Cardiovascular dysfunction and liver transplantation

Hepatokines and their role in cardiohepatic interactions in heart failure

Heart failure is one of the leading causes of death and disease worldwide. It is a condition that affects multiple systems within the body. There is a large body of evidence supporting that the liver is a major organ involved in the pathogenesis of heart failure. Cardiac hepatopathy and cirrhotic cardiomyopathy are two conditions that are associated with poor clinical outcomes in patients with heart failure. Despite the extensive proposed explanations of the mechanisms entailing heart failure, there remains a gap in the role of proteins and metabolic regulators produced by hepatocytes and their effect on the development, progression, and prognosis of heart failure, including adverse cardiac remodeling, fibrosis, cardiac cachexia, and renal dysfunction associated with heart failure. The aim of this review is to identify the major hepatokines being studied (adropin, fetuin-A, fetuin-B, FGF-21, selenoprotein P and α1-microglobulin) as modulators of metabolic homeostasis and cardiac dysfunction in heart failure. Research suggests that these factors play a role in modulating oxidative stress, fibrosis, apoptosis, inflammatory responses, immune cell activation, mitochondrial dysfunction, and cellular migration. The exact role of each of these hepatokines is under on-going research and requires more investigations for future clinical use.

Perioperative Variation of Plasma Copeptin and Its Association With Vasopressor Need During Liver Transplantation

BACKGROUND

Vasopressor usage during liver transplant is related to decreased hepatic flow, graft failure, and mortality. We measured plasma Copeptin levels in liver transplant patients based on vasopressor requirements. We hypothesize that preoperative plasma copeptin measurement helps predict the vasopressor infusion requirement during liver transplantation in preoperative evaluation.

METHODS

The plasma Copeptin of 40 patients was measured 5 times: before the operation, 15 minutes before and after reperfusion, and postoperative 12th and 24th hours. Patients were categorized into 2 groups based on vasopressor infusion for comparison.

RESULTS

There was a statistically significant rise in median serum Copeptin concentration between the preoperative phase and before reperfusion (11.2 [7.3-20.9] vs 178.5 [121.5-243.0], P < .001), as well as a statistically substantial decline between after reperfusion and postoperative 12th hours (190.6 [127-276.3] vs 74.7 [42.0-124.9], P < .001). The vasopressor-taking group had significantly higher plasma copeptin at postoperative 12th hours (96.6 [71.4-191.7] vs 55.0 [31.8-82.5], P = .030) and 24th (133.7 [72.2-175.5] vs 51.1 [24.8-85.8], P = .037). A tendency above 11.85 pmol/L of plasma Copeptine level was observed between increasing preoperative plasma Copeptin and the odds of vasopressor use.

CONCLUSION

High preoperative plasma Copeptin levels may be an indicator of vasopressor need during liver transplantation. Further studies with more samples, including a higher range of preoperative plasma Copeptin levels, are required to provide more generalizable findings and to determine thresholds applicable to LT candidates.

Takotsubo Syndrome in Orthotopic Liver Transplant: A Systematic Review and Pooled Analysis of Published Studies and Case Reports

BACKGROUND

Takotsubo syndrome (TTS) has been reported in solid-organ transplant recipients. However, the pooled data regarding TTS after liver transplant remain limited.

METHODS

A systematic review was performed through February 2022 using PubMed, Embase, Scopus, and Google Scholar to review case reports/series and original studies on liver transplant-associated TTS. Descriptive analysis was performed for case reports and pooled analysis for the prevalence using random effects models.

RESULTS

A total of 56 case reports were included from 30 articles (51.8 % male; mean age, 53 years; India 56%, US 27%, and Europe 8.93%) and 10 original studies (US 88.65%, India 10.92%) revealing liver transplant-associated TTS. The pooled prevalence of TTS was 1.1% (95% Cl, 0.6%-1.7%) of all liver transplants with comparable rates in studies from India and the US (P = .92). Indications for liver transplant included end-stage liver disease due to alcohol-related cirrhosis (25%), hepatitis C virus infection (17.9%), hepatocellular carcinoma (10.7%), and non-alcohol-related steatohepatitis (8.9%); the average Model for End-Stage Liver Disease score was 24.75. TTS commonly presented as hypotension (30%), dyspnea (14%), and oliguria, occurring mostly post-transplant (82%), whereas 14% were intraoperative. Common electrocardiogram findings were ST changes, ventricular tachycardia, and atrial fibrillation. Common echocardiogram findings showed left ventricular apical ballooning in 46.5% of cases and reduced ejection fraction < 20% in 41.9% of cases. Common complications were cardiogenic shock (32.1 %), acute kidney injury (12.5%), arrhythmia, stroke, cardiac arrest, and hepatic artery thrombosis. Mechanical circulatory support was required in 30.3%. Recurrence was reported in 15, and mortality in 30.4% of patients.

CONCLUSIONS

Takotsubo syndrome prevalence after liver transplant is significantly higher than TTS prevalence in general US hospitalizations with potentially worse outcomes. Prospective registries reporting TTS in liver transplant recipients are warranted.

Portopulmonary hypertension: peculiarities of diagnosis and treatment

Portopulmonary hypertension is defined as the development of pulmonary hypertension secondary to portal one. Its exact prevalence is difficult to determine due to the lack of routine screening in patients with portal hypertension. Hemodynamic changes associated with portal hypertension, including the hyperdynamic state, portosystemic shunts, and splanchnic vasodilation, cause significant disturbances in the pulmonary vasculature and play a key role in the pathogenesis of the disease. Without treatment, portopulmonary hypertension leads to progressive right ventricular failure with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and candidates for liver transplant, right heart catheterization remains the gold standard for disease diagnosis. Treatment of patients with portopulmonary hypertension is aimed at improving cardiac function, reducing pulmonary vascular resistance, and optimizing functional capacity. Pulmonary hypertension-specific therapy, which includes prostacyclin and its receptor agonists, endothelin receptor antagonists, phosphodiesterase inhibitors, and guanylate cyclase stimulators, plays a key role in the treatment of patients with portopulmonary hypertension. Small uncontrolled and recent single randomized controlled trials have reported promising results of vasodilator therapy in terms of clinical and hemodynamic improvement in patients, allowing certain patients to undergo liver transplantation. This review discusses the epidemiology, approach to diagnosis and treatment of patients with portopulmonary hypertension. We used MEDLINE database on the PubMed platform and the Cochrane library to search for literature sources using the keywords: portopulmonary hypertension, portal hypertension, pulmonary hypertension, liver cirrhosis, pulmonary complications.

