LSM) have moderate to high degrees of accuracy for detection of advanced liver fibrosis (≥ F2) and even higher accuracy for detection of severe fibrosis (F4 or cirrhosis). NILDA are particularly effective at the ends of the liver disease spectrum. For example, a very low LSM (less than 7 kPa) essentially excludes significant fibrosis or portal hypertension, and a very high LSM (> 25 kPa) makes significant fibrosis with portal hypertension (cirrhosis) highly likely. SUMMARY: NILDA are currently front and center in terms of assessment of the severity of liver disease. In all patients with known or suspected liver disease, noninvasive blood tests, including APRI and or FIB-4, should be the initial choice to assess the severity of liver fibrosis and/or portal hypertension. In most patients, these tests should be followed with imaging evaluation. The most commonly available imaging is LSM, which appears to be more accurate in predicting fibrosis severity, and is superior to blood tests in the assessment of portal hypertension. In situations in which there is diagnostic uncertainly, liver biopsy with or without HVPG remains an important consideration.

Quality measures in pre-liver transplant care by the Practice Metrics Committee of the American Association for the Study of Liver Diseases.

The liver transplantation (LT) evaluation and waitlisting process is subject to variations in care that can impede quality. The American Association for the Study of Liver Diseases (AASLD) Practice Metrics Committee (PMC) developed quality measures and patient-reported experience measures along the continuum of pre-LT care to reduce care variation and guide patient-centered care. Following a systematic literature review, candidate pre-LT measures were grouped into 4 phases of care: referral, evaluation and waitlisting, waitlist management, and organ acceptance. A modified Delphi panel with content expertise in hepatology, transplant surgery, psychiatry, transplant infectious disease, palliative care, and social work selected the final set. Candidate patient-reported experience measures spanned domains of cognitive health, emotional health, social well-being, and understanding the LT process. Of the 71 candidate measures, 41 were selected: 9 for referral; 20 for evaluation and waitlisting; 7 for waitlist management; and 5 for organ acceptance. A total of 14 were related to structure, 17 were process measures, and 10 were outcome measures that focused on elements not typically measured in routine care. Among the patient-reported experience measures, candidates of LT rated items from understanding the LT process domain as the most important. The proposed pre-LT measures provide a framework for quality improvement and care standardization among candidates of LT. Select measures apply to various stakeholders such as referring practitioners in the community and LT centers. Clinically meaningful measures that are distinct from those used for regulatory transplant reporting may facilitate local quality improvement initiatives to improve access and quality of care.

Accuracy of blood-based biomarkers for staging liver fibrosis in chronic liver disease: A systematic review supporting the AASLD Practice Guideline.

BACKGROUND AND AIMS: Blood-based biomarkers have been proposed as an alternative to liver biopsy for non-invasive liver disease assessment (NILDA) in chronic liver disease (CLD). Our aims for this systematic review were to evaluate the diagnostic utility of selected blood-based tests either alone, or in combination, for identifying significant fibrosis (F2-4), advanced fibrosis (F3-4) and cirrhosis (F4), as compared to biopsy in CLD. APPROACH AND RESULTS: We included a comprehensive search of databases including Ovid MEDLINE(R), EMBASE, Cochrane Database, and Scopus through to April 2022. Two independent reviewers selected 286 studies with 103,162 patients. The most frequently identified studies included the simple aminotransferase-to-platelet ratio index (APRI) and fibrosis (FIB)-4 markers (with low-to-moderate risk of bias) in hepatitis B virus (HBV) and C virus (HCV), HIV-HCV/HBV co-infection, and nonalcoholic fatty liver disease (NAFLD). Positive (LR+) and negative (LR) likelihood ratios across direct and indirect biomarker tests for HCV and HBV for F2-4, F3-4, or F4 were 1.66-6.25 and 0.23-0.80, 1.89-5.24 and 0.12-0.64, and 1.32-7.15 and 0.15-0.86 respectively; LR+ and LR for NAFLD F2-4, F3-4 and F4 were 2-65-3.37 and 0.37-0.39, 2.25-6.76 and 0.07-0.87, and 3.90 and 0.15 respectively. Overall, proportional odds ratio indicated FIB-4 <1.45 was better than APRI <0.5 for F2-4. FIB-4 >3.25 was also better than APRI >1.5 for F3-4 and F4. There was limited data for combined tests. CONCLUSIONS: Blood-based biomarkers are associated with small-to-moderate change in pre-test probability for diagnosing F2-4, F3-4, and F4 in viral hepatitis, HIV-HCV co-infection, and NAFLD, with limited comparative or combination studies for other CLD.

Association of body mass index with post-liver transplant outcomes.

