Framingham score, renal dysfunction, and cardiovascular risk in liver transplant patients

Cardiovascular disease assessment and management in liver transplantation

The prevalence and mortality related to end-stage liver disease (ESLD) continue to rise globally. Liver transplant (LT) recipients continue to be older and have inherently more comorbidities. Among these, cardiac disease is one of the three main causes of morbidity and mortality after LT. Several reasons exist including the high prevalence of associated risk factors, which can also be attributed to the rise in the proportion of patients undergoing LT for metabolic dysfunction-associated steatohepatitis (MASH). Additionally, as people age, the prevalence of now treatable cardiac conditions, including coronary artery disease (CAD), cardiomyopathies, significant valvular heart disease, pulmonary hypertension, and arrhythmias rises, making the need to treat these conditions critical to optimize outcomes. There is an emerging body of literature regarding CAD screening in patients with ESLD, however, there is a paucity of strong evidence to support the guidance regarding the management of cardiac conditions in the pre-LT and perioperative settings. This has resulted in significant variations in assessment strategies and clinical management of cardiac disease in LT candidates between transplant centres, which impacts LT candidacy based on a transplant centre's risk tolerance and comfort level for caring for patients with concomitant cardiac disease. Performing a comprehensive assessment and understanding the potential approaches to the management of ESLD patients with cardiac conditions may increase the acceptance of patients, who appear too complex, but rather require extra evaluation and may be reasonable candidates for LT. The unique physiology of ESLD can profoundly influence preoperative assessment, perioperative management, and outcomes associated with underlying cardiac pathology, and requires a thoughtful multidisciplinary approach. The strategies proposed in this manuscript attempt to review the latest expert experience and opinions and provide guidance to practicing clinicians who assess and treat patients being considered for LT. These topics also highlight the gaps that exist in the comprehensive care of LT patients and the need for future investigations in this field.

Perioperative Cardiovascular Risk Assessment and Management in Liver Transplant Recipients: A Review of the Literature Merging Guidelines and Interventions

Liver transplantation (LT) is the second most performed solid organ transplant. Coronary artery disease (CAD) is a critical consideration for LT candidacy, particularly in patients with known CAD or risk factors, including metabolic dysfunction associated with steatotic liver disease. The presence of severe CAD may exclude patients from LT; therefore, precise preoperative evaluation and interventions are necessary to achieve transplant candidacy. Cardiovascular complications represent the earliest nongraft-related cause of death post-transplantation. Timely intervention to reduce cardiovascular events depends on adequate CAD screening. Coronary disease screening in end-stage liver disease is challenging because standard noninvasive CAD screening tests have low sensitivity due to hyperdynamic state and vasodilatation. As a result, there is overuse of invasive coronary angiography to exclude severe CAD. Coronary artery calcium scoring using a computed tomography scan is a tool for the prediction of cardiovascular events, and can be used to achieve risk stratification in LT candidates. Recent literature shows that qualitative assessment on both noncontrast- and contrast-enhanced chest computed tomography can be used instead of calcium score to assess the presence of coronary calcium. With increasing prevalence, protocols to address CAD in LT candidates must be reconsidered. Percutaneous coronary intervention could allow a shorter duration of dual-antiplatelet therapy in simple lesions, with safer perioperative outcomes. Hybrid coronary revascularization is an option for high-risk LT candidates with multivessel disease nonamenable to percutaneous coronary intervention. The objective of this review is to evaluate existing methods for preoperative cardiovascular risk stratification, and to describe interventions before surgery to optimize patient outcomes and reduce cardiovascular event risk.

The Italian data on SARS-CoV-2 infection in transplanted patients support an organ specific immune response in liver recipients

Introduction

The study of immune response to SARSCoV-2 infection in different solid organ transplant settings represents an opportunity for clarifying the interplay between SARS-CoV-2 and the immune system. In our nationwide registry study from Italy, we specifically evaluated, during the first wave pandemic, i.e., in non-vaccinated patients, COVID-19 prevalence of infection, mortality, and lethality in liver transplant recipients (LTRs), using non-liver solid transplant recipients (NL-SOTRs) and the Italian general population (GP) as comparators.

Methods

Case collection started from February 21 to June 22, 2020, using the data from the National Institute of Health and National Transplant Center, whereas the data analysis was performed on September 30, 2020.To compare the sex- and age-adjusted distribution of infection, mortality, and lethality in LTRs, NL-SOTRs, and Italian GP we applied an indirect standardization method to determine the standardized rate.

Results

Among the 43,983 Italian SOTRs with a functioning graft, LTRs accounted for 14,168 patients, of whom 89 were SARS-CoV-2 infected. In the 29,815 NL-SOTRs, 361 cases of SARS-CoV-2 infection were observed. The geographical distribution of the disease was highly variable across the different Italian regions. The standardized rate of infection, mortality, and lethality rates in LTRs resulted lower compared to NL-SOTRs [1.02 (95%CI 0.81-1.23) vs. 2.01 (95%CI 1.8-2.2); 1.0 (95%CI 0.5-1.5) vs. 4.5 (95%CI 3.6-5.3); 1.6 (95%CI 0.7-2.4) vs. 2.8 (95%CI 2.2-3.3), respectively] and comparable to the Italian GP.

