Cardiac evaluation of the kidney or liver transplant candidate

Letter to the Editor: Evaluation of Cardiac Function in Children Undergoing Liver Transplantation

The recently published article, "Evaluation of Cardiac Function in Children Undergoing Liver Transplantation" by Bansal et al. presents a significant contribution to the understanding of pediatric cirrhotic cardiomyopathy and its evaluation using advanced techniques like Speckle Tracking Echocardiography (STE). This letter commends the authors for their efforts to correlate pre-transplant echocardiographic parameters with post-operative outcomes, which holds promise for advancing pediatric hepatology and cardiology. However, this study also raises several concerns regarding methodology and interpretation. Key limitations include potential selection bias from single-center recruitment and exclusion criteria, reliance solely on STE without incorporating advanced imaging modalities such as 3D echocardiography or cardiac MRI, and lack of consideration for socioeconomic and geographic factors that influence outcomes. Additionally, the study's cross-sectional design and limited adjustment for confounding variables, such as nutritional status and infections, restrict its ability to provide dynamic and comprehensive insights. Addressing these limitations through future research-encompassing diverse populations, advanced imaging, longitudinal data, and robust control of variables-will enhance the reliability and applicability of findings in this critical domain.

Liver Transplantation and the Older Adults Candidate: Perioperative Considerations

Pioneered by Thomas Starzl in the early 1970s, liver transplant (LT) is nowadays often considered a final intervention and standard of care to cure many forms of acute and chronic end-stage liver diseases. Started in recipients younger than 60 years old, LT indications are now much broader, and at least, one-fifth of the candidates are older than 65 years. Problems associated with ageing and frailty in LT recipients and their impact on the entire perioperative course are discussed according to a modern anesthesiological perspective and the anesthesiologist covering the role of the perioperative (transplant) physician.

[Abdominal organ transplantation in multimorbid patients]

Patients with an indication for transplantation of abdominal organs often suffer from terminal organ failure with a relevant number of comorbidities. This can be complicated by acute and underlying disease-related events or age-related comorbidities. The diagnostic assignment of symptoms is difficult and the available treatment options have to be adapted. During the evaluation, the waiting time for suitable donor organs and immediately prior to surgery, the treatment team, consisting of the referring physician and the interdisciplinary transplantation team needs to decide whether the transplantation can be performed.

Echocardiographic evaluation in patient candidate for liver transplant: from pathophysiology to hemodynamic optimization

Cardiovascular complications are common in patients with severe liver disease and are an important cause of peri-operative and post-transplant morbidity and mortality. Cirrhotic cardiomyopathy (CCM), often found in advanced liver disease, is characterized by diastolic dysfunction, systolic dysfunction, and electrophysiological abnormalities. While CCM may not cause symptoms at rest, it can become evident during stressful activities, such as surgery. Liver transplantation, while being the definitive treatment for end-stage liver disease (ESLD), carries significant cardiovascular risks. Preoperative cardiac evaluation is essential for assessing these risks and planning appropriate management. Cardiac imaging, particularly echocardiography, plays a crucial role in evaluating liver transplant candidates, helping to identify conditions such as CCM, pulmonary hypertension, hepatopulmonary syndrome, and others. Currently, liver transplant anesthetists must acquire echocardiographic knowledge and skills to evaluate the cardiocirculatory conditions of the transplanted patient, especially in the pre-operative phase, but also intra-operatively and post-operatively.

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.

Myocardial perfusion scintigraphy in the assessment of cardiovascular risk in adult liver transplantation

INTRODUCTION

The non-invasive diagnostic study of cardiovascular risk in patients who are going to undergo liver transplantation is not clear, especially in asymptomatic patients. Regarding myocardial perfusion scintigraphy (MPS), it has been thought that the impaired vasodilator reserve in these patients may reduce its performance. The objective is to assess the role of the MPS in the pre-surgical evaluation of patients who are going to undergo liver transplantation.

MATERIAL AND METHODS

Retrospective, descriptive and observational study was designed. All adult patients undergoing liver transplantation between 2017 and 2021 who had previous MPS were included. The findings of MPS were described and correlated with the findings of invasive angiography and with the appearance or not of peri- and post-transplant cardiovascular events.