BACKGROUND: Patients with obesity have inferior outcomes after general surgery procedures, but studies evaluating post-liver transplant (LT) outcomes have been limited by small sample sizes or lack of granularity of outcomes. We evaluated the relationship between obesity and post-LT outcomes, including those observed in other populations to be obesity-related. METHODS: Included were 1357 LT recipients prospectively enrolled in the ambulatory pre-LT setting at 8 U.S. CENTERS: Recipient were categorized by body mass index (BMI, kg/m2 ): non-obese (BMI < 30), class 1 obesity (BMI 30-<35), and classes 2-3 obesity (BMI ≥ 35). Post-transplant complications were compared by BMI using Chi-square and rank-sum testing, logistic regression, Kaplan-Meier curves, and Cox regression. RESULTS: Classes 2-3 obesity was associated with higher adjusted odds than non-obesity of venous thrombosis [adjusted odds ratio (aOR) 2.06, 95% CI 1.01-4.23, p = .047] and wound dehiscence (aOR 2.45, 95% CI 1.19-5.06, p = .02). Compared with non-obese recipients, post-LT hospital stay was significantly longer for recipients with classes 2-3 obesity [p = .01; median (Q1-Q3) 9 (6-14) vs. 8 (6-12) days) or class 1 obesity [p = .002; 9 (6-14) vs. 8 (6-11) days].  Likelihood of ICU readmission, infection, discharge to a non-home facility, rejection, 30-day readmission, and 1-year readmission were similar across BMI categories (all p > .05). CONCLUSION: Compared to non-obese recipients, obese recipients had similar post-LT survival but longer hospital stay and higher likelihood of wound dehiscence and venous thrombosis. These findings underscore that obesity alone should not preclude LT, but recipients with obesity should be monitored for obesity-related complications such as wound dehiscence and venous thrombosis.

The liver frailty index is a predictor of healthcare utilization after liver transplantation in older adults.

BACKGROUND: Older adults have higher healthcare utilization after liver transplantation (LT), yet objective risk stratification tools in this population are lacking. We evaluated the Liver Frailty Index (LFI) as one potential tool. METHODS: Ambulatory LT candidates ≥65 years without hepatocellular carcinoma (HCC) who underwent LT from 1/2012 to 6/2022 at 8 U.S. centers were included. Estimates of the difference in median using quantile regression were used to assess the adjusted association between LFI and hospitalized days within 90 days post-LT. RESULTS: Of 131 LT recipients, median (interquartile range [IQR]) (1st -3rd quartiles) age was 68 years (66-70); median pre-LT MELD-Na was 19 (15-24). Median LFI was 4.1 (3.6-4.7); 27% were frail (LFI≥4.5). Median hospitalized days within 90 days post-LT was 11 (7-20). Compared with non-frail patients, frail patients were hospitalized for a median of 5 days longer post-LT (95% CI .30-9.7, p = .04). Each .5 unit increase in pre-LT LFI was associated with an increase of 1.16 days (95%CI .42-2.69, p = .02) in hospitalized days post-LT. CONCLUSION: Among older adults undergoing LT, frailty was associated with more hospitalized days within 90 days after LT. The LFI can identify older adults who might benefit from pre-LT or early post-LT programs which may reduce post-LT healthcare utilization, such as early rehabilitation or post-hospital discharge programs.

Use of a Mobile-Assisted Telehealth Regimen to Increase Exercise in Transplant Candidates: A Home-Based Prehabilitation Pilot and Feasibility Trial.

INTRODUCTION: Physical fitness assessed by the Liver Frailty Index (LFI) and 6-minute walk test (6MWT) informs the prognosis of liver transplant candidates, although there are limited data on its reversibility after prehabilitation. On a home-based exercise trial, we aimed to improve LFI and 6MWT and to investigate trial feasibility and intervention adherence. METHODS: Liver transplant candidates with cirrhosis wore a personal activity tracker and used Exercise and Liver FITness app for 14 weeks, including a 2-week technology acclimation run-in. The 12-week intervention consisted of Exercise and Liver FITness app plus personal activity tracker and 15-/30-minute weekly calls with a physical activity coach aiming to complete ≥2 video-training sessions/week, or ≥500 step/d baseline increase for ≥8 weeks. We defined feasibility as ≥66% of subjects engaging in the intervention phase and adherence as ≥50% subjects meeting training end point. RESULTS: Thirty-one patients (61 ± 7 years, 71% female, model for end-stage liver disease 17 ± 5, ∼33% frail) consented and 21 (68%) started the intervention. In the 15 subjects who completed the study, LFI improved from 3.84 ± 0.71 to 3.47 ± 0.90 ( P = 0.03) and 6MWT from 318 ± 73 to 358 ± 64 m ( P = 0.005). Attrition reasons included death (n = 4) and surgery (n = 2). There was 57% adherence, better for videos than for walking, although daily steps significantly increased (3,508 vs baseline: 1,260) during best performance week. One adverse event was attributed to the intervention. DISCUSSION: Our clinical trial meaningfully improved LFI by 0.4 and 6MWT by 41 m and met feasibility/adherence goals. In-training daily step increase supported physical self-efficacy and intervention uptake, but maintenance remained a challenge despite counseling.

