Cardiac Imaging in Liver Transplantation Candidates: Current Knowledge and Future Perspectives

Prevalence and risk factors for cirrhotic cardiomyopathy: a prospective cross-sectional study

BACKGROUND

This study aimed to assess cardiac structure and function in patients with cirrhosis, to investigate the prevalence of cirrhotic cardiomyopathy (CCM) in patients with cirrhosis of different etiologies and to analyze the risk factors for the development of CCM.

METHODS

This study selected cirrhotic patients aged 18-75 years who were hospitalized in Qilu Hospital of Shandong University. Patients with known heart disease, chronic lung disease, severe renal insufficiency, malignancy, thyroid disease, hypertension, diabetes or pregnancy were excluded. A total of 131 patients with cirrhosis were finally included. Based on the results of echocardiography, patients who met the diagnostic definition of CCM were included in the CCM group, otherwise, they were classified as the non-CCM group. The demographic and clinical data of the two groups were compared, and the clinical characteristics and risk factors of CCM were evaluated.

RESULTS

The overall prevalence of CCM was 24.4%, and the occurrence of CCM was not related to the etiology of liver cirrhosis. The prevalence of CCM was significantly higher among cirrhotic patients complicated with ascites (31.4% vs. 16.4%; P  = 0.046) or with portal vein thrombosis (PVT) (42.9% vs. 17.1%; P  = 0.003). Older age [odds ratio (OR) = 1.058; 95% confidence interval (CI), 1.005-1.113; P  = 0.032] and PVT (OR = 2.999; 95% CI, 1.194-7.533; P  = 0.019) were independent risk factors for the development of CCM.

CONCLUSION

The prevalence of CCM in cirrhotic patients was 24.4%, and the occurrence of CCM was not related to the etiology of cirrhosis. The prevalence of CCM was higher in cirrhotic patients with ascites or PVT. Older age and PVT are independent risk factors for CCM, but validation in larger sample studies is still needed.

The Contemporary Role of Speckle Tracking Echocardiography in Cirrhotic Cardiomyopathy

Cirrhotic cardiomyopathy (CCM) is characterized by elevated cardiac output at rest, an inability to further increase contractility under stress, and diastolic dysfunction. The diagnosis of CCM is crucial as it can lead to complications during liver transplantation. However, its recognition poses challenges with conventional echocardiography techniques. Speckle tracking echocardiography (STE), particularly global longitudinal strain (GLS), is a novel index that enhances the diagnostic efficacy of echocardiography for both ischemic and non-ischemic cardiomyopathies. GLS proves more sensitive in identifying early systolic dysfunction and is also influenced by advanced diastolic dysfunction. Consequently, there is an expanding scope for GLS utilization in cirrhotic cases, with newly updated diagnostic criteria for CCM incorporating GLS. Specifically, systolic dysfunction is now defined as either a left ventricular ejection fraction below 50% or an absolute GLS below 18%. However, conflicting data on GLS alterations in liver cirrhosis patients persist, as many individuals with advanced disease and a poor prognosis exhibit a hyperdynamic state with preserved or increased GLS. Consequently, the presence of CCM, according to the updated criteria, does not exhibit a significant association-in the majority of studies-with the severity of liver disease and prognosis. Furthermore, information on other indices measured with STE, such as left atrial and right ventricular strain, is promising but currently limited. This review aims to offer a critical assessment of the existing evidence concerning the application of STE in patients with liver cirrhosis.

