The impact of coronary artery disease on outcomes after liver transplantation

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Optimizing cardiac status in the preliver transplant candidate

PURPOSE OF REVIEW

Liver transplant is a widely accepted therapy for end-stage liver disease. With advances in our understanding of transplant, candidates are increasingly older with more cardiac comorbidities. Cardiovascular disease also represents a leading cause of morbidity and mortality posttransplant.

RECENT FINDINGS

Preoperative cardiac risk stratification and treatment may improve short-term and long-term outcomes after liver transplant. Importantly, the appropriate frequency of surveillance has not been defined. Optimal timing of cardiac intervention in end-stage liver disease is likewise uncertain.

SUMMARY

The approach to risk stratification of cardiovascular disease in end-stage liver disease is outlined, incorporating the AHA/ACC scientific statement on evaluation of cardiac disease in transplant candidates and more recent expert consensus documents. Further study is needed to clarify the ideal timing and approach for cardiovascular interventions.

Liver Transplantation: Contraindication and Ineligibility

Liver transplantation (LT) is a life-saving therapeutic modality for patients with various advanced liver diseases. It is crucial to identify that the patient's illness is sufficiently advanced and unlikely to improve with medical management to justify the need for transplantation. At the same time, it is crucial to identify patients with comorbidities and far advanced disease that would result in an unacceptable outcome after LT. Specific care also is required before deciding on LT in the elderly, acute on chronic liver disease, patients with comorbidities, and hepatocellular carcinoma. Transplantation needs to be timed appropriately to avoid unnecessary LT and ensure that the decision is not left too late to avoid losing the patient without a transplant. Also, important is the decision as to when not to transplant. The current review explores some of these issues of contraindications and ineligibility for LT.

Predictive Value of Fatty Liver Index for Long-Term Cardiovascular Events in Patients Receiving Liver Transplantation: The COLT Study

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is the leading cause of early mortality in orthotopic liver transplantation (OLT) patients. The fatty liver index (FLI) is strongly associated with carotid and coronary atherosclerosis, as well as cardiovascular mortality, surpassing traditional risk factors. Given the lack of data on FLI as a predictor of cardiovascular events in OLT recipients, we conducted a retrospective study to examine this topic.

METHODS AND RESULTS

We performed a multicenter retrospective analysis of adult OLT recipients who had regular follow-up visits every three to six months (or more frequently if necessary) from January 1995 to December 2020. The minimum follow-up period was two years post-intervention. Anamnestic, clinical, anthropometric and laboratory data were collected, and FLI was calculated for all patients.

CLINICAL TRIAL

gov registration ID NCT05895669. A total of 110 eligible patients (median age 57 years [IQR: 50-62], 72.7% male) were followed for a median duration of 92.3 months (IQR: 45.7-172.4) post-liver transplantation. During this period, 16 patients (14.5%) experienced at least one adverse cardiovascular event (including fatal and non-fatal myocardial infarction and stroke). Receiver Operating Characteristic (ROC) analysis identified a cut-off value of 66.0725 for predicting cardiovascular events after OLT, with 86.7% sensitivity and 63.7% specificity (68% vs. 31%; p = 0.001). Kaplan-Meier analysis showed that patients with FLI > 66 had significantly reduced cardiovascular event-free survival than those with FLI ≤ 66 (log-rank: 0.0008). Furthermore, multivariable Cox regression analysis demonstrated that FLI > 66 and pre-OLT smoking were independently associated with increased cardiovascular risk.

CONCLUSIONS

Our findings suggest that FLI > 66 and pre-OLT smoking predict cardiovascular risk in adult OLT recipients.

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.

Liver transplantation for non-alcoholic fatty liver disease: indications and post-transplant management

Non-alcoholic fatty liver disease (NAFLD) is currently the fastest growing indication to liver transplantation (LT) in Western Countries, both for end stage liver disease and hepatocellular carcinoma. NAFLD/non-alcoholic steatohepatitis (NASH) is often expression of a systemic metabolic syndrome; therefore, NAFLD/NASH patients require a multidisciplinary approach for a proper pre-surgical evaluation, which is important to achieve a post-transplant outcome comparable to that of other indications to LT. NAFLD/NASH patients are also at higher risk of post-transplant cardiovascular events, diabetes, dyslipidemia, obesity, renal impairment and recurrent NASH. Lifestyle modifications, included diet and physical activity, are key to improve survival and quality of life after transplantation. A tailored immunosuppressive regimen may be proposed in selected patients. Development of new drugs for the treatment of recurrent NASH is awaited.

