The impact of left ventricular hypertrophy on survival in candidates for liver transplantation

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.

Doppler ultrasonography is a useful tool for the diagnosis of hemodynamics in congestive graft injury due to heart failure after liver transplantation: A case report

Introduction

Patients with end-stage liver disease often have cardiac dysfunction, which can be worsened by hemodynamic instability in liver transplantation, causing congestive graft injury.

Presentation of case

A 28-year-old male with Wilson's disease underwent liver transplantation. The patient's history included cirrhotic cardiomyopathy and a preoperative ejection fraction of 37% on echocardiography. After liver transplantation, massive transfusion and acute renal failure led to increased central venous pressure. Doppler ultrasonography (US) showed an increase in positive components of the hepatic vein triphasic wave, followed by pulsatile changes in the portal vein waveforms and an eventual to-and-fro pattern. Laboratory data showed severe elevations of hepatocellular transaminase levels. Based on Doppler US findings, we determined liver damage was due to passive congestion caused by heart failure. Immediate initiation of continuous hemodiafiltration (CHDF) and intra-aortic balloon pumping (IABP) led to the patient's recovery from severe heart failure and graft injury.

Discussion

In our case, changes in the hepatic and portal vein waveforms and marked elevation of hepatocellular transaminases implied exacerbation of heart failure caused by hepatic congestion and injury. Worsening heart failure, in turn, led to progressive liver damage as the result of hepatic passive congestion. The patient's condition was successfully managed with early initiation of CHDF and IABP.

Conclusion

Doppler US can help diagnose congestive graft injury due to heart failure in liver transplant patients and should be performed during post-transplant management of patients with cardiac dysfunction.

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Cardiac dysfunction can worsen after liver transplantation, causing congestive graft injury.

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In the post-transplant period, it is often difficult to differentiate the cause of elevated liver transaminases.

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Doppler ultrasonography helps diagnose congestive graft injury due to heart failure.

Prospective assessment of subclinical cardiovascular damage and associated factors in liver transplant recipients

Cardiovascular (CV) disease plays a major role after liver transplantation (LT). This prospective study assessed subclinical CV damage after LT by measuring pulse wave velocity (PWV), intima-media thickness (IMT) and left-ventricular mass index (LVMI) and characterized associated risk factors. We included 112 patients with a median of 1.8 years after LT (q1-q3 0.9-9.2). Fifty-three percent (n = 59) of patients had ≥2 annual assessments (median follow-up 1.6 years, q1-q3 1.1-2.0), with a total of 195 assessments. We found increased PWV (indicating arteriosclerosis) in 16% (n = 17), elevated IMT in 5% (n = 5; indicating atherosclerosis) and increased LVMI in 25% (n = 24; indicating left-ventricular hypertrophy). A linear mixed model analysis using all 195 assessments revealed that higher age and systolic blood pressure (BP) were associated with higher PWV (β = 0.069, P < 0.001 and β = 0.022, P = 0.005) and higher IMT (β = 0.005, P < 0.001 and β = 0.001, P = 0.029), while higher body mass index was associated with higher IMT (β = 0.004, P = 0.023). Higher systolic BP (β = 0.200, P = 0.034), male sex (β = 8.847, P = 0.031) and lower glomerular filtration rate (β = -0.288, P < 0.001) were associated with higher LVMI. Our data highlight not only the rate of subclinical CV damage in LT patients, but also the impact of classical CV risk factors (such as BP and body mass index) which outweighed LT-related factors. These modifiable risk factors are suitable targets for interventions to reduce CV morbidity in LT patients.

Anesthetic considerations for combined heart--liver transplantation in patients with Fontan-associated liver disease

PURPOSE OF REVIEW

The success of the Fontan procedure has led to increased survival of patients born with certain congenital heart disease to the point that new sequlae, as a result of Fontan circulation, are being discovered. Included among these is Fontan-associated liver disease (FALD). The purpose of this review is to present available literature on the perioperative management of the combined heart--liver transplantation (CHLT) in patients with FALD.

