Aerobic capacity during cardiopulmonary exercise testing and survival with and without liver transplantation for patients with chronic liver disease

Patient-perceived barriers to lifestyle interventions in cirrhosis

BACKGROUND/AIMS

Sarcopenia, muscle weakness, and physical frailty are independent predictors of mortality in cirrhosis. These adverse prognostic factors are potentially modifiable with lifestyle interventions, including adequate nutritional intake and physical activity. Our aim was to identify patient-perceived barriers and enablers to these interventions.

PATIENTS AND METHODS

Adult patients with cirrhosis were prospectively recruited from two tertiary care liver clinics. Patients were excluded if they had hepatocellular carcinoma beyond transplant criteria, other active malignancy, or advanced chronic disease.

RESULTS

A total of 127 patients (mean age: 60 ± 9 years, 58% males, and 48% with Child-Pugh-B/C (CP-B/C) disease) were included. Two-thirds of the patients had cirrhosis related to alcohol or hepatitis C. CP-B/C patients were more likely to take oral nutritional supplements (56% vs 29%) and less likely to consume animal protein daily (66% vs 85%) when compared to CP-A patients. Early satiety, altered taste, and difficulty in buying/preparing meals were more common in CP-B/C patients and even present in 20-30% of CP-A patients. Most patients reported adequate funds to purchase food. As quantified by the International Physical Activity Questionnaire-Short Form, 47% reported low activity levels, with no significant differences between groups. CP-B/C patients were more fatigued with exercise, however, overall Exercise Benefits/Barriers Scale scores were similar across groups.

CONCLUSIONS

Barriers to nutritional intake and physical activity are common in cirrhosis and should be evaluated and treated in all patients. Asking simple screening questions in clinic and referring at-risk patients to expert multidisciplinary providers is a reasonable strategy to address these barriers. Future research should evaluate techniques to overcome modifiable barriers and enhance enablers.

Malnutrition and sarcopenia predict post-liver transplantation outcomes independently of the Model for End-stage Liver Disease score

BACKGROUND

Although malnutrition and sarcopenia are prevalent in cirrhosis, their impact on outcomes following liver transplantation is not well documented.

METHODS

The associations of nutritional status and sarcopenia with post-transplant infections, requirement for mechanical ventilation, intensive care (ICU) and hospital stay, and 1 year mortality were assessed in 232 consecutive transplant recipients. Nutritional status and sarcopenia were assessed using the Royal Free Hospital-Global Assessment (RFH-GA) tool and the L3-psoas muscle index (L3-PMI) on CT, respectively.

RESULTS

A wide range of RFH-SGA and L3-PMI were observed within similar Model for End-stage Liver Disease (MELD) sub-categories. Malnutrition and sarcopenia were independent predictors of all outcomes. Post-transplant infections were associated with MELD (OR = 1.055, 95%CI = 1.002-1.11) and severe malnutrition (OR = 6.55, 95%CI = 1.99-21.5); ventilation > 24 h with MELD (OR = 1.1, 95%CI = 1.036-1.168), severe malnutrition (OR = 8.5, 95%CI = 1.48-48.87) and suboptimal donor liver (OR = 2.326, 95%CI = 1.056-5.12); ICU stay > 5 days, with age (OR = 1.054, 95%CI = 1.004-1.106), MELD (OR = 1.137, 95%CI = 1.057-1.223) and severe malnutrition (OR = 7.46, 95%CI = 1.57-35.43); hospital stay > 20 days with male sex (OR = 2.107, 95%CI = 1.004-4.419) and L3-PMI (OR = 0.996, 95%CI = 0.994-0.999); 1 year mortality with L3-PMI (OR = 0.996, 95%CI = 0.992-0.999). Patients at the lowest L3-PMI receiving suboptimal grafts had longer ICU/hospital stay and higher incidence of infections.

CONCLUSIONS

Malnutrition and sarcopenia are associated with early post-liver transplant morbidity/mortality. Allocation indices do not include nutritional status and may jeopardize outcomes in nutritionally compromised individuals.

