Coronary multidetector computed tomographic angiography to evaluate coronary artery disease in liver transplant candidates: methods, feasibility and initial experience

Perioperative Cardiovascular Risk Assessment and Management in Liver Transplant Recipients: A Review of the Literature Merging Guidelines and Interventions

Liver transplantation (LT) is the second most performed solid organ transplant. Coronary artery disease (CAD) is a critical consideration for LT candidacy, particularly in patients with known CAD or risk factors, including metabolic dysfunction associated with steatotic liver disease. The presence of severe CAD may exclude patients from LT; therefore, precise preoperative evaluation and interventions are necessary to achieve transplant candidacy. Cardiovascular complications represent the earliest nongraft-related cause of death post-transplantation. Timely intervention to reduce cardiovascular events depends on adequate CAD screening. Coronary disease screening in end-stage liver disease is challenging because standard noninvasive CAD screening tests have low sensitivity due to hyperdynamic state and vasodilatation. As a result, there is overuse of invasive coronary angiography to exclude severe CAD. Coronary artery calcium scoring using a computed tomography scan is a tool for the prediction of cardiovascular events, and can be used to achieve risk stratification in LT candidates. Recent literature shows that qualitative assessment on both noncontrast- and contrast-enhanced chest computed tomography can be used instead of calcium score to assess the presence of coronary calcium. With increasing prevalence, protocols to address CAD in LT candidates must be reconsidered. Percutaneous coronary intervention could allow a shorter duration of dual-antiplatelet therapy in simple lesions, with safer perioperative outcomes. Hybrid coronary revascularization is an option for high-risk LT candidates with multivessel disease nonamenable to percutaneous coronary intervention. The objective of this review is to evaluate existing methods for preoperative cardiovascular risk stratification, and to describe interventions before surgery to optimize patient outcomes and reduce cardiovascular event risk.

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

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

Peripheral endothelial and microvascular damage in liver cirrhosis: a systematic review and meta-analysis

OBJECTIVE

This is the first systematic review and meta-analysis of studies using any available functional method to examine differences in peripheral endothelial function between cirrhotic and non-cirrhotic individuals.

METHODS

Literature search involved PubMed, Web-of-Science and Scopus databases, as well as grey literature sources. We included studies in adult subjects evaluating endothelial function with any semi-invasive or non-invasive functional method in patients with and without liver cirrhosis.

RESULTS

From 3378 records initially retrieved, 15 studies with a total of 570 participants were included in the final quantitative meta-analysis. In 6 studies examining endothelial function with flow-mediated-dilatation no differences between patients with cirrhosis and controls were evident (WMD: 1.33, 95%CI [-2.87, 5.53], I² =97%, p<0.00001). Among studies assessing differences in endothelial-dependent or endothelial-independent vasodilation with venous-occlusion-plethysmography, there were no significant differences between the two groups. When pooling all studies together, regardless of the technique used, no significant difference in endothelial function between cirrhotic patients and controls was observed(SMD: 0.79, 95%CI[-0.04, 1.63], I2=94%, p<0.00001).

CONCLUSIONS

No differences in peripheral endothelial function assessed with semi-invasive or non-invasive functional methods exist between cirrhotic and non-cirrhotic subjects. The increasing co-existence of cardiovascular risk factors leading to impaired vascular reactivity in cirrhotic patients may partly explain these findings.

Cardiovascular manifestation of end-stage liver disease and perioperative echocardiography for liver transplantation: anesthesiologist’s view