Current clinical understanding and effectiveness of portopulmonary hypertension treatment

Portopulmonary hypertension (PoPH) is a rare subtype of Group 1 pulmonary arterial hypertension (PAH) with a poor prognosis. According to the most up-to-date definition, PoPH is characterized by a mean pulmonary arterial pressure (PAP) of &gt;20 mmHg at rest, a pulmonary artery wedge pressure of ≤15 mmHg, and a pulmonary vascular resistance (PVR) of &gt;2 Wood units with portal hypertension. Like PAH, PoPH is underpinned by an imbalance in vasoactive substances. Therefore, current guidelines recommend PAH-specific therapies for PoPH treatment; however, descriptions of the actual treatment approaches are inconsistent. Given the small patient population, PoPH is often studied in combination with idiopathic PAH; however, recent evidence suggests important differences between PoPH and idiopathic PAH in terms of hemodynamic parameters, treatment approaches, survival, socioeconomic status, and healthcare utilization. Therefore, large, multi-center registry studies are needed to examine PoPH in isolation while obtaining statistically meaningful results. PoPH has conventionally been excluded from clinical drug trials because of concerns over hepatotoxicity. Nevertheless, newer-generation endothelin receptor antagonists have shown great promise in the treatment of PoPH, reducing PVR, PAP, and World Health Organization functional class without causing hepatotoxicity. The role of liver transplantation as a treatment option for PoPH has also been controversial; however, recent evidence shows that this procedure may be beneficial in this patient population. In the future, given the shortage of liver donors, predictors of a favorable response to liver transplantation should be determined to select the most eligible patients. Collectively, advances in these three areas could help to standardize PoPH treatment in the clinic.

Transient decrease in B-type natriuretic peptide level after liver transplantation does not ensure favorable post-transplant 30-day outcomes

BACKGROUND

High B-type natriuretic peptide (BNP) levels within the first 3 postoperative days (postBNPPOD3) after liver transplantation (LT) are greatly predictive of the 30-day mortality. We evaluated clinical impact of transient decrease in postBNPPOD3 compared to pretransplant BNP (preBNP) level on mortality and major adverse cardiac event (MACE) within 30 days after LT.

METHODS

We retrospectively evaluated 3,811 LT patients who measured delta BNP (deltaBNP), defined by serial postBNPPOD3 minus preBNP. Thirty-day all-cause mortality and MACE were estimated in patients with deltaBNP < 0 (n = 594, 15.6%) and > 0 (n = 3,217, 84.4%), respectively. Kaplan-Meier survival and multivariable Cox regression analysis were used.

RESULTS

Within 30 days, 100 (2.6%) of all patients died. Unexpectedly, 30-day mortality rate (6.1% [95% CI: 4.2-8.4%] vs. 2.0% [95% CI: 1.5-2.5%], P < 0.001) and MACE (24.2% [95% CI: 20.4-28.5%] vs. 15.3% [95% CI: 14.0-16.7%], P < 0.001) were higher in patients with deltaBNP < 0 compared to those with deltaBNP > 0, respectively. Patients with deltaBNP < 0 had higher preBNP level (median [interquartile range], 251 [118, 586] vs. 43 [21, 92] pg/ml, P < 0.001) and model for end-stage liver disease score (26 [14, 37] vs. 14 [9, 23], P < 0.001) and more transfused intraoperatively. DeltaBNP < 0 remained significant after adjustments for potential confounders in multivariable analysis of 30-day mortality and MACE.

CONCLUSIONS

DeltaBNP < 0 within the first 3 postoperative days is mainly attributed to pre-LT severe liver and cardiac disease status, therefore, transient decrease in BNP level after LT does not ensure favorable post-LT 30-day outcomes.

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.

Temporary postoperative myocardial injury and long-term survival in liver transplant patients with coronary artery disease

Background: Coronary artery disease (CAD) is increasing worldwide due to the aging population and cardiometabolic syndrome. However, the extent of postoperative myocardial injury, the most common cause of death during the 30 days after noncardiac surgery, remains unclear with respect to liver transplant (LT) patients with CAD. We examined the link between post-LT high sensitivity cardiac troponin I (hs_cTnI) and long-term survival according to liver disease severity.Methods: Consecutive patients who underwent LT (n = 3,220) from 2010 to 2020 were evaluated retrospectively. CAD was defined as a history of coronary artery bypass surgery or percutaneous intervention, or previous myocardial infarction. Peak hs_cTnI levels within 30 days post-transplant were compared in patients with and without CAD. The primary endpoint was defined as an all-cause mortality at 12 years following LT. Secondary endpoints include peak hs_cTnI level within post-transplant 30 days and 30-day mortality. Survival analysis was performed using the Kaplan–Meier method.Results: CAD patients (n = 264, 8.2%) had higher peak hs_cTnI levels within 30 days post-LT than those without CAD (median [interquartile]: 0.068 [0.030–0.154] vs. 0.087 [0.037–0.203] ng/ml, respectively; P = 0.004); however, the mortality rate was comparable (14.7% vs. 14.8%, respectively, P = 0.999), at 12 years, and 1.9% vs. 1.1% (P = 0.522) at 30 days, respectively, at 30 days. Subgroup analysis with stratified liver disease severity identified a similar risk of long-term mortality.Conclusions: Although the peak hs_cTnI level within 30 days was higher in revascularized or treated CAD patients after LT compared those without CAD, long-term mortality rates at 12 years and 30-day mortality rate were comparable.

