Coronary artery disease in orthotopic liver transplantation: pretransplant assessment and management

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.

Predicting major adverse cardiovascular events after orthotopic liver transplantation using a supervised machine learning model: A cohort study

BACKGROUND

Liver transplant (LT) patients have become older and sicker. The rate of post-LT major adverse cardiovascular events (MACE) has increased, and this in turn raises 30-d post-LT mortality. Noninvasive cardiac stress testing loses accuracy when applied to pre-LT cirrhotic patients.

AIM

To assess the feasibility and accuracy of a machine learning model used to predict post-LT MACE in a regional cohort.

METHODS

This retrospective cohort study involved 575 LT patients from a Southern Brazilian academic center. We developed a predictive model for post-LT MACE (defined as a composite outcome of stroke, new-onset heart failure, severe arrhythmia, and myocardial infarction) using the extreme gradient boosting (XGBoost) machine learning model. We addressed missing data (below 20%) for relevant variables using the k-nearest neighbor imputation method, calculating the mean from the ten nearest neighbors for each case. The modeling dataset included 83 features, encompassing patient and laboratory data, cirrhosis complications, and pre-LT cardiac assessments. Model performance was assessed using the area under the receiver operating characteristic curve (AUROC). We also employed Shapley additive explanations (SHAP) to interpret feature impacts. The dataset was split into training (75%) and testing (25%) sets. Calibration was evaluated using the Brier score. We followed Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis guidelines for reporting. Scikit-learn and SHAP in Python 3 were used for all analyses. The supplementary material includes code for model development and a user-friendly online MACE prediction calculator.

RESULTS

Of the 537 included patients, 23 (4.46%) developed in-hospital MACE, with a mean age at transplantation of 52.9 years. The majority, 66.1%, were male. The XGBoost model achieved an impressive AUROC of 0.89 during the training stage. This model exhibited accuracy, precision, recall, and F1-score values of 0.84, 0.85, 0.80, and 0.79, respectively. Calibration, as assessed by the Brier score, indicated excellent model calibration with a score of 0.07. Furthermore, SHAP values highlighted the significance of certain variables in predicting postoperative MACE, with negative noninvasive cardiac stress testing, use of nonselective beta-blockers, direct bilirubin levels, blood type O, and dynamic alterations on myocardial perfusion scintigraphy being the most influential factors at the cohort-wide level. These results highlight the predictive capability of our XGBoost model in assessing the risk of post-LT MACE, making it a valuable tool for clinical practice.

CONCLUSION

Our study successfully assessed the feasibility and accuracy of the XGBoost machine learning model in predicting post-LT MACE, using both cardiovascular and hepatic variables. The model demonstrated impressive performance, aligning with literature findings, and exhibited excellent calibration. Notably, our cautious approach to prevent overfitting and data leakage suggests the stability of results when applied to prospective data, reinforcing the model's value as a reliable tool for predicting post-LT MACE in clinical practice.

Cardiac imaging for the assessment of patients being evaluated for liver transplantation

Cardiac risk assessment prior to liver transplantation has become widely accepted. With the emergence of nonalcoholic steatohepatitis among the leading causes of end-stage liver disease and the steady rise of the age of liver transplant recipients, the burden of cardiovascular diseases has markedly increased in this population. Selecting appropriate liver transplant candidates is crucial due to the increasing demand for scarce donor organs. The use of noninvasive cardiac imaging for pre-operative assessment of the cardiovascular status of liver transplant recipients has been on the rise, yet the optimal assessment strategy remains an area of active debate. In this review, we examine the relevant literature pertaining to the diagnostic and prognostic applications of noninvasive cardiac imaging in this population. We also propose a simple literature-based evaluation algorithm for CAD surveillance in liver transplant candidates.

Diagnostic Yield of Coronary Angiography in Asymptomatic Orthotopic Liver Transplantation Candidates

BACKGROUND

The ideal cardiac risk stratification strategy for orthotopic liver transplantation (OLT) is unknown. Our institution performed coronary angiography for asymptomatic OLT candidates at high risk for CAD: ≥65 years of age, diabetic and ≥55 years of age or diagnosed ≥5 years, abnormal stress test, or at the discretion of the OLT committee.

METHODS

The analysis included 301 consecutive, asymptomatic OLT candidates who underwent coronary angiography. The primary outcome was the prevalence of obstructive CAD.

RESULTS

At 2-year follow-up, OLT was performed in 44.9%, and 42.2% died. The prevalence of obstructive CAD, involvement of the proximal or mid LAD, and 3-vessel CAD were 10.3%, 6.6%, and 0.7%, respectively. Percutaneous and surgical revascularization were performed in 7.0% and 1.3%, respectively. Stress test was performed in 54.8%. The sensitivity and specificity of stress testing were 0% and 87.1%, respectively. The negative and positive predictive values of stress testing were 91.4% and 0%, respectively. Chest computed tomography (CT) was performed in 83.1%. Moderate or severe coronary artery calcification (CAC) was present in 47.8%. The sensitivity and specificity of moderate or severe CAC were 88.9% and 57.3%, respectively. The negative and positive predictive values of moderate or severe CAC were 97.7% and 20.2%, respectively. Multivariate analysis demonstrated that CAC was an independent predictor of obstructive CAD (HR 10.7; 95% CI 3.2-37.9; p < 0.001).

CONCLUSIONS

The prevalence of obstructive CAD in asymptomatic OLT candidates at high risk was uncommon. Alternative diagnostic strategies may be preferred to coronary angiography.

Serum from Patients with Severe Alcoholic Liver Cirrhosis Inhibits Proliferation and Migration of Human Coronary Artery Smooth Muscle Cells

Liver cirrhosis has been associated with an increased risk of coronary artery disease and clinical complications following percutaneous coronary revascularization. The present study is based on the hypothesis that cirrhosis may influence intimal hyperplasia following PCI. Sera from 10 patients with alcoholic liver cirrhosis and 10 age-matched healthy controls were used to stimulate cultured human coronary artery smooth muscle cells (HCASMC) for 48 h. HCASMC proliferation, migration, gene expression and apoptosis were investigated. Serum concentrations of growth factors and markers of liver function were also determined in patients and healthy controls. Treatment of HCASMC with patient sera reduced cell proliferation and migration (p < 0.05 vs. healthy controls), whereas apoptosis was unaffected (p = 0.160). Expression of genes associated with a synthetic vascular smooth muscle cell phenotype was decreased in cells stimulated with serum from cirrhotic patients (RBP1, p = 0.001; SPP1, p = 0.003; KLF4, p = 0.004). Platelet-derived growth factor-BB serum concentrations were lower in patients (p = 0.001 vs. controls). The results suggest the presence of circulating factors in patients with alcoholic liver cirrhosis affecting coronary smooth muscle cell growth. These findings may have implications for clinical outcomes following percutaneous coronary revascularization in these patients.