American College of Sports Medicine (ACSM) International Multidisciplinary Roundtable report on physical activity and nonalcoholic fatty liver disease.

BACKGROUND AND AIMS: We present findings from the inaugural American College of Sports Medicine (ACSM) International Multidisciplinary Roundtable, which was convened to evaluate the evidence for physical activity as a means of preventing or modifying the course of NAFLD. APPROACH AND RESULTS: A scoping review was conducted to map the scientific literature and identify key concepts, research gaps, and evidence available to inform clinical practice, policymaking, and research. The scientific evidence demonstrated regular physical activity is associated with decreased risk of NAFLD development. Low physical activity is associated with a greater risk for disease progression and extrahepatic cancer. During routine health care visits, all patients with NAFLD should be screened for and counseled about physical activity benefits, including reduction in liver fat and improvement in body composition, fitness, and quality of life. While most physical activity benefits occur without clinically significant weight loss, evidence remains limited regarding the association between physical activity and liver fibrosis. At least 150 min/wk of moderate or 75 min/wk of vigorous-intensity physical activity are recommended for all patients with NAFLD. If a formal exercise training program is prescribed, aerobic exercise with the addition of resistance training is preferred. CONCLUSIONS: The panel found consistent and compelling evidence that regular physical activity plays an important role in preventing NAFLD and improving intermediate clinical outcomes. Health care, fitness, and public health professionals are strongly encouraged to disseminate the information in this report. Future research should prioritize determining optimal strategies for promoting physical activity among individuals at risk and in those already diagnosed with NAFLD.

Association of Frailty With Health-Related Quality of Life in Liver Transplant Recipients.

Importance: Frailty has been recognized as a risk factor for mortality after liver transplant (LT) but little is known of its association with functional status and health-related quality of life (HRQL), termed global functional health, in LT recipients. Objective: To evaluate the association between pre-LT and post-LT frailty with post-LT global functional health. Design, Setting, and Participants: This prospective cohort study was conducted at 8 US LT centers and included adults who underwent LT from October 2016 to February 2020. Exposures: Frail was defined by a pre-LT Liver Frailty Index (LFI) score of 4.5 or greater. Main Outcomes and Measures: Global functional health at 1 year after LT, assessed using surveys (Short Form-36 [SF-36; summarized by physical component scores (PFC) and mental component summary scores (MCS)], Instrumental Activities of Daily Living scale) and performance-based tests (LFI, Fried Frailty Phenotype, and Short Physical Performance Battery). Results: Of 358 LT recipients (median [IQR] age, 60 [53-65] years; 115 women [32%]; 25 [7%] Asian/Pacific Islander, 21 [6%] Black, 54 [15%] Hispanic White, and 243 [68%] non-Hispanic White individuals), 68 (19%) had frailty pre-LT. At 1 year post-LT, the median (IQR) PCS was lower in recipients who had frailty vs those without frailty pre-LT (42 [31-53] vs 50 [38-56]; P = .002), but the median MCS was similar. In multivariable regression, pre-LT frailty was associated with a -5.3-unit lower post-LT PCS (P < .001), but not MCS. The proportion who had difficulty with 1 or more Instrumental Activities of Daily Living (21% vs 10%) or who were unemployed/receiving disability (38% vs 29%) was higher in recipients with vs without frailty. In a subgroup of 210 recipients with LFI assessments 1 year post-LT, 13% had frailty at 1 year post-LT. Recipients who had frailty post-LT reported lower adjusted SF-36-PCS scores (coefficient, -11.4; P < .001) but not SF-36-MCS scores. Recipients of LT who had frailty vs those without frailty 1 year post-LT also had worse median (IQR) Fried Frailty Phenotype scores (1 [1-2] vs 1 [0-1]) and higher rates of functional impairment by a Short Physical Performance Battery of 9 or less (42% vs 20%; P = .01). Conclusions and Relevance: In this cohort study, pre-LT frailty was associated with worse global functional health 1 year after LT. The presence of frailty after LT was also associated with worse HRQL in physical, but not mental, subdomains. These data suggest that interventions and therapeutics that target frailty that are administered before and/or early post-LT may help to improve the health and well-being of LT recipients.