Cardiomyopathy in cirrhosis: From pathophysiology to clinical care

Cirrhotic cardiomyopathy (CCM) is defined as systolic or diastolic dysfunction in the absence of prior heart disease or another identifiable cause in patients with cirrhosis, in whom it is an important determinant of outcome. Its underlying pathogenic/pathophysiological mechanisms are rooted in two distinct pathways: 1) factors associated with portal hypertension, hyperdynamic circulation, gut bacterial/endotoxin translocation and the resultant inflammatory phenotype; 2) hepatocellular insufficiency with altered synthesis or metabolism of substances such as proteins, lipids, carbohydrates, bile acids and hormones. Different criteria have been proposed to diagnose CCM; the first in 2005 by the World Congress of Gastroenterology, and more recently in 2019 by the Cirrhotic Cardiomyopathy Consortium. These criteria mainly utilised echocardiographic evaluation, with the latter refining the evaluation of diastolic function and integrating global longitudinal strain into the evaluation of systolic function, an important addition since the haemodynamic changes that occur in advanced cirrhosis may lead to overestimation of systolic function by left ventricular ejection fraction. Advances in cardiac imaging, such as cardiac magnetic resonance imaging and the incorporation of an exercise challenge, may help further refine the diagnosis of CCM. Over recent years, CCM has been shown to contribute to increased mortality and morbidity after major interventions, such as liver transplantation and transjugular intrahepatic portosystemic shunt insertion, and to play a pathophysiologic role in the genesis of hepatorenal syndrome. In this review, we discuss the pathogenesis/pathophysiology of CCM, its clinical implications, and the role of cardiac imaging modalities including MRI. We also compare diagnostic criteria and review the potential diagnostic role of electrocardiographic QT prolongation. At present, no definitive medical therapy exists, but some promising potential treatment strategies for CCM are reviewed.

Prevalence of cirrhotic cardiomyopathy according to different diagnostic criteria: alterations in ultrasonographic parameters of both left and right ventricles before and after stress

Background

We estimated the frequency of cirrhotic cardiomyopathy (CCM) using all of the proposed diagnostic criteria, to describe the whole spectrum of cardiac alterations, and to investigate the role of stress in unmasking latent cases of CCM.

Methods

Ninety consecutive patients were recruited. CCM was evaluated using the Montreal, the American Society of Echocardiography 2009 criteria, and the 2019 modified criteria of the CCM consortium. A dobutamine stress test was also performed.

Results

Left ventricular diastolic dysfunction (LVDD) was identified in 72 (80%), 36 (40%), and 10 (11.1%) patients based on the above criteria, respectively. None of the patients had right ventricular systolic dysfunction, either at rest or after stress. The dobutamine stress test revealed left systolic dysfunction in 4 (4.5%) patients. There was agreement among the 3 criteria that the presence of LVDD was not associated with the severity of liver disease, using Child-Pugh stage. However, patients with Child-B/C had longer QTc intervals (P=0.004), higher levels of brain natriuretic peptide (P=0.016), and greater echocardiographic E/e' ratio (P<0.001) and E/e'(s) (P=0.003), compared to Child-A patients, while a significant correlation was demonstrated between Child-Pugh score and E/e' (P<0.001), or E/e'(s) (P=0.002).

Conclusions

The prevalence of LVDD seems to be lower than previously considered. Right ventricular function seems to remain unimpaired. A dobutamine stress uncovered only a small percentage of patients with left systolic dysfunction. Nevertheless, the aggravation of several sonographic variables during stress, particularly in Child-B/C patients, potentially indicates a higher risk for clinical heart failure during stressful invasive interventions.

HFA-PEFF score as an independent predictor of 2-year mortality in liver cirrhosis patients

BACKGROUND AND AIMS

Cardiovascular complications of liver cirrhosis include high cardiac output heart failure with reduced afterload and diastolic dysfunction. Heart Failure Association Pre-test assessment, Echocardiography and natriuretic peptide, Functional testing, Final etiology (HFA-PEFF) (values 0-6) is a diagnostic tool for heart failure. It is a cluster of echocardiographic and biochemical parameters. The purpose of this prospective study was to assess if HFA-PEFF score is associated with the severity of liver disease and to determine its prognostic significance in patients with cirrhosis.

METHODS

Patients with cirrhosis without an acute event were enrolled. A comprehensive echocardiography study was conducted, brain natriuretic peptide and N-terminal-pro-B-type Natriuretic Peptide levels were measured and HFA-PEFF score was calculated. All patients were prospectively followed up after enrollment. The study end-point was defined as the composite of all-cause death.