Pre-Operative Cardiovascular Testing before Liver Transplantation

End-stage liver disease (ESLD) is increasingly prevalent and shares many risk factors with coronary artery disease (CAD). No specific guidelines exist for pre-liver transplant evaluation of CAD, and pretransplant cardiovascular testing varies widely. The aim of this study is to characterize pre-transplant cardiac testing practices with post-transplant clinical outcomes. We retrospectively reviewed patients undergoing initial liver transplantation at our transplant center between January 2015 and March 2019. Patients with previous liver transplantation or multi-organ transplantation were excluded. Electronic medical records were reviewed for relevant demographic and clinical data. We included 285 patients with a mean follow-up of 2.4 years. Of 274 patients (96.1%) with pre-transplant transthoracic echocardiogram (TTE), 18 (6.6%) were abnormal. Non-invasive ischemic testing was performed in 193 (68%) patients: 165 (58%) underwent stress TTE, 24 (8%) underwent myocardial perfusion imaging, 3 underwent coronary computed tomography, and 1 underwent exercise electrocardiogram. Sixteen patients (6%) had left heart catheterization of which 10 (63%) were abnormal and 5 proceeded to revascularization before transplant. There were 4 (1.4%) deaths within 30 days of transplant and 23 deaths (8.1%) in total. ST-elevation myocardial infarction was seen in 1 patient within 30 days and 1 patient after 30 days (0.7% total). No cardiovascular deaths were observed. Among patients undergoing liver transplantation, pre-transplantation cardiovascular testing is exceedingly common and post-transplant cardiovascular complications are rare. Additional research is needed to determine the optimal testing and surveillance in this patient population.

Cardiac Risk Stratification in Liver Transplantation: Results of a Tiered Assessment Protocol Based on Traditional Cardiovascular Risk Factors

Coronary artery disease (CAD) confers increased perioperative risk in patients undergoing liver transplantation (LT). Although routine screening for CAD is recommended, there are limited data on the effectiveness of screening strategies. We evaluated the safety and efficacy of a 3-tiered cardiac risk-assessment protocol that stratifies patients based on age and traditional cardiac risk factors. We peformed a single-center, prospective, observational study of consecutive adult patients undergoing LT assessment (2010-2017). Patients were stratified into low-risk (LR), intermediate-risk (IR), or high-risk (HR) cardiac groups and received standardized investigations with selective use of transthoracic echocardiography (TTE), dobutamine stress echocardiography (DSE), computed tomography coronary angiography (CTCA), and coronary angiography (CA). Primary outcomes were cardiac events (CEs) and cardiovascular death up to 30 days after LT. Overall, 569 patients were included, with 76 patients identified as LR, 256 as IR, and 237 as HR. Cardiac risk factors included diabetes mellitus (26.0%), smoking history (47.3%), hypertension (17.8%), hypercholesterolemia (7.2%), family (17.0%) or prior history of heart disease (6.0%), and obesity (27.6%). Of the patients, 42.0% had ≥2 risk factors. Overall compliance with the protocol was 90.3%. Abnormal findings on TTE, DSE, and CTCA were documented in 3, 23, and 44 patients, respectively, and 12 patients were not listed for transplantation following cardiac assessment (1 LR, 2 IR, and 9 HR). Moderate or severe CAD was identified in 25.4% of HR patients on CTCA following a normal DSE. CEs were recorded in 7 patients (1.2%), with 2 cardiovascular deaths (0.4%). Cardiac risk stratification based on traditional cardiac risk factors with the selective use of DSE, CTCA, and CA is a safe and feasible approach that results in a low perioperative cardiac event rate.

Safety and feasibility of dopamine-atropine stress echocardiography

BACKGROUND

Dobutamine-atropine stress echocardiography (DSE) has lower sensitivity in patients with advanced liver disease (ALD) due to vasodilation.

HYPOTHESIS

Dopamine-atropine stress echocardiography (DopSE) may be an alternative to DSE in ALD patients by improving the blood pressure response to stress.

METHODS

The safety and tolerability of DSE and DopSE were compared in 10 volunteers. The safety, adverse effects, and efficacy of DopSE were then assessed in 105 patients, 98 of whom had ALD. Dopamine was infused in stepwise fashion from 5 µg/kg/min to a peak dose of 40 µg/kg/min. Atropine was given before and in early stages of dopamine infusion up to cumulative dose of 1.5 mg. The hemodynamic responses of 98 ALD patients were compared with 102 patients with ALD who underwent standard DSE.

RESULTS

In normal volunteers, systolic BP increased more with DopSE compared to DSE (61 ± 19 mm Hg vs 39 ± 15 mm Hg, P = .008). In 105 patients who underwent DopSE, none had adverse effects that required early stress termination. In the groups with ALD, the systolic BP increase (38 ± 28 mm Hg vs 12 ± 27 mm Hg, P < .001) and peak rate pressure product (RPP) (22 861 ± 5289 vs 17 211 ± 3848, P = <.001) were both higher in those undergoing DopSE versus DSE. The sensitivity and specificity of DopSE were 45% and 88%, respectively for coronary disease (≥70% stenosis) in 37 patients who had angiography.

CONCLUSIONS

Dopamine-atropine stress echocardiography appears to be a safe stress modality and provides greater increases in RPP in patients with ALD compared to DSE.

Coronary Computed Tomography Angiography Demonstrates a High Burden of Coronary Artery Disease Despite Low-Risk Nuclear Studies in Pre-Liver Transplant Evaluation

We investigated the presence and severity of coronary artery disease (CAD) in orthotopic liver transplantation (OLT) candidates using coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA) as compared with the prevalence of normal and abnormal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). A total of 140 prospective OLT candidates without known CAD underwent coronary artery calcium (CAC) scans with (n = 77) or without CCTA and coronary computed tomography angiography-derived fractional flow reserve (FFR_CT ; n = 57) using a dual-source computed tomography (CT) and were followed for 2.6 ± 1.4 years. Coronary plaque was quantified using the segment-involvement score (SIS) and segment stenosis score (SSS). The mean age was 59 ± 6 years, and 65.0% of patients were male. Mean Agatston CACS was 367 ± 653, and 15.0% of patients had CACSs of 0; 83.6% received a SPECT MPI, of which 95.7% were interpreted as normal/probably normal. By CCTA, 9.1% had obstructive CAD (≥70% stenosis), 67.5% had nonobstructive CAD, and 23.4% had no CAD. Nonobstructive CAD was diffuse with mean SIS 3.0 ± 2.9 and SSS 4.5 ± 5.4. Only 14 patients had high risk-findings (severe 3v CAD, n = 4, CACS >1000 n = 10) that prompted X-ray angiography in 3 patients who had undergone CCTA, resulting in revascularization of a high-risk obstruction in 1 patient who had a normal SPECT study. Patients with end-stage liver disease have a high prevalence of nonobstructive CAD by CCTA, which is undiagnosed by SPECT MPI, potentially underestimating cardiovascular risk. Deferring X-ray angiography unless high-risk CCTA findings are present is a potential strategy for avoiding unnecessary X-ray angiography.