Discussion

According to the most recent studies on SOTRs and SARS-CoV-2 infection, our data strongly suggest that, in contrast to what was observed in NL-SOTRs receiving a similar immunosuppressive therapy, LTRs have the same risk of SARS-CoV-2 infection, mortality, and lethality observed in the general population. These results suggest an immune response to SARS-CoV-2 infection in LTRS that is different from NL-SOTRs, probably related to the ability of the grafted liver to induce immunotolerance.

Evaluation of recipients with significant comorbidity - Patients with cardiovascular disease

Liver transplant(ation) (LT) is the most effective treatment for patients with decompensated liver disease. The increasing prevalence of obesity and type 2 diabetes and the growing number of patients with non-alcoholic fatty liver disease being evaluated for LT, have resulted in a greater proportion of LT candidates presenting with a higher risk of cardiovascular disease. As cardiovascular disease is a major cause of morbidity and mortality after LT, a thorough cardiovascular evaluation pre-LT is crucial. In this review, we discuss the latest evidence on the cardiovascular evaluation of LT candidates and we focus on the most prevalent conditions, namely ischaemic heart disease, atrial fibrillation and other arrhythmias, valvular heart disease, and cardiomyopathies. LT candidates undergo an electrocardiogram, a resting transthoracic echocardiography and an assessment of their cardiopulmonary functional ability as part of their standardised pre-LT work-up. Further diagnostic work-up is undertaken based on the results of the baseline evaluation and may include a coronary computed tomography angiography in patients with cardiovascular risk factors. The evaluation of potential LT candidates for cardiovascular disease requires a multidisciplinary approach, with input from anaesthetists, cardiologists, hepatologists and transplant surgeons.

The Effect of a Comprehensive Rehabilitation Program on Respiratory Function and Functional Capacity on Patients After 1 Month to Liver Transplantation

BACKGROUND

Physical exercise is prescribed in populations with chronic diseases, but data are scarce in the liver transplantation (LT) setting.

OBJECTIVE

The aim of this study was to evaluate changes in forced expiratory volume in the first second, forced vital capacity, maximal inspiratory pressure, maximal expiratory pressure, 6-minute walking test (6MWT), 6-minute step test (6MST), Duke Activity Status Index, VO₂ (mL/kg/min), and health-related quality of life (in patients submitted to a rehabilitation program, comprising physical exercise training, breathing techniques, and educational sessions after LT.

METHODS

This cohort study enrolled patients to an 8-week period of thrice weekly comprehensive supervised rehabilitation program after 1 month of LT. A nonrandomized control cohort of LT patients were selected to match the rehabilitation group based on specific demographic data and severity of disease.

RESULTS

The rehabilitation group, compared with the control group, showed a significant improvement in respiratory parameters (forced vital capacity [0.33L vs 0.13L,P < .01]); exercise capacity (6MWT and 6MST 71.1 vs 34.1 meters; and 30.5 vs 7.5 steps; respectively P < .01); Duke Activity Status Index scores and VO₂ (21.3 vs 10.2 and 9 vs 4.3; respectively P < .01); respiratory muscle strength (maximal inspiratory pressure 21.1 vs 15.1 cmH₂O and maximal expiratory pressure 21.2 vs 10.2 cmH₂O; P < .01); and quality of life (SF-36 physical component summary 12.4 vs 2.9 P < .01).

CONCLUSION

These data suggest that improvements in physical fitness, respiratory parameters, and quality of life are achieved with a comprehensive rehabilitation program initiated early after LT.

Emerging Evidence on Coronary Heart Disease Screening in Kidney and Liver Transplantation Candidates: A Scientific Statement From the American Heart Association: Endorsed by the American Society of Transplantation

Coronary heart disease is an important source of mortality and morbidity among kidney transplantation and liver transplantation candidates and recipients and is driven by traditional and nontraditional risk factors related to end-stage organ disease. In this scientific statement, we review evidence from the past decade related to coronary heart disease screening and management for kidney and liver transplantation candidates. Coronary heart disease screening in asymptomatic kidney and liver transplantation candidates has not been demonstrated to improve outcomes but is common in practice. Risk stratification algorithms based on the presence or absence of clinical risk factors and physical performance have been proposed, but a high proportion of candidates still meet criteria for screening tests. We suggest new approaches to pretransplantation evaluation grounded on the presence or absence of known coronary heart disease and cardiac symptoms and emphasize multidisciplinary engagement, including involvement of a dedicated cardiologist. Noninvasive functional screening methods such as stress echocardiography and myocardial perfusion scintigraphy have limited accuracy, and newer noninvasive modalities, especially cardiac computed tomography-based tests, are promising alternatives. Emerging evidence such as results of the 2020 International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease trial emphasizes the vital importance of guideline-directed medical therapy in managing diagnosed coronary heart disease and further questions the value of revascularization among asymptomatic kidney transplantation candidates. Optimizing strategies to disseminate and implement best practices for medical management in the broader end-stage organ disease population should be prioritized to improve cardiovascular outcomes in these populations.

