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

Diagnostic accuracy and cost-effectiveness of the CAR-OLT score in predicting cardiac risk for liver transplantation

BACKGROUND

The CAR-OLT score predicts major adverse cardiovascular events 1 year after liver transplant (LT).

AIM

To test the hypothesis that the CAR-OLT score may help avoid cardiac stress tests in LT candidates.

METHODS

This retrospective single-center cohort study included all adult patients undergoing elective evaluation for first cadaveric donor orthotopic LT for liver cirrhosis with or without hepatocellular carcinoma at Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricerca e Cura a Carattere Scientifico in Rome, Italy. Cardiac contraindications for LT listing were defined after a center-specific cardiac workup, which included cardiac stress tests for most patients. The diagnostic accuracy of the CAR-OLT score was evaluated using the area under the receiver operating characteristic (AUROC) method.

RESULTS

A total of 342 LT candidates were evaluated between 2015 and 2019, with a moderate cardiovascular risk profile (37% diabetes, 34% hypertension, 22% obesity). Of these, 80 (23%) candidates underwent coronary angiography. Twenty-one (6%) candidates were given cardiac contraindications to LT listing, 48% of which were due to coronary artery disease. The CAR-OLT score predicted cardiac contraindications to LT listing with an AUROC of 0.81. The optimal cut-off for sensitivity was a CAR-OLT score ≤ 23, which showed a 99% negative predictive value for cardiac contraindications to LT listing. A total of 84 (25%) LT candidates with a CAR-OLT score ≤ 23 underwent 87 non-invasive cardiac tests and 13 coronary angiographies pre-listing, with estimated costs of approximately 48000€. The estimated savings per patient was €574.70 for the Italian National Health System.

CONCLUSION

A CAR-OLT score ≤ 23 can identify LT candidates who can be safely listed without the need for cardiac stress tests, providing time and cost savings. These findings require external validation.

Harnessing LRET in a rationally designed "sandwich" fluorescent probe for selective ClO- sensing

Upconversion nanoparticles (UCNPs), as a type of light-emitting nanomaterials excited by near-infrared (NIR) light, can circumvent interference from spontaneous fluorescence and scattered light emitted by biological molecules in sensing applications. Traditional homogeneous core-shell UCNPs struggle to locate the position of luminescent doped ions (such as Tm3+) within the NaYF4 matrix, only the luminescent ions close to the surface of the particles can be efficiently quenched, with a low bursting efficiency that produces a considerable background. The full effectiveness energy transfer exists only by sufficiently close proximity between donor and acceptor. Here, a distance dependence "sandwich" structured NIR fluorescent probe UCNPs-IR820 was developed based on luminescence resonance energy transfer (LRET), where the luminescent ions (Tm3+) were secured in a intermediate layer of a core-middle-shell UCNPs structure, which could be quenched by the specific distance external adjacent receptor molecule (cyanine NIR dye IR820). In the presence of the analyte ClO-, the double bonds of IR820 were oxidized, unable to absorb the luminescence from the core-middle-shell "sandwich" UCNPs, thus an "off to on" luminescence was restored. This core-middle-shell design could effectively enhance the effect of LRET-based detection strategies through physically meaningful distance constraints, providing new ideas for the design of future UCNP-based NIR fluorescent probes.

Perioperative Management During Liver Transplantation: A National Survey From the French Special Interest Group in "Liver Anesthesiology and Intensive Care"

BACKGROUND

Perioperative management practices in liver transplantation (LT) evolve very quickly. There are few specific recommendations, often based on a low level of evidence, resulting in wide heterogeneity of practices.

METHODS

We performed a survey in all 16 French centers in 2021 by focusing on center organization, preoperative cardiovascular assessment, antimicrobial prophylaxis, hemostasis management, intraoperative use of hemodynamic monitoring and renal replacement therapy, immunosuppression, and postoperative prevention of arterial complications and compared it with current recommendations.

RESULTS

The organization of perioperative LT care involved 1 single team throughout the perioperative LT process in 7 centers (43.7%). The coronary evaluation was systematic in one-third of the centers and guided by risk factors in the other centers. Antibiotic prophylaxis was strictly intraoperative in only 7 centers (44%). Antifungal prophylaxis targeting high-risk LT recipients was administered in 15 centers (93%). Intraoperative coagulation assessment was based on standard coagulation tests in 8 centers (50%), on viscoelastic assays in 4 centers (25%), and both methods in 4 centers (25%). Hemodynamic monitoring practices greatly varied between centers.Concerning immunosuppression, molecules and dosages were heterogeneous. Aspirin was systematically administered in one-third of cases (6 centers; 37.5%). Of the 21 recommendations tested, the concordance rate was 100% for 3 recommendations and <50% for 7 recommendations.

CONCLUSIONS

Our study precisely describes French practices regarding LT in perioperative care and highlights the paucity of data in this setting, leading to very weak recommendations that are poorly followed in LT centers.

New Scenarios in Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND AND AIMS

Despite liver transplantation (LT) is considered the optimal treatment for hepatocellular carcinoma (HCC), particularly in patients with impaired liver function, the shortage of donors has forced the application of very restrictive criteria for selecting ideal candidates for whom LT can offer the best outcome. With the evolving LT landscape due to the advent of direct-acting antivirals (DAAs) and the steady increase in donors, major efforts have been made to expand the transplant eligibility criteria for HCC. In addition, the emergence of immune checkpoint inhibitors (ICIs) for the treatment of HCC, with demonstrated efficacy in earlier stages, has revolutionized the therapeutic approach for these patients, and their integration in the setting of LT is challenging. Management of immunological compromise from ICIs, including the wash-out period before LT and post-LT immunosuppression adjustments, is crucial to balance the risk of graft rejection against HCC recurrence. Additionally, the effects of increased immunosuppression on non-hepatic complications must be understood to prevent them from becoming obstacles to long-term OS.

METHODS AND RESULTS

In this review, we will evaluate the emerging evidence and its implications for the future of LT in HCC. Addressing these novel challenges and opportunities, while integrating the current clinical evidence with predictive algorithms, would ensure a fair balance between individual patient needs and the overall population benefit in the LT system.

Mineralocorticoid receptor blockage in kidney transplantation: too much of a good thing or not?