Liver transplantation (LT) is the curative therapy for decompensated cirrhosis. However, anesthesiologists can find it challenging to manage patients undergoing LT due to the underlying pathologic conditions of patients with end-stage liver disease and the high invasiveness of the procedure, which is frequently accompanied by massive blood loss. Echocardiography is a non-invasive or semi-invasive imaging tool that provides real-time information about the structural and functional status of the heart and is considered to be able to improve outcomes by enabling accurate and detailed assessments. This article reviews the pathophysiologic changes of the heart accompanied by cirrhosis that mainly affect hemodynamics. We also present a comparative review of the diagnostic criteria for cirrhotic cardiomyopathy published by the World Congress of Gastroenterology in 2005 and the Cirrhotic Cardiomyopathy Consortium in 2019. This article discusses the conditions that could affect hemodynamic stability and postoperative outcomes, such as coronary artery disease, left ventricular outflow tract obstruction, portopulmonary hypertension, hepatopulmonary syndrome, pericardial effusion, cardiac tamponade, patent foramen ovale, and ascites. Finally, we cover a number of intraoperative factors that should be considered, including intraoperative blood loss, rapid reaccumulation of ascites, manipulation of the inferior vena cava, post-reperfusion syndrome, and adverse effects of excessive fluid infusion and transfusion. This article aimed to summarize the cardiovascular manifestations of cirrhosis that can affect hemodynamics and can be evaluated using perioperative echocardiography. We hope that this article will provide information about the hemodynamic characteristics of LT recipients and stimulate more active use of perioperative echocardiography.

Introduction of a standardized protocol for cardiac risk assessment in candidates for liver transplant - A retrospective cohort analysis

INTRODUCTION

Recommendations on non-invasive imaging to assess pre-operative cardiac risk among liver transplant candidates vary amongst societal guidelines and individual institutional practices. In 2018, a standardized pre-transplant coronary evaluation protocol was established at Beth Israel Deaconess Medical Center, Boston MA, to ensure appropriate and consistent pre-operative testing was performed.

METHODS

All patients who underwent liver transplant evaluation between January 1st, 2016 and December 31st, 2019, were retrospectively analyzed and divided into three cohorts; before the introduction of the protocol (prior to 2018), initial protocol favoring invasive coronary angiography (ICA) (2018), and amended protocol favoring coronary computed tomography angiography (CCTA) (post-2018). We described clinical characteristics, candidacy for transplant, and cardiovascular complications during follow-up. As an unadjusted exploratory analysis, the Cochran-Armitage Exact Trend Test was used to examine univariate differences across time.

RESULTS

A total of 462 patients underwent liver transplant evaluation during the study period. Among these, 218 (47.2%) patients underwent stress test, 50 (10.8%) underwent CCTA, and 68 (14.8%) underwent ICA. Across the three time periods, there was an increase in the proportion of CCTAs performed (3%, 6.3%, and 26.3% respectively; p <0.001) and proportion of patients diagnosed with obstructive CAD using CCTA (0%, 30%, and 51.4% respectively; p = 0.04). There was no significant difference in post-transplant cardiac complications among patients evaluated before 2018, during 2018, and after 2018 (5.9% vs. 5.6 vs. 6.0%; p=1.0).

CONCLUSION

Our findings suggest it is reasonable to shift practice to a less invasive approach utilizing CCTA or nuclear stress testing when assessing liver transplant candidates at increased cardiovascular risk.

Morphological Cardiac Alterations in Liver Cirrhosis: An Autopsy Study

Background

Cirrhosis can cause various cardiac complications and severely affect the prognosis of the patient suffering from cirrhosis. Anatomical, morphological variations in the heart of patients with liver cirrhosis in the absence of known cardiac disease has not been well described. There is a paucity of studies in the literature on cardiac alterations in cirrhosis. Early detection of known cardiac alterations can further help in improving the quality of life.

Materials and Methods

A cross-sectional descriptive study was conducted in the departments of pathology and forensic medicine of our institution. An autopsy-based prospective study of forty consecutive patients with final diagnosis of liver cirrhosis were included. Patients with a known history of cardiac disease/anomaly were excluded from the study. Macroscopic and microscopic changes in the heart and coronaries were noted and statistically analyzed.

Results

Analysis of the hearts on gross examination showed cardiomegaly in 31 patients (77.5%). All cases had left ventricular hypertrophy. Endocardial thickening was seen in 22 patients (55%). Calcified mitral valve was seen in 9 patients (22.5%).On microscopy, apart from hypertrophy, the pathological changes like interstitial oedema (47.5%), fibrosis (45%), cardiac muscle disarray (87.5%), fatty infiltrate (10%), pericarditis (5%), and severe coronary artery atherosclerosis (17.5%) were seen in the patients.

Conclusion

Knowledge about the involvement of the heart in liver cirrhosis is essential for both the physician and the surgeons to prevent adverse outcomes during liver transplantation and can further help in improving the quality of life of the patient.