Glomerular filtration rate early after liver transplantation independently predicts atherosclerotic events

Cardiovascular disease (CVD) is an important cause of mortality among liver transplantation (LT) recipients; however, the data on CVD risk stratification following LT are limited. Thus, the primary aim of this study was to evaluate the association between decline in renal function early after LT and atherosclerotic events. This retrospective study included all patients receiving LT between 2007 and 2019. Early renal function was quantified as estimated glomerular filtration rate (GFR) 6 months after LT. The primary endpoint for the study was a composite atherosclerotic cardiovascular event of three-point major adverse cardiovascular events (MACEs), which includes nonfatal myocardial infarction (MI), nonfatal stroke, or death from CVD. A total of 553 LT recipients met entry criteria. After a median follow-up of 74 months (interquartile range 46-111), 94 (17%) LT recipients died and CVD-associated death occurred in 20 patients. MACE-3 occurred in 66 (12%) patients, with nonfatal MI being the most common event (n = 30). A strong inverse relationship between early GFR and MACE-3 was noted in unadjusted analysis with hazard ratio (HR) 0.96 (95% confidence interval [CI] 0.95-0.98; p = 0.0001) and remained significant even after accounting for age, sex, coronary artery disease, diabetes mellitus, hypertension, calcineurin inhibitor use, and Framingham Risk Score (FRS; HR 0.96, 95% CI 0.95-0.97; p = 0.0001 per unit increase in GFR). Furthermore, an independent interaction between GFR, FRS, and likelihood of developing an MACE-3 was noted. GFR 6 months following LT is a strong predictor of developing atherosclerotic events. This relationship is independent of traditional CVD risk stratification models (e.g. FRS) and thus has the potential to be incorporated into CVD risk assessment after LT but requires further validation.

Metabolic syndrome before liver transplantation: does it have an impact on post liver transplantation outcomes?

INTRODUCTION

Metabolic syndrome (MS) and cardiovascular risk factors are commonin liver transplant (LT) candidates and recipients. Cardiovascular events and de novo tumours are increasingly common causes of mortality in liver transplant recipients. The aim of this study is (i) to assess the prevalence of MS in LT recipients and its growth over the years and (ii) if the presence of MS pre-LT is associated with a higher risk of post-LT cardiovascular events (CVE), de novo tumours or early and late survival.

PATIENTS AND METHODS

Retrospective study that included LT recipients from January 2012 to December 2017. Baseline features (MS before LT and at 1year post-LT) and outcomes (CVE, de novo tumours and survival) were recorded.

RESULTS

483 recipients were included, MS was present pre-LT in 20% with an increasing prevalence over time, from16% in 2012 to 34% in 2017 (p=0.025). One-year post-LT, an additional 12% had developed de novo MS .At a median of 56-months follow-up, 13% developed a CVE and 9% a de novo tumour. One and 5-yr survival rates were91% and 83 % in those with pre-LT MS and 93% and 85 % in those without (p=0.94).The presence of MS before LT was independently associated with a higher risk of post-LT CVE (HR: 2.66 IC (95%): 1.6-4.4 p< 0.001), but not with de novo tumors (p=0.94) nor early and late survival (p=0.58 and p=0.87).

CONCLUSION

Pre-LT MS is increasing among LT candidates and is associated with a higher risk of post-LT morbidity CVE yet without affecting mortality.

The Role of Arterial Stiffness in the Estimation of Cardiovascular Risk in Liver Transplant Recipients

Background

Long-term cardiovascular (CV) events are a frequent cause of death and disability after liver transplant (LT). Although a more in-depth, risk-adapted control of CV risk factors may result in improved post-LT CV outcomes, an accurate stratification of the CV risk of LT recipients to better implement preventive strategies is lacking. Aortic pulse wave velocity (aPWV) is a surrogate of arterial stiffness that has been suggested as a biomarker of CV risk; it has never been evaluated in adult LT recipients.

Methods

In a single-center prospective study, we included 122 LT recipients at 12 (n = 39), 60 (n = 45), or 120 (n = 38) mo after LT. aPWV estimation by oscillometry, clinical assessment of CV risk factors, and CV risk estimation by standard clinical scores (systematic coronary risk evaluation and pooled cohort equation) were performed. The incidence of CV events during prospective follow-up was registered.

Results

aPWV was independently associated with age and the grade of control of blood pressure. After a median follow-up of 35 mo, 15 patients (12%) presented a CV event. Higher aPWV, diabetes, past or present smoking habit, previous CV events, lower eGFR, being in systematic coronary risk evaluation or pooled cohort equation high-risk groups, and higher levels of total cholesterol, LDL-cholesterol, creatinine, and triglycerides were associated with the incidence of CV events at univariate analysis; aPWV, past or present smoking habit, and triglycerides were independent predictors of CV events.

Conclusions

According to our results, aPWV mirrors CV risk in LT recipients and thus may be a useful CV risk biomarker in this population. Considering these preliminary results, its accuracy in stratifying risk requires confirmation in further studies.

Predictive Cardiometabolic Risk Profiling of Patients Using Vascular Age in Liver Transplantation

Liver transplantation is the last therapeutic option in patients with end-stage liver diseases. The adequate clinical management of transplant-patients impacts their vital prognosis and decisions on many occasions are made from the interaction of multiple variables involved in the process. This work is based on the National Liver Transplantation Program in Uruguay. We performed predictive analysis of cardiometabolic diseases on the transplanted cohort between 2014 and 2019, considering vascular age as a key factor. This aims at classification of the cohort based on the vascular age of the evaluated patients before transplantation for risk-profiling. Predicted high-risk group of the patients showed substantial deterioration of post-transplant health-conditions, including higher mortality rate. In our knowledge, this is the first study in Latin America incorporating vascular age toward predictive analysis of cardiometabolic risk factors in liver transplantations. Predictive risk-modeling using vascular age in a pre-transplantation scenario provides significant opportunity for early prediction of post-transplant risk factors, leading to efficient treatment with anticipation.