RESULTS

Seventy-two consecutive patients [median age 59 years (inter-quartile range: 52-65), 72.2% males, Model for End-stage Liver Disease (MELD) 12.9 (8.5-16.3)] were included. The 52.8% had a high HFA-PEFF score (5 or 6) and the 47.2% intermediate/low score (0-4). HFA-PEFF score was correlated with MELD score (rho = 0.566, P  < 0.001), but not with age, SBP and heart rate. The median follow-up was 24.2 (9.5-38.8) months. The 1- and 2-year cumulative mortality was higher in patients with high HFA-PEFF compared to those with intermediate/low (log-rank P  < 0.001 for both). The predicted 2-year probability of survival in high vs intermediate/low HFA-PEFF was found to be a prognostic factor of death even when adjusted for age, gender and MELD score [hazard ratio = 3.539 (1.134-11.046), P  = 0.029].

CONCLUSION

HFA-PEFF score is high among patients with liver cirrhosis, especially those with advanced liver disease. HFA-PEFF score is associated with survival even when adjusting for cirrhosis severity.

The predictive value of revised diastolic dysfunction in outcomes of liver transplantation: A propensity score matching analysis

Background

Diastolic dysfunction (DD), one of the earliest signs of cirrhotic cardiomyopathy (CCM), is included in the revised 2019 CCM criteria. Nonetheless, relevant research regarding the effects of revised DD on post-liver transplantation (LT) outcomes remains limited.

Methods

This retrospective study enrolled patients who underwent LT for decompensated cirrhosis, from January 2018 to March 2021. Patients were divided into DD and non-DD groups. Clinical data were collected. Patients were followed up with, for at least 1 year post-LT; cardiovascular adverse events (AEs) and survival status were recorded. Risk factors were identified using 1:2 propensity score matching (PSM), after adjusting for confounding factors. The caliper value was set to 0.02.

Results

Of 231 patients, 153 were diagnosed with DD (male, 81.8%; mean age, 51.5 ± 9.5 years). Nineteen patients with DD died within 1 year, post-LT. After PSM, 97 and 60 patients were diagnosed with and without DD, respectively. Patients with DD had longer intensive care unit (ICU) stays, higher perioperative cardiovascular AEs, and higher mortality rates than those without DD. In a multivariate analysis, interventricular septum (IVS), left atrial volume index (LAVI), and potassium levels were independent prognostic factors of perioperative cardiovascular AEs, while a decreased early diastolic mitral annular tissue velocity (e'), increased neutrophil-to-lymphocyte ratio (NLR) and tumor markers were predictors of mortality within 1 year post-LT after PSM (P < 0.05).

Conclusion

Cardiac DD may contribute to perioperative cardiovascular AEs and mortality post-LT. Clinicians should be aware of decompensated cirrhosis in patients with DD.

Cardiology Assessment of Patients Undergoing Evaluation for Orthotopic Liver Transplantation

Orthotopic liver transplantation (OLT) is a viable treatment option for end-stage liver disease. Significant perioperative stress is placed on the cardiovascular system because of hemodynamic changes and the length of the operation. Diagnosis and treatment of cardiovascular disease before OLT are imperative to ensure favorable outcomes. Considerable variability exists among practitioners caring for these patients. Institutions tailor their protocols on the basis of local and historical practices, the preferences of the cardiologists, and the OLT team, and algorithms are not often revised or updated on the basis of the available evidence. In collaboration with cardiology and hepatology experts from leading OLT centers, we sought to examine the diagnostic cardiovascular workup of OLT candidates, including a review of the available literature on the diagnostic modalities used to screen cardiovascular disease before OLT. We advocate an emphasis on noninvasive methods to assess cardiovascular risk with reserved use of invasive risk stratification in select patients.

Echocardiographic assessment of cardiovascular function and clinical outcomes in liver transplant recipients

BACKGROUND & AIMS

Cardiovascular disease contributes to a high rate of morbidity and mortality after liver transplantation (LT). However, the progression of cardiac function and cardiac remodeling in LT recipients remains poorly understood. This study sought to evaluate the progression of cardiac function and structure in LT recipients and identify independent predictors of prognosis using echocardiography.

METHODS

From 2009 to 2019, 178 adult LT recipients at a tertiary academic transplant center were retrospectively studied. Transthoracic echocardiograms 1-year pre- and post-LT were assessed. Primary outcomes were progression of systolic and diastolic function. Secondary outcomes included left ventricular remodeling, all-cause mortality, and heart failure readmission post-LT. Subgroup analyzes were performed for etiology of native liver disease. A multivariable model was constructed to examine independent predictors of outcomes.