Although, kidney transplantation (KT) is the best treatment option for patients with end-stage kidney disease, long-term complications including chronic kidney allograft disease (CKAD) and major adverse cardiovascular events (MACE) are common. To decrease these complications new therapeutic options are necessary. Mineralocorticoid receptor antagonists (MRAs) are one of the promising drugs in this context. In the general population, MRAs had favorable effects on blood pressure regulation, MACE, proteinuria and progression of chronic kidney disease. In the context of KT, there are limited studies showing beneficial effects such as reducing proteinuria and oxidative stress. In this review, we performed a narrative review to assess the use and impact of MRAs in kidney transplant recipients. We found that in KTRs, MRAs are safe and they have favorable or neutral impact on blood pressure, glomerular filtration rate, urinary protein/albumin excretion, and oxidative stress. No data was found regarding major cardiovascular adverse events.

Risk of Coronary Artery Disease in Patients with Liver Cirrhosis: A Systematic Review and Meta-analysis

Background and Aims

Coronary artery disease (CAD) is increasingly observed in patients with liver cirrhosis. However, data on the incidence and prevalence of CAD in cirrhotic patients are heterogeneous, and the association remains uncertain. In this study, we aimed to conduct a systematic review and meta-analysis to address these issues.

Methods

PubMed, EMBASE, and Cochrane Library databases were searched. Incidence, prevalence, and factors associated with CAD were pooled using a random-effects model. Risk ratio (RR) and odds ratio (OR), with their 95% confidence interval (CI), were calculated to evaluate differences in CAD incidence and prevalence between patients with and without liver cirrhosis.

Results

Fifty-one studies were included. The pooled incidences of CAD, acute coronary syndromes, and myocardial infarction (MI) were 2.28%, 2.02%, and 1.80%, respectively. Liver cirrhosis was not significantly associated with CAD incidence (RR = 0.77; 95% CI = 0.46-1.28) or MI (RR = 0.87; 95% CI = 0.49-1.57). The pooled prevalence of CAD, acute coronary syndromes, and MI was 18.87%, 12.54%, and 6.12%, respectively. Liver cirrhosis was not significantly associated with CAD prevalence (OR = 1.29; 95% CI = 0.83-2.01) or MI (OR = 0.58; 95% CI = 0.28-1.22). Non-alcoholic steatohepatitis, hepatitis C virus, advanced age, male sex, diabetes mellitus, hypertension, hyperlipidemia, smoking history, and family history of CAD were significantly associated with CAD in cirrhotic patients.

Conclusions

CAD is common in cirrhotic patients, but cirrhosis itself may not be associated with an increased CAD risk. In addition to traditional risk factors, non-alcoholic steatohepatitis and hepatitis C virus infection are also associated with CAD presence in cirrhotic patients.

Anesthetic Considerations for Robotic Liver Transplantation

Liver transplantation has traditionally been performed through a large, bilateral subcostal incision. Recently, liver transplant programs across the world, including our own, have reported successful liver transplants via total robotic approaches on recipients with low Model for End-stage Liver Disease scores and preexisting abdominal wall laxity. This review discusses the unique anesthetic considerations of robotic liver transplantation based on our group's initial experience with this novel surgical approach. Robotic liver transplantation presents a unique set of considerations and challenges for the anesthesiologist, and a thorough understanding of liver disease, liver transplant surgery, venovenous bypass, and the various implications of robotic surgery is essential to ensure optimal patient outcomes. Specific management topics discussed here include appropriate patient selection, preoperative assessment, and intraoperative management. We also discuss certain theoretical and actual challenges that our group has experienced.

Alcoholic Cardiomyopathy in Patients With Advanced Alcoholic Liver Disease: Single-Center Experience and Review of Literature

The impact of excessive alcohol on human health is associated with a lifetime cumulative use of alcohol and is further affected by various factors such as age, gender, nutritional status, concurrent cigarette smoking or drug use, diabetes, obesity, other cardiovascular diseases, and socio-economic status. Alcohol cardiomyopathy (ACM) is a type of acquired dilated cardiomyopathy, which is associated with long-term heavy alcohol consumption with historical rates varying from 3.8% to 47 % among patients with heart failure. Data regarding the prevalence of concurrent ACM in patients with alcoholic liver disease is limited. Among 483 patients with advanced liver disease who underwent liver transplant evaluation at a single transplant center during 2016-2021, based on screening transthoracic echocardiogram and a clear definition, none (0%) of the patients had alcoholic cardiomyopathy (range ejection fraction: 55-80%), 7% had left ventricular dilation (mild dilation: 82%), and 12.4% had diastolic dysfunction. We also review data regarding known risk factors, natural progression, and treatment of ACM, and further explore the evidence regarding the concurrence of alcohol-associated disease in liver with other organs such as heart and pancreas. In persons with excessive alcohol consumption, abstinence from alcohol or moderating its use has been shown to help decrease the progression of heart failure, arrythmias, and hypertension as well as liver dysfunction. Focus on the identification of both genetic markers and modifiable risk factors associated with various organ injuries in conjunction with public health policies for the safe use of alcohol is needed to mitigate the risk of alcohol use disorder.

A Review of Cardiac Preoperative Screening Guidelines for Liver Transplantation

Orthotopic liver transplant (OLT) medicine is a constantly evolving field, especially with the demographics of individuals with advanced liver disease drastically changing. OLT candidates are now older, and there is an increase of nonalcoholic steatohepatitis cirrhosis due to the epidemic of obesity, which has also resulted in an increase in cardiac comorbidities in this population. The pathophysiology of liver cirrhosis creates many complexities during the pre- and postoperative management of OLT. We discuss the role of screening for common co-existent cardiovascular comorbidities, including coronary artery disease, congestive heart failure, arrhythmias, and portopulmonary hypertension, as well as challenges in the standardization of pre-liver transplant cardiovascular care.

Quantitative evaluation of myocardial perfusion in coronary heart disease by myocardial contrast and dobutamine stress echocardiography

OBJECTIVE

We aimed to investigate how combining myocardial contrast echocardiography (MCE) with dobutamine stress echocardiography (DSE) could help evaluate myocardial perfusion in coronary heart disease patients and understand changes in microcirculation across different levels of coronary artery blockage.

METHODS

We conducted MCE and DSE tests on 53 coronary heart disease patients, categorizing ischemic myocardium into four groups: A (<50%), B (50%-69%), C (70%-89%), and D (≥90%). Dynamic myocardial perfusion images were captured during rest and peak dobutamine stress from various angles, analyzing parameters like plateau value A, slope β, and the product A × β, reflecting different aspects of myocardial blood flow.