Cardiac and Pulmonary Vascular Risk Stratification in Liver Transplantation

Cardiovascular disease complications are the leading cause of early (short-term) mortality among liver transplant recipients. The increasingly older candidate pool has multiple comorbidities necessitating cardiac and pulmonary vascular disease risk stratification of patients for optimal allocation of scarce donor livers. Arrhythmias, heart failure, stroke, and coronary artery disease are common pretransplant cardiovascular comorbidities and contribute to cardiovascular complications after liver transplant. Valvular heart disease and portopulmonary hypertension present intraoperative challenges during liver transplant surgery. The Cardiovascular Risk in Orthotopic Liver Transplantation score estimates the risk of cardiovascular complications in liver transplant candidates within the first year after transplant.

NAFLD and liver transplantation: Disease burden, current management and future challenges

Non-alcoholic fatty liver disease (NAFLD), specifically its progressive form non-alcoholic steatohepatitis (NASH), represents the fastest growing indication for liver transplantation in Western countries. Diabetes mellitus, morbid obesity and cardiovascular disease are frequently present in patients with NAFLD who are candidates for liver transplantation. These factors require specific evaluation, including a detailed pre-surgical risk stratification, in order to improve outcomes after liver transplantation. Moreover, in the post-transplantation setting, the incidence of cardiovascular events and metabolic complications can be amplified by immunosuppressive therapy, which is a well-known driver of metabolic alterations. Indeed, patients with NASH are more prone to developing early post-transplant complications and, in the long-term, de novo malignancy and cardiovascular events, corresponding to higher mortality rates. Therefore, a tailored multidisciplinary approach is required for these patients, both before and after liver transplantation. Appropriate candidate selection, lifestyle modifications and specific assessment in the pre-transplant setting, as well as pharmacological strategies, adjustment of immunosuppression and a healthy lifestyle in the post-transplant setting, play a key role in correct management.

Incidence, Predictors, and Impact on Survival of Long-term Cardiovascular Events After Liver Transplantation

BACKGROUND

Information on the risk factors, particularly kidney function, and impact of long-term cardiovascular events (CVE) after liver transplantation (LT) remains scarce.

METHODS

This is a retrospective, single-center study that included consecutive LT recipients between 2007 and 2017. The incidence of CVE, their risk factors, and their impact on patient survival were investigated.

RESULTS

We included 627 LT recipients. The incidence of CVE was 8% and 20% at 12 and 60 months after LT, respectively. The independent risk factors of long-term (beyond 12 mo) CVE were age at LT (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.01-1.07), male gender (HR, 2.48; 95% CI, 1.21-5.05), history of pre-LT cardiovascular disease (HR, 2.19; 95% CI, 1.2-3.98), and immunosuppression with cyclosporine A (HR, 1.93; 95% CI, 1.14-3.3). In patients with pre-LT cardiovascular disease, creatinine levels 12 months after LT significantly impacted the risk of long-term CVE. Long-term CVE (HR, 2.12; 95% CI, 1.24-3.61), hepatitis C as the etiology of liver disease (HR, 2.18; 95% CI, 1.29-3.67), cytomegalovirus infection (HR, 1.89; 95% CI, 1.08-3.3), and donor age (HR, 1.02; 95% CI, 1.01-1.04) were independent factors associated with post-LT patient death.

CONCLUSIONS

Age, male gender, cardiovascular disease before LT, and cyclosporine A were associated with the risk of long-term CVE. The impact of serum creatinine was restricted to patients with pre-LT cardiovascular disease. In these patients, preservation of kidney function early after LT may lessen the incidence of CVE, which are an independent predictor of post-LT death.

Cardiovascular and metabolic disease in the liver transplant recipient

Liver transplantation has led to great improvements in long-term survival in patients with decompensated liver disease and hepatocellular carcinoma. Cardiovascular disease is the leading cause of non-graft-related deaths and has increased prevalence in liver allograft recipients. This is partly secondary to higher post-transplant rates of metabolic risk factors-notably obesity, hypertension, dyslipidemia, and diabetes mellitus, which comprise metabolic syndrome. Post-transplantation metabolic syndrome is expected to be a growing factor in morbidity and mortality as transplant candidates trend older, the rates of metabolic risk factors in the general population increase, non-alcoholic steatohepatitis grows disproportionally as an indication for transplantation, and post-transplantation survival lengthens. This review discusses the incidence and contributory factors for post-transplant increases in metabolic disease, as well as the burden of cardiovascular disease in the liver allograft recipient. Patients with pre-transplant diabetes or obesity are at particularly high risk for post-transplant metabolic syndrome, and would likely benefit from closer surveillance and more aggressive medical management of risk factors. In metabolic disease resistant to initial medical therapies, tailoring of immunosuppressive regimens may further assist in minimizing long-term cardiovascular disease, although this must be done with caution to avoid worsening the risk of graft failure.

