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

Cardiovascular disease assessment and management in liver transplantation

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

CACS, CCTA and mCAD-LT score in the pre-transplant assessment of coronary artery disease and the prediction of post-transplant cardiovascular events

BACKGROUND

The optimal cardiovascular assessment of liver transplant (LT) candidates is unclear. We aimed to evaluate the performance of CT-based coronary tests (coronary artery calcium score [CACS] and coronary CT angiography [CCTA]) and a modification of the CAD-LT score (mCAD-LT, excluding family history of CAD) to diagnose significant coronary artery disease (CAD) before LT and predict the incidence of post-LT cardiovascular events (CVE).

METHODS

We retrospectively analysed a single-centre cohort of LT candidates who underwent non-invasive tests; invasive coronary angiography (ICA) was performed depending on the results of non-invasive tests. mCAD-LT was calculated in all patients.

RESULTS

Six-hundred-and-thirty-four LT candidates were assessed and 351 of them underwent LT. CACS, CCTA and ICA were performed in 245, 123 and 120 LT candidates, respectively. Significant CAD was found in 30% of patients undergoing ICA. The AUROCs of mCAD-LT (.722) and CCTA (.654) were significantly higher than that of CACS (.502) to predict the presence of significant CAD. Specificity of the tests ranged between 31% for CCTA and 53% for CACS. Among patients who underwent LT, CACS ≥ 400 and mCAD-LT were independently associated with the incidence of CVE; in patients who underwent CCTA before LT, significant CAD at CCTA also predicted post-LT CVE.

CONCLUSION

In this cohort, mCAD-LT score and CT-based tests detect the presence of significant CAD in LT candidates, although they tend to overestimate it. Both mCAD-LT score and CT-based tests classify LT recipients according to their risk of post-LT CVE and can be used to improve post-LT risk mitigation.

Management of the liver transplant candidate with high cardiac risk: Multidisciplinary best practices and recommendations

In a setting characterized by a growing prevalence of patients with alcohol-associated and metabolic dysfunction-associated steatotic liver diseases, coupled with an aging patient demographic, the incidence of cardiac comorbidities in liver transplant candidates is on the rise. These comorbidities not only pose barriers to transplant eligibility but also impact the intraoperative course and affect posttransplant outcomes. As such, there is a significant need to optimize the clinical management of these cardiac comorbidities. However, there is a scarcity of evidence regarding the best practices for managing cardiac comorbidities such as coronary and valvular heart diseases, arrhythmia, and cardiomyopathy in this population, both before and during transplant surgery. These conditions necessitate a coordinated and multidisciplinary approach to care. In this manuscript, we conduct a comprehensive review of the most recent evidence pertaining to the preoperative and intraoperative management of these cardiac comorbidities in liver transplant candidates. Our aim is to provide recommendations that improve and standardize their clinical care.

Unlocking the Potential of Immunotherapy in Cardiovascular Disease: A Comprehensive Review of Applications and Future Directions

Immunotherapy has emerged as a pioneering therapeutic approach that harnesses the immune system's abilities to combat diseases, particularly in the field of oncology where it has led to significant advancements. However, despite its significant impact in the field of oncology, the potential of immunotherapy in the context of cardiovascular disease (CVD) has not been thoroughly investigated. The purpose of this narrative review is to address the existing knowledge and potential uses of immunotherapy in the field of cardiovascular disease (CVD), with the intention of filling the existing gap in understanding. Furthermore, the review thoroughly examines the future prospects of this swiftly advancing field, providing insights into the aspects that necessitate further investigation and addressing the forthcoming challenges. The review is organized into four distinct sections to enhance comprehension. The first section introduces immunotherapy, presenting the fundamental concepts and principles. The second section explores the immunomodulatory mechanisms in cardiovascular disease (CVD), with a specific focus on the intricate interplay between the immune system and the development of cardiovascular pathogenesis. The utilization of immunotherapy in specific cardiovascular conditions will be examined, investigating the application of immunotherapy in the context of different cardiovascular diseases. The future prospects and challenges in immunotherapy for cardiovascular diseases will be discussed, highlighting the potential areas for future research and addressing the barriers that must be overcome to effectively implement immunotherapeutic interventions in the management of cardiovascular diseases.