RESULTS

Parametric values of myocardial perfusion (PVMPs) were significantly lower in group D at rest compared with other groups (p < 0.001). PVMPs increased notably at peak dobutamine stress in groups A, B, and C (p < 0.001). Groups A and B had higher PVMPs than groups C and D, with group D significantly lower (p < 0.001). β reserve values decreased gradually from group A to D, with significantly lower values of A and A × β in groups C and D compared with A and B (p < 0.001). Sensitivity and specificity for predicting >70% coronary artery blockage was 80%, 66%, and 74%, 80%, respectively, using specific thresholds.

CONCLUSION

Combining MCE with DSE is highly sensitive and accurate in diagnosing obstructive coronary artery blockages. It also helps assess myocardial microcirculation perfusion and left ventricular reserve function, which decline with increasing severity of coronary artery blockage.

Cardiac evaluation of renal transplant candidates with heart failure

Patients with advanced kidney disease are at elevated risk of developing heart failure and appropriate risk stratification is important to permit them to receive kidney transplantation. The American Heart Association and American College of Cardiology joint statement provides guidance on risk stratification for the major cause of heart failure for these patients in its recommendations for coronary heart disease. Herein we provide an overview of the available literature on risk stratification for nonischemic heart failure and functional heart disease states such as pulmonary hypertension. Many of these options for optimizing these patients before transplant include optimizing their volume status, often with more aggressive ultrafiltration. Kidney transplantation remains the treatment of choice for patients with advanced kidney disease and cardiac disease, the correction of the azotemic substances with kidney transplantation has been associated with improved survival than remaining on dialysis long-term. The findings in the studies reviewed here are expected to help clinicians refine current strategies for evaluating potential kidney transplant recipients.

EASL Clinical Practice Guidelines on liver transplantation

Liver transplantation (LT) is an established life-saving procedure. The field of LT has changed in the past 10 years from several perspectives, with the expansion of indications, transplantation of patients with acute-on-chronic liver failure, evolution of transplant oncology, the use of donations after cardiac death, new surgical techniques, and prioritisation of recipients on the waiting list. In addition, the advent of organ perfusion machines, the recognition of new forms of rejection, and the attention paid to the transition from paediatric to adult patients, have all improved the management of LT recipients. The purpose of the EASL guidelines presented here is not to cover all aspects of LT but to focus on developments since the previous EASL guidelines published in 2016.

Heart failure medication use and follow-up patterns in renal transplant recipients with reduced ejection fraction: A single-center experience

Background

The role of medical therapy for heart failure with reduced ejection fraction (HFrEF) in subjects with end-stage renal disease receiving renal transplantation (RT) is understudied. Here, we describe post-RT HFrEF medical management practices at a single urban, academic tertiary care center.

Methods

RT recipients between January 1, 2015 and November 30, 2020 with history of ejection fraction (EF) <40 % prior to RT were included. Medications, renal function, blood pressure, cardiology follow-up, and echocardiograms ≥90d post-RT were retrospectively collected for 2 years post-RT.

Results and conclusions

47/750 (6.3 %) of RT recipients had prior HFrEF diagnosis, of whom 26 experienced improvement in EF prior to RT. Pre-RT medical therapy included beta blocker (BB) in 43 (92 %) of subjects and renin-angiotensin-aldosterone inhibitors (RAASi) in 23 (49 %). By 24 months post-RT, BB were used in 34 (76 %) and RAASi were used in 12 (27 %) of subjects. Rates of post-RT cardiology follow-up (51 %) and echocardiogram (38 %) were lower than expected in this cohort. Of 29 subjects potentially eligible for RAASi based on preserved renal function and no hyperkalemia or hypotension episodes during follow-up, only 6 (21 %) received RAASi. Of 6 subjects with post-RT EF <50 %, 4 were eligible but did not receive RAASi. Multidisciplinary collaboration between cardiology and transplant teams may help improve care for this high-risk patient population.

Association of Cardiopulmonary Hemodynamics and Outcomes in Pulmonary Hypertension Following Kidney Transplantation: A Multicenter Retrospective Cohort Study

BACKGROUND

Pulmonary hypertension (PH) frequently complicates the evaluation of kidney transplantation (KT) candidates, and is associated with increased adverse outcomes (mortality, delayed graft function [DGF], and major adverse cardiovascular event) following KT.

RESEARCH QUESTION

What is the relationship between cardiopulmonary hemodynamics and post-KT outcomes?

STUDY DESIGN AND METHODS

We conducted a multicenter retrospective cohort study of adults undergoing KT between October 1, 2011 and October 1, 2021, who underwent right heart catheterization (RHC) to assess cardiopulmonary hemodynamics within 1 year of transplantation. Frailty models and logistic regression models were used to evaluate the association between cardiopulmonary hemodynamics and outcomes (mortality, DGF, major adverse cardiovascular event) following KT.

RESULTS

A total of 117 patients were included in the final analysis, predominantly male (72%), with a median age of 57 years. PH, defined as mean pulmonary artery pressure (mPAP) > 20 mm Hg, was present in most of the cohort (n = 93; 79%). The cohort was monitored for a median of 29.9 months post-KT, during which about one-fourth experienced mortality (23%) or DGF (25%) events, and approximately one-third (34%) experienced major adverse cardiovascular event. Although echocardiographic measures of pulmonary artery pressure failed to identify post-KT outcomes, a mPAP of ≥ 30 mm Hg on RHC was associated with post-KT major adverse cardiovascular event (hazard ratio, 2.60; 95% CI, 1.10-6.10) and more prevalent in those experiencing post-KT mortality (63% vs 32%; P = .001). Precapillary pulmonary hypertension was also associated with post-KT mortality (hazard ratio, 3.71; 95% CI, 1.07-12.90).

INTERPRETATION

Precapillary pulmonary hypertension and an mPAP of ≥ 30 mm Hg on RHC, but not echocardiographic evidence of PH, was associated with mortality and major adverse cardiovascular event following KT. These data suggest that RHC hemodynamics are superior to echocardiographic measures of PH in association with outcomes following KT, and RHC-derived mPAP in particular may have value in predicting major adverse cardiovascular event and mortality post-KT.

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.