Quality and diagnostic performance of coronary computed tomography angiogram (CCTA): A comparison between pre-liver and pre-kidney transplant patients

PURPOSE

Assess and compare the quality and diagnostic performance of CCTA between pre-liver and pre-kidney transplant patients, and gauge impact of CCTA on ICA requirements.

METHODS

Patients without known coronary artery disease (CAD) were selected for CCTA if considered high-risk or after abnormal stress testing. All pre-liver and pre-kidney CCTAs between March 2018 and August 2020 were retrospectively included. CCTA quality was qualitatively graded as excellent/good/fair/poor, and CAD graded as < or ≥50% stenosis. Heart rate, coronary artery calcium (CAC) scores, and fractional flow reserve CT (FFR_CT) results were collected. CAD stenosis was graded on invasive coronary angiogram (ICA) images, with ≥50% stenosis defined as significant.

RESULTS

162 pre-transplant patients (91 pre-liver, 71 pre-kidney). Pre-kidney patients had poorer CCTA quality (p = 0.04) and higher heart rate (median: 65 bpm vs 60 bpm, p < 0.001). Out of 147 diagnostic CCTAs (pre-liver: 84, pre-kidney: 63), 73 (49.7%) had a ≥50% stenosis (pre-liver: 38 (45.2%), pre-kidney:35 (55.6%)). 12/38 (31.6%) had a significantly reduced FFR_CT, and 19/53 (35.8%) had ≥50% stenosis on ICA. Among patients whose CCTA was diagnostic and had ICA, stenosis severity was concordant in 10/23 (43.5%) pre-liver and 10/25 (40%) pre-kidney patients. All discordant cases had stenosis 'over-called' on CCTA.

CONCLUSION

Diagnostic-quality CCTAs in high-risk pre-transplant patients are achievable and can greatly reduce ICA requirements by excluding significant CAD. CCTA quality is poorer in pre-kidney transplant patients compared to pre-liver, possibly due to higher heart rate.

Cardiac Risk Stratification in Liver Transplantation: Results of a Tiered Assessment Protocol Based on Traditional Cardiovascular Risk Factors

Coronary artery disease (CAD) confers increased perioperative risk in patients undergoing liver transplantation (LT). Although routine screening for CAD is recommended, there are limited data on the effectiveness of screening strategies. We evaluated the safety and efficacy of a 3-tiered cardiac risk-assessment protocol that stratifies patients based on age and traditional cardiac risk factors. We peformed a single-center, prospective, observational study of consecutive adult patients undergoing LT assessment (2010-2017). Patients were stratified into low-risk (LR), intermediate-risk (IR), or high-risk (HR) cardiac groups and received standardized investigations with selective use of transthoracic echocardiography (TTE), dobutamine stress echocardiography (DSE), computed tomography coronary angiography (CTCA), and coronary angiography (CA). Primary outcomes were cardiac events (CEs) and cardiovascular death up to 30 days after LT. Overall, 569 patients were included, with 76 patients identified as LR, 256 as IR, and 237 as HR. Cardiac risk factors included diabetes mellitus (26.0%), smoking history (47.3%), hypertension (17.8%), hypercholesterolemia (7.2%), family (17.0%) or prior history of heart disease (6.0%), and obesity (27.6%). Of the patients, 42.0% had ≥2 risk factors. Overall compliance with the protocol was 90.3%. Abnormal findings on TTE, DSE, and CTCA were documented in 3, 23, and 44 patients, respectively, and 12 patients were not listed for transplantation following cardiac assessment (1 LR, 2 IR, and 9 HR). Moderate or severe CAD was identified in 25.4% of HR patients on CTCA following a normal DSE. CEs were recorded in 7 patients (1.2%), with 2 cardiovascular deaths (0.4%). Cardiac risk stratification based on traditional cardiac risk factors with the selective use of DSE, CTCA, and CA is a safe and feasible approach that results in a low perioperative cardiac event rate.