Poor Outcomes of Patients With NAFLD and Moderate Renal Dysfunction or Short-Term Dialysis Receiving a Liver Transplant Alone.

The outcomes of patients with moderate renal impairment and the impact of liver disease etiology on renal function recovery after liver transplant alone (LTA) are largely unknown. We explored whether NAFLD patients with pre-LTA moderate renal dysfunction (GFR 25-45 ml/min/1.73 m2) may be more susceptible to develop post-LTA severe renal dysfunction (GFR<15 ml/min/1.73 m2) than ALD patients, as well as other overall outcomes. Using the UNOS/OPTN database, we selected patients undergoing liver transplant for NAFLD or ALD (2006-2016), 15,103 of whom received LTA. NAFLD patients with moderate renal dysfunction were more likely to develop subsequent GFR<15 ml/min/1.73 m2 than ALD patients (11.1% vs. 7.38%, p < 0.001). Patients on short-term dialysis pre-LTA (≤12 weeks) were more likely to develop severe renal dysfunction (31.7% vs. 18.1%), especially in NAFLD patients, and were more likely to receive a further kidney transplant (15.3% vs. 3.7%) and had lower survival (48.6% vs. 50.4%) after LTA (p < 0.001 for all). NAFLD was an independent risk factor for post-LTA severe renal dysfunction (HR = 1.2, p = 0.02). NAFLD patients with moderate renal dysfunction and those receiving short-term dialysis prior to LTA are at a higher risk of developing subsequent severe renal dysfunction. Underlying etiology of liver disease may play a role in predicting development and progression of renal failure in patients receiving LTA.

The closing survival gap after liver transplantation for hepatocellular carcinoma in the United States.

BACKGROUND: Socio-economic inequalities among different racial/ethnic groups have increased in many high-income countries. It is unclear, however, whether increasing socio-economic inequalities are associated with increasing differences in survival in liver transplant (LT) recipients. METHODS: Adults undergoing first time LT for hepatocellular carcinoma (HCC) between 2002 and 2017 recorded in the Scientific Registry of Transplant Recipients (SRTR) were included and grouped into three cohorts. Patient survival and graft survival stratified by race/ethnicity were compared among the cohorts using unadjusted and adjusted analyses. RESULTS: White/Caucasians comprised the largest group (n=9,006, 64.9%), followed by Hispanic/Latinos (n=2,018, 14.5%), Black/African Americans (n=1,379, 9.9%), Asians (n=1,265, 9.1%) and other ethnic/racial groups (n=188, 1.3%). Compared to Cohort I (2002-2007), the 5-year survival of Cohort III (2012-2017) increased by 18% for Black/African Americans, by 13% for Whites/Caucasians, by 10% for Hispanic/Latinos, by 9% for patients of other racial/ethnic groups and by 8% for Asians (All P values<0.05). Despite Black/African Americans experienced the highest survival improvement, their overall outcomes remained significantly lower than other ethnic∕racial groups (adjusted HR for death=1.20; 95%CI 1.05-1.36; P=0.005; adjusted HR for graft loss=1.21; 95%CI 1.08-1.37; P=0.002). CONCLUSION: The survival gap between Black/African Americans and other ethnic/racial groups undergoing LT for HCC has significantly decreased over time. However, Black/African Americans continue to have the lowest survival among all racial/ethnic groups.

Use of Computed Tomography Coronary Calcium Score for Coronary Artery Disease Risk Stratification During Liver Transplant Evaluation.

Background: End-stage liver disease (ESLD) is not considered a risk factor for atherosclerotic cardiovascular disease (ASCVD). However, lifestyle characteristics commonly associated with increased ASCVD risk are highly prevalent in ESLD. Emerging literature shows a high burden of asymptomatic coronary artery disease (CAD) in patients with ESLD and a high ASCVD risk in liver transplantation (LT) recipients. Coronary artery calcium score (CAC) is a noninvasive test providing reliable CAD risk stratification. We implemented an LT evaluation protocol with CAC playing a central role in triaging and determining the need for further CAD assessment. Here, we inform our results from this early experience. Methods: Patients with ESLD referred for LT evaluation were prospectively studied. We compared accuracy of CAC against that of CAD risk factors/scores, troponin I, dobutamine stress echocardiogram (DSE), and single-photon emission computed tomography (SPECT) to detect coronary stenosis ≥70 (CAD ≥ 70) per left heart catheterization (LHC). Thirty-day post-LT cardiac outcomes were also analyzed. Results: One hundred twenty-four of 148 (84%) patients underwent CAC, 106 (72%) DSE/SPECT, and 50 (34%) LHC. CAC ≥ 400 was found in 35 (28%), 100 to 399 in 17 (14%), and <100 in 72 (58%). LHC identified CAD ≥ 70% in 8 of 29 (28%), 2 of 9 (22%), and 0 of 4, respectively. Two acute coronary syndromes occurred after LT in a patient with CAC 811 (CAD < 70%), and one with CAC 347 (CAD ≥ 70%). No patients with CAC < 100 presented with acute coronary syndrome after LT. When using CAD ≥ 70% as primary endpoint of LT evaluation, CAC ≥ 346 was the only test showing predictive usefulness (negative predictive value 100%). Conclusions: CAC is a promising tool to guide CAD risk stratification and need for LHC during LT evaluation. Patients with a CAC < 100 can safely undergo LT without the need for LHC or cardiac stress testing, whereas a CAC < 346 accurately rules out significant CAD stenosis (≥70%) on LHC, outperforming other CAD risk-stratification strategies.