Coronary Computed Tomography Angiography in Combination with Coronary Artery Calcium Scoring for the Preoperative Cardiac Evaluation of Liver Transplant Recipients

Liver transplantation is the best treatment option for early-stage hepatocellular carcinoma, liver cirrhosis, fulminant liver failure, and end-stage liver diseases. Even though advances in surgical techniques and perioperative care have improved postoperative outcomes, perioperative cardiovascular complications are a leading cause of postoperative morbidity and mortality following liver transplantation. Ischemic coronary artery disease (CAD) and cardiomyopathy are the most common cardiovascular diseases and could be negative predictors of postoperative outcomes in liver transplant recipients. Therefore, comprehensive cardiovascular evaluations are required to assess perioperative risks and prevent concomitant cardiovascular complications that would preclude good outcomes in liver transplant recipients. The two major types of cardiac computed tomography are the coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA). CCTA in combination with the CACS is a validated noninvasive alternative to coronary angiography for diagnosing and grading the severity of CAD. A CACS > 400 is associated with significant CAD and a known important predictor of posttransplant cardiovascular complications in liver transplant recipients. In this review article, we discuss the usefulness, advantages, and disadvantages of CCTA combined with CACS as a noninvasive diagnostic tool for preoperative cardiac evaluation and for maximizing the perioperative outcomes of liver transplant recipients.

Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study

Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk (i.e., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT (i.e., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

Predictive value of exhaled nitric oxide and aerobic capacity for sepsis complications after liver transplantation

Our objective was to investigate the predictive value of fractional nitric oxide (NO) concentration in exhaled breath (FeNO) and aerobic capacity (peak VO₂ ) for postoperative sepsis in liver transplantation candidates. Patients were identified and charts of all consecutive patients were prospectively reviewed. Bacterial sepsis represented the commonest postoperative complications (30%), which was attributed to peritonitis, pneumonia, and catheter-related infections. Preoperative FeNO and peak VO₂ values were lower in patients with postoperative sepsis. Patients with sepsis required higher needs for mechanical ventilation and ICU length of stay. Inverse correlation was found between logarithmically FeNO-transformed data and systolic pulmonary artery pressure (r = -0.348; P = 0.018). Multivariate analyses using bootstrap sampling method indicated that odds of sepsis were associated with lower values of peak exercise VO₂ [OR = 0.790 (0.592; 0.925)] and reduced log(FeNo) [OR = 0.027 (0.001; 0.451)], but not with higher MELD scores [OR = 1.141 (0.970; 1.486)]. By evaluating the cutoff for the ROC curves in each bootstrap resampling, median and 95% confidence interval were calculated for peak VO₂ : 17 [16.2; 22] ml/kg/min and FeNO: 17.2 [13.0; 33.9] ppb. We conclude that low peak exercise VO₂ and reduced FeNO may help identify patients who are at risk to develop perioperative sepsis.

Systematic review: pre- and post-operative prognostic value of cardiopulmonary exercise testing in liver transplant candidates

BACKGROUND

Cardiopulmonary exercise testing (CPET) is the gold standard for the objective assessment of functional status. In many conditions, CPET outperforms the traditional variables in predicting mortality.

AIM

In patients with cirrhosis listed for liver transplantation, our primary aim was to determine the prognostic value of CPET for pre-and post-transplant mortality and, in particular, whether CPET remained predictive after adjustment for liver disease severity.

METHODS

A systematic literature review was conducted in databases Medline, Scopus, Embase and PubMed. Where possible, data were pooled for meta-analyses using a DerSimonian and Laird random effects model.

RESULTS

A total of seven studies were retrieved, including 1107 patients with a mean MELD of 14.2 (standard deviation 1.6) and peak baseline VO2 of 17.4 mL/kg/min. In all of the studies in which multivariable analysis was performed, CPET variables were independent predictors of pre-transplant mortality (three studies) and post-transplant mortality (four studies). In the three studies where we could aggregate post-transplant mortality data, post-transplant mortality was predicted by AT with a mean difference of 2.0 (95% confidence interval, CI: 0.42-3.59; Z = 2.48, P = 0.01) between survivors and nonsurvivors. The peak VO2 was not significant (0.77 95% CI: -1.36 to 2.90; Z = 0.71, P = 0.48).

CONCLUSIONS

Patient's listed for liver transplant have significant functional limitations, with a weighted mean VO2 below the threshold level required for independent living. Although heterogeneity in study designs with respect to timing, CPET variables, and cut-off values precluded the determination of CPET mortality thresholds, the studies support CPET as an objective and independent predictor of pre- and post-transplant mortality.

Sarcopenia in Patients with Chronic Liver Disease: Can It Be Altered by Diet and Exercise?

Sarcopenia, a loss of muscle mass, is being increasingly recognized to have a deleterious effect on outcomes in patients with chronic liver disease. Factors related to diet and the inflammatory nature of chronic liver disease contribute to the occurrence of sarcopenia in these patients. Sarcopenia adversely influences quality of life, performance, morbidity, success of transplantation, and even mortality. Specific deficiencies in macronutrients (protein, polyunsaturated fatty acids) and micronutrients (vitamins C, D, and E, carotenoids, and selenium) have been linked to sarcopenia. Lessons learned from nutritional therapy in geriatric patient populations may provide strategies to manage sarcopenia in patients with liver disease. Combining diet modification and nutrient supplementation with an organized program of exercise may help ameliorate or even reverse the effects of sarcopenia on an already complex disease process.