The interplay between gastrointestinal and cardiovascular diseases: a narrative review focusing on the clinical perspective

Both cardiovascular and gastrointestinal disorders represent considerable health burden on community clinics and hospitals with overwhelming economic cost. An overlap in the occurrence of these disorders is encountered in daily practice. Both affect each other in bidirectional manner through several mechanisms including altered hemodynamics, systemic inflammation, bacterial overgrowth and interactions and adverse effects of medications. In addition, to the known overlap in the symptoms occurrence of upper gastrointestinal tract diseases and cardiovascular diseases (CVDs). Awareness of this interplay and its clinical manifestations optimizes patient management, and could prevent catastrophic consequences and even save lives. In this review, we highlighted the clinical aspects of this bidirectional association between gastrointestinal and CVDs aiming to shed light on this topic and improve patients' care.

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.

Risk of ambulatory colonoscopy in patients with cirrhosis: a propensity-score matched cohort study

Background and study aims  Patients with cirrhosis demonstrate alterations in physiology, hemodynamics, and immunity which may increase procedural risk. There exist sparse data regarding the safety of performing ambulatory colonoscopy in patients with cirrhosis. Patients and methods  From a population-based sample of three North American states (California, Florida, and New York), we collected data on 3,590 patients with cirrhosis who underwent ambulatory colonoscopy from 2009 to 2014. We created a control cohort propensity score-matched for cirrhotic severity who did not undergo colonoscopy (N = 3,590) in order to calculate the attributable risk for adverse events. The primary endpoint was the rate of unplanned hospital encounters (UHEs) within 14 days of colonoscopy (or from a synthetic index date for the control cohort). Predictors for UHE were assessed in multivariable regression. Results  The attributable risk for any UHE following colonoscopy was 3.1 % (confidence interval [CI] 2.1-4.1 %, P  < 0.001). There was increased risk for infection (0.9 %, CI 0.7-1.1 %), spontaneous bacterial peritonitis (0.1 %, CI 0.0-0.3 %), decompensation of ascites (0.3 %, CI 0.2-0.4 %), and cardiovascular event (0.4 %, CI 0.3-0.5 %). There was no increased attributable risk for gastrointestinal bleeding, perforation, or development of the hepatorenal syndrome. The presence of ascites at time of procedure was the only predictor for UHE in the fully-adjusted model (OR 2.6, CI 1.9-3.5, P  < 0.001). Conclusions  There is a moderate though detectable increase in risk for adverse event following ambulatory colonoscopy in patients with cirrhosis. The presence of ascites in particular portends higher risk. These data may guide clinicians when counseling patients with cirrhosis on the choice of colorectal cancer screening modality.

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.

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

Cardiovascular dysfunction in cirrhotic patients is a recognized clinical entity commonly referred to as cirrhotic cardiomyopathy. Systematic inflammation, autonomic dysfunction, and activation of vasodilatory factors lead to hyperdynamic circulation with high cardiac output and low peripheral vascular resistance. Counter acting mechanisms as well as direct effects on cardiac cells led to systolic or diastolic dysfunction and electromechanical abnormalities, which are usually masked at rest but exposed at stress situations. While cardiovascular complications and mortality are common in patients undergoing liver transplantation, they cannot be adequately predicted by conventional cardiac examination including transthoracic echocardiography. Newer echocardiography indices and other imaging modalities such as cardiac magnetic resonance have shown increased diagnostic accuracy with predictive implications in cardiovascular diseases. The scope of this review was to describe the role of cardiac imaging in the preoperative assessment of liver transplantation candidates with comprehensive analysis of the future perspectives anticipated by the use of newer echocardiography indices and cardiac magnetic resonance applications.

Preoperative dobutamine stress echocardiography in patients undergoing orthotopic liver transplantation

BACKGROUND

Coronary artery disease (CAD) is associated with increased mortality in patients who undergo orthotopic liver transplantation (OLT). Chronic vasodilatory state and poor exercise tolerance in patients with end-stage liver disease make dobutamine stress echocardiography (DSE) preferred for preoperative evaluation of CAD prior to OLT. We studied the incidence of positive DSE results and the association between DSE results and perioperative and longer-term events.

HYPOTHESIS

DSE results pre-OLT will predict short and long term outcomes.