Immunosuppression in liver transplant

The increasing potency of immunosuppression (IS) agents resulted in significantly decreased rates of steroid resistant rejection and rejection related graft loss in liver transplantation (LT). Currently, more than two thirds of late mortality after LT is unrelated to graft function. However, the increased benefit of more potent IS drugs, coupled with the prolonged survival of transplant recipients led to longer patients exposure to these drugs and their unwanted adverse effects, creating a double-edged sword. In this article the authors describe the mechanism of action and the adverse effects of the most commonly used immunosuppressed drugs, and the most commonly used IS regimens for both induction and maintenance regimens. The balance between the ideal IS regimen to prevent rejection and the need to minimize the dose of IS drugs in order to prevent the adverse effects related to its use requires the knowledge of the science and the experience with the art of medicine. The different protocols aimed at protecting renal function and preventing the development of de novo cancer and metabolic syndrome are discussed here. The main causes of mortality late after liver transplant are associated with prolonged use of IS medications, and clear evidence exists about over-immunosuppression of recipients of liver transplant. The current status of strategies of IS minimization and withdrawal are reviewed in this article, with evaluation of its benefits and pitfalls.

Pathogenesis of non-alcoholic fatty liver disease and implications on cardiovascular outcomes in liver transplantation

Along with the obesity epidemic there has been a major increase in non-alcoholic fatty liver disease (NAFLD) prevalence, paralleling a steady increase in cirrhosis of the liver and hepatocellular cancer (HCC) related to NAFLD. Currently, NAFLD (related HCC and cirrhosis) is the second most common cause for liver transplantation (LT) and it is projected to take the top spot in the next 3-5 years. Patients with NAFLD cirrhosis and HCC have a unique set of comorbidities which potentially increases their risk for cardiovascular disease (CVD) and mortality. However, a review of the published data in NAFLD patients who undergo LT, does not paint a clear picture. While CVD is the most common cause of non-graft related mortality over the long-term, the short and intermediate-term survival post LT in NAFLD cirrhosis appears to be on par with other etiologies when age and comorbidities are factored. The cardiovascular complications are increased in the immediate post-transplant period but there is a shift from ischemic complications to arrhythmias and heart failure (HF). NAFLD recurs in 80-100% patients and occurs de novo in about 50% after LT, potentially impacting their long-term morbidity and mortality. This review summarizes the available data on CVD in NAFLD patients before and after LT, explains what is currently known about the epidemiology and pathogenesis of CVD in NAFLD and posits strategies to improve wait-list and post-transplant survival.

Alcohol use disorder and liver transplant: new perspectives and critical issues

Alcoholic liver disease is a consolidated indication for liver transplantation, but many unsolved issues can be highlighted. Patients with alcohol use disorder develop peculiar comorbidities that can become contraindications for transplantation. Moreover, a number of social and psychological patterns should be evaluated to select candidates with a low risk of alcohol relapse and adequate post-transplant adherence. In this context, the 6-month rule is too rigid to be widely applied. A short period of abstinence (1 to 3 months) is useful to estimate recovery of liver function and, possibly to avoid transplant. Cardiovascular disorders and extra-hepatic malignancies represent the main clinical issues after transplant. Patients transplanted due to alcoholic disease are a major risk for other liver diseases. Severe corticosteroid-resistant alcoholic acute hepatitis is a debated indication for transplant. However, available data indicate that well-selected patients have excellent post-transplant outcomes. Behavioral therapy, continued psychological support and a multidisciplinary team are essential to achieve and maintain complete alcohol abstinence during the transplant process. Alcoholic liver disease is an excellent indication for a liver transplant but patients with alcohol use disorder deserve a personalized approach and dedicated resources.

Post-transplant diabetes mellitus and preexisting liver disease - a bidirectional relationship affecting treatment and management

Liver cirrhosis and diabetes mellitus (DM) are both common conditions with significant socioeconomic burden and impact on morbidity and mortality. A bidirectional relationship exists between DM and liver cirrhosis regarding both etiology and disease-related complications. Type 2 DM (T2DM) is a well-recognized risk factor for chronic liver disease and vice-versa, DM may develop as a complication of cirrhosis, irrespective of its etiology. Liver transplantation (LT) represents an important treatment option for patients with end-stage liver disease due to non-alcoholic fatty liver disease (NAFLD), which represents a hepatic manifestation of metabolic syndrome and a common complication of T2DM. The metabolic risk factors including immunosuppressive drugs, can contribute to persistent or de novo development of DM and NAFLD after LT. T2DM, obesity, cardiovascular morbidities and renal impairment, frequently associated with metabolic syndrome and NAFLD, may have negative impact on short and long-term outcomes following LT. The treatment of DM in the context of chronic liver disease and post-transplant is challenging, but new emerging therapies such as glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium–glucose cotransporter 2 inhibitors (SGLT2i) targeting multiple mechanisms in the shared pathophysiology of disorders such as oxidative stress and chronic inflammation are a promising tool in future patient management.

Management of metabolic syndrome and cardiovascular risk after liver transplantation

Cardiovascular events are the second most prevalent cause of non-hepatic mortality in liver transplant recipients. The incidence of these events is projected to rise because of the growing prevalence of non-alcoholic steatohepatitis as a transplant indication and the ageing population of liver transplant recipients. Recipients with metabolic syndrome are up to four times more likely to have a cardiovascular event than recipients without, therefore prevention and optimal treatment of the components of metabolic syndrome are key in reducing the risk of these events. Although data on the treatment of metabolic comorbidities specifically in liver transplant recipients are scarce, there is detailed guidance from learned societies that mostly mirrors the guidance for patients at increased cardiovascular risk in the general population. In this Review, we discuss the management of the components of metabolic syndrome following liver transplantation and provide practical stepwise guidance. We also emphasise the need for adequately powered studies for the treatment of metabolic comorbidities in liver transplant recipients.