Frailty, mortality, and health care utilization after liver transplantation: From the Multicenter Functional Assessment in Liver Transplantation (FrAILT) Study.

BACKGROUND AND AIMS: Frailty is a well-established risk factor for poor outcomes in patients with cirrhosis awaiting liver transplantation (LT), but whether it predicts outcomes among those who have undergone LT is unknown. APPROACH AND RESULTS: Adult LT recipients from 8 US centers (2012-2019) were included. Pre-LT frailty was assessed in the ambulatory setting using the Liver Frailty Index (LFI). "Frail" was defined by an optimal cut point of LFI ≥ 4.5. We used the 75th percentile to define "prolonged" post-LT length of stay (LOS; ≥12 days), intensive care unit (ICU) days (≥4 days), and inpatient days within 90 post-LT days (≥17 days). Of 1166 LT recipients, 21% were frail pre-LT. Cumulative incidence of death at 1 and 5 years was 6% and 16% for frail and 4% and 10% for nonfrail patients (overall log-rank p = 0.02). Pre-LT frailty was associated with an unadjusted 62% increased risk of post-LT mortality (95% CI, 1.08-2.44); after adjustment for body mass index, HCC, donor age, and donation after cardiac death status, the HR was 2.13 (95% CI, 1.39-3.26). Patients who were frail versus nonfrail experienced a higher adjusted odds of prolonged LT LOS (OR, 2.00; 95% CI, 1.47-2.73), ICU stay (OR, 1.56; 95% CI, 1.12-2.14), inpatient days within 90 post-LT days (OR, 1.72; 95% CI, 1.25-2.37), and nonhome discharge (OR, 2.50; 95% CI, 1.58-3.97). CONCLUSIONS: Compared with nonfrail patients, frail LT recipients had a higher risk of post-LT death and greater post-LT health care utilization, although overall post-LT survival was acceptable. These data lay the foundation to investigate whether targeting pre-LT frailty will improve post-LT outcomes and reduce resource utilization.

Provider Attitudes Toward Risk-Based Hepatocellular Carcinoma Surveillance in Patients With Cirrhosis in the United States.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) surveillance rates are suboptimal in clinical practice. We aimed to elicit providers' opinions on the following aspects of HCC surveillance: preferred strategies, barriers and facilitators, and the impact of a patient's HCC risk on the choice of surveillance modality. METHODS: We conducted a web-based survey among gastroenterology and hepatology providers (40% faculty physicians, 21% advanced practice providers, 39% fellow-trainees) from 26 US medical centers in 17 states. RESULTS: Of 654 eligible providers, 305 (47%) completed the survey. Nearly all (98.4%) of the providers endorsed semi-annual HCC surveillance in patients with cirrhosis, with 84.2% recommending ultrasound ± alpha fetoprotein (AFP) and 15.4% recommending computed tomography (CT) or magnetic resonance imaging (MRI). Barriers to surveillance included limited HCC treatment options, screening test effectiveness to reduce mortality, access to transportation, and high out-of-pocket costs. Facilitators of surveillance included professional society guidelines. Most providers (72.1%) would perform surveillance even if HCC risk was low (≤0.5% per year), while 98.7% would perform surveillance if HCC risk was ≥1% per year. As a patient's HCC risk increased from 1% to 3% to 5% per year, providers reported they would be less likely to order ultrasound ± AFP (83.6% to 68.9% to 57.4%; P < .001) and more likely to order CT or MRI ± AFP (3.9% to 26.2% to 36.1%; P < .001). CONCLUSIONS: Providers recommend HCC surveillance even when HCC risk is much lower than the threshold suggested by professional societies. Many appear receptive to risk-based HCC surveillance strategies that depend on patients' estimated HCC risk, instead of our current "one-size-fits all" strategy.