RESULTS

Systolic function significantly worsened, with reduction in stroke volume (45-37 ml/m² , p < .001), left ventricular ejection fraction (LVEF) (65%-62%, p < .001) and cardiac index (3.00-2.60 L/min/m² , p < .001). Conversely, there were significant improvements in diastolic indices, including tricuspid regurgitation V_max (228-215 cm/s, p = .017), left atrial volume index (LAVI) (32-26 ml/m² , p < .001) and right ventricular systolic pressure (RVSP) (31-28 mmHg, p = .001). Additionally, patients had increased relative wall thickness (RWT) (p < .001) and decreased left ventricular end-diastolic dimension/body surface area (p < .001) post-LT. The independent predictors for all-cause mortality and heart failure were increased pre-LT mitral annular early diastolic velocity (HR 1.11, CI 1.02-1.22, p = .018), LAVI (HR 1.06, CI 1.02-1.11, p = .007) and decreased LVEF (HR .89, CI .82-.97, p = .006). The effect of non-alcoholic steatohepatitis on cardiovascular outcomes post-LT was largely comparable to that of Hepatitis B.

CONCLUSION

This study showed reduced systolic and improved diastolic function in LT recipients and highlighted the utility of pre-LT echocardiogram in the prognostication and risk stratification of LT candidates.

The fundamental role of stress echo in evaluating coronary artery disease in specific patient populations

Stress echocardiography (SE) was initially used for assessing patients with known or suspected coronary heart disease by detecting and evaluating myocardial ischemia and viability. The implementation of SE has gradually been extended to several cardiovascular diseases beyond coronary artery disease, and SE protocols have been modified and adapted for the detection of coronary artery disease (CAD) or other cardiovascular diseases in specific patient populations. This review attempts to summarize current data concerning SE implementation and clinical value in these specific and diverse populations: patients with an intramural course of a coronary artery - known as a myocardial bridge, chronic severe or end-stage hepatic disease, chronic severe or end-stage kidney disease, cardiac allograft vasculopathy, patients scheduled for solid-organ transplantation and other intermediate and high-risk surgery and, finally, patients treated with anticancer drugs or radiotherapy.

Transthoracic ultrasound; seeking the heart in a patient with a large left-sided cirrhotic hydrothorax

A case of a patient with liver cirrhosis and a large left-sided pleural effusion displacing the heart rightward is presented and the best views to acquire images enabling evaluation of the cardiac function are highlighted. Understanding the modified intrathoracic anatomy in patients with pleural effusions enables quick and focused assessment and can shorten evaluation time while preserving high image quality.

Cardiovascular Evaluation of Liver Transplant Patients by Using Coronary Calcium Scoring in ECG-Synchronized Computed Tomographic Scans

Background: The goal of cardiac evaluation of patients awaiting orthotopic liver transplantation (OLT) is to identify the patients at risk for cardiovascular events (CVEs) in the peri- and postoperative periods by opportunistic evaluation of coronary artery calcium (CAC) in non-gated abdominal computed tomographs (CT). Methods: We hypothesized that in patients with OLT, a combination of Lee’s revised cardiac index (RCRI) and CAC scoring would improve diagnostic accuracy and prognostic impact compared to non-invasive cardiac testing. Therefore, we retrospectively evaluated 169 patients and compared prediction of CVEs by both methods. Results: Standard workup identified 22 patients with a high risk for CVEs during the transplant period, leading to coronary interventions. Eighteen patients had a CVE after transplant and a CAC score > 0. The combination of CAC and RCRI ≥ 2 had better negative (NPV) and positive predictive values (PPV) for CVEs (NPV 95.7%, PPV 81.6%) than standard non-invasive stress tests (NPV 92.0%, PPV 54.5%). Conclusion: The cutoff value of CAC > 0 by non-gated CTs combined with RCRI ≥ 2 is highly sensitive for identifying patients at risk for CVEs in the OLT population.