Results of a multidisciplinary strategy to improve the management of cardiovascular risk factors after liver transplantation

Although liver transplantation (LT) recipients are at high cardiovascular risk (CVR), the management of CVR factors (CVRF) after LT is far from optimal and needs to be improved. For this reason, we developed a multidisciplinary protocol to standardize the identification, risk stratification, management, and targets of therapy of CVRF during the first post-LT year. The grade of identification and control of CVRF 12 months after LT in the postintervention cohort (LT January 2018-January 2020, n = 150) were compared with a control cohort who underwent LT between July 2015 and December 2016 (n = 100). Before LT, the prevalence of metabolic-associated fatty liver disease as the indication of LT and the presence of obesity were significantly higher in the postintervention cohort, whereas the prevalence of other CVRF and renal dysfunction tended to be higher. Cyclosporine A was used less frequently in the postintervention cohort, whereas everolimus tended to increase. At 12 months after LT, the proportion of patients with measured blood pressure (88% vs. 56%), glycosilated hemoglobin (HbA1c; 96% vs. 72%), and high-density lipoprotein/low-density lipoprotein cholesterol (67% vs. 33%) was higher in the postintervention than in the control cohort (all p < 0.001). Blood pressure (64% vs. 36%, p = 0.02) and HbA1c (85% vs. 70%, p = 0.1) were within target in more individuals with hypertension and diabetes mellitus, respectively, in the postintervention cohort. Median total cholesterol levels were lower in the postintervention (184 mg/dl; interquartile range [IQR], 160-210 mg/dl) than in the control cohort (212 mg/dl; IQR, 186-240 mg/dl; p = 0.02). At 2 years after LT, the incidence of cardiovascular events was 14% in the control cohort and 6% in the postintervention cohort (p = 0.063). In conclusion, a multidisciplinary, multiprofessional strategy can achieve a higher grade of assessment and management of post-LT CVR despite a worsening metabolic profile of LT recipients.

Cirrhotic cardiomyopathy: Appraisal of the original and revised criteria in predicting posttransplant cardiac outcomes

Cardiovascular disease (CVD) significantly contributes to morbidity and mortality after liver transplantation (LT). Cirrhotic cardiomyopathy (CCM) is a risk factor for CVD after transplant. CCM criteria were originally introduced in 2005 with a revision proposed in 2020 reflecting echocardiographic technology advancements. This study assesses the two criteria sets in predicting major adverse cardiac events (MACE) after transplant. This single-center retrospective study reviewed adult LT recipients between January 1, 2009, and December 31, 2018. Patients with insufficient pre-LT echocardiographic data, prior ischemic heart disease, portopulmonary hypertension, or longitudinal care elsewhere were excluded. The primary composite outcome was MACE (arrhythmia, heart failure, cardiac arrest, and/or cardiac death) after transplant. Of 1165 patients, 210 met the eligibility criteria. CCM was present in 162 patients (77%) per the original criteria and 64 patients (30%) per the revised criteria. There were 44 MACE and 31 deaths in the study period. Of the deaths, 38.7% occurred secondary to CVD. CCM defined by the original criteria was not associated with MACE after LT (p = 0.21), but the revised definition was significantly associated with MACE (hazard ratio [HR], 1.93; 95% confidence interval, 1.05-3.56; p = 0.04) on multivariable analysis. Echocardiographic variable analysis demonstrated low septal e' as the most predictive variable for MACE after LT (HR, 3.45; p < 0.001). CCM, only when defined by the revised criteria, was associated with increased risk for MACE after LT, validating the recently revised CCM definition. Abnormal septal e', reflecting impaired relaxation, appears to be the most predictive echocardiographic criterion for MACE after LT.

Gender specific survival rates after deceased donor liver transplantation: A retrospective cohort

Background

According to the literature, there are sex allocation inequalities in liver transplantation (LT). Sex disparities in outcomes after LT have been debated. This study aimed to evaluate sex-specific outcomes after LT, specifically short-term mortality and long-term survival rates.

Methods

A retrospective cohort of the entire LT series from to 2010–2019 in a single center in which the inclusion criteria were adults ≥18 YO age who underwent primary deceased donor LT. Mortality rate was evaluated within 30 days and 6 months. Survival rate was evaluated at 1,3 and 5 years of age.