Five-year all-cause mortality in critically ill liver transplant patients with coronary artery disease: analysis of acute-on chronic liver failure

Background: Patients with acute-on-chronic liver failure (ACLF) are critically ill and have high waiting-list mortality. Although studies demonstrated that appropriately treated coronary artery disease (CAD) should not be regarded as a contraindication to liver transplant (LT), data regarding long-term outcomes in critically ill liver LT recipients are lacking. The aim of this study was to compare the rates of all-cause death at 5 years following LT in patients with ACLF with or without CAD.Methods: Between 2010 and 2020, we evaluated 921 consecutive LT patients (MELD score, 32 ± 9) and ACLF classified by CLIF-C ACLF score. Up to 5-year all-cause death according to the CAD status was examined. CAD was defined as a preoperative history of coronary artery bypass graft or a percutaneous intervention and old myocardial infarction. Kaplan-Meier survival analysis was used.Results: Up to 5 years, 212 (23.0%) of all ACLF patients (n = 921) in whom 17 (29.3%) of 58 CAD patients died. In patients with CAD (6.3%, 58/921), the Kaplan-Meier cumulative mortality rate at 5 years was numerically higher but was not statistically significant when compared with those without CAD (32.9% vs. 23.5%, log-rank, P = 0.25). In subgr oup analysis, there were comparable risks of cumulative mortalities at 5 years across the stratification of ACLF grade 1, 2, and 3 (log-rank P = 0.062, P = 0.72, and P = 0.999, respectively).Conclusions: All-cause mortality is high in patients with ACLF after LT but is not related to the presence of revascularized or treated CAD, across the stratification of ACLF grades.

Liver stiffness and liver function index in liver fibrosis patients afflicted with electrocardiographic abnormalities

Introduction

Heart disorders are one of the causes of death in cirrhotic patients.

Objectives

This study aimed to investigate liver stiffness and liver function indices in liver fibrosis patients afflicted with electrocardiographic abnormalities.

Patients and Methods

wo hundred patients entered this cross-sectional study. First, all of the patients underwent liver elastography. They were then divided into four groups based on the results obtained. Patients in three of the total groups (I-III) had fibrosis and those in the fourth group (IV) had cirrhosis. Afterward, electrocardiograms were taken from the patients, and based on the existence of electrocardiographic abnormalities, the patients were divided into two groups (group 1, consisting of liver fibrosis patients with a heart disease and group 2, consisting of those without a heart disease). Finally, liver function index, liver stiffness, frequency of variables, and their relationship with the presence or absence of electrocardiographic (ECG) abnormalities were analyzed.

Results

Forty-eight percent of the patients were afflicted with ECG abnormalities. The majority of the patients in each of the two groups were male. The differences between patients with and without electrocardiographic abnormalities as regards to liver stiffness, liver function index, and platelet count were found to be statistically significant (P < 0.05). However, the differences between the two groups with regard to serum transaminase levels did not appear to be statistically significant (P > 0.05).

Conclusion

It seems that liver stiffness and liver function index are non-invasive factors for predicting the presence of accompanying heart disorders in patients suffering from liver fibrosis.

Features of Cirrhotic Cardiomyopathy Early in the Lives of Infants With Biliary Atresia Correlate With Outcomes Following Kasai Portoenterostomy

Cirrhotic cardiomyopathy (CCM), detected during two-dimensional echocardiography (2DE), is prevalent in patients with biliary atresia (BA) awaiting transplant. Whether CCM occurs early in the lives of infants with BA is unknown. The aim of this study was to explore the incidence and consequence of CCM in patients with BA, focusing on the earliest ages when 2DE was performed. A cohort of 78 patients with BA at a single center underwent 2DE (median age = 132 days) during the first year of life. Left ventricular mass index (LVMI) to upper limit of normal (ULN) ratio ≥ 1.0 was present in 60% of patients who never underwent Kasai portoenterostomy (KPE; n = 15), 49% with nondraining KPE (n = 41), and 21% with draining KPE (n = 19). Patients with a draining KPE (median age at 2DE = 72 days) had a lower LVMI/ULN ratio (0.75 [interquartile range [IQR] 0.70, 0.91]) compared to those with a nondraining KPE (0.99 [IQR 0.78, 1.17] median age of 141 days; P = 0.012). In those whose 2DE was performed within 7 days of KPE (n = 19, median age of 61 days), the LVMI/ULN ratio was lower in those with a future draining KPE (0.73 [IQR 0.66, 0.75]) compared to the group with a future nondraining KPE (1.03 [IQR 0.88, 1.08], P = 0.002). Logistic regression modeling revealed LVMI/ULN ratio ≥ 1.0 as a predictor of KPE outcome, with an odds ratio of 16.7 (95% confidence interval 1.36-204; P = 0.028) for a future nondraining KPE compared to those with a LVMI/ULN ratio < 1.0. Conclusion: 2DE early in the lives of patients with BA revealed features of CCM that correlated with future outcomes. If validated in a multicenter study, this could lead to 2DE as a useful clinical tool in the care of infants with BA.

A Case of Severe Tricuspid Valve Regurgitation in a Patient Undergoing Orthotopic Liver Transplantation: Whether to Proceed, or Not

A 38-year-old male presented for orthotopic liver transplantation complicated by new-onset torrential tricuspid regurgitation before incision. Subclinical volume overload and functional tricuspid regurgitation created a challenging scenario in which the benefits of expeditious transplant were weighed against the risks of allograft congestion and failure. Intraoperative transesophageal echocardiography proved critical in diagnosing severe tricuspid regurgitation and guided clinical decision making. In this article, we describe the intraoperative presentation of acutely elevated right heart pressures and the subsequent management of this patient prior to ultimately successful liver transplantation.

Cardiovascular disease risk in liver transplant recipients transplanted due to chronic viral hepatitis

Background

Cardiovascular disease (CVD) is a major cause of morbidity and mortality after liver transplantation, mostly in patients transplanted for nonalcoholic steatohepatitis, obesity and diabetes. Few data exist on cardiovascular diseases among patients transplanted for viral hepatitis.

Objective

Our aim is to clarify the cardiovascular risk and subclinical vascular damage among liver transplant recipients for chronic viral hepatitis (i.e. hepatits C virus, hepatis B virus and hepatitis D virus infection).

Methods

Adult patients (age ≥ 18 years) with orthotopic liver transplants (OLT) due to viral hepatitis who signed informed consent, and were admitted for a routine follow-up between June 2019 and September 2020 at the Infectious Disease outpatient clinic of the University of Campania Luigi Vanvitelli, Naples, Italy, were prospectively enrolled. An estimation of cardiovascular risk was assessed using three main risk charts, echocolor-Doppler of epiaortic vessels was performed to assess subclinical Intima-Media changes.