Outcomes of percutaneous coronary interventions in patients with liver transplant

OBJECTIVE

Our aim is to describe characteristics of liver transplant patients undergoing percutaneous coronary interventions (PCI) as well as in-hospital outcomes including the mortality and peri-procedural complications from the largest publicly available inpatient database in the United States from 2002 to 2014.

BACKGROUND

Outcomes of PCI are well studied in patients with end-stage liver disease but not well studied in patients who receive liver transplant (LT).

METHODS

Data derived from Nationwide Inpatient Sample (NIS) were analyzed for years 2002-2014. Adult Hospitalizations with PCI were identified using ICD-9-CM procedure codes. LT status and various complications were identified by using previously validated ICD-9-CM diagnosis codes. Endpoints were in-hospital mortality and peri-procedural complications. Propensity match analysis was performed to compare the endpoints between two groups.

RESULTS

During the study period, 8,595,836 patients underwent PCI; 4,080 (0.04%) patients had prior LT status. 93% of patients were above age 59 years, 79% were males and 69% were nonwhites. Out of the total patients with LT status, 73% had hypertension, 57% had diabetes mellitus, and 47% had renal failure. Post-PCI complications were studied further in both liver and non-LT patients after 1:1 propensity match which showed the incidence of acute kidney injury (AKI) was higher in LT group (12.3 vs 10.7%, p = .024) but dialysis requiring AKI was similar.

CONCLUSION

Among the LT recipients undergoing PCI, majority were nonwhite males. Almost more than half of the recipients had diabetes mellitus and renal failure. Incidence of AKI was higher in LT group, but other peri-procedural complications were comparable.

Preoperative cardiac assessment in liver transplant candidates

New and extended indications, older age, higher cardiovascular risk, and the long-standing cirrhosis-associated complications mandate specific skills for an appropriate preoperative assessment of the liver transplant (LT) candidate. The incidence of cardiac diseases (dysrhythmias, cardiomyopathies, coronary artery disease, valvular heart disease) are increasing among LT recipients: however, no consensus exists among clinical practice guidelines for cardiovascular screening and risk stratification. In spite of different "transplant center-centered protocols", basic "pillars" are common (electrocardiography, baseline echocardiography, functional assessment). Owing to intrinsic limitations, yields and relevance of noninvasive stress tests, under constant scrutiny even if used, are discussed, focusing the definition of the "high risk" candidate and exploring noninvasive imaging and new forms of stress imaging. The aim is to find an appropriate and rational stepwise algorithm. The final commitment is to select the right candidate for a finite resource, the graft, able to save (and change) lives.

SPECT myocardial perfusion imaging in liver transplantation candidates

BACKGROUND

The optimal cardiovascular evaluation prior to liver transplantation remains controversial and includes stress echocardiography, stress MPI, cardiac CTA, and coronary angiography. This study summarizes our experience of the past decade using SPECT MPI in patients with end-stage liver disease, including patient characteristics, stress testing protocols, test results, the need for repeat testing, and downstream testing.

METHODS

All patients who underwent a clinically indicated stress SPECT MPI study as part of their pre-liver transplant evaluation from 2004 to 2014 were reviewed from the Nuclear Cardiology database. Results of perfusion imaging, repeat testing, subsequent angiography, and need for revascularization were reviewed.

RESULTS

A total of 2500 patients were referred for SPECT MPI, of those 111 had known CAD and 271 underwent more than one MPI study. Compared to other patients undergoing stress MPI, pre-liver transplant patients were younger, had fewer cardiac risk factors and lower prevalence of prior cardiac history, and used pharmacologic stress more often. During the study decade, patient age increased, prevalence of hypertension increased and smoking decreased, prevalence of known CAD increased, and the number of abnormal studies decreased. Abnormal perfusion results were present in 7.8% of pre-liver transplant patients compared to 34.3% of all other patients. In a multivariate model, age and lower ejection fraction were associated with an abnormal MPI result. Of the 64 patients who underwent subsequent invasive or non-invasive coronary angiography after an abnormal MPI, obstructive CAD was diagnosed in 25 patients (1.0%), non-obstructive CAD was diagnosed in 23 patients (0.9%), and normal coronaries found in 16 patients (0.6%); a total of 18 (0.7%) of these underwent coronary revascularization. The average time to repeat testing was 27.2 ± 17.9 months. In a multivariate model, younger age and exercise stress were associated with repeat testing. In only 17 patients out of 271 with a normal initial perfusion, the repeat study became abnormal. The use of stress-first imaging was successful in 80% of patients with a reduction in Tc-99m dose from 39.1 to 18.3 mCi.

CONCLUSION

Abnormal SPECT MPI results in candidates for liver transplantation are infrequent compared to non-liver transplant patients and the incidence of obstructive CAD on subsequent angiography even less. Repeat testing in those on the transplant waiting list after initial normal test results appears to be of limited value. Stress-first protocols may be considered for the majority of these patients to reduce testing time and radiation exposure.

One-Year Outcomes of Percutaneous Coronary Intervention in Patients with End-Stage Liver Disease

Background:

Patients with cirrhosis and coronary artery disease (CAD) are at high risk for morbidity during surgical revascularization so they are often referred for complex percutaneous coronary intervention (PCI). Percutaneous coronary intervention in the cirrhotic population also has inherent risks; however, quantifiable data on long-term outcomes are lacking.

Methods:

Patients with angiographically significant CAD and cirrhosis were identified from the catheterization lab databases of the University of Pennsylvania Health System between 2007 and 2015. Outcomes were obtained from the medical record and telephonic contact with patients/families.

Results:

Percutaneous coronary intervention was successfully performed in 42 patients (51 PCIs). Twenty-nine patients with significant CAD were managed medically (36 angiograms). The primary outcome (a composite of mortality, subsequent revascularization, and myocardial infarction) was not significantly different between the 2 groups during a follow-up period at 1 year (PCI: 50%, Control: 40%, P = .383). In the PCI group, a composite adverse outcome rate that included acute kidney injury (AKI), severe bleed, and peri-procedural stroke was elevated (40%), with severe bleeding occurring after 23% of PCI events and post-procedural AKI occurring after 26% of events. The medical management group had significantly fewer total matched adverse outcomes (17% vs 40% in the PCI group, P = .03), with severe bleeding occurring after 11% of events and AKI occurring after 6% of events. Increased risk of adverse events following PCI was associated with severity of liver disease by Child-Pugh class.

Conclusions:

Percutaneous coronary intervention in patients with cirrhosis is associated with an elevated risk of adverse events, including severe bleeding and AKI.