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.

Outcomes of Liver Transplantation in Patients with Preexisting Coronary Artery Disease

BACKGROUND

Advances in surgical and medical technology over the years has made liver transplantation possible for older and higher risk patients. Despite rigorous preoperative cardiac testing, cardiovascular events remain a major cause of death after orthotopic liver transplantation (OLT). However, there are little data on the outcomes of OLT in patients with preexisting coronary artery disease (CAD). This study aimed to compare all-cause and cardiovascular mortality of patients with and without history of CAD undergoing OLT.

METHODS

Six hundred ninety-three adult patients with cirrhosis underwent liver transplantation between July 2013 and December 2018 (female n = 243, male n = 450; median age 59).

RESULTS

During the study period of 5 y (median follow-up, 24.1 mo), 92 of 693 patients (13.3%) died. All-cause mortality in the CAD group was significantly higher than in the non-CAD group (26.7% versus 9.6%; P <0.01). Cardiovascular events accounted for 52.5% of deaths (n = 21) in patients with CAD compared with 36.5% (n = 19) in non-CAD patients. At 6 mo, patients with combined nonalcoholic steatohepatitis (NASH)/CAD had significantly worse survival than those with CAD or NASH alone ( P <0.01). After 6 mo, patients with CAD alone had similar survival to those with combined NASH/CAD.

CONCLUSIONS

Patients with preexisting CAD before liver transplantation are at higher risk of death from any cause, specifically cardiovascular-related death. This risk increases with coexisting NASH. The presence of NASH and CAD at the time of liver transplant should prompt the initiation of aggressive risk factor modification for patients with CAD.

Temporary postoperative myocardial injury and long-term survival in liver transplant patients with coronary artery disease

Background: Coronary artery disease (CAD) is increasing worldwide due to the aging population and cardiometabolic syndrome. However, the extent of postoperative myocardial injury, the most common cause of death during the 30 days after noncardiac surgery, remains unclear with respect to liver transplant (LT) patients with CAD. We examined the link between post-LT high sensitivity cardiac troponin I (hs_cTnI) and long-term survival according to liver disease severity.Methods: Consecutive patients who underwent LT (n = 3,220) from 2010 to 2020 were evaluated retrospectively. CAD was defined as a history of coronary artery bypass surgery or percutaneous intervention, or previous myocardial infarction. Peak hs_cTnI levels within 30 days post-transplant were compared in patients with and without CAD. The primary endpoint was defined as an all-cause mortality at 12 years following LT. Secondary endpoints include peak hs_cTnI level within post-transplant 30 days and 30-day mortality. Survival analysis was performed using the Kaplan–Meier method.Results: CAD patients (n = 264, 8.2%) had higher peak hs_cTnI levels within 30 days post-LT than those without CAD (median [interquartile]: 0.068 [0.030–0.154] vs. 0.087 [0.037–0.203] ng/ml, respectively; P = 0.004); however, the mortality rate was comparable (14.7% vs. 14.8%, respectively, P = 0.999), at 12 years, and 1.9% vs. 1.1% (P = 0.522) at 30 days, respectively, at 30 days. Subgroup analysis with stratified liver disease severity identified a similar risk of long-term mortality.Conclusions: Although the peak hs_cTnI level within 30 days was higher in revascularized or treated CAD patients after LT compared those without CAD, long-term mortality rates at 12 years and 30-day mortality rate were comparable.

Five-year all-cause mortality in critically ill liver transplant patients with coronary artery disease: analysis of acute-on chronic liver failure