Cardiorespiratory Fitness From Cardiopulmonary Exercise Testing Is a Comprehensive Risk-stratifying Tool in Liver Transplant Candidates

Background

Cardiovascular disease and physical decline are prevalent and associated with morbidity/mortality in liver transplant (LT) patients. Cardiopulmonary exercise testing (CPX) provides comprehensive cardiopulmonary and exercise response assessments. We investigated cardiorespiratory fitness (CRF) and cardiac stress generated during CPX in LT candidates.

Methods

LT candidates at 2 centers underwent CPX. Standard-of-care cardiac stress testing (dobutamine stress echocardiography, DSE) results were recorded. Physical function was assessed with liver frailty index and 6-min walk test. CPX/DSE double products were calculated to quantify cardiac stress. To better study the association of CPX-derived metrics with physical function, the cohort was divided into 2 groups based on 6-min walk test median (372 m).

Results

Fifty-four participants (62 ± 8 y; 65% men, Model for End-Stage Liver Disease-Na 14 [10-18]) underwent CPX. Peak oxygen consumption was 14.1 mL/kg/min for an anerobic threshold of 10.2 mL/kg/min, with further CRF decline in the lower 6MWT cohort despite lack of liver frailty index-frailty in 90%. DSE was nondiagnostic in 18% versus 4% of CPX (P = 0.058). All CPX were negative for ischemia. A double product of ≥25 000 was observed in 32% of CPX and 11% of DSE (P = 0.020). Respiratory function testing was normal. No patient presented major cardiovascular events at 30 d post-LT.

Conclusions

CPX provided efficient and effective combined cardiopulmonary risk and frailty assessments of LT candidates in a 1-stop test. The CRF was found to be very low despite preserved physical function or lack of frailty.

Brain natriuretic peptide and N-terminal pro b-type natriuretic peptide in kidney transplantation: More than just cardiac markers

Although kidney transplantation (KT) is the best treatment option for most patients with end-stage kidney disease (ESKD) due to reduced mortality, morbidity and increased quality of life, long- term complications such as chronic kidney allograft dysfunction (CKAD) and increased cardiovascular disease burden are still major challenges. Thus, routine screening of KT recipients (KTRs) is very important to identify and quantify risks and guide preventative measures. However, no screening parameter has perfect sensitivity and specificity, and there is unmet need for new markers. In this review, we evaluate brain natriuretic peptide (BNP) and N-terminal pro b-type natriuretic peptide (NT-proBNP) as promising markers for risk stratification in the kidney transplant recipients (KTRs). The usefulness of these markers are already proven in heart failure, hypertension, coronary artery disease. In the context of KT, evidence is emerging. BNP and NT-proBNP has shown to be associated with kidney function, graft failure, echocardiographic parameters, major cardiovascular events and mortality but the underlying mechanisms are not known. Although BNP and NT-proBNP interact with immune system, renin angiotensin system and sympathetic system; it is not known whether these interactions are responsible for the clinical findings observed in KTRs. Future studies are needed whether these biomarkers show clinical efficacy, especially with regard to hard outcomes such as major adverse cardiovascular events and graft dysfunction and whether routine implementation of these markers are cost effective in KTRs.

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.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Perioperative Considerations in Older Kidney and Liver Transplant Recipients: A Review

With the growth of the older adult population, the number of older adults waitlisted for and undergoing kidney and liver transplantation has increased. Transplantation is an important and definitive treatment for this population. We present a contemporary review of the unique preoperative, intraoperative, and postoperative issues that patients older than 65 y face when they undergo kidney or liver transplantation. We focus on geriatric syndromes that are common in older patients listed for kidney or liver transplantation including frailty, sarcopenia, and cognitive dysfunction; discuss important considerations for older transplant recipients, which may impact preoperative risk stratification; and describe unique challenges in intraoperative and postoperative management for older patients. Intraoperative challenges in the older adult include using evidence-based best anesthetic practices, maintaining adequate perfusion pressure, and using minimally invasive surgical techniques. Postoperative concerns include controlling acute postoperative pain; preventing cardiovascular complications and delirium; optimizing immunosuppression; preventing perioperative kidney injury; and avoiding nephrotoxicity and rehabilitation. Future studies are needed throughout the perioperative period to identify interventions that will improve patients' preoperative physiologic status, prevent postoperative medical complications, and improve medical and patient-centered outcomes in this vulnerable patient population.

Detection of Coronary Artery Disease With Coronary Computed Tomography Angiography and Stress Testing in Candidates for Liver Transplant

Cardiac complications are the leading cause of morbidity and mortality in recipients of liver transplant (LT). Previous guidelines recommended stress testing to exclude coronary artery disease (CAD), although recent guidelines recommend coronary computed tomography angiography (CCTA). We aimed to assess the prevalence and predictors of CAD on CCTA and compare CCTA with stress testing in consecutive adult candidates for LT who underwent CAD noninvasive assessment between 2020 and 2023. Patients who underwent a stress test between January and December 2020 formed the stress cohort, and patients who underwent CCTA between January 2021 and September 2023 formed the CCTA cohort. There were 141 patients in the stress test cohort and 269 patients in the CCTA cohort. Stress test results were nondiagnostic or inconclusive in 18 patients (12.8%) whereas CCTA was nondiagnostic in 6 patients (2.2%). In patients evaluated with CCTA, mean coronary artery calcium (CAC) score was 332 ± 716 AU, with moderate or greater (>50%) stenosis in 33 patients (12.3%). New CAD was diagnosed in 158 patients (58.7%) using CCTA and in 5 patients (3.5%) using stress tests. Clinically actionable CAD (coronary artery calcium >100) on CCTA was present in 96 patients (35.7%). The number of CAD risk factors was associated with the presence of CAD on CCTA. In conclusion, there was a great burden of CAD, mainly nonobstructive, in a large cohort of candidates for LT who underwent CAD testing over a 4-year period. The current recommended risk-based evaluation of candidates for LT using CCTA as a first-line test was feasible and effective. Diagnosis of clinically actionable CAD on CCTA provides a vast opportunity for optimizing cardiac care in candidates for and recipients of LT.

Coronary Plaque Characteristics in Patients With Chronic Kidney Failure: Impact on Cardiovascular Events and Mortality

BACKGROUND

In patients with coronary artery disease, coronary plaques with high-risk features and low-attenuation plaque burden are independent measures associated with major adverse cardiovascular events (MACEs). Patients with chronic kidney failure may have different coronary artery disease characteristics. The aim was to assess the association of coronary plaque characteristics and coronary artery disease extent with MACE and all-cause mortality in patients with chronic kidney failure.