Reduced myocardial reserve in cirrhotic patients: an evaluation by dobutamine stress speckle tracking and tissue Doppler imaging (TDI) echocardiography

Introduction: Despite the normal systolic function at rest, cirrhotic patients often suffer from volume overload and symptoms of heart failure as they face stressful situations. This study investigated the myocardial reserve in cirrhotic patients at resting condition and peak stress by dobutamine speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI).

Methods: Twenty cirrhotic patients and 10 normal individuals aged 30-50 were selected randomly. For all of the participants, complete echocardiographic study of 2D, STE and TDI was done at rest and peak stress status with dobutamine. The following parameters were assessed: ejection fraction (EF), global longitudinal LV strain (GLS), strain rate in the septal basal segment and lateral wall and E’ in the septal basal segment by color-coded method.

Results: At baseline, EF was higher than 55% in both groups. GLS was higher (-22.6±2.4%) in the case group than the control group (-19.2±1.9%) at resting condition. After stress, it showed a greater increase (-22.5±1.7%) in the controls compared to cirrhotic patients (-22.6±3.3%; mean difference = 2.6 ± 2.03, P = 0.02). In cirrhotic patients, the average strain rate in the basal septal segment decreased after stress (-1.2 ± 0.3/s to-1.1 ± 0.3/s), but it increased in the control group (-1.1 ± 0.2/s to -1.8 ± 0.2/s).

Conclusion: Despite the presence of normal resting systolic function in cirrhotic patients, there was insufficient increase or even a decrease in myocardial function with stress; this may indicate the absence of sufficient myocardial reserve in cirrhotic patients. These findings would help to explain the reason for occurrence of heart failure or hemodynamic changes in cirrhotic patients.

The diagnostic and prognostic utility of risk factors defined by the AHA/ACCF on the evaluation of cardiac disease in liver transplantation candidates

Background

The diagnostic and prognostic utility of risk factors proposed by the 2012 American Heart Association and American College of Cardiology Foundation (AHA/ACCF) Scientific Statement on the cardiac assessment of asymptomatic liver transplantation candidates have not been validated. We investigated whether the sum of risk factors proposed by the AHA/ACCF can identify liver transplant candidates at increased cardiac risk.

Methods

In a retrospective cohort of consecutive liver transplantation recipients, we calculated, for each subject, the pre-transplantation sum of AHA/ACCF risk factors (age > 60 years, prior cardiovascular disease, hypertension, dyslipidemia, diabetes mellitus, smoking, and left ventricular hypertrophy). The primary outcome was the presence of severe coronary artery disease (CAD), defined as ≥70% stenosis or ≥ 50% left main stenosis on pre-transplantation angiography. The secondary outcomes were the composite of cardiac death or myocardial infarction (MI) and the composite of cardiac death, MI, or coronary revascularization.

Results

Among 220 liver transplant recipients, the sum of AHA/ACCF risk factors had good discriminatory capacity for severe CAD [area under the curve, 0.77; 95% confidence interval (CI), 0.62–0.92; P = 0.007]; having ≥3 risk factors provided 75% sensitivity and 77% specificity for severe CAD. During mean post-transplantation follow-up of 48 ± 31 months, having ≥3 risk factors was associated with increased risk of the secondary composite outcomes of cardiac death or MI [hazard ratio, 2.39; P = 0.044] and cardiac death, MI, or coronary revascularization [hazard ratio, 2.39; P = 0.044].

Conclusions

In patients undergoing cardiac assessment prior to liver transplantation, the sum of risk factors proposed by the AHA/ACCF provides significant diagnostic and prognostic utility. Having ≥3 AHA/ACCF risk factors is a reasonable threshold to prompt non-invasive stress testing in asymptomatic liver transplantation candidates.

Specific issues concerning the management of patients on the waiting list and after liver transplantation

The present document is a second contribution collecting the recommendations of an expert panel of transplant hepatologists appointed by the Italian Association for the Study of the Liver (AISF) concerning the management of certain aspects of liver transplantation, including: the issue of prompt referral; the management of difficult candidates; malnutrition; living related liver transplants; hepatocellular carcinoma; and the role of direct acting antiviral agents before and after transplantation. The statements on each topic were approved by participants at the AISF Transplant Hepatology Expert Meeting organized by the Permanent Liver Transplant Commission in Mondello on 12-13 May 2017. They are graded according to the GRADE grading system.

Dobutamine stress echocardiography, myocardial perfusion scintigraphy, invasive coronary angiography, and post-liver transplantation events: Systematic review and meta-analysis

The impact of coronary artery disease on the clinical course of patients enrolled for liver transplantation (LT) has changed over the years as these patients become older and sicker. The purpose of this systematic review and meta-analysis was to investigate the value of dobutamine stress echocardiography (DSE), myocardial perfusion scintigraphy (MPS), and invasive coronary angiography (ICA) in predicting cardiac events post-LT in cirrhotic patients. A literature search was conducted using Scopus, Web of Science, EMBASE, MEDLINE (via PubMed), BIREME (regional medical library of the Pan American Health Organization), LILACS (Latin American and Caribbean Health Sciences Literature), Cochrane Library for Systematic Reviews, and OpenGrey Repository (www.opengrey.eu) electronic databases. A total of 322 records were retrieved for DSE, 90 for MPS, and 149 for ICA. In the final analysis, 11 records for DSE, 7 for MPS, and 8 for ICA were included. The relative risk and confidence interval for major adverse cardiac events were 30.2 (2.8-325.4) for DSE, 2.6 (1.09-6.1) for MPS, and 2.1 (1.0-2.3) for ICA, while the relative risk and confidence interval for all-cause mortality was 4.7 for DSE (1.8-12.0), 2.7 (1.25-5.9) for MPS, and 1.5 (0.89-3.2) for ICA. In conclusion, this meta-analysis found that DSE, MPS, and ICA do not satisfactorily predict increased risk of perioperative MACE or all-cause mortality among cirrhotic patients listed for LT, among small and heterogenous studies.

Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis in Liver Transplantation

The number of transplants caused by nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NASH) has been progressively increasing and this is expected to become the most common indication for liver transplant in the United States. Patients with NASH show many features of the metabolic syndrome and, as a result, are at higher risk for postoperative cardiovascular morbidity and mortality. Despite this, patients with NASH have long-term graft and patient survival rates comparable with other causes of chronic liver disease. Posttransplant metabolic syndrome is a common occurrence that increases the risk of steatosis in the graft liver.