RECENT FINDINGS

The perioperative management of a combined heart-liver transplant in a patient with Fontan circulation is complex. The patient is at risk for hemodynamic disturbances, significant blood loss, coagulopathies, and metabolic derangements. The maintenance of an appropriate transpulmonary pressure gradient is paramount to success. Postoperative management should be accomplished by a multidisciplinary care team. Limited series have demonstrated good outcomes in patients who have undergone CHLT.

SUMMARY

The perioperative management of CHLT in patients with FALD is complex and available literature is limited. Future studies are needed to further assess proper perioperative management of patients with FALD who undergo CHLT.

Pre-Liver Transplant Cardiac Catheterization Is Associated With Low Rate of Myocardial Infarction and Cardiac Mortality

BACKGROUND AND AIMS

A study at Indiana University demonstrated a reduction in myocardial infarction (MI) incidence with increased frequency of cardiac catheterization (CATH) in liver transplant (LT) candidates. A strict protocol for performing CATH based upon predefined risk factors, rather than noninvasive testing alone, was applied to a subgroup (2009-2010) from that study. CATH was followed by percutaneous coronary intervention (PCI) in cases of significant coronary artery disease (CAD; ≥50% stenosis). The current study applies this screening protocol to a larger cohort (2010-2016) to assess post-LT clinical outcomes.

APPROACH AND RESULTS

Among 811 LT patients, 766 underwent stress testing (94%) and 559 underwent CATH (69%), of whom 10% had CAD requiring PCI. The sensitivity of stress echocardiography in detecting significant CAD was 37%. Predictors of PCI included increasing age, male gender, and personal history of CAD (P < 0.05 for all). Compared to patients who had no CATH, patients who underwent CATH had higher mortality (P = 0.07), and the hazard rates (HR) for mortality increased with CAD severity (normal CATH, HR, 1.35; 95% confidence interval [CI], 0.79-2.33; P = 0.298; nonobstructive CAD, HR, 1.53; 95% CI, 0.84-2.77; P = 0.161; and significant CAD, HR, 1.96; 95% CI, 0.93-4.15; P = 0.080). Post-LT outcomes were compared to the 2009-2010 subgroup from the previous study and showed similar 1-year overall mortality (8% and 6%, P = 0.48), 1-year MI incidence (<1% and <1%, P = 0.8), and MI deaths as a portion of all deaths (3% and 9%, P = 0.35).

CONCLUSIONS

Stress echocardiography alone is not reliable in screening LT patients for CAD. Aggressive CAD screening with CATH is associated with low rate of MI and cardiac mortality and validates the previously published protocol when extrapolated over a larger sample and longer follow-up period.

A Systematic Review for Variables to Be Collected in a Transplant Database for Improving Risk Prediction

BACKGROUND

This systematic review was commissioned to identify new variables associated with transplant outcomes that are not currently collected by the Organ Procurement and Transplantation Network (OPTN).

METHODS

We identified 81 unique studies including 1 193 410 patients with median follow-up of 36 months posttransplant, reporting 108 unique risk factors.

RESULTS

Most risk factors (104) were recipient related; few (4) were donor related. Most risk factors were judged to be practical and feasible to routinely collect. Relative association measures were small to moderate for most risk factors (ranging between 1.0 and 2.0). The strongest relative association measure for a heart transplant outcome with a risk factor was 8.6 (recipient with the previous Fontan operation), for a kidney transplant 2.8 (sickle cell nephropathy as primary cause of end-stage renal disease), for a liver transplant 14.3 (recipient serum ferritin >500 µg/L), and for a lung transplant 6.3 (Burkholderia cepacia complex infection for 1 y or less). OPTN may consider some of these 108 variables for future collection to enhance transplant research and clinical care.

CONCLUSIONS

Evidence-based approaches can be used to determine variables collected in databases and registries. Several candidate variables have been identified for OPTN.