Recipient Age for Liver Transplantation: Should It Be Limited? A Propensity Score Matching Analysis of a Large European Series

BACKGROUND AND AIMS

The demand for older patients not to be denied access to liver transplantation (LT) has intensified as the European population continues to live longer and maintains better health.

AIM

This study aims to ascertain the impact of recipient age on the post-LT survival in 2 well-balanced populations at Vall d'Hebron University Hospital.

METHODS

From January 1990 to December 2016, LT recipients (young group: 50-65 years of age; elderly group: >65 years of age) were compared by means of a propensity score matching (PSM) method.

RESULTS

Prior to PSM, graft survival and patient survival were worse for the elderly group (P < .001). In 1126 LT recipients, a caliper width of 0.01 was used based on the donor (age, sex, cause of donor death, and donor intensive care unit stay) and recipient covariates (sex, body mass index, indication for LT, intraoperative blood transfusion, cardiovascular risk factors, and Model for End-Stage Liver Disease [MELD]-Era). After PSM, 206 patients were matched; 1-, 5-, and 10-year patient survival rates were 77%, 63%, and 52% vs 80%, 64%, and 45% (P = .50) for young vs elderly recipients, respectively. Similar graft survival rates were observed in both groups (P = .42).

CONCLUSIONS

Advanced age alone should not exclude patients from LT.

Physical Condition, Glycemia, Liver Function, and Quality of Life in Liver Transplant Recipients After a 12-Month Supervised Exercise Program

BACKGROUND AND AIMS

Despite the excellent long-term outcomes in liver transplant (LT) recipients, several medical complications related to lifestyle still represent an issue. This study examined the effects of a 12-month supervised aerobic and strength training program on the aerobic capacity, muscle strength, metabolic profile, liver function, and quality of life of a cohort of LT recipients.

METHODS

LT recipients with stable liver function were assigned to interventional exercise (group A) or usual care (group B). Aerobic capacity, muscle strength, metabolic profile, liver and kidney function, and health-related quality of life were assessed at baseline and after 6 and 12 months. Group A attended supervised training sessions 3 times per week for 12 months. Group B received general recommendations about home-based exercise.

RESULTS

Forty patients from 6 Italian LT centers were randomized. Twenty-nine (72.5%, men-to-women ratio 23:6, mean age, 52 ± 8 years) LT recipients completed the study. Baseline characteristics were similar between groups except for body mass index and time from LT. No episode of acute rejection nor increase of transaminases occurred. Maximum workload and body mass index increased in both groups over time, but fasting glucose significantly decreased in group A (94.0 ± 15.0 mg/dL vs 90.0 ± 17.0 mg/dL; P = .037) and increased in controls (95.0 ± 24.0 mg/dL vs 102.0 ± 34.0 mg/dL, P = .04). Upper limb muscle strength increased only in supervised LT recipients. Vitality and general and mental health domains significantly improved after physical exercise.

CONCLUSIONS

Supervised combined training was safe and effective in increasing aerobic capacity, muscle strength, and quality of life and in improving glucose metabolism in stable LT recipients.

International Liver Transplantation Consensus Statement on End-stage Liver Disease Due to Nonalcoholic Steatohepatitis and Liver Transplantation

Nonalcoholic steatohepatitis (NASH)-related cirrhosis has become one of the most common indications for liver transplantation (LT), particularly in candidates older than 65 years. Typically, NASH candidates have concurrent obesity, metabolic, and cardiovascular risks, which directly impact patient evaluation and selection, waitlist morbidity and mortality, and eventually posttransplant outcomes. The purpose of these guidelines is to highlight specific features commonly observed in NASH candidates and strategies to optimize pretransplant evaluation and waitlist survival. More specifically, the working group addressed the following clinically relevant questions providing recommendations based on the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system supported by rigorous systematic reviews and consensus: (1) Is the outcome after LT similar to that of other etiologies of liver disease? (2) Is the natural history of NASH-related cirrhosis different from other etiologies of end-stage liver disease? (3) How should cardiovascular risk be assessed in the candidate for LT? Should the assessment differ from that done in other etiologies? (4) How should comorbidities (hypertension, diabetes, dyslipidemia, obesity, renal dysfunction, etc.) be treated in the candidate for LT? Should treatment and monitoring of these comorbidities differ from that applied in other etiologies? (5) What are the therapeutic strategies recommended to improve the cardiovascular and nutritional status of a NASH patient in the waiting list for LT? (6) Is there any circumstance where obesity should contraindicate LT? (7) What is the optimal time for bariatric surgery: before, during, or after LT? (8) How relevant is donor steatosis for LT in NASH patients?

Association Between Renal Dysfunction and Major Adverse Cardiac Events After Liver Transplantation: Evidence from an International Randomized Trial of Everolimus-Based Immunosuppression

Background

Prospective evidence is lacking regarding the association between renal dysfunction and cardiovascular events after liver transplantation.

Material/Methods

Data were analyzed post hoc regarding renal function and major adverse cardiac events in a two-year prospective trial of de novo liver transplant recipients randomized at 30 days post-transplant to (i) everolimus [EVR]/reduced tacrolimus [EVR/rTAC] (ii) EVR with tacrolimus discontinued [TAC Elimination] or (iii) standard tacrolimus [TAC Control].