Multidisciplinary approach to cardiac and pulmonary vascular disease risk assessment in liver transplantation: An evaluation of the evidence and consensus recommendations

Liver transplant (LT) candidates today are older, have greater medical severity of illness, and have more cardiovascular comorbidities than ever before. In addition, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Cirrhotic cardiomyopathy, a condition characterized by increased cardiac output and a reduced ventricular response to stress, is present in up to 30% of patients with cirrhosis, thus challenging perioperative management. Current noninvasive tests that assess for subclinical coronary and myocardial disease have low sensitivity, and altered hemodynamics during the LT surgery can unmask latent cardiovascular disease either intraoperatively or in the immediate postoperative period. Therefore, this review, assembled by a group of multidisciplinary experts in the field and endorsed by the American Society of Transplantation Liver and Intestine and Thoracic and Critical Care Communities of Practice, provides a critical assessment of the diagnosis of cardiac and pulmonary vascular disease and interventions aimed at managing these conditions in LT candidates. Key points and practice-based recommendations for the diagnosis and management of cardiac and pulmonary vascular disease in this population are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

Preoperative Cardiac Risk Assessment in Patients Undergoing Liver Transplant Due to Hepatocellular Carcinoma: Should It Be Different?

OBJECTIVES

Liver transplant is a high-risk surgery for cardiac events. The risk of 30-day major cardiac adverse events is estimated at more than 5%. In this retrospective study, we evaluated our preoperative cardiac risk assessment approach.

MATERIALS AND METHODS

We evaluated 58 adult patients who underwent liver transplant between May 2011 and May 2015. Preoperative cardiac risk factors and results of diagnostic tests were noted. Patients were divided into 2 groups: patients with or without hepatocellular carcinoma. Electrocardiogram, echocardiogram, and treadmill tests were performed for preoperative cardiac evaluation in all candidates for liver transplant. Results of these tests showed our preference for myocardial perfusion scintigraphy and/or coronary angiography and heart catheterization.

RESULTS

Mean age of patients was 46.5 ± 14.5 years. The most common cardiovascular risk factor was family history of coronary artery disease (24.1%) in all patients. Diabetes mellitus (15.5%) was the most common risk factor in the patient group without hepatocellular carcinoma. Three patients had already known coronary artery disease (5.2%). Of 16 patients (27.6%) who underwent coronary angiography, 4 were in the hepatocellular carcinoma group. Coronary revascularization by stent implantation was necessary for 1 patient in the hepatocellular carcinoma group; 1 patient in the group without hepatocellular carcinoma underwent preoperative coronary bypass surgery.

CONCLUSIONS

No consensus exists for cardiovascular risk stratification and preoperative cardiovascular evaluation of liver transplant candidates. Noninvasive stress tests are not always feasible for all liver transplant candidates because of poor mobility and poor exercise capacity. With early diagnoses of cardiovascular conditions and preventive recommendations, liver transplant can be performed safely before spread of the disease, which is essential for carcinoma patients. Angiographic evaluation of liver transplant candidates for hepatocellular carcinoma is strongly recommended.

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.

Assessment of adult patients with chronic liver failure for liver transplantation in 2015: who and when?

In 2015, there are a few absolute contraindications to liver transplantation. In adult patients, survival post-liver transplant is excellent, with 1-year survival rate >90% and 5-year survival rates >80% and predicted median allograft survival beyond 20 years. Patients with a Child-Turcotte Pugh score ≥9 or a model for end-stage liver disease (MELD) score >15 should be referred for liver transplantation, with patients who have a MELD score >17 showing a 1-year survival benefit with liver transplantation. A careful selection of hepatocellular cancer patients results in excellent outcomes, while consideration of extra-hepatic disease (reversible vs irreversible) and social support structures are crucial to patient assessment. Alcoholic liver disease remains a challenge, and the potential to cure hepatitis C virus infection together with the emerging issue of non-alcoholic fatty liver disease-associated chronic liver failure will change the landscape of the who in the years ahead. The when will continue to be determined largely by the severity of liver disease based on the MELD score for the foreseeable future.

Atherosclerosis in chronic hepatitis C virus patients with and without liver cirrhosis

Background

Chronic Hepatitis C virus (HCV) infection and liver cirrhosis may be associated with atherosclerosis and coronary artery disease (CAD). There are two phases to atherosclerosis, Subclinical and Clinical. Assessment of atherosclerosis may be started at its Subclinical phase by the evaluation of Epicardial Fat Thickness (EpFT) and Carotid Intima Thickness (CIMT).

Aim of the study

The aim of the study was to evaluate Clinical and Subclinical atherosclerosis in chronic HCV patients with and without liver cirrhosis by evaluating CIMT and EpFT and correlating the results with Child-Pugh functional scoring of cirrhosis as well as with ultrasound and laboratory parameters that define the severity of liver disease.

Patients and methods

This study involved 64 chronic HCV patients that were divided into two groups: 24 patients without liver cirrhosis and 40 patients with liver cirrhosis in addition to 20 apparently healthy volunteers serving as control. All of the 84 subjects were subjected to the following: Clinical evaluation; Routine Laboratory Evaluation (CBC, Liver Function Tests, Renal Function Tests, Serum electrolytes, Cholesterol, Triglycerides, HBs antigen and HCV antibody); ECG; Abdominal ultrasound; Echocardiographic evaluation of segmental wall motion abnormalities and EpFT and B-Mode Carotid ultrasonography for evaluation of CIMT.

Results

In the cirrhotic HCV group, the CIMT and EpFT were both significantly increased [Compared to control group (p = 0.000), compared to the non-cirrhotic HCV group (p = 0.000)]. In the non-cirrhotic HCV group, the CIMT and EpFT were both significantly increased compared to the control group with a p-value of 0.003 for CIMT and 0.048 for EpFT. The CIMT and EpFT were also positively correlated with each other (r = 0.456, p = 0.001). There was a statistically significant increase in the EpFT and CIMT in Child class B patients compared to Child class A (p = 0.007 for CIMT and p = 0.028 for EpFT) and in Child class C patients compared to Child class B patients (p = 0.001 for CIMT and 0.005 for EpFT). CIMT and EpFT were correlated positively with AST (r = 0.385, p = 0.002 for CIMT, and r = 0.379, p = 0.003 for EpFT), Total Bilirubin (r = 0.378, p = 0.003 for CIMT, and r = 0.384, p = 0.002 for EpFT), INR% (r = 0.456, p = 0.001 for CIMT, and r = 0.384, p = 0.001 for EpFT), CRP (r = 0.378, p = 0.003 for CIMT, and r = 0.386, p = 0.002 for EpFT), spleen span (r = 0.417, p = 0.001 for CIMT, and r = 0.437, p = 0.001 for EpFT) and portal Vein Diameter (r = 0.372, p = 0.003 for CIMT, and r = 0.379, p = 0.003 for EpFT). CIMT and EpFT were correlated negatively with Albumin (r = -0.379, p = 0.003 for CIMT, and r = -0.370, p = 0.003 for EpFT), platelets count (r = -0.382, p = 0.002 for CIMT, and r = -0.378, p = 0.003 for EpFT) and Liver Span (r = -0.433, p = 0.001 for CIMT, and r = -0.424, p = 0.001 for EpFT).