Results

A total of 161 patients were evaluated; of these 15 were excluded because not affected by viral hepatitis. 146 patients were considered. 83 patients (56.8%) were considered at high cardiovascular risk according to Framingham, 54 patients (36.9%) to American Heart Association Arteriosclerotic Cardiovascular Disease (ASCVD) score and 19 (13.0%) to Heart Score. Only 8 patients (5.4%) showed a normal carotid ultrasound, while 52 patients (35.6%) had a carotid artery Intima-Media Thickness (IMT) and 86 (58.9%) an atherosclerotic plaque.

Conclusions

Liver transplant recipients for virus-related associated liver disease are, in light of the high percentage of carotid lesions, at high risk of CVD. Risk charts compared to subclinical carotid lesions which represent damage already established and a real localization of the disease, seem to underestimate the cardiovascular risk. A chronic inflammatory status, could play a key role. It’s important to raise the awareness of cardiovascular risk in liver transplant patients to prevent cardiovascular diseases and improve the timing of early diagnosis of premature vascular lesions.

Ability of dynamic preload indices to predict fluid responsiveness in a high femoral-to-radial arterial pressure gradient: a retrospective study

Background

Dynamic preload indices may predict fluid responsiveness in end-stage liver disease. However, their usefulness in patients with altered vascular compliance is uncertain. This study is the first to evaluate whether dynamic indices can reliably predict fluid responsiveness in patients undergoing liver transplantation with a high femoral-to-radial arterial pressure gradient (PG).

Methods

Eighty liver transplant recipients were retrospectively categorized as having a normal (n = 56) or high (n = 24, difference in systolic pressure ≥ 10 mmHg and/or mean pressure ≥ 5 mmHg) femoral-to-radial arterial PG, measured immediately after radial and femoral arterial cannulation. The ability of dynamic preload indices (stroke volume variation, pulse pressure variation [PPV], pleth variability index) to predict fluid responsiveness was assessed before the surgery. Fluid replacement of 500 ml of crystalloid solution was performed over 15 min. Fluid responsiveness was defined as ≥ 15% increase in the stroke volume index. The area under the receiver-operating characteristic curve (AUC) indicated the prediction of fluid responsiveness.

Results

Fourteen patients in the normal, and eight in the high PG group were fluid responders. The AUCs for PPV in the normal, high PG groups and total patients were 0.702 (95% confidence interval [CI] 0.553–0.851, P = 0.008), 0.633 (95% CI 0.384–0.881, P = 0.295) and 0.667 (95% CI 0.537–0.798, P = 0.012), respectively. No other index predicted fluid responsiveness.

Conclusion

PPV can be used as a dynamic index of fluid responsiveness in patients with end-stage liver disease but not in patients with altered vascular compliance.

Intraoperative lactic acid concentration during liver transplantation and cutoff values to predict early mortality: a retrospective analysis of 3,338 cases

Background

We aimed to explore the distribution of intraoperative lactic acid (LA) level during liver transplantation (LT) and determine the optimal cutoff values to predict post-LT 30-day and 90-day mortality.

Methods

Intraoperative LA data from 3,338 patients were collected between 2008 to 2019 and all-cause mortalities within 30 and 90 days were retrospectively reviewed. Of the three LA levels measured during preanhepatic, anhepatic, and neohepatic phase of LT, the peak LA level was selected to explore the distribution and predict early post-LT mortality. To determine the best cutoff values of LA, we used a classification and regression tree algorithm and maximally selected rank statistics with the smallest P value.

Results

The median intraoperative LA level was 4.4 mmol/L (range: 0.5-34.7, interquartile range: 3.0-6.2 mmol/L). Of the 3,338 patients, 1,884 (56.4%) had LA levels > 4.0 mmol/L and 188 (5.6%) had LA levels > 10 mmol/L. Patients with LA levels > 16.7 mmol/L and 13.5-16.7 mmol/L showed significantly higher 30-day mortality rates of 58.3% and 21.2%, respectively. For the prediction of the 90-day mortality, 8.4 mmol/L of intraoperative LA was the best cutoff value.

Conclusions

Approximately 6% of the LT recipients showed intraoperative hyperlactatemia of > 10 mmol/L during LT, and those with LA > 8.4 mmol/L were associated with significantly higher early post-LT mortality.

Serious acid-base disorder or life-threatening arrhythmia in patients with ABO-incompatible liver transplantation who received therapeutic plasma exchange - A report of two cases

Background

Excessive citrate load during therapeutic plasma exchange (TPE) can cause metabolic alkalosis with compensatory hypercarbia and electrolyte disturbances. If TPE is required immediately before ABO-incompatible (ABOi) liver transplant (LT) surgery, metabolic derangement and severe electrolyte disturbance could worsen during LT anesthesia.

Case

We report two ABOi LT cases who received TPE on the day of surgery because isoagglutinin titers did not be dropped below 1:8. One case had a surprisingly high metabolic alkalosis with a pH of 7.73 immediately after tracheal intubation because of hyperventilation during mask bagging. The other experienced sudden ventricular tachycardia and blood pressure drop after surgical incision accompanied with severe hypokalemia of 1.8 mmol/L despite supplementation with potassium.

Conclusions

Special attention should be paid to patients who just completed TPE the operative day morning as they are vulnerable to severe acid-base disturbances and life-threatening ventricular arrhythmias in ABOi LT.

The Prognostic Role of Right Ventricular Stroke Work Index during Liver Transplantation

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan–Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12–1.36, p < 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15–1.37, p < 0.001). Kaplan–Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

Prognostic Value of B-Type Natriuretic Peptide in Liver Transplant Patients: Implication in Posttransplant Mortality

BACKGROUND AND AIMS

Despite frequent cirrhotic cardiomyopathy or subclinical heart failure (HF), the prognostic value of peri-liver transplant (LT) B-type natriuretic peptide (BNP) has been poorly studied in advanced liver disease. We examined the association between BNP and mortality in a large cohort of LT patients and identified risk factors for peri-LT BNP increase.