METHODS

We studied 460 patients who underwent DSE within 1 year prior to OLT between 2004 and 2011. Primary events included death and MI at 30 days post-OLT. We also recorded longer-term deaths.

RESULTS

Four patients (0.9%) had an ischemic response to DSE, 360 (78%) were normal, and 96 (21%) were nondiagnostic. Fourteen patients (3%) had a primary event at 30 days following OLT (13 deaths and 1 NSTEMI), and there were 108 (24%) deaths at 4.6±2 years of follow-up. No patient with ischemia on DSE had a 30-day event. The accuracy, sensitivity, specificity, and positive and negative predictive values of DSE that was not normal (ie, ischemic or nondiagnostic response) to predict 30-day post-OLT events were 76%, 14%, 78%, 2%, and 97%, respectively. On Cox survival analysis, only baseline left ventricular ejection fraction (HR: 0.90, 95% CI: 0.85-0.96, P < 0.001) was associated with longer-term deaths.

CONCLUSIONS

Patients undergoing pre-OLT DSE have very low incidence of an ischemic response on DSE, and it has no association with 30-day events.

Pronounced Coronary Arteriosclerosis in Cirrhosis: Influence on Cardiac Function and Survival?

BACKGROUND

The relation between excessive alcohol consumption and coronary arteriosclerosis has remained controversial. The etiology of cirrhosis has been considered a substantial risk factor for development of arteriosclerotic lesions. The coronary artery calcium-score derived from coronary CT angiography is a robust marker of coronary arteriosclerosis.

AIMS

To study the burden of coronary arteriosclerosis in cirrhotic patients of various etiologies and association to cardiac dysfunction and survival.

METHODS

Fifty-seven patients with cirrhosis without cardiovascular disease underwent coronary CT angiography, tissue Doppler echocardiography, electrocardiogram and registration of clinical and biochemical characteristics.

RESULTS

In patients with cirrhosis the median coronary artery calcium-score was increased in comparison with age and race-adjusted healthy reference values (men: 328 vs. 9 HU and women: 136 vs. 0 HU; p < 0.001). Moreover, the coronary artery calcium-score in alcohol-related cirrhosis was significantly higher than in nonalcohol-related cirrhosis (362 vs. 46 HU, p < 0.001). Coronary artery calcium-score correlated with age (p = 0.002) but not with established cardiovascular risk factors including smoking, type 2 diabetes, hypertension, gender, or hypercholesterolemia. Coronary artery calcium-score was associated with diastolic dysfunction, lateral e´ (p = 0.025), but not with other markers of cardiac dysfunction. During a median follow-up of 25 months 12 patients (21%) died but coronary artery calcium-score was not associated with survival.

CONCLUSIONS

Coronary arteriosclerosis was particular extensive in patients with alcoholic cirrhosis. However, the current results suggest that coronary arteriosclerosis only have limited influence on cardiac function and survival. Surprisingly, no other established risk factors apart from age seemed to interfere with coronary arteriosclerosis in cirrhotic patients.

Multidisciplinary approach to cardiac and pulmonary vascular disease risk assessment in liver transplantation: An evaluation of the evidence and consensus recommendations

Liver transplant (LT) candidates today are older, have greater medical severity of illness, and have more cardiovascular comorbidities than ever before. In addition, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Cirrhotic cardiomyopathy, a condition characterized by increased cardiac output and a reduced ventricular response to stress, is present in up to 30% of patients with cirrhosis, thus challenging perioperative management. Current noninvasive tests that assess for subclinical coronary and myocardial disease have low sensitivity, and altered hemodynamics during the LT surgery can unmask latent cardiovascular disease either intraoperatively or in the immediate postoperative period. Therefore, this review, assembled by a group of multidisciplinary experts in the field and endorsed by the American Society of Transplantation Liver and Intestine and Thoracic and Critical Care Communities of Practice, provides a critical assessment of the diagnosis of cardiac and pulmonary vascular disease and interventions aimed at managing these conditions in LT candidates. Key points and practice-based recommendations for the diagnosis and management of cardiac and pulmonary vascular disease in this population are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score