Background: Patients with acute-on-chronic liver failure (ACLF) are critically ill and have high waiting-list mortality. Although studies demonstrated that appropriately treated coronary artery disease (CAD) should not be regarded as a contraindication to liver transplant (LT), data regarding long-term outcomes in critically ill liver LT recipients are lacking. The aim of this study was to compare the rates of all-cause death at 5 years following LT in patients with ACLF with or without CAD.Methods: Between 2010 and 2020, we evaluated 921 consecutive LT patients (MELD score, 32 ± 9) and ACLF classified by CLIF-C ACLF score. Up to 5-year all-cause death according to the CAD status was examined. CAD was defined as a preoperative history of coronary artery bypass graft or a percutaneous intervention and old myocardial infarction. Kaplan-Meier survival analysis was used.Results: Up to 5 years, 212 (23.0%) of all ACLF patients (n = 921) in whom 17 (29.3%) of 58 CAD patients died. In patients with CAD (6.3%, 58/921), the Kaplan-Meier cumulative mortality rate at 5 years was numerically higher but was not statistically significant when compared with those without CAD (32.9% vs. 23.5%, log-rank, P = 0.25). In subgr oup analysis, there were comparable risks of cumulative mortalities at 5 years across the stratification of ACLF grade 1, 2, and 3 (log-rank P = 0.062, P = 0.72, and P = 0.999, respectively).Conclusions: All-cause mortality is high in patients with ACLF after LT but is not related to the presence of revascularized or treated CAD, across the stratification of ACLF grades.

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.

Introduction of a standardized protocol for cardiac risk assessment in candidates for liver transplant - A retrospective cohort analysis

INTRODUCTION

Recommendations on non-invasive imaging to assess pre-operative cardiac risk among liver transplant candidates vary amongst societal guidelines and individual institutional practices. In 2018, a standardized pre-transplant coronary evaluation protocol was established at Beth Israel Deaconess Medical Center, Boston MA, to ensure appropriate and consistent pre-operative testing was performed.

METHODS

All patients who underwent liver transplant evaluation between January 1st, 2016 and December 31st, 2019, were retrospectively analyzed and divided into three cohorts; before the introduction of the protocol (prior to 2018), initial protocol favoring invasive coronary angiography (ICA) (2018), and amended protocol favoring coronary computed tomography angiography (CCTA) (post-2018). We described clinical characteristics, candidacy for transplant, and cardiovascular complications during follow-up. As an unadjusted exploratory analysis, the Cochran-Armitage Exact Trend Test was used to examine univariate differences across time.

RESULTS

A total of 462 patients underwent liver transplant evaluation during the study period. Among these, 218 (47.2%) patients underwent stress test, 50 (10.8%) underwent CCTA, and 68 (14.8%) underwent ICA. Across the three time periods, there was an increase in the proportion of CCTAs performed (3%, 6.3%, and 26.3% respectively; p <0.001) and proportion of patients diagnosed with obstructive CAD using CCTA (0%, 30%, and 51.4% respectively; p = 0.04). There was no significant difference in post-transplant cardiac complications among patients evaluated before 2018, during 2018, and after 2018 (5.9% vs. 5.6 vs. 6.0%; p=1.0).

CONCLUSION

Our findings suggest it is reasonable to shift practice to a less invasive approach utilizing CCTA or nuclear stress testing when assessing liver transplant candidates at increased cardiovascular risk.

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

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

Cardiovascular risk stratification in the noncardiac solid organ transplant candidate

PURPOSE OF REVIEW

Solid organ transplantation (SOT) has become a widely accepted therapy for end-stage disease across the spectrum of thoracic and abdominal organs. With contemporary advances in medical and surgical therapies in transplantation, candidates for SOT are increasingly older with a larger burden of comorbidities, including cardiovascular disease (CVD). CVD, in particular, is a leading cause of morbidity and mortality in SOT candidates with end-stage disease of noncardiac organs [1].

RECENT FINDINGS

Identification of coronary artery disease (CAD), heart failure, and valvular disease are important in noncardiac SOT to ensure both appropriate peri-transplant management and equitable organ allocation. Although the American College of Cardiology (ACC) and the American Heart Association (AHA) have published guidelines and recommendations for the perioperative cardiovascular evaluation of patients undergoing noncardiac surgery, the implications of both symptomatic and asymptomatic CVD differ in patients with end-stage organ failure being considered for SOT when compared to the general population.

SUMMARY

Herein, we review the epidemiology, diagnosis, and evidence for the management of CVD in kidney and liver transplantation, combining current guidelines from the 2012 ACC/AHA scientific statement on cardiac disease evaluation in SOT with more contemporary evidenced-based algorithms.