RESULTS

There were a total of 188 transplanted patients (mean age: 57 years, SD: 12), 178 had previous myocardial perfusion, 82 (46%) patients had no cardiovascular risk factors, and 5 (2.8%) had a history of coronary disease. Of the MPS, 177 were with dipyridamole stress performed on average 10 months before transplantation. Only 17/178 (9.5%) studies were abnormal. The mean follow-up was 38 months (SD: 10). Of the patients with normal MPS, only 2 (1.2%) presented cardiovascular events, both with studies performed more than 2 years before the procedure. There were no deaths of cardiovascular origin.

CONCLUSIONS

MPS is a safe and reliable technique for cardiovascular assessment of patients who are candidates for liver transplantation, given the low rate of false negatives during follow-up.

Liver Transplantation and the Elderly Candidate: Perioperative Considerations

Pioneered by Thomas Starzl in the early 1970s, liver transplant (LT) is nowadays often considered a final intervention and standard of care to cure many forms of acute and chronic end-stage liver diseases. Started in recipients younger than 60 years old, LT indications are now much broader, and at least, one-fifth of the candidates are older than 65 years. Problems associated with ageing and frailty in LT recipients and their impact on the entire perioperative course are discussed according to a modern anesthesiological perspective and the anesthesiologist covering the role of the perioperative (transplant) physician.

NAFLD: A pretransplant and post-transplant conundrum

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Factors associated with cardiovascular events after simultaneous liver-kidney transplant from the US Multicenter Simultaneous Liver-Kidney Transplant Consortium

Cardiovascular disease is a leading complication after both liver and kidney transplantation. Factors associated with and rates of cardiovascular events (CVEs) after simultaneous liver-kidney transplant (SLKT) are unknown. This was a retrospective cohort study of adult SLKT recipients between 2002 and 2017 at six centers in six United Network for Organ Sharing regions in the US Multicenter SLKT Consortium. The primary outcome was a CVE defined as hospitalization due to acute coronary syndrome, arrhythmia, congestive heart failure, or other CV causes (stroke or peripheral vascular disease) within 1 year of SLKT. Among 515 SLKT subjects (mean age ± SD, 55.4 ± 10.6 years; 35.5% women; 68.1% White), 8.7% had a CVE within 1 year of SLKT. The prevalence of a CVE increased from 3.3% in 2002-2008 to 8.9% in 2009-2011 to 14.0% in 2012-2017 ( p  = 0.0005). SLKT recipients with a CVE were older (59.9 vs. 54.9 years, p  < 0.0001) and more likely to have coronary artery disease (CAD) (37.8% vs. 18.4%, p  = 0.002) and atrial fibrillation (AF) (27.7% vs. 7.9%, p  = 0.003) than those without a CVE. There was a trend toward older age by era of SLKT ( p  = 0.054). In multivariate analysis adjusted for cardiac risk factors at transplant, age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02, 1.11), CAD (OR, 3.62; 95% CI, 1.60, 8.18), and AF (OR, 2.36; 95% CI, 1.14, 4.89) were associated with a 1-year CVE after SLKT. Conclusion : Among SLKT recipients, we observed a 4-fold increase in the prevalence of 1-year CVEs over time. Increasing age, CAD, and AF were the main potential explanatory factors for this trend independent of other risk factors. These findings suggest that CV risk protocols may need to be tailored to this high-risk population.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Kidney Transplantation and Diagnostic Imaging: The Early Days and Future Advancements of Transplant Surgery

The first steps for modern organ transplantation were taken by Emerich Ullmann (Vienne, Austria) in 1902, with a dog-to-dog kidney transplant, and ultimate success was achieved by Joseph Murray in 1954, with the Boston twin brothers. In the same time period, the ground-breaking work of Wilhelm C. Röntgen (1895) and Maria Sklodowska-Curie (1903), on X-rays and radioactivity, enabled the introduction of diagnostic imaging. In the years thereafter, kidney transplantation and diagnostic imaging followed a synergistic path for their development, with key discoveries in transplant rejection pathways, immunosuppressive therapies, and the integration of diagnostic imaging in transplant programs. The first image of a transplanted kidney, a urogram with intravenous contrast, was shown to the public in 1956, and the first recommendations for transplantation diagnostic imaging were published in 1958. Transplant surgeons were eager to use innovative diagnostic modalities, with renal scintigraphy in the 1960s, as well as ultrasound and computed tomography in the 1970s. The use of innovative diagnostic modalities has had a great impact on the reduction of post-operative complications in kidney transplantation, making it one of the key factors for successful transplantation. For the new generation of transplant surgeons, the historical alignment between transplant surgery and diagnostic imaging can be a motivator for future innovations.