Conclusion

EpFT and CIMT significantly increased in chronic hepatitis C virus patients especially in those with cirrhosis and closely correlated with each other. Their thickness also correlated with the Child-Pugh functional scoring of cirrhosis as well as with ultrasound and laboratory parameters that define the severity of liver disease.The echocardiographic assessment of EpFT and the carotid Doppler assessment of CIMT may provide appropriate and simple screening markers for subclinical atherosclerosis and cardiovascular risk in chronic HCV patients with and without cirrhosis.

Nonalcoholic fatty liver: optimizing pretransplant selection and posttransplant care to maximize survival

PURPOSE OF REVIEW

Nonalcoholic steatohepatitis (NASH) is projected to become the most common indication for liver transplantation in the near future. NASH recipients have concurrent obesity, metabolic, and cardiovascular risks, which directly impact patient selection, posttransplant morbidity and potentially long-term outcomes. The purpose of this review is to highlight strategies to optimize pretransplant selection, outcomes, and posttransplant risk modification to optimize patient and graft survival.

RECENT FINDINGS

NASH recipients are at risk for pretransplant cardiovascular disease, diabetes mellitus, and related renovascular complications. Stringent selection criteria identify those patients most likely to benefit from liver transplantation without adverse cardiovascular events yet, the incidence of these events remains high in NASH recipients. High BMI imparts postoperative morbidity because of infections, wound complications, and longer lengths of hospital stay. Aggressive management of modifiable risk factors such as obesity, hyperlipidemia, diabetes mellitus, and hypertension is recommended.

SUMMARY

Although patient and graft survival in NASH recipients is excellent, long-term reduction in healthcare utilization and outcomes in these patients would benefit from risk factor modification. Periodic reassessment of coronary artery disease and early consideration of bariatric surgery is recommended in this population.

Anesthetic and operative considerations for laparoscopic liver resection

We enumerate the broad range of anesthetic considerations that affect the outcome of patients undergoing laparoscopic liver resection. Key elements for excellent outcomes after laparoscopic liver resection are careful patient selection and risk stratification, appropriate monitoring, techniques to reduce blood loss and transfusion, and active recovery management. Although some of these key elements are the same for open liver operation, there are specific anesthetic considerations of which both the surgical and anesthesia teams must be aware to achieve optimal patient outcomes after laparoscopic liver resection. While unique advantages of laparoscopic liver resection typically include decreased intraoperative bleeding, transfusion requirements, and a lower incidence of postoperative ascites, specific challenges include management of the complicated interplay between low-volume anesthesia and increased intraabdominal pressure due to pneumoperitoneum, with additional considerations regarding circulatory support to treat acute blood loss with need for emergent conversion in some cases. This article will address in detail the preoperative, intraoperative, and postoperative anesthetic considerations for patients undergoing laparoscopic liver resection that both the surgical and anesthesia team should be aware of to optimize outcomes.

Preoperative cardiovascular investigations in liver transplant candidate: An update

Cardiovascular complications are a major cause of morbidity and mortality in patients with end-stage liver disease (ESLD) undergoing liver transplantation. Identifying candidates at the highest risk of postoperative cardiovascular complications is the cornerstone for optimizing the outcome. Ischaemic heart disease contributes to major portion of cardiovascular complications and therefore warrants evaluation in the preoperative period. Patients of ESLD usually demonstrate increased cardiac output, compromised ventricular response to stress, low systemic vascular resistance and occasionally bradycardia. Despite various recommendations for preoperative evaluation of cardiovascular disease in liver transplant candidates, a considerable controversy on screening methodology persists. This review critically focuses on the rapidly expanding body of evidence for diagnosis and risk stratification of cardiovascular disorder in liver transplant candidates.

Cardiac imaging for the assessment of patients being evaluated for kidney or liver transplantation

Cardiac risk assessment prior to kidney and liver transplantation is controversial. Given the paucity of available organs, selecting appropriate recipients with favorable short- and long-term cardiovascular risk profile is crucial. Using noninvasive cardiac imaging tools to guide cardiovascular risk assessment and management can also be challenging and controversial. In this article, we address the burden of coronary artery disease among kidney and liver transplant candidates and review the literature pertaining to the diagnostic accuracy and the prognostic value of noninvasive cardiac imaging techniques in this population.

Myocardial perfusion imaging is an effective screening test for coronary artery disease in liver transplant candidates

A reliable screening test for coronary artery disease (CAD) in liver transplant (LT) candidates with end-stage liver disease is essential because a high percentage of perioperative mortality and morbidity is CAD-related. In this study, the effectiveness of myocardial perfusion imaging (MPI) for identification of significant CAD in LT candidates was evaluated. Records of 244 patients meeting criteria for MPI were evaluated: 74 met inclusion criteria; 40 had a positive MPI and cardiology follow-up; 27 had a negative MPI and underwent LT; and seven had a negative MPI and then had coronary angiography or a significant cardiac event. A selective MPI interpretation strategy was established where MPI-positive patients were divided into high, intermediate, and low CAD risk groups. The overall incidence of CAD in this study population was 5.1% and our strategy resulted in PPV 20%, NPV 94%, sensitivity 80%, and specificity 50% for categorizing CAD risk. When applied only to the subset of patients categorized as high CAD risk, the strategy was more effective, with PPV 67%, NPV 97%, sensitivity 80%, and specificity 94%. We determined that renal dysfunction was an independent predictive factor for CAD (p < 0.0001, odds ratio = 8.1), and grades of coronary occlusion correlated significantly with chronic renal dysfunction (p = 0.0079).

Appraising cardiac dysfunction in liver transplantation: an ongoing challenge

End-stage liver disease (ESLD) is a multisystemic disease that adversely and mutually aggravates other organs such as the heart. Cardiac dysfunction in ESLD encompasses a spectrum of disease that could be aggravated, precipitated or be occurring hand-in-hand with coexisting aetiological factors precipitating cirrhosis. Additionally and more complexly, liver transplantation, the curative modality of ESLD, is responsible for additional intra- and postoperative short- and long-term cardiac morbidity. The phenotypic distinction of the different forms of cardiac dysfunction in ESLD albeit important prognostically and therapeutically is not allowed by the current societal recommendations, due to conceptual, and methodological limitations in the appraisal of cardiac function and structure in ESLD and in designing studies that are based on this appraisal. This review comprehensively discusses the spectrum of cardiac dysfunction in ESLD, discusses the limitations of the current appraisal of cardiac dysfunction in ESLD, and proposes a hypothetical approach for studying cardiac dysfunction in liver transplant candidates.