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.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

Cardiac Risk Assessment in Liver Transplant Candidates: Current Controversies and Future Directions

In the changing landscape of liver transplantation (LT), we are now evaluating older and sicker patients with more cardiovascular comorbidities, and the spectrum of cardiovascular disease is uniquely physiologically impacted by end-stage liver disease. Cardiac complications are now the leading cause of morbidity and mortality in LT recipients, and the pretransplant risk is exacerbated immediately during the transplant operation and continues long term under the umbrella of immunosuppression. Accurate risk estimation of cardiac complications before LT is paramount to guide allocation of limited health care resources and to improve both short-term and long-term clinical outcomes for patients. Current screening and diagnostic testing are limited in their capacity to accurately identify early coronary disease and myocardial dysfunction in persons with end-stage liver disease physiology. Furthermore, a number of testing modalities have not been evaluated in patients with end-stage liver disease. As a result, there is wide variation in cardiac risk assessment practices across transplant centers. In this review, we propose a definition for defining cardiac events in LT, evaluate the current evidence for surgery-related, short-term and long-term cardiac risk assessment in LT candidates, propose an evidence-based testing algorithm, and highlight specific gaps in knowledge and current controversies, identifying areas for future research.

Utility of Framingham Score for Optimizing Preoperative Evaluation Among Patients Undergoing Liver Transplant Evaluation

BACKGROUND

Cardiac testing of candidates for liver transplant (LT) requires balancing risks and benefits of cardiac procedures. The goal of this study was to evaluate the utility of the Framingham score (FS) for optimizing preoperative risk stratification for coronary artery disease (CAD).

METHODS

In this single-center retrospective study of 615 adults undergoing LT evaluation from 2016 to 2019, data of preoperative evaluation, post-LT 1-year mortality, and post-LT cardiac events were reviewed. Patients >30 years of age with normal echocardiogram underwent FS calculation. Elevated FS (≥35%) patients were triaged to undergo angiogram for CAD evaluation; FS <35% patients underwent stress testing as initial CAD evaluation.

RESULTS

Of 615 patients referred for LT, 481 underwent cardiac testing. Ninety-five were excluded from the FS pathway because of age, abnormal baseline echocardiogram, or known CAD. Of the remaining 386 patients in the FS pathway, 342 had a low FS and 44 had a high FS. In patients with low FS, 90% underwent stress testing as initial test; 16% underwent invasive testing at some time. In those with elevated FS, 59% underwent invasive testing as initial test. Listing rate and posttransplant outcomes were similar between patients with low and high FS.

CONCLUSION

We demonstrated the feasibility of a simple algorithmic evaluation process using FS for optimizing pre-LT risk stratification for CAD. Although exceptions to the protocol occur, the proposed protocol allows for a streamlined approach by prioritizing testing based on cardiac risk. This approach may maximize diagnostic yield while limiting invasive procedures.

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.

Combined off pump coronary artery bypass graft and liver transplant

Background:

Prospective recipients of liver transplant (LT) have a high prevalence rate of coronary artery disease (CAD) requiring revascularization. In patients of Child Turcot Pugh Class B and C performing LT prior to cardiac revascularization on cardiopulmonary bypass leads to a high risk of major adverse cardiovascular events (MACE). Whereas, isolated cardiac surgery prior to LT has perioperative risk of coagulopathy, sepsis, and hepatic decompensation. We present four cases of end stage liver disease who underwent concomitant living donor liver transplant (LDLT) with off pump coronary artery bypass graft (OPCAB) in an effort to decrease the morbidity and mortality.

Methods:

The cases were performed in a tertiary care centre over two years. Four patients scheduled for LDLT, who were diagnosed with significant CAD, underwent single sitting OPCAB and LDLT. Cardiac surgery was performed first and once patient was stable, it was followed by LDLT. The morbidity parameters in terms of duration of intubation, blood transfusion, hospital stay, ICU stay, requirement of dialysis, atrial fibrillation and sepsis was compared with similar studies.

Results:

The blood transfusion requirement (median 8 units PRBC), incidence of atrial fibrillation (25%), sepsis (25%), and renal dysfunction (0%) was less than the combined surgery conducted on cardiopulmonary bypass. The rate of median intubation time, length of ICU stay, hospital stay, and one year mortality rate was comparable with other studies.

Conclusions:

Morbidity with combined OPCAB and LDLT is less than combined on pump coronary artery bypass surgery with LDLT. Combined CABG with LDLT may be performed with acceptable outcomes in CTP class B and C cirrhosis.

Enhanced recovery after low- and medium-risk liver transplantation. A single-center prospective observational cohort study

BACKGROUND & AIMS

Few studies have fully applied an enhanced recovery after surgery (ERAS) protocol to liver transplantation (LT). Our aim was to assess the effects of a comprehensive ERAS protocol in our cohort of low- and medium-risk LT patients.