Cardiovascular disease (CVD) complications are important causes of morbidity and mortality after orthotopic liver transplantation (OLT). There is currently no preoperative risk-assessment tool that allows physicians to estimate the risk for CVD events following OLT. We sought to develop a point-based prediction model (risk score) for CVD complications after OLT, the Cardiovascular Risk in Orthotopic Liver Transplantation risk score, among a cohort of 1,024 consecutive patients aged 18-75 years who underwent first OLT in a tertiary-care teaching hospital (2002-2011). The main outcome measures were major 1-year CVD complications, defined as death from a CVD cause or hospitalization for a major CVD event (myocardial infarction, revascularization, heart failure, atrial fibrillation, cardiac arrest, pulmonary embolism, and/or stroke). The bootstrap method yielded bias-corrected 95% confidence intervals for the regression coefficients of the final model. Among 1,024 first OLT recipients, major CVD complications occurred in 329 (32.1%). Variables selected for inclusion in the model (using model optimization strategies) included preoperative recipient age, sex, race, employment status, education status, history of hepatocellular carcinoma, diabetes, heart failure, atrial fibrillation, pulmonary or systemic hypertension, and respiratory failure. The discriminative performance of the point-based score (C statistic = 0.78, bias-corrected C statistic = 0.77) was superior to other published risk models for postoperative CVD morbidity and mortality, and it had appropriate calibration (Hosmer-Lemeshow P = 0.33).

CONCLUSION

The point-based risk score can identify patients at risk for CVD complications after OLT surgery (available at www.carolt.us); this score may be useful for identification of candidates for further risk stratification or other management strategies to improve CVD outcomes after OLT. (Hepatology 2017;66:1968-1979).

Atherosclerosis in chronic hepatitis C virus patients with and without liver cirrhosis

Background

Chronic Hepatitis C virus (HCV) infection and liver cirrhosis may be associated with atherosclerosis and coronary artery disease (CAD). There are two phases to atherosclerosis, Subclinical and Clinical. Assessment of atherosclerosis may be started at its Subclinical phase by the evaluation of Epicardial Fat Thickness (EpFT) and Carotid Intima Thickness (CIMT).

Aim of the study

The aim of the study was to evaluate Clinical and Subclinical atherosclerosis in chronic HCV patients with and without liver cirrhosis by evaluating CIMT and EpFT and correlating the results with Child-Pugh functional scoring of cirrhosis as well as with ultrasound and laboratory parameters that define the severity of liver disease.

Patients and methods

This study involved 64 chronic HCV patients that were divided into two groups: 24 patients without liver cirrhosis and 40 patients with liver cirrhosis in addition to 20 apparently healthy volunteers serving as control. All of the 84 subjects were subjected to the following: Clinical evaluation; Routine Laboratory Evaluation (CBC, Liver Function Tests, Renal Function Tests, Serum electrolytes, Cholesterol, Triglycerides, HBs antigen and HCV antibody); ECG; Abdominal ultrasound; Echocardiographic evaluation of segmental wall motion abnormalities and EpFT and B-Mode Carotid ultrasonography for evaluation of CIMT.

Results

In the cirrhotic HCV group, the CIMT and EpFT were both significantly increased [Compared to control group (p = 0.000), compared to the non-cirrhotic HCV group (p = 0.000)]. In the non-cirrhotic HCV group, the CIMT and EpFT were both significantly increased compared to the control group with a p-value of 0.003 for CIMT and 0.048 for EpFT. The CIMT and EpFT were also positively correlated with each other (r = 0.456, p = 0.001). There was a statistically significant increase in the EpFT and CIMT in Child class B patients compared to Child class A (p = 0.007 for CIMT and p = 0.028 for EpFT) and in Child class C patients compared to Child class B patients (p = 0.001 for CIMT and 0.005 for EpFT). CIMT and EpFT were correlated positively with AST (r = 0.385, p = 0.002 for CIMT, and r = 0.379, p = 0.003 for EpFT), Total Bilirubin (r = 0.378, p = 0.003 for CIMT, and r = 0.384, p = 0.002 for EpFT), INR% (r = 0.456, p = 0.001 for CIMT, and r = 0.384, p = 0.001 for EpFT), CRP (r = 0.378, p = 0.003 for CIMT, and r = 0.386, p = 0.002 for EpFT), spleen span (r = 0.417, p = 0.001 for CIMT, and r = 0.437, p = 0.001 for EpFT) and portal Vein Diameter (r = 0.372, p = 0.003 for CIMT, and r = 0.379, p = 0.003 for EpFT). CIMT and EpFT were correlated negatively with Albumin (r = -0.379, p = 0.003 for CIMT, and r = -0.370, p = 0.003 for EpFT), platelets count (r = -0.382, p = 0.002 for CIMT, and r = -0.378, p = 0.003 for EpFT) and Liver Span (r = -0.433, p = 0.001 for CIMT, and r = -0.424, p = 0.001 for EpFT).