METHODS

Potential kidney transplant candidates who underwent coronary computed tomography angiography as part of the cardiac screening program before kidney transplantation were included. We evaluated high-risk plaques and diameter stenosis semiqualitatively and quantified coronary artery calcium score and plaque burden (percentage atheroma volume).

RESULTS

In 484 patients with chronic kidney failure and few or no symptoms of coronary artery disease (mean age, 53±12 years; 62% men; 32% on dialysis), 56 (12%) patients suffered MACE and 69 (14%) patients died during a median follow-up of 4.9 years. High-risk plaques were present in 39 (70%) patients with MACE. Median calcified plaque burden was 3.7% in patients with MACE versus 0.2% in patients without MACE. The median low-attenuation plaque burden was 0.3% versus 0.03%, respectively. In semiqualitative analyses, the presence of high-risk plaque and a higher coronary artery calcium score were associated with increased risk of MACE (hazard ratio (HR), 2.0 [95% CI, 1.0-3.7]; P=0.040; HR, 1.2 [95% CI, 1.0-1.3]; P=0.014), respectively. Neither were associated with all-cause mortality. In quantified analysis, increasing levels of both calcified and low-attenuation plaque burdens were associated with risk of MACE (HR, 2.6 [95% CI, 1.8-3.7]; P<0.001; HR, 2.6 [95% CI, 1.5-4.5]; P=0.001 [per variable doubling, respectively]) and all-cause mortality (HR, 1.6 [95% CI, 1.2-2.1]; P=0.002; HR, 1.8 [95% CI, 1.1-3.0]; P=0.028, respectively).

CONCLUSIONS

In patients with chronic kidney failure, calcified and low-attenuation plaque burdens were independently associated with MACE and all-cause mortality, while high-risk plaques and coronary artery calcium score were only associated with MACE.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01344434.

Pretransplant cardiac stress testing and transplant wait time in kidney transplantation candidates

OBJECTIVE

Routine screening for cardiovascular disease before kidney transplantation remains controversial. This study aims to compare cardiac testing rates in patients with end-stage renal disease, referred and not referred for transplantation, and assess the impact of testing on transplant wait times.

METHODS

This is a retrospective cohort study of 22 687 end-stage renal disease patients from 2011 to 2022, within an integrated health system. Cardiac testing patterns, and the association between cardiac testing and transplant wait times and post-transplant mortality were evaluated.

RESULTS

Of 22 687 patients (median age 66 years, 41.1% female), 6.9% received kidney transplants, and 21.0% underwent evaluation. Compared with dialysis patients, transplant patients had a 5.6 times higher rate of stress nuclear myocardial perfusion imaging with single-photon emission (rate ratio (RR) 5.64, 95% CI 5.37 to 5.92), a 6.5 times higher rate of stress echocardiogram (RR 6.51, 95% CI 5.65 to 7.51) and 16% higher cardiac catheterisation (RR 1.16, 95% CI 1.06 to 1.27). In contrast, revascularisation rates were significantly lower in transplant patients (RR 0.46, 95% CI 0.36 to 0.58). Transplant wait times were longer for patients who underwent stress testing (median 474 days with no testing vs 1053 days with testing) and revascularisation (1796 days for percutaneous intervention and 2164 days for coronary artery bypass surgery). No significant association was observed with 1-year post-transplant mortality (adjusted OR 1.99, 95% CI 0.46 to 8.56).

CONCLUSIONS

This study found a higher rate of cardiac testing in dialysis patients evaluated for kidney transplants. Cardiac testing was associated with longer transplant wait time, but no association was observed between testing and post-transplant mortality.

Kidney Transplant Candidacy: Addressing Common Medical and Psychosocial Barriers to Transplant

Improving access to kidney transplants remains a priority for the transplant community. However, many medical, psychosocial, geographic, and socioeconomic barriers exist that prevent or delay transplantation for candidates with certain conditions. There is a lack of consensus regarding how to best approach many of these issues and barriers, leading to heterogeneity in transplant centers' management and acceptance practices for a variety of pretransplant candidate issues. In this review, we address several of the more common contemporary patient medical and psychosocial barriers frequently encountered by transplant programs. The barriers discussed here include kidney transplant candidates with obesity, older age, prior malignancy, cardiovascular disease, history of nonadherence, and cannabis use. Improving understanding of how to best address these specific issues can empower referring providers, transplant programs, and patients to address these issues as necessary to progress toward eventual successful transplantation.

Cardiac evaluation of the liver transplant candidate

PURPOSE OF REVIEW

This review aims to summarize recent changes in the cardiac evaluation of adult liver transplant candidates. Over the last several years, there have been significant advances in the use of coronary computed tomography angiography (CCTA) with and without fractional flow reserve (FFR) and increasingly widespread availability of coronary calcium scoring for risk stratification for obstructive coronary artery disease. This has led to novel strategies for risk stratification in cirrhotic patients being considered for liver transplant and an updated American Heart Association (AHA) position paper on the evaluation of liver and kidney transplant candidates. The diagnosis of cirrhotic cardiomyopathy has been refined. These new diagnostic criteria require that specific echocardiographic parameters are evaluated in all patients. The definition of pulmonary hypertension on echocardiography has been altered and no longer utilizes right atrium (RA) pressure estimates based on inferior vena cava (IVC) size and collapse. This provides more volume neutral estimates of pulmonary pressure.

RECENT FINDINGS

Although CCTA has outstanding negative predictive value, false positive results are not uncommon and often lead to further testing. Revised diagnostic criteria for cirrhotic cardiomyopathy improve risk stratification for peri-operative volume overload and outcomes. Refined pulmonary hypertension criteria provide improved guidance for right heart catheterization (RHC) and referral to subspecialists. There are emerging data regarding the safety and efficacy of TAVR for severe aortic stenosis in cirrhotic patients.

SUMMARY

Increased utilization of noninvasive testing, including CCTA and/or coronary calcium scoring, can improve the negative predictive value of testing for obstructive coronary artery disease and potentially reduce reliance on coronary angiography. Application of the 2020 criteria for cirrhotic cardiomyopathy will improve systolic and diastolic function assessment and subsequent perioperative risk stratification. The use of global strain scores is emphasized, as it provides important information beyond ejection fraction and diastolic parameters. A standardized one-parameter echo cut-off for elevated pulmonary pressures simplifies both evaluation and follow-up. Innovative transcutaneous techniques for valvular stenosis and regurgitation offer new options for patients at prohibitive surgical risk.