METHODS

The ERAS protocol included pre-, intra-, and post-operative steps. During the five-year study period, 181 LT were performed in our institution. Two cohorts were identified: low risk patients (n = 101) had a laboratory model for end-stage liver disease (MELD) score of 20 points or less at the time of LT, received a liver from a donor after brain death, and had a balance of risk score of 9 points or less; medium-risk patients (n = 15) had identical characteristics except for a higher MELD score (21-30 points). In addition, we analyzed the remaining patients (n = 65) who were transplanted over the same study period separately using the ERAS protocol.

RESULTS

The low-risk cohort showed a low need for packed red blood cells transfusion (median: 0 units) and renal replacement therapy (1%), as well as a short length of stay both in the intensive care unit (13 h) and in the hospital (4 days); morbidity during one-year follow-up, and probability of surviving to one year (89.30%) and five years (76.99%) were in line with well-established reference data. Similar findings were observed in the medium-risk cohort.

CONCLUSIONS

This single-center prospective observational cohort study provides evidence that ERAS is feasible and safe for low- and medium-risk LT.

Intraoperative management and early post-operative outcomes of patients with coronary artery disease who underwent orthotopic liver transplantation

BACKGROUND

Coronary artery disease (CAD) is frequently observed in aging end-stage liver disease (ESLD) patients who require orthotopic liver transplantation (OLT). This situation is challenging for both the patients and the medical staff.

METHODS

We retrospectively studied the case records of 26 ESLD patients with CAD who underwent OLT with total clamping of the inferior vena cava between 2014 and 2018. We analyzed the details of the pre-operative evaluation, intraoperative anesthetic management and post-operative prognosis of these patients.

RESULTS

All patients tolerated the anhepatic stage well. Post-reperfusion syndrome (PRS) was observed in 13 patients (50%) and 2 of them were severe but corrected well. ST-segment depression was frequently observed during the anhepatic stage and reperfusion stage. No mortality due to cardiac-related events occurred among the patients during hospitalization. OLT with the modified piggyback technique could successfully be performed in ESLD patients with mild and moderate CAD.

CONCLUSIONS

A thorough evaluation and optimization of recipients, strict monitoring and optimized management of circulation, knowledge of the complicated changes during OLT procedures, and strategies to ameliorate post-reperfusion syndrome favorite the outcomes.

Mind the Gap: Statin Underutilization and Impact on Mortality in Liver Transplant Recipients

Liver transplant (LT) recipients are at a substantially increased risk of cardiovascular disease compared due to accelerated development and progression of hypertension, diabetes, obesity and dyslipidemia. As a result, cardiovascular disease is a leading cause of morbidity and mortality post-LT. This is in spite of aggressive pre-transplant evaluation for prevalent cardiovascular disease, in particular coronary artery disease (CAD), and exclusion of very high-risk patients from LT. However the commonest causes of early (<1 year) cardiovascular disease complications are arrhythmias and heart failure, whereas coronary heart disease complications typically manifest later after LT.

The relationship between coronary artery disease and cardiovascular events early after liver transplantation

BACKGROUND & AIMS

Cardiovascular complications are major contributors to mortality at liver transplantation (LT). However, the impact of coronary artery disease (CAD) on these complications is not well-understood as the literature is limited by non-invasive assessment of CAD, which is suboptimal in patients with cirrhosis. Thus, the current study evaluated cardiovascular events at LT stratified according to the presence and severity of CAD quantified on coronary angiography.

METHODS

All patients who had LT from January 2010 to January 2017 were evaluated (N = 348), but analysis was restricted to patients who had coronary angiography prior to LT (N = 283). Protocol coronary angiography was performed in all patients' ages >50 years, history of CAD, abnormal cardiac stress test or risk factors for CAD. The primary outcome was a cardiovascular composite outcome including myocardial infraction (MI), cardiac arrest, stroke, cardiac death, heart failure or arrhythmia occurring within 4 weeks after LT.

RESULTS

CAD was present in 92(32.5%) patients and 32(11.3%) had obstructive CAD. During the study period, 72(25.4%) patients met the primary cardiovascular outcome, the most common being arrhythmia (N = 59 or 20.8%). Non-ST elevation MI occurred in 11(3.9%) of patients. A total of 10 deaths (3.5%) occurred, of which 6(2.1%) were attributable to cardiac death. There was no evidence of a relationship between the presence and severity of CAD and composite cardiovascular events. In multiple regression modelling, only diabetes [OR 2.62, 95%CI (1.49, 4.64), P < 0.001] was associated with the likelihood of having a cardiovascular event.