APPROACH AND RESULTS

Using prospectively collected data from the Asan LT Registry between 2008 and 2019, 3,811 patients who measured serial pretransplant BNP (preBNP) and peak BNP levels within the first 3 posttransplant days (postBNP_POD3 ) were analyzed. Thirty-day all-cause mortality predicted by adding preBNP and/or postBNP_POD3 to the traditional Revised Cardiac Risk Index (RCRI) was evaluated. PreBNP > 400 pg/mL (known cutoff of acute HF) was found in 298 (7.8%); however, postBNP_POD3  > 400 pg/mL was identified in 961 (25.2%) patients, specifically in 40.4% (531/1,315) of those with a Model for End-Liver Disease score (MELDs) > 20. Strong predictors of postBNP_POD3  > 400 pg/mL were preBNP, hyponatremia, and MELDs, whereas those of preBNP > 400 pg/mL were MELDs, kidney failure, and respiratory failure. Among 100 (2.6%) post-LT patients who died within 30 days, patients with postBNP_POD3  ≤ 150 pg/mL (43.1%, reference group), 150-400 pg/mL (31.7%), 400-1,000 pg/mL (18.5%), 1,000-2,000 pg/mL (4.7%), and >2,000 pg/mL (2.0%) had 30-day mortalities of 0.9%, 2.2%, 4.0%, 7.7%, and 22.4%, respectively. Adding preBNP, postBNP_POD3 , and both BNP to RCRI improved net reclassification index to 22.5%, 29.5%, and 33.1% of 30-day mortality, respectively.

CONCLUSIONS

PostBNP_POD3  > 400 pg/mL after LT was markedly prevalent in advanced liver disease and mainly linked to elevated preBNP. Routine monitoring of peri-LT BNP provides incremental prognostic information; therefore, it could help risk stratification for mortality as a practical and useful biomarker in LT.

CAD-LT score effectively predicts risk of significant coronary artery disease in liver transplant candidates

BACKGROUND & AIMS

Patients with cirrhosis and significant coronary artery disease (CAD) are at risk of peri-liver transplantation (LT) cardiac events. The coronary artery disease in liver transplantation (CAD-LT) score and algorithm aim to predict the risk of significant CAD in LT candidates and guide pre-LT cardiac evaluation.

METHODS

Patients who underwent pre-LT evaluation at Indiana University (2010-2019) were studied retrospectively. Stress echocardiography (SE) and cardiac catheterization (CATH) reports were reviewed. CATH was performed for predefined CAD risk factors, irrespective of normal SE. Significant CAD was defined as CAD requiring percutaneous or surgical intervention. A multivariate regression model was constructed to assess risk factors. Receiver-operating curve analysis was used to compute a point-based risk score and a stratified testing algorithm.

RESULTS

A total of 1,771 pre-LT patients underwent cardiac evaluation, including results from 1,634 SE and 1,266 CATH assessments. Risk-adjusted predictors of significant CAD at CATH were older age (adjusted odds ratio 1.05; 95% CI 1.03-1.08), male sex (1.69; 1.16-2.50), diabetes (1.57; 1.12-2.22), hypertension (1.61; 1.14-2.28), tobacco use (pack years) (1.01; 1.00-1.02), family history of CAD (1.63; 1.16-2.28), and personal history of CAD (6.55; 4.33-9.90). The CAD-LT score stratified significant CAD risk as low (≤2%), intermediate (3% to 9%), and high (≥10%). Among patients who underwent CATH, a risk-based testing algorithm (low: no testing; intermediate: non-invasive testing vs. CATH; high: CATH) would have identified 97% of all significant CAD and potentially avoided unnecessary testing (669 SE [57%] and 561 CATH [44%]).

CONCLUSIONS

The CAD-LT score and algorithm (available at www.cad-lt.com) effectively stratify pre-LT risk for significant CAD. This may guide more targeted testing of candidates with fewer tests and faster time to waitlist.

LAY SUMMARY

The coronary artery disease in liver transplantation (CAD-LT) score and algorithm effectively stratify patients based on their risk of significant coronary artery disease. The CAD-LT algorithm can be used to guide a more targeted cardiac evaluation prior to liver transplantation.

Correlation between radial and femoral arterial blood pressure during reperfusion in living donor liver transplantation

Background and Aims

Accurate blood pressure measurements are the mainstay for the efficient management of abrupt cardiovascular changes during reperfusion in liver transplant. We sought to compare the femoral and radial pressures during reperfusion and at T1:baseline, T2: 1 h in dissection: T3:portosystemic shunt, T4:reperfusion, T5: at bile duct anastomosis.

Methods

A retrospective study was performed amongst 102 adult patients who underwent R lobe living donor liver transplantation. Mean arterial pressure (MAP) and systolic arterial pressure (SAP) at 10 s intervals at reperfusion and at five fixed time points were compared by intraclass correlation coefficient (ICC) and limits of agreement by Bland-Altman statistics.

Results

MAP by both routes had a good correlation at all time points during reperfusion (overall ICC: 0.946 [0.938, 0.949]) in comparison with SAP (overall ICC: 0.650 [0.6128, 0.684]). At the lowest reperfusion pressure (reperfusion point), MAP showed high levels of agreements (ICC: 0.833 [0.761, 0.885]), whereas SAP showed only a poor level of agreement (ICC 0.343 [0.153, 0.508]). The Bland-Altman analysis for MAP showed a bias of 7.18 (5.94) mmHg and limits of agreement of - 4.5 mmHg to + 18.8 mmHg and for SAP a bias of 25.2 (22.04) mmHg and limits of agreement of - 18.0 mmHg to + 68.4 mmHg at the reperfusion point. The incidence of post-reperfusion syndrome (PRS) was 52.94% by femoral and 57.84% by radial routes.

Conclusions

Radial MAP correlated well with femoral MAP during reperfusion and at predefined time points and can be used interchangeably for intraoperative monitoring. A high incidence of PRS was noted by our technique of measurement.

Rupture Risk of Intracranial Aneurysm and Prediction of Hemorrhagic Stroke after Liver Transplant

Postoperative hemorrhagic stroke (HS) is a rare yet devastating complication after liver transplantation (LT). Unruptured intracranial aneurysm (UIA) may contribute to HS; however, related data are limited. We investigated UIA prevalence and aneurysmal subarachnoid hemorrhage (SAH) and HS incidence post-LT. We identified risk factors for 1-year HS and constructed a prediction model. This study included 3544 patients who underwent LT from January 2008 to February 2019. Primary outcomes were incidence of SAH, HS, and mortality within 1-year post-LT. Propensity score matching (PSM) analysis and Cox proportional hazard analysis were performed. The prevalence of UIAs was 4.63% (n = 164; 95% confidence interval (CI), 3.95–5.39%). The 1-year SAH incidence was 0.68% (95% CI, 0.02–3.79%) in patients with UIA. SAH and HS incidence and mortality were not different between those with and without UIA before and after PSM. Cirrhosis severity, thrombocytopenia, inflammation, and history of SAH were identified as risk factors for 1-year HS. UIA presence was not a risk factor for SAH, HS, or mortality in cirrhotic patients post-LT. Given the fatal impact of HS, a simple scoring system was constructed to predict 1-year HS risk. These results enable clinical risk stratification of LT recipients with UIA and help assess perioperative HS risk before LT.