Quantitative myocardial perfusion in liver transplantation candidates: Poorly metabolized caffeine inhibition of vasodilatory stress

BACKGROUND

Data on cardiac positron emission tomography (PET) in liver transplantation (LT) candidates are limited with no prior study accounting for poorly metabolized caffeine reducing stress perfusion.

METHOD

Consecutive LT candidates (n = 114) undergoing cardiac rest/stress PET were instructed to abstain from caffeine for 2 days extended to 5 and 7 days. Due to persistently high prevalence of measurable blood caffeine after 5-day caffeine abstinence, dipyridamole (n = 41) initially used was changed to dobutamine (n = 73). Associations of absolute flow, coronary flow reserve (CFR), detectable blood caffeine, and Modified End-Stage Liver Disease (MELD) score for liver failure severity were evaluated. Coronary flow data of LT candidates were compared to non-LT control group (n = 102 for dipyridamole, n = 29 for dobutamine).

RESULTS

Prevalence of patients with detectable blood caffeine was 63.3%, 36.7% and 33.3% after 2-, 5- and 7-day of caffeine abstinence, respectively. MELD score was associated with detectable caffeine (odd ratio 1.18,P < 0.001). CFR was higher during dipyridamole stress without-caffeine versus with-caffeine (2.22 ± 0.80 vs 1.55 ± 0.37,P = 0.048) but lower than dobutamine stress (2.22 ± 0.80 vs 2.82 ± 1.02,P = 0.026). Mediation analysis suggested that the dominant association between CFR and MELD score in dipyridamole group derived from caffeine-impaired CFR and liver failure/caffeine interaction. CFR in LT candidates was lower than non-LT control population in both dipyridamole and dobutamine group.

CONCLUSION

We demonstrate exceptionally high prevalence of detectable blood caffeine in LT candidates undergoing stress PET myocardial perfusion imaging resulting in reduced CFR with dipyridamole compared to dobutamine. The delayed caffeine clearance in LT candidates makes dobutamine a preferred stress agent in this population.

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.

Coronary artery calcium assessment on non-gated chest CT to optimize pre-operative cardiac screening in liver transplantation

BACKGROUND

Guidelines recommend standard pre-operative cardiac screening in all liver transplantation (LT) recipients, despite the relatively low prevalence of obstructive coronary artery disease. Most LT recipients often have non-gated computed tomography (CT) performed of the chest and abdomen. This study evaluated the ability of coronary artery calcification (CAC) assessment on consecutively available scans, to identify a selection of low-risk patients, in whom further cardiac imaging can be safely withheld.

METHODS

LT recipients with prior non-gated CT chest-abdomen were included. CAC was visually scored on a semi-quantitative ordinal scale. Stress myocardial perfusion, coronary CT angiography (CCTA) and invasive coronary angiography (ICA) were used as golden standard. The sensitivity and specificity of CAC to exclude and predict obstructive CAD were assessed. In addition, peri- and postoperative mortality and cardiac events were analyzed.

RESULTS

149 LT recipients (ranged 31-71 years) were included. In 75% of patients, no CAC and mild CAC could rule out obstructive CAD on CCTA and ICA with 100% certainty. The threshold of mild CAC had a sensitivity of 100% for both CCTA and ICA and a specificity of 91% and 68%, respectively. None of the patients with no or mild calcifications experienced peri- and post-operative cardiac events or died of cardiac causes.

CONCLUSION

Visual evaluation of CAC on prior non-gated CT can accurately and safely exclude obstructive CAD in LT recipients. Incorporation of these already available data can optimize cardiac screening, by safely withholding or correctly allocating dedicated cardiac imaging in LT recipients. Thereby, reducing patients' test burden and save health care expenses.

A holistic review of sodium intake in kidney transplant patients: More questions than answers

Kidney transplantation (KT) is the best treatment option for end-stage kidney disease (ESKD). Acute rejection rates have decreased drastically in recent years but chronic kidney allograft disease (CKAD) is still an important cause of allograft failure and return to dialysis. Thus, there is unmet need to identify and reverse the cause of CKAD. Additionally, cardiovascular events after KT are still leading causes of morbidity and mortality. One overlooked potential contributor to CKAD and adverse cardiovascular events is increased sodium/salt intake in kidney transplant recipients (KTRs). In general population, the adverse effects of high sodium intake are well known but in KTRs, there is a paucity of evidence despite decades of experience with KT. Limited research showed that sodium intake is high in most KTRs. Moreover, excess sodium intake is associated with elevated blood pressure and albuminuria in some studies involving KTRs. There is also experimental evidence suggesting that increased sodium intake is associated with histologic graft damage. Critical knowledge gaps still remain, including the exact amount of sodium restriction needed in KTRs to optimize outcomes and allograft survival. Additionally, best methods to measure sodium intake and practices to follow-up are not clarified in KTRs. To meet these deficits, prospective long term studies are warranted in KTRs. Moreover, preventive measures must be determined and implemented both at individual and societal levels to achieve sodium restriction in KTRs.

Deep Learning-Based Prediction Modeling of Major Adverse Cardiovascular Events After Liver Transplantation

Objective

To validate deep learning models' ability to predict post-transplantation major adverse cardiovascular events (MACE) in patients undergoing liver transplantation (LT).

Patients and Methods

We used data from Optum's de-identified Clinformatics Data Mart Database to identify liver transplant recipients between January 2007 and March 2020. To predict post-transplantation MACE risk, we considered patients' demographics characteristics, diagnoses, medications, and procedural data recorded back to 3 years before the LT procedure date (index date). MACE is predicted using the bidirectional gated recurrent units (BiGRU) deep learning model in different prediction interval lengths up to 5 years after the index date. In total, 18,304 liver transplant recipients (mean age, 57.4 years [SD, 12.76]; 7158 [39.1%] women) were used to develop and test the deep learning model's performance against other baseline machine learning models. Models were optimized using 5-fold cross-validation on 80% of the cohort, and model performance was evaluated on the remaining 20% using the area under the receiver operating characteristic curve (AUC-ROC) and the area under the precision-recall curve (AUC-PR).

Results

Using different prediction intervals after the index date, the top-performing model was the deep learning model, BiGRU, and achieved an AUC-ROC of 0.841 (95% CI, 0.822-0.862) and AUC-PR of 0.578 (95% CI, 0.537-0.621) for a 30-day prediction interval after LT.