Pretransplant left ventricular hypertrophy in association with postoperative myocardial injury in liver transplantation

Pretransplant left ventricular hypertrophy (LVH) is a common finding during preoperative cardiac evaluation. We hypothesized that patients with pretransplant LVH were associated with a higher risk of postoperative myocardial injury (PMI) in adult patients undergoing liver transplantation (LT). A retrospective cohort analysis was performed by reviewing the medical records of adult patients who underwent LT between January 2006 and October 2013. Of 893 patients, the incidences of mild, moderate, and severe LVH were 7.8%, 5.6%, and 2.5%, respectively. Propensity match was used to eliminate the pretransplant imbalance between the LVH and non-LVH groups. In after-match patients, 23.5% of LVH patients developed PMI compared to 11.8% in the control group (P = .011). The incidence of PMI in patients with moderate-severe degrees of LVH was significantly higher compared with that in patients with mild LVH (27.9% vs 19.1%, P = .016). When controlling intraoperative variables, patients with LVH had 4.5 higher odds of developing PMI (95% CI1.18-17.19, P = .028). Patients experiencing PMI had significantly higher 1-year mortality (37.5% vs 15.7%, log-rank test P < .001). Our results suggest that patients with pretransplant LVH were at a high risk of developing PMI and should be monitored closely in the perioperative period. More studies are warranted.

Preoperative cardiac assessment in liver transplant candidates

New and extended indications, older age, higher cardiovascular risk, and the long-standing cirrhosis-associated complications mandate specific skills for an appropriate preoperative assessment of the liver transplant (LT) candidate. The incidence of cardiac diseases (dysrhythmias, cardiomyopathies, coronary artery disease, valvular heart disease) are increasing among LT recipients: however, no consensus exists among clinical practice guidelines for cardiovascular screening and risk stratification. In spite of different "transplant center-centered protocols", basic "pillars" are common (electrocardiography, baseline echocardiography, functional assessment). Owing to intrinsic limitations, yields and relevance of noninvasive stress tests, under constant scrutiny even if used, are discussed, focusing the definition of the "high risk" candidate and exploring noninvasive imaging and new forms of stress imaging. The aim is to find an appropriate and rational stepwise algorithm. The final commitment is to select the right candidate for a finite resource, the graft, able to save (and change) lives.

Liver Transplantation in Patients With Cardiac Disease

Liver transplantation (LT) is a unique surgical procedure that has major hemodynamic and cardiovascular implications. Recently, there has been significant interest focused on cardiovascular issues that affect LT patients in all phases of the perioperative period. The preoperative cardiac evaluation is a major step in the selection of LT candidates. LT candidates are aging in concordance with the general population; cardiovascular disease and their risk factors are highly associated with older age. Underlying cardiovascular disease has the potential to affect outcomes in LT patients and has a major impact on candidate selection. The prolonged hemodynamic and metabolic instability during LT may contribute to adverse outcomes, especially in patients with underlying cardiovascular disease. Cardiovascular events are not unusual during LT; transplant anesthesiologists must be prepared for these events. Advanced cardiovascular monitoring techniques and treatment modalities are now routinely used during LT. Postoperative cardiovascular complications are common in both the early and late posttransplant periods. The impact of cardiac complications on posttransplant mortality is well recognized. Emerging knowledge regarding cardiovascular disease in LT patients and its impact on posttransplant outcomes will have an important role in guiding the future perioperative management of LT patients.

The Circulatory System in Liver Disease

In the cirrhotic liver, distortion of the normal liver architecture is caused by structural and vascular changes. Portal hypertension is often associated with a hyperdynamic circulatory syndrome in which cardiac output and heart rate are increased and systemic vascular resistance is decreased. The release of several vasoactive substances is the primary factor involved in the reduction of mesenteric arterial resistance, resulting in sodium and water retention with eventual formation of ascites. Management of these patients with acute cardiac dysfunction often requires invasive hemodynamic monitoring in an intensive care unit setting to tailor decisions regarding use of fluids and vasopressors.