Usefulness of Controlled Attenuation Parameter and Liver Stiffness Measurement for the Identification of Extended-criteria Donors and Risk-assessment in Liver Transplantation.

BACKGROUND: Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) are noninvasive surrogates for hepatic steatosis and fibrosis, respectively, and could help identify extended criteria donors in liver transplantation (LT). We aimed to determine the accuracy of CAP/LSM in deceased donors along with post-LT changes. METHODS: Accuracy of preprocurement CAP/LSM to grade/stage steatosis/fibrosis was determined using liver biopsy as reference. Transplant outcomes, including primary nonfunction (PNF) and early allograft dysfunction, were recorded. Recipients underwent CAP/LSM as outpatients. Areas under the receiver operating characteristic curve and regression models were constructed to analyze data. RESULTS: We prospectively evaluated 160 allografts (138 transplanted). Same-probe paired baseline/post-LT CAP was 231 dB/m (181-277)/225 (187-261) (P = 0.61), and LSM 7.6 kPa (6.3-10.8)/5.9 (4.6-8.7) (P = 0.002), respectively. CAP reading was affected by BMI and LSM by ALT, race and bilirubin. Although CAP did not correlate with steatosis from frozen sections (ρ = 0.08, P = 0.47), it correlated with steatosis from permanent sections (ρ = 0.32, P < 0.001) and with oil red O histomorphometry (ρ = 0.35, P = 0.001). CAP identified moderate-to-severe steatosis with an areas under the receiver operating characteristic curve curve of 0.79 (0.66-0.91), for a negative predictive value of 100% at a cutoff value of 230 dB/m. LSM correlated with fibrosis staging (ρ = 0.22, P = 0.007) and it identified discarded allografts with advanced fibrosis/cirrhosis. Patients with no to minimal fibrosis had an LSM of 7.6 (6-10.1) kPa. CONCLUSIONS: Our results are proof-of-concept of the utility of CAP/LSM during organ procurement. Establishing the precise role of these noninvasive tools in the organ allocation process mandates confirmatory studies.

Frailty and the Risk of Acute Kidney Injury Among Patients With Cirrhosis.

Acute kidney injury (AKI) and frailty are major drivers of outcomes among patients with cirrhosis. What is unknown is the impact of physical frailty on the development of AKI. We included adults with cirrhosis without hepatocellular carcinoma listed for liver transplantation at nine US centers (n = 1,033). Frailty was assessed using the Liver Frailty Index (LFI); "frail" was defined by LFI ≥ 4.2. Chronic kidney disease as a baseline estimated glomerular filtration rate <60 mL/min/1.73 m2 . Our primary outcome, AKI, was defined as an increase in serum creatinine ≥0.3 mg/dL or a serum creatinine ≥1.5-fold increase. Wait-list mortality was defined as either a death on the wait list or removal for being too sick. We performed Cox regression analyses to estimate the hazard ratios (HRs) for AKI and wait-list mortality. Of 1,033 participants, 41% were frail and 23% had CKD. Twenty-one percent had an episode of AKI during follow-up. Frail versus nonfrail patients were more likely to develop AKI (25% vs. 19%) and wait-list mortality (21% vs. 13%) (P < 0.01 for each). In multivariable Cox regression, each of the following groups was associated with a higher risk of AKI as compared with not frail/no CKD: frail/no CKD (adjusted HR [aHR] = 1.87, 95% confidence interval [CI] = 1.29-2.72); not frail/CKD (aHR = 4.30, CI = 2.88-6.42); and frail/CKD (aHR = 4.85, CI = 3.33-7.07). We use a readily available metric, LFI, to identify those patients with cirrhosis most at risk for AKI. We highlight that serum creatinine and creatinine-based estimations of glomerular filtration rate may not fully capture a patient's vulnerability to AKI among the frail phenotype. Conclusion: Our work lays the foundation for implementing physical frailty in clinical practice to identify AKI earlier, implement reno-protective strategies, and expedite liver transplantation.

Prehabilitation-Driven Changes in Frailty Metrics Predict Mortality in Patients With Advanced Liver Disease.