Conclusion

Using longitudinal claims data, deep learning models can efficiently predict MACE after LT, assisting clinicians in identifying high-risk candidates for further risk stratification or other management strategies to improve transplant outcomes based on important features identified by the model.

Enhancing pre-transplant cardiac assessment: Validation and utility of the CAD-LT score with CCTA in liver transplant candidates

BACKGROUND

Coronary computed tomography angiography (CCTA) is increasingly being used in the preoperative workup for liver transplantation (LT). We sought to assess the utility of integrating CCTA with the novel CAD-LT (Coronary Artery Disease in Liver Transplantation) score and its impact on reducing the need for invasive coronary angiography prior to LT.

METHODS

We conducted a retrospective cohort study of consecutive patients (age ≥ 18 years) who underwent CCTA for LT workup between 2011 and 2018 at the Victorian Liver Transplant Unit, Melbourne, Australia. CAD-LT scores, a traditional risk factor-based criteria, were calculated, and patients stratified as low-, intermediate- or high-risk.

RESULTS

Overall, 229 patients underwent CCTA. The mean age was 66 ± 5 years (82% male) with a modest-to-high risk factor burden (diabetes, 53%; hypertension, 46%; current or former smoker, 62%). The mean CAD-LT score of our cohort was 12.4 ± 4.0. No patients were classified as low-risk, 49 patients (21.4%) were deemed intermediate-risk and 180 patients (78.6%) were deemed high-risk. A high CAD-LT score (≥ 9) showed high sensitivity (95.3% [95% CI 86-98%]) and modest specificity (27.8% [95% CI 21-35%]) for the detection of obstructive coronary artery disease on CCTA, with a negative predictive value of 94%. Following multidisciplinary discussions, only 41 patients (18%) of patients proceeded to ICA of which 27% received percutaneous coronary intervention.

CONCLUSIONS

The use of CCTA in patients deemed intermediate- to high-risk by the CAD-LT score has the potential to reduce the need for invasive coronary angiography in patients undergoing LT workup.

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.

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.

Pretransplant screening for coronary artery disease: data are required before practice change

Declining rates of peritransplant cardiovascular death, an increasing burden of pretransplant tests, and concerns about the effectiveness of screening candidates for coronary artery disease have led many transplant programs to de-escalate screening protocols. Recent Kidney Disease: Improving Global Outcomes and American Heart Association scientific statements and guidelines neatly summarize current evidence, but also identify areas of need. Here, we argue that key questions should be addressed by adequately powered clinical trials before our long-held screening paradigms are completely rewritten.

Coronary Artery Disease Assessment and Cardiovascular Events in Middle-Aged Patients on Hemodialysis

OBJECTIVE

To explore whether, in younger patients on dialysis with longer life expectancy, assessment of coronary artery disease (CAD) could identify individuals at higher risk of events and revascularization might improve outcomes in selected patients contrary to what had been observed in elderly patients.

METHODS

From August 1997 to January 2019, 2265 patients with stage 5 chronic kidney disease were prospectively referred for cardiovascular assessment. For this study, we selected 1374 asymptomatic patients aged between 18 and 64 years. After clinical risk stratification and cardiac scintigraphy by single-photon emission computed tomography, 866 patients underwent coronary angiography. The primary end point was the composite incidence of nonfatal/fatal major adverse cardiovascular events during a follow-up period of 0.1 to 189.7 months (median, 26 months). The secondary end point was all-cause mortality.

RESULTS

The primary end point occurred in 327 (23.8%) patients. Clinically stratified high-risk patients had a 3-fold increased risk of the primary end point. The prevalence of abnormal findings on perfusion scans was 29.2% (n=375), and significant CAD was found in 449 (51.8%) of 866 patients who underwent coronary angiography. An abnormal finding on myocardial perfusion scan and the presence of CAD were significantly associated with a 74% and 22% increased risk of cardiovascular events, respectively. In patients undergoing percutaneous coronary intervention or coronary artery bypass grafting (n=99), there was an 18% reduction in the risk of all-cause death relative to patients receiving medical treatment (P=.03).

CONCLUSION

In this cohort of middle-aged, asymptomatic patients on dialysis, assessment of CAD identified individuals at higher risk of events, and coronary intervention was associated with reducing the risk of death in selected patients.

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.

The Minimisation of Cardiovascular Disease Screening for Kidney Transplant Candidates

Background: There is increasing evidence that cardiac screening prior to kidney transplantation does not improve its outcomes. However, risk aversion to perioperative events means that, in practice, testing remains common, limiting the availability of 'real-world' data to support any change. Our objective was to assess perioperative and 1-year post-transplant cardiovascular events in a kidney transplant candidate cohort who received minimal cardiovascular screening. Methods: The retrospective cohort study included all adult kidney-only transplant recipients in a single UK region between January 2015 and December 2021. Kidney transplant recipients asymptomatic of cardiac disease, even those with established risk factors, did not receive cardiac stress testing. The perioperative and 1-year post-transplant cardiovascular event incidences were examined. Logistic regression was used to identify variables of statistical significance that predicted cardiovascular or cerebrovascular events. Results: A total of 895 recipients fulfilled the inclusion criteria. Prior to transplantation, 209 (23%) recipients had an established cardiac diagnosis, and 193 (22%) individuals had a diagnosis of diabetes. A total of 18 (2%) patients had a perioperative event, and there was a 5.7% incidence of cardiovascular events 1 year post-transplantation. The cardiovascular mortality rate was 0.0% perioperatively, 0.2% at 3 months post-transplant, and 0.2% at 1 year post-transplant. Conclusions: This study demonstrates comparable rates of cardiovascular events despite reduced screening in asymptomatic recipients. It included higher risk individuals who may, on the basis of screening results, have been excluded from transplantation in other programmes. It provides further evidence that extensive cardiac screening prior to kidney transplantation is unlikely to be offset by reduced rates of cardiovascular events.

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.

Heart failure with severely reduced ejection fraction after liver transplantation: a case report and review of the literature

BACKGROUND

Liver transplantation (LT) is a strenuous event for the cardiovascular system. Cardiovascular events (CVE), including heart failure (HF), arrhythmias and myocardial ischemia, are important causes of peri- and post-liver transplantation morbidity and mortality.