Adverse cardiac events after orthotopic liver transplantation: a cross-sectional study in 389 consecutive patients

Current American College of Cardiology/American Heart Association guidelines caution that preoperative noninvasive cardiac tests may have poor predictive value for detecting coronary artery disease in liver transplant candidates. The purpose of our study was to evaluate the role of clinical predictor variables for early and late cardiac morbidity and mortality and the predictive values of noninvasive cardiac tests for perioperative cardiac events in a high-risk liver transplant population. In all, 389 adult recipients were retrospectively analyzed for a median follow-up time of 3.4 years (range = 2.3-4.4 years). Overall survival was 83%. During the first year after transplantation, cardiovascular morbidity and mortality rates were 15.2% and 2.8%. In patients who survived the first year, cardiovascular morbidity and mortality rates were 3.9% and 2%, with cardiovascular etiology as the third leading cause of death. Dobutamine stress echocardiography (DSE) and single-photon emission computed tomography had respective sensitivities of 9% and 57%, specificities of 98% and 75%, positive predictive values of 33% and 28%, and negative predictive values of 89% and 91% for predicting early cardiac events. A rate blood pressure product less than 12,000 with DSE was associated with an increased risk for postoperative atrial fibrillation. Correspondence analysis identified a statistical association between nonalcoholic steatohepatitis/cryptogenic cirrhosis and postoperative myocardial ischemia. Logistic regression identified 3 risk factors for postoperative acute coronary syndrome: age, history of coronary artery disease, and pretransplant requirement for vasopressors. Multivariable analysis showed statistical associations of the Model for End-Stage Liver Disease score and the development of acute kidney injury as risk factors for overall cardiac-related mortality. These findings may help in identifying high-risk patients and may lead to the development of better cardiac tests.

Evaluation of solid organ transplant candidates for coronary artery disease

Solid organ transplantation has increased in frequency in the United States, having evolved from an area of experimentation into accepted therapy for end-organ failure. As organ transplantation has become more common, the average age of transplant recipients has increased, thus increasing the potential for multiple comorbidities including coronary artery disease (CAD). CAD has been shown to be a major cause of morbidity and mortality in kidney, lung and liver transplant recipients. Identification of CAD in solid organ transplant candidates allows for stratification of short- and long-term risk, ensuring proper use of valuable allograft resources while guiding further patient management. Assessment of asymptomatic transplant candidates for CAD is difficult. Many patients undergo stress echocardiography or nuclear imaging, which have demonstrated inconsistent rates of sensitivity and specificity for the detection of CAD in these patient populations. Cardiac computed tomography is a potential tool for detecting CAD in these populations, but has questionable utility at this time. Coronary angiography has an important role in detecting CAD in high-risk transplant candidates, affecting their long-term management and risk.

Role of cardiac catheterization and percutaneous coronary intervention in the preoperative assessment and management of patients before orthotopic liver transplantation

Limited data regarding the optimal risk assessment strategy for evaluating candidates for orthotopic liver transplantation (OLT) exist. Our center has adopted a policy of performing cardiac catheterization (CATH) in patients with predefined risk factors, and this is followed by percutaneous coronary intervention (PCI) when it is indicated, even in the presence of negative stress test findings. The aim of this single-center, retrospective study of all patients who underwent OLT between 2000 and 2010 was to assess the effect of our policy on cardiovascular (CV) complications and survival rates after OLT. Data, including 1-year all-cause and CV mortality, postoperative myocardial infarctions (MIs), and frequencies of CATH and PCI, were abstracted. The study was divided into 3 subperiods to reflect the changes in policy over this period: (A) 2000-2004, (B) 2005-2008, and (C) 2009-2010. One thousand two hundred twenty-one patients underwent OLT between 2000 and 2010. The rate of catheterization increased during the 3 time periods (P < 0.001), as did the rate of PCI (P < 0.05). All-cause mortality decreased over the periods (P < 0.001), as did the MI rate (P < 0.001). Thirty-five of the 57 patients requiring PCI had normal stress tests. The mortality rate associated with postoperative MIs was significantly higher than the overall all-cause mortality rate. In conclusion, a significant improvement in the overall survival rate over the 3 analyzed time periods was noted. Increases in the frequencies of CATH and PCI corresponded to significant reductions in postoperative MIs and 1-year all-cause mortality rates. The increased use of CATH and PCI was associated with reduced overall all-cause mortality through reductions in the incidence of both fatal and nonfatal MIs. Further analyses of the role of stress testing and CATH in evaluating and treating patients before OLT are required to optimize this process.

Safety of transradial cardiac catheterization in patients with end-stage liver disease

BACKGROUND

Transradial access may be advantageous for patients with end-stage liver disease (ESLD) who need to undergo left heart catheterization (LHC). We aimed to assess the safety of transradial cardiac catheterization in patients listed for orthotopic liver transplantation.

METHODS

This is a retrospective analysis of consecutive adult patients with the diagnosis of ESLD, who underwent LHC via transradial access as part of a pre-operative liver transplantation evaluation. All the patients also underwent right heart catheterization (RHC) via brachial or femoral vein. The primary outcome measure was procedure-related major bleeding. Secondary outcomes included access site minor bleeding, in-hospital mortality, radial access failure, and acute kidney injury.

RESULTS

A total of 82 consecutive patients with ESLD, who underwent LHC via transradial access, were enrolled in the study. All patients also underwent RHC (n = 45 via brachial and n = 37 via femoral vein). The median age was 59 (54, 67) years old, and 58% were male. History of coronary artery disease or heart failure was present in 17% of patients. The median MELD score was 19 (13, 24.5), baseline hemoglobin was 10.5 mg/dL (9.4, 11.8), INR was 1.4 (1.2, 1.8) and platelets were 74,000 (53,000, 117,000)/mm(3) . The most common etiology of liver failure was viral hepatitis (51%), followed by alcoholic cirrhosis (24%) and non-alcoholic steatohepatitis (21%). Angiographically significant coronary artery disease was present in 17 (21%) patients. Major bleeding and acute kidney injury each occurred in two patients (2.4%). There were no instances of vascular complications. There were no deaths attributable to complications from cardiac catheterization.

CONCLUSION

Upper extremity right and left heart catheterization appears to be a safe method to evaluate coronary anatomy and hemodynamics in a severely ill population of patients with ESLD awaiting transplant.

Echocardiography in liver transplant candidates

Involvement of the cardiovascular system in patients with end-stage liver disease (ESLD) is well recognized and may be seen in several scenarios in adult liver transplantation (LT) candidates. The hemodynamic effects of ESLD may result in apparent heart disease, or in some instances may mask cardiac disease. Alternatively, cardiac disease can occasionally be the underlying etiology of ESLD. LT imposes significant hemodynamic stresses, with cardiovascular complications accounting for considerable perioperative mortality and morbidity. Pre-operative assessment of the cardiac status of LT candidates is thus critically important for risk stratification and management. Cardiac imaging plays an integral role in the assessment of LT candidates. In this review, we discuss the role of cardiac imaging, including transthoracic echocardiography with Doppler and contrast enhancement, noninvasive functional assessment for routine pre-operative assessment of coronary artery disease, and transesophageal echocardiography in select cases to aid in intra-operative fluid management and monitoring in LT candidates.