CONCLUSION

Cardiovascular disease mortality is the most important contributor of early mortality after LT but is not related to the severity of CAD.

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.

A Holistic Clustering Methodology for Liver Transplantation Survival

BACKGROUND

Liver transplants account for a high number of procedures with major investments from all stakeholders involved; however, limited studies address liver transplant population heterogeneity pretransplant predictive of posttransplant survival.

OBJECTIVE

The aim of the study was to identify novel and meaningful patient clusters predictive of mortality that explains the heterogeneity of liver transplant population, taking a holistic approach.

METHODS

A retrospective cohort study of 344 adult patients who underwent liver transplantation between 2008 through 2014. Predictors were summarized severity scores for comorbidities and other suboptimal health states grouped into 11 body systems, the primary reason for transplantation, demographics/environmental factors, and Model for End Liver Disease score. Logistic regression was used to compute the severity scores, hierarchical clustering with weighted Euclidean distance for clustering, Lasso-penalized regression for characterizing the clusters, and Kaplan-Meier analysis to compare survival across the clusters.

RESULTS

Cluster 1 included patients with more severe circulatory problems. Cluster 2 represented older patients with more severe primary disease, whereas Cluster 3 contained healthiest patients. Clusters 4 and 5 represented patients with musculoskeletal (e.g., pain) and endocrine problems (e.g., malnutrition), respectively. There was a statistically significant difference for mortality between clusters (p < .001).

CONCLUSIONS

This study developed a novel methodology to address heterogeneous and high-dimensional liver transplant population characteristics in a single study predictive of survival. A holistic approach for data modeling and additional psychosocial risk factors has the potential to address holistically nursing challenges on liver transplant care and research.

Pretransplant coronary artery disease is a predictor for myocardial infarction and cardiac death after liver transplantation

BACKGROUND

Cardiovascular disease is a serious problem of liver transplant (LT) recipients because of increased cardiovascular risk due to immunosuppressive therapy, higher age, intraoperative risk and comorbidities (such as diabetes and nicotine abuse). Reported frequency of cardiovascular events after LT shows a high variability between different LT cohorts. Our aim was to analyze a cohort of LT recipients from a single center in Germany to evaluate frequency of the cardiovascular endpoints (CVE) myocardial infarction and/or cardiac death after LT and to investigate correlations of CVE post LT with pretransplant patient characteristics.

PATIENTS

In total, data from 352 LT patients were analyzed. Patients were identified from an administrative transplant database, and all data were retrieved from patients' charts and reports.

RESULTS

During the median follow-up of 4.0 (0-13) years, 10 cases of CVE were documented (six myocardial infarctions and four coronary deaths). The frequency of CVE did not differ according to classic cardiovascular risk factors such as body mass index (p=0.071), total cholesterol (p=0.533), hypertension (p=0.747), smoking (p=1.000) and pretransplant diabetes mellitus (p=0.146). In patients with pretransplant coronary heart disease (n=24; 6.8%) CVE were found more frequently (p=0.024).

CONCLUSION

In summary, we found a rate of 2.8% CVE after LT in a German transplant cohort. Pretransplant CHD was the only risk factor for CVE, but showed no significant impact on overall survival.

Coronary artery disease in decompensated patients undergoing liver transplantation evaluation