Conclusion

EpFT and CIMT significantly increased in chronic hepatitis C virus patients especially in those with cirrhosis and closely correlated with each other. Their thickness also correlated with the Child-Pugh functional scoring of cirrhosis as well as with ultrasound and laboratory parameters that define the severity of liver disease.The echocardiographic assessment of EpFT and the carotid Doppler assessment of CIMT may provide appropriate and simple screening markers for subclinical atherosclerosis and cardiovascular risk in chronic HCV patients with and without cirrhosis.

Cardiac involvement in patients with cirrhosis: a focus on clinical features and diagnosis

Cirrhotic heart has been traditionally considered protected from cardiovascular disease, even if a large amount of literature has recently shown that patients affected by chronic liver disease are exposed to cardiovascular events, as well. Since the first recognition of cardiac involvement in cirrhosis, all published studies explain that decompensated cirrhotic patients suffer from haemodynamic changes, currently known as hyperdynamic syndrome, which finally lead to cirrhotic cardiomyopathy. This is defined by the presence of a subclinical systolic dysfunction unmasked under stress conditions, impaired diastolic function and electrophysiological abnormalities, in the absence of any known cardiac disease. In this review, we will discuss the clinical and diagnostic features of this condition, the prevalence of associated comorbidities, echocardiographic, electrocardiographic and cardiac magnetic resonance hallmarks and the possible diagnostic role of serum biomarkers.

Arrhythmia risk in liver cirrhosis

Interactions between the functioning of the heart and the liver have been described, with heart diseases affecting the liver, liver diseases affecting the heart, and conditions that simultaneously affect both. The heart is one of the most adversely affected organs in patients with liver cirrhosis. For example, arrhythmias and electrocardiographic changes are observed in patients with liver cirrhosis. The risk for arrhythmia is influenced by factors such as cirrhotic cardiomyopathy, cardiac ion channel remodeling, electrolyte imbalances, impaired autonomic function, hepatorenal syndrome, metabolic abnormalities, advanced age, inflammatory syndrome, stressful events, impaired drug metabolism and comorbidities. Close monitoring of cirrhotic patients is needed for arrhythmias, particularly when QT interval-prolonging drugs are given, or if electrolyte imbalances or hepatorenal syndrome appear. Arrhythmia risk may persist after liver transplantation due to possible QT interval prolongation, persistence of the parasympathetic impairment, post-transplant reperfusion and chronic immunosuppression, as well as consideration of the fact that the transplant itself is a stressful event for the cardiovascular system. The aims of the present article were to provide a review of the most important data regarding the epidemiology, pathophysiology, and biomarkers of arrhythmia risk in patients with liver cirrhosis, to elucidate the association with long-term outcome, and to propose future research directions.

Cardiac imaging for the assessment of patients being evaluated for kidney or liver transplantation

Cardiac risk assessment prior to kidney and liver transplantation is controversial. Given the paucity of available organs, selecting appropriate recipients with favorable short- and long-term cardiovascular risk profile is crucial. Using noninvasive cardiac imaging tools to guide cardiovascular risk assessment and management can also be challenging and controversial. In this article, we address the burden of coronary artery disease among kidney and liver transplant candidates and review the literature pertaining to the diagnostic accuracy and the prognostic value of noninvasive cardiac imaging techniques in this population.