Assessment of biventricular function in patients with hepatopulmonary syndrome

Cardiac function impairment in the setting of hepatopulmonary syndrome (HPS) in patients with end stage liver disease remains an issue of debate. The current study evaluated possible correlations between HPS and biventricular systolic function in patients with decompensated cirrhosis. Consecutive liver transplantation candidates with stable decompensated cirrhosis were prospectively evaluated. HPS was defined as the presence of an elevated alveolar-arterial oxygen gradient and intrapulmonary vasodilatation, detected by contrast enhanced echocardiography. HPS severity was determined based on arterial blood oxygen pressure values, while shunt size was assessed with a semi-quantitative method. Demographic, clinical and laboratory parameters were also prospectively collected. In total, 130 patients (mean age 56.5, M/F: 94/36, MELD score 14.6 ± 5.6) were enrolled, of whom 45 (34.6%) fulfilled the criteria for HPS diagnosis (mild: 57.7%, moderate: 33.3%, severe 4.4% and very severe 4.4%). Significantly lower absolute left ventricular (LV) global longitudinal strain (GLS) values (- 21.6 ± 2.3 vs. - 22.6 ± 2.5%, p = 0.041) were measured in patients with HPS compared to cirrhotic patients without HPS, while there was no statistically significant difference regarding right ventricular GLS (- 22.1 ± 3.3 vs. - 23.2 ± 3.5%, p = 0.061) between the two groups. Lower LV ejection fraction values were also recorded in the HPS group (53.9 ± 3.5 vs. 56.3 ± 4.5%, p < 0.01). No other echocardiographic parameter was correlated to HPS. Intrapulmonary shunt grading was correlated to HPS classification (χ² = 19.8, p < 0.01), with lower arterial oxygen values being recorded in higher stages of intrapulmonary shunt. In patients with cirrhosis, the presence of HPS is associated with worse LV contractile performance.

Speckle Tracking Analysis Reveals Altered Left Atrial and Ventricular Myocardial Deformation in Patients with End-Stage Liver Disease

Background: Cardiac function can be influenced by liver cirrhosis and should be thoroughly evaluated before liver transplantation. We investigated left ventricular (LV) and, for the first time, left atrial (LA) strain and strain rate in end-stage liver cirrhosis patients of different etiologies. Methods: This retrospective, cross-sectional study evaluated left heart function in 80 cirrhosis patients and 30 controls using standardized echocardiographic techniques and speckle tracking technology (STE) analysis. Serum markers of liver function were used for correlation analysis. Results: While conventional parameters demonstrated no alteration in systolic function, speckle tracking analysis showed a significant increase in LV longitudinal strain throughout all cardiac layers, with significant correlation to model of end-stage liver disease (MELD) score. LA reservoir and conduit strain as well as LA strain rate in all phases were significantly reduced in end-stage liver disease (ESLD) patients compared to control. STE for the evaluation of LA phasic function seemed to be more sensitive than volumetric methods. Kaplan-Meier curves showed a trend towards reduced post-transplant survival in patients with a reduced LA reservoir and conduit strain. Conclusion: STE analysis detected increased LV and decreased LA deformation in cirrhosis patients, thus proving to be highly sensitive to cardiac changes and useful for more precise cardiac evaluation.

Preoperative Evaluation of Coronary Artery Disease in Liver Transplant Candidates: Many Unanswered Questions in Clinical Practice

Cardiovascular (CV) complications represent the first non-graft-related cause of death and the third overall cause of death among patients undergoing liver transplantation (LT). History of coronary artery disease is related to increased CV mortality following LT. Although it is of paramount importance to stratify CV risk in pre-LT patients, there is no consensus regarding the choice of the optimal non-invasive cardiac imaging test. Algorithms proposed by scientific associations include non-traditional risk factors, which are associated with increased cardiac risk profiles. Thus, an individualized pre-LT evaluation protocol should be followed. As the average age of patients undergoing LT and the number of candidates continue to rise, the “3 W” questions still remain unanswered, Who, Which and When? Who should be screened for coronary artery disease (CAD), which screening modality should be used and when should the asymptomatic waitlisted patients repeat cardiac evaluation? Prospective studies with large sample sizes are warranted to define an algorithm that can provide better risk stratification and more reliable survival prediction.