Coronary artery disease (CAD) is an important contributor to morbidity and mortality in patients undergoing liver transplantation (LT). However, the current literature is limited by sampling bias and nondefinitive assessment of CAD. The current study examines the prevalence of CAD via per protocol coronary angiography and its relationship to etiology of liver disease in patients undergoing liver transplantation evaluation (LTE). Data on 228 patients were prospectively collected who had coronary angiography as part of LTE between 2011 and 2014. Coronary angiography was done in all patients age ≥50 years or with CAD risk factors. CAD was defined as any coronary artery stenosis, whereas stenosis ≥ 70% in distribution of 1 or 3 major coronary arteries was considered as single- or triple-vessel disease. CAD was detected in 36.8% of patients, with the highest prevalence among nonalcoholic steatohepatitis (NASH) patients with cirrhosis (52.8%). Prevalence of single-vessel disease was higher among patients with NASH compared with hepatitis C virus (HCV) and alcoholic cirrhosis (15.1% versus 4.6% versus 6.6%; P = 0.02). Similarly, patients with NASH were more likely to have triple-vessel disease when compared with HCV and alcoholic cirrhosis (9.4% versus 0.9% versus 0%; P = 0.001). While adjusting for traditional risk factors for CAD, only NASH as etiology of liver disease remained significantly associated with CAD. Complications from diagnostic coronary angiography or percutaneous coronary intervention were low (2.6%). In conclusion, patients undergoing LTE have a high prevalence of CAD, which varies widely depending on etiology of liver cirrhosis. The procedural complications from coronary angiography are low. Liver Transplantation 24 333-342 2018 AASLD.

Pretransplant diabetes mellitus predicts worse outcomes of liver transplantation: evidence from meta-analysis

BACKGROUND

It has been demonstrated that the prognosis of liver transplantation (LT) is significantly influenced by pretransplant factors, such as diabetes mellitus (DM). However, inconsistent observations are obtained.

METHODS

We comprehensively searched PubMed, Embase and Web of Science to identify eligible cohort studies to evaluate the impact of preexisting DM on LT prognosis. Overall mortality and graft loss, as the most frequently observed parameters, were used to evaluate the outcomes of LT. Hazard ratios (HRs) with their 95% confidence intervals (CIs) were pooled to assess the effect of DM.

RESULTS

15,768 diabetic LT recipients and 60,176 non-diabetic LT recipients from 13 populations were included in this meta-analysis. Preexisting DM increased the risk for overall death of LT by 40% (95% CI 1.22-1.61), compared with DM-free patients. In addition, the risk for graft loss was also elevated by pretransplant DM (HR 1.28, 95% CI 1.07-1.54). Both analyses showed high heterogeneities (I ² = 85.2 and 93.2%, respectively) and their sources were not identified by meta-regression analyses. In terms of the additive effect of hepatitis C virus (HCV) infection on poor outcomes of diabetic LT recipients, stratified meta-analyses were conducted. It was demonstrated that HCV infection increased the risk for mortality by 73% (95% CI 1.64-1.83), relatively higher than non-HCV recipients (HR 1.32, 95% CI 1.25-1.39) and general population (HR 1.40, 95% CI 1.22-1.61).

CONCLUSION

Preexisting DM predicts worse patient and graft survivals of LT. Concomitant HCV infection would further deteriorate this unfavorable impact. Given the high heterogeneities and the insufficient evidences, more studies are still warranted to support these observations.

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.

Outcome of Liver Transplant Recipients With Revascularized Coronary Artery Disease: A Comparative Analysis With and Without Cardiovascular Risk Factors

BACKGROUND

Coronary artery disease (CAD) is a significant problem during evaluation for liver transplantation (LT). We aim to assess survival in LT recipients based on presence, severity, extent of CAD, and cardiac events within 90 days of LT.

METHODS

Eighty-seven LT recipients with history of pre-LT angiogram (December 2005 to December 2012) were compared with 2 control groups without prior angiogram, 72 LT recipients matched for cardiovascular risk factors (control group I), and 119 consecutive LT recipients without any CV risk factors (control group II). CAD was assessed by (1) vessel score (≥50% reduction in luminal diameter), and (2) Extent score (Reardon scoring system).

RESULTS

Of the 87 LT recipients (study group), 58 (66.7%) had none or less than 50% stenosis, 29 (33.3%) had obstructive CAD (≥50% stenosis), 7 (8%) with single-vessel disease, and 22 (25.3%) with multivessel disease. In the study group, irrespective of prerevascularization severity of CAD (P = 0.357), number of segments involved (0, 1-2, > 2 segments, P = 0.304) and extent of CAD based on Reardon score (0, 1-9, >10, P = 0.224), comparable posttransplant survival was noted. Overall, patient survival in the revascularized CAD group was comparable to angiogram group without obstructive CAD, and both control group I and control group II (P = 0.184, Log Rank). Postoperative cardiac events within 90 days of LT predicted poor survival in study group as well as control groups.

CONCLUSIONS

Severity or extent of CAD does not impact post-LT survival, if appropriately revascularized. Early postoperative cardiac events are associated with inferior survival in LT recipients, irrespective of underlying CAD.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.