Results

A total of 240 primary and deceased donor LTs (153 men and 87 women) were included. Mean age 55.2Y men and 51.6Y women (p = 0.02). Hepatocellular carcinoma (HCC) was the direct indication in 32.7% of the men and only 17.4% of the women. The leading primary liver morbidities were viral hepatitis (B, C, and D) in 38.3% (N = 92) and nonalcoholic steatohepatitis (NASH) in 20.8% (N = 50) of patients. Thirty-day mortality was 14%, which was significantly higher in men (18%) than in women (8%). Survival rates after 5 years were 64.9% and 78.3%, respectively. Multivariate analysis through logistic regression that included age, direct indication, MELD, and primary liver morbidity revealed statistically significant female to male Odds-Ratio of 0.4 in 30 days, 6 m mortality and a statistically significant higher long-term survival.

Conclusions

Our observations revealed better female outcomes, namely, lower short-term mortality and higher long-term survival. Given the consistency after stratification and given the multivariate analysis, this is unlikely to be attributable to confounders. Such findings suggesting consistently better female outcomes have not been previously reported; hence, multi center study is encouraged.

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Gender outcome disparities after liver transplantation (LT) is debated.

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We present retrospective cohort of 240 consecutive LT in a single center.

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We found significant lower short-term mortality rates and better long-term survival in women.

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The outcome disparity was consistent in most underlying liver diseases.

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We had not identified factors that may confound sex outcome disparity.

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

INTRODUCTION

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Limited tumour progression beyond Milan criteria while on the waiting list does not result in unacceptable impairment of survival

BACKGROUND & AIMS

Defining optimum management of patients progressing beyond Milan criteria on the waiting list is a controversial topic. Our aim was to determine whether the policy of allowing a limited progression beyond enlistment criteria permits acceptable post-transplant outcomes in terms of survival and recurrence.

METHODS

Patients with hepatocellular carcinoma included on the waiting list for orthotopic liver transplantation (OLT) between January 1989 and December 2016 were analysed. Tumour features were assessed at inclusion on the waiting list, before OLT and at explant pathology. Patients were retained on the waiting list despite exceeding enlistment criteria if not presenting with macrovascular invasion, extrahepatic spread or cancer-related symptoms.

RESULTS

A total of 495 patients constituted the target population. Comparison between the Milan-in (n = 434) and Milan-out (n = 61) groups showed statistically significant differences in: largest tumour size; BCLC stage; patients treated before OLT; alpha-fetoprotein, and time on the waiting list. Milan-out patients showed a significantly higher number of poorly differentiated nodules, satellitosis and microscopic vascular invasion. The 1-, 3-, 5- and 10-year survival rate was 89.6%, 82.5%, 75%, and 55.5%, vs. 83.6%, 70.5%, 65.5%, and 53.9% for Milan-in/Milan-out patients, respectively. Recurrence rates at 1, 3, 5 and 10 years were 1.2%, 3.3%, 5.5%, and 10.8% vs. 7.1% 14.5%, 23%, and 23% for Milan-in and Milan-out patients, respectively (p <0.01).

CONCLUSION

This study shows that although limited tumour progression without reaching major adverse predictors (vascular invasion, extrahepatic spread, cancer symptoms) has an expected impact on recurrence rate, overall survival remains above the minimum proposed benchmark of 65% at 5 years. The clinically relevant increase in tumour recurrence must be considered when analysing the benefit of this approach in the face of limited organ supply.

LAY SUMMARY

When considering orthotopic liver transplantation for patients with hepatocellular carcinoma, optimum results are achieved when transplanting patients within the Milan criteria. However, the most appropriate strategy for patients who progress beyond these criteria while on the waiting list is still unclear. Herein, we show that transplantation is associated with acceptable overall survival in select patients who progress beyond the Milan criteria, although recurrence rates were notably higher. Therefore, the assessment of transplantation viability in these patients must consider the availability of organs and the impact on other patient categories.

Long-term mortality risk stratification of liver transplant recipients: real-time application of deep learning algorithms on longitudinal data

BACKGROUND

Survival of liver transplant recipients beyond 1 year since transplantation is compromised by an increased risk of cancer, cardiovascular events, infection, and graft failure. Few clinical tools are available to identify patients at risk of these complications, which would flag them for screening tests and potentially life-saving interventions. In this retrospective analysis, we aimed to assess the ability of deep learning algorithms of longitudinal data from two prospective cohorts to predict complications resulting in death after liver transplantation over multiple timeframes, compared with logistic regression models.