Markedly prolonged QTc interval in end-stage liver disease and risk of 30-day cardiovascular event after liver transplant

BACKGROUND AND AIM

The proportional increase of corrected QT interval (QTc) along end-stage liver disease (ESLD) severity may lead to inconsistent outcome reporting if based on conventional threshold of prolonged QTc. We investigated the comprehensive QTc distribution among ESLD patients and assessed the association between QTc > 500 ms, a criterion for diagnosing severe long-QT syndrome, and the 30-day major adverse cardiovascular event (MACE) after liver transplantation (LT) and identified the risk factors for developing QTc > 500 ms.

METHODS

Data were collected prospectively from the Asan LT Registry between 2011 and 2018, and outcomes were retrospectively reviewed. Multivariable analysis and propensity score-weighted adjusted odds ratios (ORs) were calculated. Thirty-day MACEs were defined as the composite of cardiovascular mortality, arrhythmias, myocardial infarction, pulmonary thromboembolism, and/or stroke.

RESULTS

Of 2579 patients, 194 (7.5%) had QTc > 500 ms (QTc500_Group), and 1105 (42.8%) had prolonged QTc (QTcP_Group), defined as QTc > 470 ms for women and >450 ms for men. The 30-day MACE occurred in 336 (13%) patients. QTc500_Group showed higher 30-day MACE than did those without (20.1% vs 12.5%, P = 0.003), with corresponding adjusted OR of 1.24 (95% CI: 1.06-1.46, P = 0.007). However, QTcP_Group showed comparable 30-day MACE (13.3% vs 12.8% without prolonged QTc, P = 0.764). Significant risk factors for QTc > 500 ms development were advanced liver disease, female sex, hypokalemia, hypocalcemia, high left ventricular end-diastolic volume, and tachycardia.

CONCLUSION

Our results revealed that, among ESLD patients, a novel threshold of QTc > 500 ms was associated with post-LT 30-day MACE but not with conventional threshold, indicating that a longer QTc threshold should be considered for this unique patient population.

Diagnostic accuracy of cardiac testing for coronary artery disease in potential liver transplant recipients: A systematic review and meta-analysis

Background

The incidence of coronary artery disease (CAD) in Liver transplant (LT) patients is much higher than prior estimates and the morbidity and mortality are significant in this group of patients. Coronary angiography is the gold standard for detection of CAD, a non-invasive test that allows appropriate risk stratification would be preferred. In this systematic review and meta-analysis, we sought to assess the pooled diagnostic accuracy of various noninvasive cardiac imaging tests in detecting CAD in patients listed for LT.

Methods

We performed a systematic review and meta-analysis of studies comparing sensitivity and specificity of non-invasive tests to that of coronary angiography in diagnosing coronary artery disease in patients undergoing liver transplantation.

Results

Five studies (616 participants) evaluated myocardial perfusion imaging (MPI); five studies (1243 participants) dobutamine stress echocardiography (DSE); and three (87 participants), other tests. MPI had a pooled sensitivity of 0.62 (95% CI 0.37, 0.83), specificity of 0.60 (95% CI 0.39, 0.79), diagnostic odds ratio (DOR) of 2.5 (95% CI 1.7, 5.64) and Area under the curve (AUC) 0.649. DSE had a pooled sensitivity of 0.25 (95%CI 0.09, 0.51), specificity of 0.68 (95% CI 0.44, 0.84) and DOR of 0.7 (95% CI 0.12, 3.84).

Conclusions

Our results show that both MPI and DSE are not effective screening tools for detecting CAD in patients with end-stage liver disease (ESLD). Future studies are needed to evaluate the role of real-time myocardial contrast echocardiography (RTMCE) and coronary artery calcium score (CAC) with coronary CT angiography in patients with ESLD.

von Willebrand factor to protein C ratio-related thrombogenicity with systemic inflammation is predictive of graft dysfunction after liver transplantation: Retrospective cohort study

INTRODUCTION

Early allograft dysfunction (EAD) is known to be a prototype of graft failure and ultimately influences long-term graft failure or death. We hypothesized that pretransplant thrombogenicity evaluated by procoagulant and anticoagulant, von Willebrand factor (vWF), factor Ⅷ (FⅧ), protein C (PC) and their imbalance ratio of vWF-to-PC (vWFPCR) and FVIII-to-PC (FⅧPCR), is associated with EAD and 90-day graft failure after living-related liver transplantation (LDLT) and contributes to further exacerbation of graft dysfunction when coexists with systemic inflammation.

MATERIAL AND METHODS

Of 1199 prospectively registered LDLT patients, 698 with measurements of each thrombogenicity parameters were analyzed. Risk factors for EAD development were searched and subsequent best cut-offs was calculated according to the receiver operator characteristic curve analysis. When comparing the outcome, multivariable regression analysis and inverse probability of treatment weighting (IPTW) of the propensity score were performed.

RESULTS

The prevalence of EAD was 10.7% (n = 75/698) after LDLT. Of parameters, vWFPCR had highest predictivity potential of EAD with the best cut-off of 8.06. The relationship between vWFPCR≥8.06 showed significant association with EAD development (OR [95%CI], 2.55[1.28-5.09], P = 0.008) and 90-day graft failure (HR [95%CI], 2.24 [1-4.98], P = 0.043) after IPTW-adjustment. Furthermore, risk of EAD increased proportionally with increasing C-reactive protein as a continuous metric of systemic inflammation, and more steeply in those with higher thrombogenicity (i.e., higher vWFPCR). Adding vWFPCR to MELD score improved EAD risk prediction by 21.9%.

CONCLUSIONS

Pretransplant thrombogenicity assessed by imbalance of pro- and anticoagulant, was significantly associated with EAD and 90-day graft failure after LDLT and this association was worsened by systemic inflammation.