Results

By month 24 post-transplant, 32/716 patients had experienced a first major cardiac event (4.5%): 4.1% (10/245), 2.2% (5/229) and 7.0% (17/242) of patients in the EVR/rTAC, TAC Elimination and TAC Control groups, respectively (p=0.043). The cumulative eGFR area under the curve (AUC) from randomization to month 24 was 119 706, 123 082, and 105 946 mL in the EVR/rTAC, TAC Elimination, and TAC Control groups, respectively, corresponding to a mean eGFR AUC of 82.4, 83.0, and 71.9 mL/min/1.73 m². Cox regression modeling showed that mean eGFR AUC was inversely associated with time to first major cardiac event: the hazard ratio per mL/min/1.73 m² was −0.0000015 [95% CI −0.00000078; −0.0000024] (p<0.001).

Conclusions

These findings confirm retrospective evidence that the risk of major cardiac events increases with deteriorating renal function after liver transplantation and demonstrate the need for careful cardiovascular risk management in patients with renal impairment. Immunosuppression based on everolimus with tacrolimus withdrawal, or to a lesser extent tacrolimus reduction, improves both renal function and the risk of major cardiac events compared to standard tacrolimus therapy in liver transplant recipients.

Cytomegalovirus reactivation in liver transplant recipients due to hepatitis C cirrhosis is associated with higher cardiovascular risk - an observational, retrospective study

The association between cytomegalovirus (CMV) reactivation and cardiovascular risk has been reported in solid organ transplant populations; however, it has yet to be assessed in liver transplantation (LT). We aim to evaluate whether CMV reactivation is associated with cardiovascular events (CVE) in HCV-LT patients. LT patients (2010 and 2014) due to HCV cirrhosis were included. Clinically significant CMV (CS-CMV) was defined as viral load (VL) >5000 copies/ml, need of therapy or CMV disease. Baseline variables and endpoint measures (CVE, survival, severe recurrent hepatitis C, de novo tumors, and diabetes) were collected. One hundred and forty patients were included. At LT, a history of AHT was present in 23%, diabetes 22%, tobacco use 45%, obesity 20%, and renal impairment (eGFR < 60 ml/min) in 26.5%. CS-CMV reactivation occurred in 25% of patients. Twenty-six patients (18.5%) developed a CVE. Cox regression analysis revealed two factors significantly associated with CVE: Pre-LT DM [HR = 4.6 95% CI (1.6, 13), P = 0.004] and CS-CMV [HR = 4.7 95% CI (1.8, 12.5), P = 0.002]. CS-CMV was not independently associated with the remaining endpoints except for survival (P = 0.03). In our series, CS-CMV reactivation was associated with a greater risk of developing CVE, thus confirming data from other solid organ transplant populations and emphasizing the need for adequate CMV control.

A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score

Cardiovascular disease (CVD) complications are important causes of morbidity and mortality after orthotopic liver transplantation (OLT). There is currently no preoperative risk-assessment tool that allows physicians to estimate the risk for CVD events following OLT. We sought to develop a point-based prediction model (risk score) for CVD complications after OLT, the Cardiovascular Risk in Orthotopic Liver Transplantation risk score, among a cohort of 1,024 consecutive patients aged 18-75 years who underwent first OLT in a tertiary-care teaching hospital (2002-2011). The main outcome measures were major 1-year CVD complications, defined as death from a CVD cause or hospitalization for a major CVD event (myocardial infarction, revascularization, heart failure, atrial fibrillation, cardiac arrest, pulmonary embolism, and/or stroke). The bootstrap method yielded bias-corrected 95% confidence intervals for the regression coefficients of the final model. Among 1,024 first OLT recipients, major CVD complications occurred in 329 (32.1%). Variables selected for inclusion in the model (using model optimization strategies) included preoperative recipient age, sex, race, employment status, education status, history of hepatocellular carcinoma, diabetes, heart failure, atrial fibrillation, pulmonary or systemic hypertension, and respiratory failure. The discriminative performance of the point-based score (C statistic = 0.78, bias-corrected C statistic = 0.77) was superior to other published risk models for postoperative CVD morbidity and mortality, and it had appropriate calibration (Hosmer-Lemeshow P = 0.33).

CONCLUSION

The point-based risk score can identify patients at risk for CVD complications after OLT surgery (available at www.carolt.us); this score may be useful for identification of candidates for further risk stratification or other management strategies to improve CVD outcomes after OLT. (Hepatology 2017;66:1968-1979).