METHODS

In this machine learning analysis, model development was done on a set of 42 146 liver transplant recipients (mean age 48·6 years [SD 17·3]; 17 196 [40·8%] women) from the Scientific Registry of Transplant Recipients (SRTR) in the USA. Transferability of the model was further evaluated by fine-tuning on a dataset from the University Health Network (UHN) in Canada (n=3269; mean age 52·5 years [11·1]; 1079 [33·0%] women). The primary outcome was cause of death, as recorded in the databases, due to cardiovascular causes, infection, graft failure, or cancer, within 1 year and 5 years of each follow-up examination after transplantation. We compared the performance of four deep learning models against logistic regression, assessing performance using the area under the receiver operating characteristic curve (AUROC).

FINDINGS

In both datasets, deep learning models outperformed logistic regression, with the Transformer model achieving the highest AUROCs in both datasets (p<0·0001). The AUROC for the Transformer model across all outcomes in the SRTR dataset was 0·804 (99% CI 0·795-0·854) for 1-year predictions and 0·733 (0·729-0·769) for 5-year predictions. In the UHN dataset, the AUROC for the top-performing deep learning model was 0·807 (0·795-0·842) for 1-year predictions and 0·722 (0·705-0·764) for 5-year predictions. AUROCs ranged from 0·695 (0·680-0·713) for prediction of death from infection within 5 years to 0·859 (0·847-0·871) for prediction of death by graft failure within 1 year.

INTERPRETATION

Deep learning algorithms can incorporate longitudinal information to continuously predict long-term outcomes after liver transplantation, outperforming logistic regression models. Physicians could use these algorithms at routine follow-up visits to identify liver transplant recipients at risk for adverse outcomes and prevent these complications by modifying management based on ranked features.

FUNDING

Canadian Donation and Transplant Research Program, CIFAR AI Chairs Program.

Identifying Modifiable Predictors of Long-Term Survival in Liver Transplant Recipients With Diabetes Mellitus Using Machine Learning

Diabetes mellitus (DM) significantly impacts long-term survival after liver transplantation (LT). We identified survival factors for LT recipients who had DM to inform preventive care using machine-learning analysis. We analyzed risk factors for mortality in patients from across the United States using the Scientific Registry of Transplant Recipients (SRTR). Patients had undergone LT from 1987 to 2019, with a follow-up of 6.47 years (standard deviation [SD] 5.95). Findings were validated on a cohort from the University Health Network (UHN) from 1989 to 2014 (follow-up 8.15 years [SD 5.67]). Analysis was conducted with Cox proportional hazards and gradient boosting survival. The training set included 84.67% SRTR data (n = 15,289 patients), and the test set included 15.33% SRTR patients (n = 2769) and data from UHN patients (n = 1290). We included 18,058 adults (12,108 [67.05%] men, average age 54.21 years [SD 9.98]) from the SRTR who had undergone LT and had complete data for investigated features. A total of 4634 patients had preexisting DM, and 3158 had post-LT DM. The UHN data consisted of 1290 LT recipients (910 [70.5%] men, average age 54.0 years [SD 10.4]). Increased serum creatinine and hypertension significantly impacted mortality with preexisting DM 1.36 (95% confidence interval [CI], 1.21-1.54) and 1.20 (95% CI, 1.06-1.35) times, respectively. Sirolimus use increased mortality 1.36 times (95% CI, 1.18-1.58) in nondiabetics and 1.33 times (95% CI, 1.09-1.63) in patients with preexisting DM. A similar effect was found in post-LT DM, although it was not statistically significant (1.38 times; 95% CI, 1.07-1.77; P = 0.07). Survival predictors generally achieved a 0.60 to 0.70 area under the receiver operating characteristic for 5-year mortality. LT recipients who have DM have a higher mortality risk than those without DM. Hypertension, decreased renal function, and sirolimus for maintenance immunosuppression compound this mortality risk. These predisposing factors must be intensively treated and modified to optimize long-term survival after transplant.