Anesthesia for Liver Transplantation

Orthotopic liver transplantation is the only definitive treatment for end-stage liver disease. More than 6000 procedures are performed in the United States annually with excellent survival rates. The shortage of donor organs leads to continued interest in techniques to enlarge the potential donor pool. Patients presenting for liver transplant suffer from important cardiovascular, respiratory, renal, neurological, and gastroenterological comorbidity. In the Western world, liver failure is increasingly caused by steatohepatitis, and transplant candidates are thus becoming older and more comorbid. The role of the transplant anesthesiologist is highly important in the preoperative assessment, intraoperative management, and postoperative care of these complex and sick patients. Appropriate investigation and management of comorbidities such as coronary artery disease and portopulmonary hypertension is controversial and differs between programs. The transplant procedure is a major surgery, and although massive transfusion is no longer commonplace, there is potential for significant hemodynamic instability, coagulopathy, and metabolic disturbance. Liver transplant surgery can be divided into the preanhepatic phase, the anhepatic phase, and the reperfusion phase, with important anesthetic considerations at each point.  An understanding of the surgical techniques used for vascular exclusion of the liver and the role of venovenous bypass is crucial for the anesthesiologist. Recent trends in perioperative care include the use of antifibrinolytic drugs and point-of-care coagulation tests, intraoperative renal replacement therapy, and “fast-track” extubation and postoperative care. Care of patients with fulminant hepatic failure or those receiving split-liver grafts requires special consideration.

Liver transplantation outcome in patients with angiographically proven coronary artery disease: a multi-institutional study

Over the last decade the age of liver transplant (LT) recipients and the likelihood of coronary artery disease (CAD) in this population have increased. There are no multicenter studies that have examined the impact of CAD on LT outcomes. In this historical cohort study, we identified adult LT recipients who underwent angiography prior to transplantation at seven institutions over a 12-year period. For each patient we recorded demographic data, recipient and donor risk factors, duration of follow-up, the presence of angiographically proven obstructive CAD (≥50% stenosis) and post-LT survival. Obstructive CAD was present in 151 of 630 patients, the CAD(+) group. Nonobstructive CAD was found in 479 patients, the CAD(-) group. Patient survival was similar for the CAD(+) group (adjusted HR 1.13, CI = [0.79, 1.62], p = 0.493) compared to the CAD(-) group. The CAD(+) patients were further stratified into severe (CADsev, >70% stenosis, n = 96), and moderate CAD (CADmod, 50-70% stenosis, n = 55) groups. Survival for the CADsev (adjusted HR = 1.26, CI = [0.83, 1.91], p = 0.277) and CADmod (adjusted HR = 0.93, CI = [0.52, 1.66], p = 0.797) groups were similar to the CAD(-) group. We conclude that when current CAD treatment strategies are employed prior to transplant, post-LT survival is not significantly different between patients with and without obstructive CAD.

Trekking new ground: overcoming medical and social impediments for extended criteria liver transplant recipients

1. There is an increasing recognition that previously marginal candidates for liver transplantation can receive therapies that allow transplant to take place. 2. Coronary artery disease is an increasing co-morbidity in liver transplant candidates. 3. Physio-social issues require written guidelines and patient advocates. 4. Methadone maintenance therapy per se is not a contra-indication to liver transplantation.

Anesthetic Considerations in Hepatectomies under Hepatic Vascular Control

Background. Hazards of liver surgery have been attenuated by the evolution in methods of hepatic vascular control and the anesthetic management. In this paper, the anesthetic considerations during hepatic vascular occlusion techniques were reviewed. Methods. A Medline literature search using the terms "anesthetic," "anesthesia," "liver," "hepatectomy," "inflow," "outflow occlusion," "Pringle," "hemodynamic," "air embolism," "blood loss," "transfusion," "ischemia-reperfusion," "preconditioning," was performed. Results. Task-orientated anesthetic management, according to the performed method of hepatic vascular occlusion, ameliorates the surgical outcome and improves the morbidity and mortality rates, following liver surgery. Conclusions. Hepatic vascular occlusion techniques share common anesthetic considerations in terms of preoperative assessment, monitoring, induction, and maintenance of anesthesia. On the other hand, the hemodynamic management, the prevention of vascular air embolism, blood transfusion, and liver injury are plausible when the anesthetic plan is scheduled according to the method of hepatic vascular occlusion performed.

Update in liver transplantation

PURPOSE OF REVIEW

Successful transplant outcomes require optimal patient selection and timing. This review will update clinicians with current status and challenges in liver transplantation. Currently, the major limitation facing liver transplant centers is the shortage of organs. The limited availability of organs has led to long waiting periods for liver transplantation and consequently many patients become seriously ill or die while on the waiting list.

RECENT FINDINGS

This has major implications in the selection of patients, as well as the timing of transplant, for optimal use of these scarce organs. Indications and contraindications have changed slightly over the years and will be reviewed in this article.

SUMMARY

Timing for transplantation has changed more dramatically in the recent years because major changes to organ allocation systems have been undertaken to provide clinicians with a better way to prioritize patients for liver transplant.

Coronary artery stents and antiplatelet therapy in patients with cirrhosis

GOALS

To describe our experience with coronary artery stenting and antiplatelet therapy in cirrhotic patients and compare rates of bleeding with a control group.

BACKGROUND

Although there are data on cardiac evaluation and perioperative cardiac risk in cirrhotic patients, there is a paucity of information on outcomes in cirrhotic patients with coronary artery stents. Cirrhotic patients may be at increased risk for complications, including gastrointestinal bleeding as a result of antiplatelet therapy prescribed after stenting.

STUDY

We performed a retrospective study of complications in cirrhotics that received a coronary artery stent followed by clopidogrel and aspirin prescribed to prevent stent occlusion. Cirrhotics with stents were compared with an age and sex-matched control group with cirrhosis without stents and not on aspirin.

RESULTS

Among 423 cirrhotic patients who underwent liver transplant evaluation, 16 patients (3.8%) received a stent of which 9 underwent liver transplant. Two patients with varices (12.5%) in the stent group had fatal variceal bleeding and 2 controls (6.3%) had nonfatal variceal bleeding during follow-up while on antiplatelet therapy (P=0.86). There were no significant differences in transfusion requirements between the 9 liver transplant recipients with stents compared with the control group, P=0.69 for packed red blood cells.

CONCLUSIONS

In our experience, it is safe for cirrhotic patients without varices to receive a coronary artery stent and for cirrhotic patients with coronary artery stents to be considered for liver transplantation. Larger prospective studies are needed to confirm these results and evaluate the risk of bleeding in cirrhotics with varices who receive coronary artery stents and antiplatelet therapy.