Preoperative high-sensitivity troponin I and B-type natriuretic peptide, alone and in combination, for risk stratification of mortality after liver transplantation

Background

Given the severe shortage of donor liver grafts, coupled with growing proportion of cardiovascular death after liver transplantation (LT), precise cardiovascular risk assessment is pivotal for selecting recipients who gain the greatest survival benefit from LT surgery. We aimed to determine the prognostic value of pre-LT combined measurement of B-type natriuretic peptide (BNP) and high-sensitivity troponin I (hsTnI) in predicting early post-LT mortality.

Methods

We retrospectively evaluated 2,490 consecutive adult LT patients between 2010 and 2018. Cut-off values of BNP and hsTnI for predicting post-LT 90-day mortality were calculated. According to the derived cut-off values of two cardiac biomarkers, alone and in combination, adjusted hazard ratios (aHR) of post-LT 90-day mortality were determined using multivariate Cox regression analysis.

Results

Mortality rate after 90 days was 2.9% (72/2,490). Rounded cut-off values for post-LT 90-day mortality were 400 pg/ml for BNP (aHR 2.02 [1.15, 3.52], P = 0.014) and 60 ng/L for hsTnI (aHR 2.65 [1.48, 4.74], P = 0.001), respectively. Among 273 patients with BNP ≥ 400 pg/ml, 50.9% of patients were further stratified into having hsTnI ≥ 60 ng/L. Combined use of pre-LT cardiac biomarkers predicted post-LT 90-day mortality rate; both non-elevated: 1.0% (21/2,084), either one is elevated: 9.0% (24/267), and both elevated: 19.4% (27/139, log-rank P < 0.001; aHR vs non-elevated 4.23 [1.98, 9.03], P < 0.001).

Conclusions

Concomitant elevation of both cardiac biomarkers posed significantly higher risk of 90-day mortality after LT. Pre-LT assessment cardiac strain and myocardial injury, represented by BNP and hsTnI values, would contribute to prioritization of LT candidates and help administer target therapies that could modify early mortality.

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.

Systolic anterior motion of mitral chordae tendineae: prevalence and clinical implications in liver transplantation

Background

Although systolic anterior motion (SAM) of the mitral valve anterior leaflet is well-known to cause hemodynamic perturbation in many anesthetic situations, the prevalence and clinical implication of SAM of mitral chordae tendineae (chordal SAM) in liver transplantation (LT) has not been evaluated. We aimed to assess the impact of chordal SAM on intraoperative postreperfusion syndrome and short and long-term all-cause mortality.

Methods

We retrospectively evaluated 1751 LT recipients from January 2011 to June 2017 who had preoperative echocardiography. Echocardiography-derived parameters and the prevalence of post-reperfusion syndrome between those with chordal SAM and without chordal SAM were compared. The cumulative mortality rate according to the presence of chordal SAM was evaluated by the Kaplan-Meier survival curve.

Results

Of the enrolled recipients, 21 (1.2%) had chordal SAM in preoperative echocardiography. Compared to those without chordal SAM, patients with chordal SAM had a smaller end-systolic volume index (median 18 ml/m² vs. 22 ml/m², P = 0.015) and end-diastolic volume index (median 52 ml/m² vs. 63 ml/m², P = 0.011). However, there was no difference in systolic and diastolic function in echocardiography. The prevalence of intraoperative post-reperfusion syndrome did not show any difference (42.9% vs. 45.3%, P = 1.000). Over the mean 4.8-year follow-up, cumulative 90-day and overall mortality also did not show a difference (Log rank P > 0.05, both).

Conclusions

Preoperative screening of echocardiography in LT recipients detects 1.2% of chordal SAM. It is found with small left ventricular volume, but is not related with intraoperative post-reperfusion syndrome and short- and long-term postoperative all-cause mortality in LT.

Appraisal of Cardiac Ejection Fraction With Liver Disease Severity: Implication in Post-Liver Transplantation Mortality

BACKGROUND AND AIMS

Enhanced sympathetic nervous activation and peripheral vasodilation in end-stage liver disease (ESLD) may limit the importance of left ventricular ejection fraction (LVEF) as an influential prognosticator. We sought to understand the LVEF and cardiac dimensions in ESLD patients in order to define the LVEF threshold to predict all-cause mortality after liver transplantation (LT).

APPROACH AND RESULTS

Data were collected prospectively from the Asan LT Registry between 2008 and 2016, and outcomes were retrospectively reviewed. LVEF, end-diastolic volume index (EDVI), and end-diastolic elastance (Eed) were measured by preoperative echocardiography. Of 2,799 patients, 452 (16.2%) had LVEF ≤ 60%, with 29 (1.0%) having LVEF < 55% and 269 (9.6%) had LVEF ≥ 70%. Over a median of 5.4-year follow-up, 329 (11.8%) patients died: 104 (3.7%) died within 90 days. LVEF (range, 30%-81%) was directly proportionate to Model for End-stage Liver Disease (MELD) scores, an index of liver disease severity, in survivors but showed a fixed flat-line pattern in nonsurvivors (interaction P = 0.004 between groups), with lower EDVI (P = 0.013) and higher Eed (P = 0.001) in the MELD ≥ 20 group. Patients with LVEF ≤ 60% had higher 90-day (13% vs. 7.4%; log rank, P = 0.03) and median 5.4-year (26.7% vs. 16.2%; log rank, P = 0.003) mortality rates in the MELD ≥ 20 group, respectively, compared to those with LVEF > 60%. Specifically, in the MELD > 35 group, median 5.4-year mortality rate was 53.3% in patients with LVEF ≤ 60% versus 24% in those with LVEF > 60% (log rank P < 0.001). By contrast, mortality rates of LVEF ≤ 60% and > 60% were similar in the MELD < 20 group (log rank P = 0.817).

CONCLUSIONS

LVEF ≤ 60% is strongly associated with higher post-LT mortality rates in the MELD ≥ 20 group, indicating the need to appraise both LVEF and liver disease severity simultaneously. Enhanced diastolic elastance with low EDVI provides insights into pathogenesis of low LVEF in nonsurvivors with MELD ≥ 20.