CASE PRESENTATION

We describe the case of a 45-year-old male patient who developed heart failure with severely reduced ejection fraction (HFrEF) after receiving liver transplantation (LT) for end-stage post-alcoholic liver cirrhosis. Preoperative transthoracic echocardiography (TTE) demonstrated borderline left ventricular ejection fraction (LVEF) of 50% and diastolic dysfunction grade 2. On coronary angiography, the patient had no coronary stenoses. Persistent vasopressor need, increasing creatinine levels and progressive pleural effusion characterized the early postoperative period. TTE on postoperative day 6 revealed a new finding of a markedly reduced LVEF of 15%, accompanied by a discrete increase in hs-TnI and CK-MB without electrocardiographic (ECG) ST-T abnormalities. LVEF did not recover completely (EF 45%) during follow-up. The patient had a sudden death 4.5 months post-liver transplantation.

CONCLUSION

Our case demonstrates that the risk of post-LT systolic dysfunction is not excluded by preoperative resting examinations within normal range and highlights the need for preoperative cardiac stress assessment (e.g. dobutamine echocardiography or stress cardiac magnetic resonance imaging) before LT. In addition, patients on a liver-transplant waiting list with cardiac dysfunction should be followed by a multidisciplinary team including a dedicated cardiology team experienced in managing liver-related cardiac pathology.

Standardized risk-stratified cardiac assessment and early posttransplant cardiovascular complications in kidney transplant recipients

Introduction

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in kidney transplant recipient (KTR). There is a dearth of standardized guidelines on optimal cardiovascular evaluation of transplant candidates.

Methods

This single-center cohort study aims to determine the effectiveness of our standardized risk-stratified pretransplant cardiovascular screening protocol, which includes coronary angiography (CAG), in identifying advanced CVD, the proper pretransplant management of which could lead to a reduction in the incidence of major cardiac events (MACE) in the early posttransplant period.

Results

Out of the total 776 KTR transplanted between 2017 and 2019, CAG was performed on 541 patients (69.7%), of whom 22.4% were found to have obstructive coronary artery disease (CAD). Asymptomatic obstructive CAD was observed in 70.2% of cases. In 73.6% of cases, CAG findings resulted in myocardial revascularization. MACE occurred in 5.6% (N = 44) of the 23 KTR with pretransplant CVD and 21 without pretransplant CVD. KTR with posttransplant MACE occurrence had significantly worse kidney graft function at the first year posttransplant (p = 0.00048) and worse patient survival rates (p = 0.0063) during the 3-year follow-up period compared with KTR without MACE. After adjustment, the independent significant factors for MACE were arrhythmia (HR 2.511, p = 0.02, 95% CI 1.158-5.444), pretransplant history of acute myocardial infarction (HR 0.201, p = 0.046, 95% CI 0.042-0.970), and pretransplant myocardial revascularization (HR 0.225, p = 0.045, 95% CI 0.052-0.939).

Conclusion

Asymptomatic CVD is largely prevalent in KTR. Posttransplant MACE has a negative effect on grafts and patient outcomes. Further research is needed to assess the benefits of pretransplant myocardial revascularization in asymptomatic kidney transplant candidates.

Comparative Effectiveness of PET and SPECT MPI for Predicting Cardiovascular Events After Kidney Transplant

BACKGROUND

Advanced chronic kidney disease is associated with high cardiovascular risk, even after kidney transplant. Pretransplant cardiac testing may identify patients who require additional assessment before transplant or would benefit from risk optimization. The objective of the current study was to determine the relative prognostic utility of pretransplant positron emission tomography (PET) and single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for posttransplant major adverse cardiovascular events (MACEs).

METHODS

We retrospectively followed patients who underwent MPI before kidney transplant for the occurrence of MACE after transplant including myocardial infarction, stroke, heart failure, and cardiac death. An abnormal MPI result was defined as a total perfusion deficit >5% of the myocardium. To determine associations of MPI results with MACE, we utilized Cox hazard regression with propensity weighting for PET versus SPECT with model factors, including demographics and cardiovascular risk factors.

RESULTS

A total of 393 patients underwent MPI (208 PET and 185 SPECT) and were followed for a median of 5.9 years post-transplant. Most were male (58%), median age was 58 years, and there was a high burden of hypertension (88%) and diabetes (33%). A minority had abnormal MPI (n=58, 15%). In propensity-weighted hazard regression, abnormal PET result was associated with posttransplant MACE (hazard ratio, 3.02 [95% CI, 1.78-5.11]; P<0.001), while there was insufficient evidence of an association of abnormal SPECT result with MACE (1.39 [95% CI, 0.72-2.66]; P=0.33). The explained relative risk of the PET result was higher than the SPECT result (R2 0.086 versus 0.007). Normal PET was associated with the lowest risk of MACE (2.2%/year versus 3.6%/year for normal SPECT; P<0.001).

CONCLUSIONS

Kidney transplant recipients are at high cardiovascular risk, despite a minority having obstructive coronary artery disease on MPI. PET MPI findings predict posttransplant MACE. Normal PET may better discriminate lower risk patients compared with normal SPECT, which should be confirmed in a larger prospective study.

Role of Complement-dependent Cytotoxicity Crossmatch and HLA Typing in Solid Organ Transplant

BACKGROUND

Solid organ transplantation is a life-saving medical operation that has progressed greatly because of developments in diagnostic tools and histocompatibility tests. Crossmatching for complement-dependent cytotoxicity (CDC) and human leukocyte antigen (HLA) typing are two important methods for checking graft compatibility and reducing the risk of graft rejection. HLA typing and CDC crossmatching are critical in kidney, heart, lung, liver, pancreas, intestine, and multi-organ transplantation.

METHODS

A systematic literature search was conducted on the internet, using PubMed, Scopus, and Google Scholar databases, to identify peer-reviewed publications about solid organ transplants, HLA typing, and CDC crossmatching.

CONCLUSION

Recent advances in HLA typing have allowed for high-resolution evaluation, epitope matching, and personalized therapy methods. Genomic profiling, next-generation sequencing, and artificial intelligence have improved HLA typing precision, resulting in better patient outcomes. Artificial intelligence (AI) driven virtual crossmatching and predictive algorithms have eliminated the requirement for physical crossmatching in the context of CDC crossmatching, boosting organ allocation and transplant efficiency. This review elaborates on the importance of HLA typing and CDC crossmatching in solid organ transplantation.