Nutrition in liver transplantation: too little or too much?

PURPOSE OF REVIEW

The purpose of this study was to review the most recent findings on approaches to managing the obesity and muscle wasting that are found in patients before and after liver transplantation.

RECENT FINDINGS

A number of articles have contributed to the accumulating evidence that morbid obesity is not an absolute contraindication to liver transplantation with survival outcomes similar across BMI groups. Obesity is, however, a risk factor for early post-transplant complications and obesity-related comorbidities markedly increase this risk. Very limited data are as yet available, dietary, or otherwise, related to amelioration of these comorbidities and evidence that weight loss leads to improved outcomes in obese patients is lacking. Abdominal computed tomography imaging is increasingly being used to identify muscle wasting, and poorer post-transplant survival is seen in patients with significant muscle wasting. This modality has confirmed the persistence of depleted muscle stores after transplant extending well beyond 1 year. Coupled with this is a high incidence of weight gain and metabolic syndrome and the associated risks. Although dietary intervention and exercise are considered possible approaches to address these issues, work in these areas so far is sparse.

SUMMARY

An urgent need exists for interventional studies on the basis of nutrition and/or exercise to address the challenges presented by both obesity and muscle wasting, which likely coexist in many patients in both the pretransplant and the post-transplant periods.

Meeting report of the 2014 joint international congress of the International Liver Transplantation Society, Liver Intensive Care Group of Europe, and European Liver and Intestinal Association

The 2014 Annual Meeting of the International Liver Transplantation Society was held in London, England. This was the 20th meeting of the Society and was marked by a joint meeting including the European Liver and Intestinal Association as well as the Liver Intensive Care Group of Europe. The meeting included symposia, invited lectures, debates, oral presentations, and posters. The principal themes were living donation, expanding the deceased donor pool, machine preservation, and new oral therapies for hepatitis C virus. This report highlights the scientific discussions of this meeting.

Pre-Transplant Aerobic Capacity and Prolonged Hospitalization After Liver Transplantation

Introduction

Patients with end stage liver disease (ESLD) referred for liver transplantation (LT) are forwarded to pulmonary evaluation before being operated. ESLD is associated with muscle wasting, reduced exercise tolerance and aerobic capacity.

Objectives

We assessed the association between aerobic capacity (AC), liver disease severity and postoperative LT outcomes in a series of LT candidates in a university affiliated hospital in Brazil.

Methods

Pre-LT oxygen uptake at peak (pre-VO_2peak), liver disease severity, and early pos-LT outcomes such as length of intensive care unit (ICU) stay, <5 and ≥5 days and hospitalization, <20 and ≥20 days and postoperative mortality were compared. Pre-VO_2peak was measured through the cardiopulmonary exercise testing (CPET). Severity of liver disease was estimated by the Model for End-Stage Liver Disease (MELD) categorization into MELD < 18 and MELD ≥ 18 groups. Student's t-test was used to compare these groups. A logistic regression model was built to verify the effect of those variables on the length of ICU stay, length of hospitalization and postoperative mortality.

Results

A total of 47 patients were include in analysis. Pre-VO_2peak was similar to that of healthy sedentary individuals (75 ± 18%) and worse in the MELD ≥ 18 group as compared to the MELD < 18 group (19.51 ± 7.87 vs 25.21 ± 8.76 mL/kg/min, respectively; p = 0.048). According to the multivariate analysis, only a lower pre-VO_2peak (<20.09 ± 4.83 mL/kg/min) was associated to a greater length of hospitalization (p = 0.01).

Conclusions

In LT candidates, a reduced pre-VO_2peak may predict a higher risk of greater pos-LT length of hospitalization. The length of ICU stay and postoperative mortality were not associated with variables studied. This finding should be evaluated in other studies before making specific recommendations about a routine use of CPET in LT candidates.

Insufficient Protein Intake Is Associated With Increased Mortality in 630 Patients With Cirrhosis Awaiting Liver Transplantation

BACKGROUND

For patients awaiting liver transplantation, we aimed to determine the prevalence and predictors of insufficient protein intake as well as to determine whether very low protein intake was an independent predictor of malnutrition and mortality.