Predictors of Cardiovascular Events After Liver Transplantation

Indications for liver transplant have been extended, and older and sicker patients are undergoing transplantation. Infectious, malignant, and cardiovascular diseases account for the most posttransplant deaths. Cirrhotic patients can develop heart disease through systemic diseases affecting the heart and the liver, cirrhosis-specific heart disease, or common cardiovascular. No single factor can predict posttransplant cardiovascular complications. Patients with history of cardiovascular disease, and specific abnormalities on echocardiography, electrocardiography, or serum markers of heart disease seem to be at increased risk of complications. Pretransplant cardiovascular evaluation is essential to detecting these risk factors so their effects can be mitigated through appropriate intervention.

Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study

Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk (i.e., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT (i.e., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

Pretransplant echocardiographic parameters as markers of posttransplant outcomes in liver transplant recipients

Despite advances in liver transplantation and preoperative risk stratification, there remains significant posttransplant morbidity and mortality from cardiovascular and renal disease. There are limited and conflicting data on the role of pretransplant echocardiography to predict these outcomes. The purpose of our study was to determine if pretransplant echocardiographic parameters were associated with posttransplant survival and the development of incident cardiovascular events and chronic kidney disease (CKD). We conducted a retrospective cohort study of 397 adult liver transplant recipients at the University of Pennsylvania from January 1, 2005 to September 30, 2014. Patients with acute liver failure, those without a diagnosis of cirrhosis (eg, polycystic liver disease without portal hypertension), retransplants, and multiorgan transplants were excluded. In multivariable Cox regression models, tricuspid regurgitation graded greater than mild was associated with significantly increased posttransplant mortality (hazard ratio, 1.68; 95% confidence interval [CI], 1.03-2.75; P = 0.04). In multivariable competing risk models, increasing pulmonary artery systolic pressure (PASP) was associated with significantly increased risk of hospitalization for myocardial infarction or heart failure (subhazard ratio per 5 mm Hg increase in PASP, 1.79; 95% CI, 1.48-2.17; P < 0.001). In multivariable competing risk models, increased left ventricular ejection fraction (LVEF) was associated with a numerical but nonsignificant increased risk of stage 4 or 5 CKD (subhazard ratio, 1.11 per 5% increase in LVEF; 95% CI, 0.99-1.24; P = 0.07). In a post hoc analysis, LVEF ≥ 65% was the best cutoff for increased risk of CKD (subhazard ratio, 1.75; 95% CI, 1.06-2.89; P = 0.03). In conclusion, several pretransplant echocardiographic parameters were associated with posttransplant morbidity and mortality, suggesting that pretransplant echocardiography may be used as a tool to risk-stratify patients for posttransplant outcomes.

A detailed evaluation of cardiac function in cirrhotic patients and its alteration with or without liver transplantation

BACKGROUND

Cirrhosis has been shown to be associated with left ventricular (LV) myocardial dysfunction, but studies of right ventricular (RV) function in cirrhotic patients compared with controls are scarce. Limited studies have prospectively evaluated the progression of myocardial function in patients with cirrhosis and assessed changes in cardiac function following liver transplantation (LTx). So the aim of the study was to evaluate biventricular myocardial function in cirrhotic patients and its alteration with or without liver transplantation.

METHODS

A total of 103 patients with cirrhosis (age 55±7 years, male 75%) were recruited. Conventional and 2-dimensional speckle tracking echocardiography was performed to determine the presence of LV and RV (biventricular) dysfunction. For comparison, 48 matched control subjects were included. Follow-up echocardiography was performed in 41 patients following LTx and in 26 patients who did not undergo LTx.

RESULTS

Patients with cirrhosis had biventricular dilatation, increased LV mass, impaired LV diastolic function, and biventricular systolic strain compared with controls. Following LTx, cirrhotic patients had reduced biventricular dilatation, a smaller LV mass, and improved biventricular systolic strain after a mean duration of 18.2±6.6 months. Patients who did not undergo LTx had a further increase in LV mass but no significant change in biventricular dimensions or systolic strain (mean duration of 20.4±8.3 months).

CONCLUSIONS

The present study demonstrates that patients with cirrhosis had biventricular dilatation and impaired biventricular systolic strain compared with controls. Following LTx, biventricular dilatation reduced and biventricular systolic strain improved. In contrast, patients who did not undergo LTx experienced a further increase in LV mass.