INTRODUCTION: Frailty is a predictor of morbidity and mortality in cirrhosis. Although evidence for prehabilitation is promising, the data for liver transplant (LT) candidates are limited. The primary aim of this study was to evaluate the effect of a novel prehabilitation strategy on changes in frailty metrics and survival in LT candidates. The secondary aim was to determine liver-related and extrahepatic conditions associated with frailty. METHODS: In this ambispective cohort study, all patients underwent frailty assessment using the liver frailty index (LFI), 6-minute walk test, and gait speed test performed by a dedicated physical therapist. Home-based exercise prescription was individualized to each patient's baseline physical fitness. RESULTS: We included 517 patients (59% men, median age 61 years, and a model for end-stage liver disease score of 12) evaluated during 936 PT visits. Frailty metrics were affected by age, sex, and liver-related parameters, but not by model for end-stage liver disease. Patients with nonalcoholic fatty liver disease and alcohol-related cirrhosis had worse frailty metrics by all tools. We demonstrated the feasibility of prehabilitation in improving both LFI and 6-minute walk test, particularly in adherent patients. A median LFI improvement of 0.3 in frail patients was associated with improved survival in univariate analysis. Compliance with physical therapist visits (hazards ratio = 0.35 [0.18-0.67] for 2 visits and hazards ratio = 0.54 [0.31-0.94] for ≥3 visits) was independently associated with increased survival. DISCUSSION: Prehabilitation improves frailty metrics in LT candidates and is associated with a survival advantage. Our findings provide a framework for the standardized prehabilitation program in LT candidates while prioritizing compliance, adherence, and on-training LFI goal accomplishment.

Magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) is a viable alternative to liver biopsy for steatosis quantification in living liver donor transplantation.

This study aimed to investigate whether magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) can be a viable noninvasive alternative to liver biopsy for the quantification of living liver donor steatosis. Hepatic steatosis for 143 donors was graded by MRI-PDFF. Study endpoints included liver volume regeneration in donors, recipient outcomes including length of hospital stay, deaths, primary non-function (PNF), early allograft dysfunction (EAD), and small for size syndrome (SFSS). Correlation between MRI-PDFF determined donor steatosis and endpoints were analyzed. Donors had lower steatosis grade than non-donors. Donor remnant liver regenerated to an average of 82% of pre-donation volume by 101 ± 24 days with no complications. There was no correlation between percent liver regeneration and steatosis severity. Among recipients, 4 underwent redo-transplantation and 6 died, with no association with degree of steatosis. 52 recipients (36%) fulfilled criteria for EAD (driven by INR), with no difference in hepatic steatosis between groups. MRI-PDFF reliably predicted donor outcomes. Living donors with no or mild steatosis based on MRI-PDFF (ie, <20%) and meeting other criteria for donation can expect favorable post-surgical outcomes, including liver regeneration. Recipients had a low rate of death or retransplantation with no association between mild hepatic steatosis and EAD.

Association of Frailty and Sex With Wait List Mortality in Liver Transplant Candidates in the Multicenter Functional Assessment in Liver Transplantation (FrAILT) Study.

Importance: Female liver transplant candidates experience higher rates of wait list mortality than male candidates. Frailty is a critical determinant of mortality in patients with cirrhosis, but how frailty differs between women and men is unknown. Objective: To determine whether frailty is associated with the gap between women and men in mortality among patients with cirrhosis awaiting liver transplantation. Design, Setting, and Participants: This prospective cohort study enrolled 1405 adults with cirrhosis awaiting liver transplant without hepatocellular carcinoma seen during 3436 ambulatory clinic visits at 9 US liver transplant centers. Data were collected from January 1, 2012, to October 1, 2019, and analyzed from August 30, 2019, to October 30, 2020. Exposures: At outpatient evaluation, the Liver Frailty Index (LFI) score was calculated (grip strength, chair stands, and balance). Main Outcomes and Measures: The risk of wait list mortality was quantified using Cox proportional hazards regression by frailty. Mediation analysis was used to quantify the contribution of frailty to the gap in wait list mortality between women and men. Results: Of 1405 participants, 578 (41%) were women and 827 (59%) were men (median age, 58 [interquartile range (IQR), 50-63] years). Women and men had similar median scores on the laboratory-based Model for End-stage Liver Disease incorporating sodium levels (MELDNa) (women, 18 [IQR, 14-23]; men, 18 [IQR, 15-22]), but baseline LFI was higher in women (mean [SD], 4.12 [0.85] vs 4.00 [0.82]; P = .005). Women displayed worse balance of less than 30 seconds (145 [25%] vs 149 [18%]; P = .003), worse sex-adjusted grip (mean [SD], -0.31 [1.08] vs -0.16 [1.08] kg; P = .01), and fewer chair stands per second (median, 0.35 [IQR, 0.23-0.46] vs 0.37 [IQR, 0.25-0.49]; P = .04). In unadjusted mixed-effects models, LFI was 0.15 (95% CI, 0.06-0.23) units higher in women than men (P = .001). After adjustment for other variables associated with frailty, LFI was 0.16 (95% CI, 0.08-0.23) units higher in women than men (P < .001). In unadjusted regression, women experienced a 34% (95% CI, 3%-74%) increased risk of wait list mortality than men (P = .03). Sequential covariable adjustment did not alter the association between sex and wait list mortality; however, adjustment for LFI attenuated the mortality gap between women and men. In mediation analysis, an estimated 13.0% (IQR, 0.5%-132.0%) of the gender gap in wait list mortality was mediated by frailty. Conclusions and Relevance: These findings demonstrate that women with cirrhosis display worse frailty scores than men despite similar MELDNa scores. The higher risk of wait list mortality that women experienced appeared to be explained in part by frailty.