MATERIALS AND METHODS

Adults with cirrhosis who were activated on our local liver transplant waiting list between January 2000 and October 2009 were included. Estimated protein intake was derived from dietary records. Patients with incomplete dietary records were excluded. Multivariable logistic regression and competing risk analysis were used.

RESULTS

Of 742 potential patients, 112 were excluded due to insufficient data, leaving 630 patients for evaluation. Mean protein intake was 1.0 ± 0.36 g/kg/d and only 24% of patients met the expert consensus recommended threshold of > 1.2 g/kg of protein per day. Very low protein intake (< 0.8 g/kg/d) was associated with worse liver disease severity (as measured by Child-Pugh or MELD). Protein intake below 0.8 g/kg/d was an independent predictor both of malnutrition as measured by the subjective global assessment (adjusted odds ratio [95% confidence interval (CI)]: 2.0 [1.3-3.0]) and of transplant waiting list mortality (adjusted hazard ratio [95% CI]: 1.8 [1.2-2.7]).

CONCLUSION

In this large cohort of liver transplant waitlisted patients, very low protein intake was prevalent and independently associated with malnutrition and mortality. Unlike many other prognostic factors, protein intake is potentially modifiable. Prospective studies are warranted to evaluate the effect of targeted protein repletion on clinically relevant outcomes such as muscle mass, muscle function, immune function, and mortality.

Eight weeks of exercise training increases aerobic capacity and muscle mass and reduces fatigue in patients with cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis have reduced exercise tolerance, measured objectively as decreased peak exercise oxygen uptake (peak VO2). Reduced peak VO2 is associated with decreased survival time. The effect of aerobic exercise training on peak VO2 has not been well studied in patients with cirrhosis. We evaluated the safety and efficacy of 8 weeks of supervised exercise on peak VO2, quadriceps muscle thickness, and quality of life.

METHODS

In a prospective pilot study, stable patients (79% male, 57.6 ± 6.7 years old) with Child-Pugh class A or B cirrhosis (mean Model for End-Stage Liver Disease score, 10 ± 2.2) were randomly assigned to groups that received exercise training (n = 9) or usual care (controls, n = 10) at the University of Alberta Hospital in Canada from February through June 2013. Supervised exercise was performed on a cycle ergometer 3 days/week for 8 weeks at 60%-80% of baseline peak VO2. Peak VO2, quadriceps muscle thickness (measured by ultrasound), thigh circumference, answers from Chronic Liver Disease Questionnaires, EQ-visual analogue scales, 6-minute walk distance, and Model for End-Stage Liver Disease scores were evaluated at baseline and at week 8. Analysis of covariance was used to compare variables.

RESULTS

At week 8, peak VO2 was 5.3 mL/kg/min higher in the exercise group compared with controls (95% confidence interval, 2.9-7.8; P = .001). Thigh circumference (P = .001), thigh muscle thickness (P = .01), and EQ-visual analogue scale determined self-perceived health status (P = .01) was also significantly higher in the exercise group compared with controls at week 8; fatigue subscores of the Chronic Liver Disease Questionnaires were lower in the exercise group compared with controls (P = .01). No adverse events occurred during cardiopulmonary exercise testing or training.

CONCLUSIONS

In a controlled prospective pilot trial, 8 weeks of supervised aerobic exercise training increased peak VO2 and muscle mass and reduced fatigue in patients with cirrhosis. No relevant adverse effects were observed. Larger trials are needed to evaluate the effects of exercise in patients with cirrhosis. ClinicalTrials.gov number: NCT01799785.

Nutrition and exercise in the management of liver cirrhosis

Liver cirrhosis (LC) patients often have protein-energy malnutrition (PEM) and decreased physical activity. These conditions often lead to sarcopenia, which is the loss of skeletal muscle volume and increased muscle weakness. Recent studies have demonstrated that PEM and sarcopenia are predictors for poor survival in LC patients. Nutrition and exercise management can improve PEM and sarcopenia in those patients. Nutrition management includes sufficient dietary intake and improved nutrient metabolism. With the current high prevalence of obesity, the number of obese LC patients has increased, and restriction of excessive caloric intake without the exacerbation of impaired nutrient metabolism is required for such patients. Branched chain amino acids are good candidates for supplemental nutrients for both obese and non-obese LC patients. Exercise management can increase skeletal muscle volume and strength and improve insulin resistance; however, nutritional status and LC complications should be assessed before an exercise management regimen is implemented in LC patients. The establishment of optimal exercise regimens for LC patients is currently required. In this review, we describe nutritional status and its clinical impact on the outcomes of LC patients and discuss general nutrition and exercise management in LC patients.