Preoperative echocardiography as a prognostic tool for liver transplant in patients with hypertrophic cardiomyopathy

2024 Clinical Update in Liver Transplantation

In this review, the authors highlight recent advances in the care of liver transplantation patients important to anesthesiologists. The number of liver transplants continues to increase annually, and the challenges of managing complex patients require knowledge of the unique pathophysiology of end-stage liver disease. Regional anesthesia, specifically fascial plane blocks, allows for improved nonopioid pain control in recipients and potentially decreases length of stay. The use of transesophageal echocardiography (TEE) in liver transplantation allows for real-time assessment of cardiac function. Diagnosing the dreaded intracardiac thrombus with TEE during liver transplantation is essential for prompt treatment. Additionally, existing structural cardiac disease may lead to left ventricular outflow obstruction and require specific treatment modalities. Again, the use of TEE is important in making this diagnosis. Combined heart-liver transplantations are complex surgical procedures. The use of mechanical circulatory support may be necessary in some cases and anesthesiologists should understand the underlying disease process to inform the use of such support. Finally, living donation for liver transplantation remains an option for directed or anonymous donation. Anesthesiologists' role in managing donors starts in the evaluation process through postoperative pain management and showcases the broad skillset of anesthesiologists.

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.

The role of echocardiographic assessment for the risk of adverse events in liver transplant recipients: A systematic review and meta-analysis

BACKGROUND & AIMS

Echocardiographic findings may provide valuable information about the cardiac conditions in cirrhotic patients waiting for liver transplantation (LT). However, data on the ability of the different echocardiographic parameters to predict post-transplant risk of mortality are scarce and heterogeneous. This systematic review evaluates the role of different echocardiographic features as predictors of post-LT mortality. A meta-analysis was also performed according to the observed results.

METHODS

A systematic review was conducted according to PRISMA guidelines. Medline (PubMed) database was searched through February 2023 for relevant published original articles reporting the prognostic value of echocardiographic findings associated with outcomes of adult LT recipients. The risk of bias in included articles was assessed using ROBINS-E tool. Methodological quality varied from low to high across the risk of bias domains.

RESULTS

Twenty-three studies were identified after the selection process; ten were enrollable for the meta-analyses. According to the results observed, the E/A ratio fashioned as a continuous value (HR = 0.43, 95%CI = 0.25-0.76; P = 0.003), and tricuspid regurgitation (HR = 2.36, 95%CI = 1.05-5.31; P = 0.04) were relevant predicting variables for post-LT death. Other echocardiographic findings failed to merge with statistical relevance.

CONCLUSION

Tricuspid regurgitation and left ventricular diastolic dysfunction play a role in the prediction of post-LT death. More studies are needed to clarify further the impact of these echocardiographic features in the transplantation setting.

Hypertrophic Cardiomyopathy: Genetic Foundations, Outcomes, Interconnections, and Their Modifiers

Hypertrophic cardiomyopathy (HCM) is the most prevalent heritable cardiomyopathy. HCM is considered to be caused by mutations in cardiac sarcomeric protein genes. Recent research suggests that the genetic foundation of HCM is much more complex than originally postulated. The clinical presentations of HCM are very variable. Some mutation carriers remain asymptomatic, while others develop severe HCM, terminal heart failure, or sudden cardiac death. Heterogeneity regarding both genetic mutations and the clinical course of HCM hinders the establishment of universal genotype-phenotype correlations. However, some trends have been identified. The presence of a mutation in some genes encoding sarcomeric proteins is associated with earlier HCM onset, more severe left ventricular hypertrophy, and worse clinical outcomes. There is a diversity in the mechanisms implicated in the pathogenesis of HCM. They may be classified into groups, but they are interrelated. The lack of known supplementary elements that control the progression of HCM indicates that molecular mechanisms that exist between genotype and clinical presentations may be crucial. Secondary molecular changes in pathways implicated in HCM pathogenesis, post-translational protein modifications, and epigenetic factors affect HCM phenotypes. Cardiac loading conditions, exercise, hypertension, diet, alcohol consumption, microbial infection, obstructive sleep apnea, obesity, and environmental factors are non-molecular aspects that change the HCM phenotype. Many mechanisms are implicated in the course of HCM. They are mostly interconnected and contribute to some extent to final outcomes.

Evaluation of recipients with significant comorbidity - Patients with cardiovascular disease

Liver transplant(ation) (LT) is the most effective treatment for patients with decompensated liver disease. The increasing prevalence of obesity and type 2 diabetes and the growing number of patients with non-alcoholic fatty liver disease being evaluated for LT, have resulted in a greater proportion of LT candidates presenting with a higher risk of cardiovascular disease. As cardiovascular disease is a major cause of morbidity and mortality after LT, a thorough cardiovascular evaluation pre-LT is crucial. In this review, we discuss the latest evidence on the cardiovascular evaluation of LT candidates and we focus on the most prevalent conditions, namely ischaemic heart disease, atrial fibrillation and other arrhythmias, valvular heart disease, and cardiomyopathies. LT candidates undergo an electrocardiogram, a resting transthoracic echocardiography and an assessment of their cardiopulmonary functional ability as part of their standardised pre-LT work-up. Further diagnostic work-up is undertaken based on the results of the baseline evaluation and may include a coronary computed tomography angiography in patients with cardiovascular risk factors. The evaluation of potential LT candidates for cardiovascular disease requires a multidisciplinary approach, with input from anaesthetists, cardiologists, hepatologists and transplant surgeons.