Combined resistance and endurance training at a moderate-to-high intensity improves physical condition and quality of life in liver transplant patients

Although currently moderate and high intensity concurrent physical exercise is prescribed in populations with special needs due to its greater effect on physical condition and health-related quality of life (HRQOL), there are no data in the liver transplantation (LT) setting. The aim of this study is to evaluate changes in maximal strength, aerobic capacity, body composition, liver function, and HRQOL in LT patients after a moderate-to-high intensity combined resistance-endurance training. Six months after LT, 54 patients were randomized into 2 groups: intervention group (IG) and control group (CG). A total of 50 patients completed the study with repeat testing at 6 and 12 months after LT. The IG completed a 6-month exercise training program, consisting of exercising 2 days for 24 weeks in the hospital facilities, whereas the CG followed usual care recommendations. Patients completed a 5-multijoint exercise circuit with elastic bands involving the major muscle groups. The effects of the concurrent training program on maximal oxygen consumption, overall and regional maximal strength, body composition, liver function, and HRQOL were analyzed. The IG showed a significant improvement (P < 0.05) in outcome measurements compared with the CG in aerobic capacity, hip extension, elbow flexion, overall maximal strength, physical functioning, and vitality of HRQOL, whereas no changes were observed in body composition and liver function tests. In conclusion, this is the first study that combines supervised resistance and aerobic training performed at moderate-to-high intensity in LT recipients. It results in significant improvements in aerobic capacity, maximal strength, and HRQOL. Liver Transplantation 23 1273-1281 2017 AASLD.

Incidence of and Risk Assessment for Adverse Cardiovascular Outcomes After Liver Transplantation: A Systematic Review

BACKGROUND

Cardiovascular events represent a major source of morbidity and mortality after liver transplantation and will likely increase given the aging population and nonalcoholic fatty liver disease as a leading indication for transplant. The optimal cardiovascular risk stratification approach in this evolving patient population remains unclear. The aims of this systematic review are to: (1) refine the definition, (2) characterize the incidence, and (3) identify risk factors for cardiovascular events post-liver transplantation. Additionally, we evaluated performance characteristics of different cardiac testing modalities.

METHODS

MEDLINE via PubMed, EMBASE, Web of Science, and Scopus were searched for studies published between 2002 and 2016 (model of end-stage liver disease era). Two authors independently reviewed articles to select eligible studies and performed data abstraction.

RESULTS

Twenty-nine studies representing 57 493 patients from 26 unique cohorts were included. Definitions of cardiovascular outcomes were highly inconsistent. Incidence rates were widely variable: 1% to 41% for outcomes of 6 months or shorter and 0% to 31% for outcomes longer than 6 months. Multivariate analyses demonstrated that older age and history of cardiac disease were the most consistent predictors of cardiovascular events posttransplant (significant in 8/23 and 7/22, studies, respectively). Predictive capacity of various cardiac imaging modalities was also discrepant.

CONCLUSIONS

The true incidence of cardiovascular outcomes post-liver transplant remains unknown in large part due to lack of consensus regarding outcome definition. Overall, poor data quality and gaps in knowledge limit the ability to clearly identify predictors of outcomes, but existing data support a more aggressive risk stratification protocol for patients of advanced age and/or with preexisting cardiac disease.

Cardiovascular assessment in liver transplant for non-alcoholic steatohepatitis patients: What we do, what we should do

Non-alcoholic fatty liver disease (NAFLD) is increasing considerably due to the current lifestyle, which means that it is becoming one of the main indications for liver transplantation. On the other hand, there is a strong association between NAFLD and cardiovascular disease. This has been evidenced in many studies revealing a higher presence of carotid plaques or carotid intima-media thickness, leading to cardiovascular events and, ultimately, mortality. According to the liver transplant guidelines, screening for heart disease in transplant candidates should be performed by electrocardiogram and transthoracic echocardiography while a stress echocardiogram should be reserved for those with more than two cardiovascular risk factors or greater than 50 years old. However, there are no specific recommendations in NAFLD patients requiring a liver transplantation, despite its well-known cardiovascular risk association. Many studies have shown that these patients probably require a more exhaustive assessment and a global approach including other specialists such as cardiologists or nutritionists. Also, the incidence of cardiovascular disease is also increased in NAFLD patients in the post-transplantation period in comparison with other etiologies, because of the pre-existent risk factors together with the immunosuppressive therapy. Therefore, an early intervention on the lifestyle and the individualized selection of the immunosuppressive regimen could lead to a modification of the cardiovascular risk factors in NAFLD patients requiring a liver transplantation.

Cardiovascular morbidity and mortality after liver transplantation: The protective role of mycophenolate mofetil

Cardiovascular (CV) diseases are recognized longterm causes of death after liver transplantation (LT). The objective of this multicenter study was to analyze the prevalence and the evolution of CV risk factors and CV morbidity and mortality in 1819 LT recipients along 5 years after LT. The influence of baseline variables on survival, morbidity, and mortality was studied. There was a continuous and significant increase of the prevalence of all the CV risk factors (except smoking) after LT. CV diseases were the fourth cause of mortality in the 5 years after LT, causing 12% of deaths during the follow-up. Most CV events (39%) occurred in the first year after LT. Preexisting CV risk factors such as age, pre-LT CV events, diabetes, metabolic syndrome, and hyperuricemia, and mycophenolate-free immunosuppressive therapy, increased post-LT CV morbidity and mortality. The development of new-onset CV risk factors after LT, such as dyslipidemia and obesity, independently affected late CV morbidity and mortality. Tacrolimus and steroids increased the risk of posttransplant diabetes, whereas cyclosporine increased the risk of arterial hypertension, dyslipidemia, and metabolic syndrome. In conclusion, CV complications and CV mortality are frequent in LT recipients. Preexisting CV risk factors, immunosuppressive drugs, but also the early new onset of obesity and dyslipidemia after LT play an important role on late CV complications. A strict metabolic control in the immediate post-LT period is advisable for improving CV risk of LT recipients. Liver Transplantation 23 498-509 2017 AASLD.