Identifying an Optimal Liver Frailty Index Cutoff to Predict Waitlist Mortality in Liver Transplant Candidates.

BACKGROUND AND AIMS: Frailty, as measured by the Liver Frailty Index (LFI), is associated with liver transplant (LT) waitlist mortality. We sought to identify an optimal LFI cutoff that predicts waitlist mortality. APPROACH AND RESULTS: Adults with cirrhosis awaiting LT without hepatocellular carcinoma at nine LT centers in the United States with LFI assessments were included. Multivariable competing risk analysis assessed the relationship between LFI and waitlist mortality. We identified a single LFI cutoff by evaluating the fit of the competing risk models, searching for the cutoff that gave the best model fit (as judged by the pseudo-log-likelihood). We ascertained the area under the curve (AUC) in an analysis of waitlist mortality to find optimal cutoffs at 3, 6, or 12 months. We used the AUC to compare the discriminative ability of LFI+Model for End Stage Liver Disease-sodium (MELDNa) versus MELDNa alone in 3-month waitlist mortality prediction. Of 1,405 patients, 37 (3%), 82 (6%), and 135 (10%) experienced waitlist mortality at 3, 6, and 12 months, respectively. LFI was predictive of waitlist mortality across a broad LFI range: 3.7-5.2. We identified an optimal LFI cutoff of 4.4 (95% confidence interval [CI], 4.0-4.8) for 3-month mortality, 4.2 (95% CI, 4.1-4.4) for 6-month mortality, and 4.2 (95% CI, 4.1-4.4) for 12-month mortality. The AUC for prediction of 3-month mortality for MELDNa was 0.73; the addition of LFI to MELDNa improved the AUC to 0.79. CONCLUSIONS: LFI is predictive of waitlist mortality across a wide spectrum of LFI values. The optimal LFI cutoff for waitlist mortality was 4.4 at 3 months and 4.2 at 6 and 12 months. The discriminative performance of LFI+MELDNa was greater than MELDNa alone. Our data suggest that incorporating LFI with MELDNa can more accurately represent waitlist mortality in LT candidates.

Frailty as Tested by Gait Speed Is a Risk Factor for Liver Transplant Respiratory Complications.

OBJECTIVES: Frailty and sarcopenia are known risk factors for adverse liver transplant outcomes and mortality. We hypothesized that frailty or sarcopenia could identify the risk for common serious transplant-related adverse respiratory events. METHODS: For 107 patients (74 men, 33 women) transplanted over 1 year, we measured frailty with gait speed, chair stands, and Karnofsky Performance Scale (KPS) and sarcopenia with Skeletal Muscle Index on computed tomography at L3. We recorded the stress-tested cardiac double product as an index of cardiac work capacity. Outcomes included days of intubation, aspiration, clinical pneumonia, reintubation/tracheostomy, days to discharge, and survival. We modeled the outcomes using unadjusted regression and multivariable analyses controlled for (i) age, sex, and either Model for End-Stage Liver Disease-Na (MELDNa) or Child-Turcotte-Pugh scores, (ii) hepatocellular carcinoma status, and (iii) chronic obstructive pulmonary disease and smoking history. Subgroup analysis was performed for living donor liver transplant and deceased donor liver transplant recipients. RESULTS: Gait speed was negatively associated with aspiration and pulmonary infection, both in unadjusted and MELDNa-adjusted models (adjusted odds ratio for aspiration 0.10 [95% confidence interval [CI] 0.02-0.67] and adjusted odds ratio for pulmonary infection 0.12 [95% CI 0.02-0.75]). Unadjusted and MELDNa-adjusted models for gait speed (coefficient -1.47, 95% CI -2.39 to -0.56) and KPS (coefficient -3.17, 95% CI -5.02 to -1.32) were significantly associated with shorter intubation times. No test was associated with length of stay or need for either reintubation or tracheostomy. DISCUSSION: Slow gait speed, an index of general frailty, indicates significant risk for post-transplant respiratory complications. Intervention to arrest or reverse frailty merits exploration as a potentially modifiable risk factor for improving transplant respiratory outcomes.