Sarcopenia in Cirrhosis: Looking Beyond the Skeletal Muscle Loss to See the Systemic Disease

Sarcopenia is a common complication of cirrhosis and is defined as a progressive and generalized loss of skeletal muscle mass, strength, and function. Sarcopenia is associated with poor prognosis and increased mortality. How sarcopenia and muscle wasting relate to such poor outcomes requires looking beyond the overt muscle loss and at this entity as a systemic disease that affects muscles of vital organs including cardiac and respiratory muscles. This review explores the pathophysiological pathways and mechanisms that culminate in poor outcomes associated with sarcopenia. This provides a launching pad to identify potential targets for therapeutic intervention and optimization to improve patient outcomes.

Preoperative echocardiographic evaluation of cardiac systolic and diastolic function in liver transplant recipients with diabetes mellitus: a propensity-score matched analysis

Background

Methods

Results

Conclusions

Cardiovascular and Metabolic Consequences of Liver Transplantation: A Review

Liver transplantation (LT) is considered the curative treatment option for selected patients who suffer from end-stage or acute liver disease or hepatic malignancy (primary). After LT, patients should be carefully monitored for complications that may appear, partially due to immunosuppressive therapy, but not entirely. Cardiovascular diseases are frequently encountered in patients with LT, being responsible for high morbidity and mortality. Patients with underlying cardiovascular and metabolic pathologies are prone to complications after the transplant, but these complications can also appear de novo, mostly associated with immunosuppressants. Metabolic syndrome, defined by obesity, hypertension, dyslipidemia, and hyperglycemia, is diagnosed among LT recipients and is aggravated after LT, influencing the long-term survival. In this review, our purpose was to summarize the current knowledge regarding cardiovascular (CV) diseases and the metabolic syndrome associated with LT and to assess their impact on short and long-term morbidity and mortality.

Risk stratification of myocardial injury after liver transplantation in patients with computed tomographic coronary angiography-diagnosed coronary artery disease

We aimed to determine if the severity of computed tomographic coronary angiography (CTCA)-diagnosed coronary artery disease (CAD) is associated with postliver transplantation (LT) myocardial infarction (MI) within 30 days and early mortality. We retrospectively evaluated 2118 consecutive patients who underwent CAD screening using CTCA. Post-LT type-2 MI, elicited by oxygen supply-and-demand mismatch within a month after LT, was assessed according to the severity of CTCA-diagnosed CAD. Obstructive CAD (>50% narrowing, 9.2% prevalence) was identified in 21.7% of patients with 3 or more known CAD risk factors of the American Heart Association. Post-LT MI occurred in 60 (2.8%) of total patients in whom 90-day mortality rate was 16.7%. Rates of post-LT MI were 2.1%, 3.1%, 3.4%, 4.3%, and 21.4% for normal, nonobstructive CAD, and 1-, 2-, and 3-vessel obstructive CAD, respectively. Two-vessel or 3-vessel obstructive CAD showed a 4.9-fold higher post-LT MI risk compared to normal coronary vessels. The sensitivity and negative predictive value of obstructive CAD in detecting post-LT MI were, respectively, 20% and 97.5%. In conclusion, negative CTCA finding in suspected patients can successfully exclude post-LT MI, whereas proceeding with invasive angiography is needed to further risk-stratify in patients with significant CTCA-diagnosed CAD. Prognostic role of CTCA in predicting post-LT MI needs further research.

Quantitative Analysis of an Intraoperative Digitalized Esophageal Heart Sound Signal to Speculate on Perturbed Cardiovascular Function

Although visualization of heart sounds, known as phonocardiography, provides valuable information on cardiovascular hemodynamics, its use has not been widely encouraged due to the scarcity of information on its interpretation. In the present study, using the intraoperative phonocardiogram recorded by an esophageal stethoscope, we quantitatively evaluated the time and frequency domains of modulation of the heart sounds components and their association with left ventricular contractility and systemic vascular resistance under the effects of various cardiovascular drugs. We analyzed 29 pairs of intraoperative digitalized phonocardiographic signals and their corresponding hemodynamic data before and after cardiovascular drug administration (ephedrine, esmolol, phenylephrine, and/or nicardipine) in 17 patients who underwent liver transplantation. The S1 and S2 components of the heart sounds (the first and second heart sounds, respectively) were identified and their modulation in time and frequency domains was analyzed. As an index of cardiovascular function, systolic tissue Doppler wave velocity (TDI S'), maximal dP/dt from the arterial waveform, and systemic vascular resistance were simultaneously evaluated. Ephedrine/esmolol and phenylephrine/nicardipine primarily affected the S1 and S2 components of the heart sounds, respectively. This result implies that the intraoperative phonocardiogram may have the potential to be useful in detecting the changes in contractility and afterload that commonly occur in patients receiving anesthesia. In an era of constant need for noninvasive hemodynamic assessment, phonocardiography has the potential for use as a novel and informative tool for monitoring of hemodynamic function.

Respiratory Variations in Electrocardiographic R-Wave Amplitude during Acute Hypovolemia Induced by Inferior Vena Cava Clamping in Patients Undergoing Liver Transplantation

The aim of this study was to analyze whether the respiratory variation in electrocardiogram (ECG) standard lead II R-wave amplitude (ΔRDII) could be used to assess intravascular volume status following inferior vena cava (IVC) clamping. This clamping causes an acute decrease in cardiac output during liver transplantation (LT). We retrospectively compared ΔRDII and related variables before and after IVC clamping in 34 recipients. Receiver operating characteristic (ROC) curve and area under the curve (AUC) analyses were used to derive a cutoff value of ΔRDII for predicting pulse pressure variation (PPV). After IVC clamping, cardiac output significantly decreased while ΔRDII significantly increased (p = 0.002). The cutoff value of ΔRDII for predicting a PPV >13% was 16.9% (AUC: 0.685) with a sensitivity of 57.9% and specificity of 77.6% (95% confidence interval 0.561 – 0.793, p = 0.015). Frequency analysis of ECG also significantly increased in the respiratory frequency band (p = 0.016). Although significant changes in ΔRDII during vena cava clamping were found at norepinephrine doses <0.1 µg/kg/min (p = 0.032), such changes were not significant at norepinephrine doses >0.1 µg/kg/min (p = 0.093). ΔRDII could be a noninvasive dynamic parameter in LT recipients presenting with hemodynamic fluctuation. Based on our data, we recommended cautious interpretation of ΔRDII may be requisite according to vasopressor administration status.