Appraising cardiac dysfunction in liver transplantation: an ongoing challenge

End-stage liver disease (ESLD) is a multisystemic disease that adversely and mutually aggravates other organs such as the heart. Cardiac dysfunction in ESLD encompasses a spectrum of disease that could be aggravated, precipitated or be occurring hand-in-hand with coexisting aetiological factors precipitating cirrhosis. Additionally and more complexly, liver transplantation, the curative modality of ESLD, is responsible for additional intra- and postoperative short- and long-term cardiac morbidity. The phenotypic distinction of the different forms of cardiac dysfunction in ESLD albeit important prognostically and therapeutically is not allowed by the current societal recommendations, due to conceptual, and methodological limitations in the appraisal of cardiac function and structure in ESLD and in designing studies that are based on this appraisal. This review comprehensively discusses the spectrum of cardiac dysfunction in ESLD, discusses the limitations of the current appraisal of cardiac dysfunction in ESLD, and proposes a hypothetical approach for studying cardiac dysfunction in liver transplant candidates.

Adverse cardiac events after orthotopic liver transplantation: a cross-sectional study in 389 consecutive patients

Current American College of Cardiology/American Heart Association guidelines caution that preoperative noninvasive cardiac tests may have poor predictive value for detecting coronary artery disease in liver transplant candidates. The purpose of our study was to evaluate the role of clinical predictor variables for early and late cardiac morbidity and mortality and the predictive values of noninvasive cardiac tests for perioperative cardiac events in a high-risk liver transplant population. In all, 389 adult recipients were retrospectively analyzed for a median follow-up time of 3.4 years (range = 2.3-4.4 years). Overall survival was 83%. During the first year after transplantation, cardiovascular morbidity and mortality rates were 15.2% and 2.8%. In patients who survived the first year, cardiovascular morbidity and mortality rates were 3.9% and 2%, with cardiovascular etiology as the third leading cause of death. Dobutamine stress echocardiography (DSE) and single-photon emission computed tomography had respective sensitivities of 9% and 57%, specificities of 98% and 75%, positive predictive values of 33% and 28%, and negative predictive values of 89% and 91% for predicting early cardiac events. A rate blood pressure product less than 12,000 with DSE was associated with an increased risk for postoperative atrial fibrillation. Correspondence analysis identified a statistical association between nonalcoholic steatohepatitis/cryptogenic cirrhosis and postoperative myocardial ischemia. Logistic regression identified 3 risk factors for postoperative acute coronary syndrome: age, history of coronary artery disease, and pretransplant requirement for vasopressors. Multivariable analysis showed statistical associations of the Model for End-Stage Liver Disease score and the development of acute kidney injury as risk factors for overall cardiac-related mortality. These findings may help in identifying high-risk patients and may lead to the development of better cardiac tests.

Transradial cardiac catheterization in liver transplant candidates

Transradial (TR) cardiac catheterization is effective and offers lower rates of vascular complications and bleeding compared with transfemoral cardiac catheterization. We sought to describe the safety and feasibility of TR cardiac catheterization in liver transplant candidates (LTCs). We retrospectively reviewed 1,071 consecutive cases of TR cardiac catheterization in 1,045 patients from May 2008 to December 2011 at a single institution. The primary end point was radial approach failure. Ten percent of TR cases (n = 107) were performed in LTCs and 90% (n = 964) were performed in non-LTCs. The LTC group had lower rates of cardiovascular diseases and cardiovascular risk factors. The LTC group had a significantly lower platelet count (75,000 vs 237,000/mm(3), p <0.01), higher international normalized ratio (1.7 vs 1.1, p <0.01), and lower mean arterial pressure (78 vs 89 mm Hg, p <0.01). The mean Model for End-Stage Liver Disease score was 21 in LTCs. Percutaneous coronary interventions were performed in 4% of LTCs and 15% of non-LTCs (p <0.01). The radial approach failure rate was 10% in LTCs and 7% in non-LTCs (p = 0.15). In conclusion, radial approach failure was similar between the LTC and non-LTC groups. Despite significant differences in platelet count and international normalized ratio, there was no difference in the incidence of adverse events between the groups, suggesting that TR cardiac catheterization is safe and effective in LTCs.

Predicting the severity and prognosis of trismus after intensity-modulated radiation therapy for oral cancer patients by magnetic resonance imaging

To develop magnetic resonance imaging (MRI) indicators to predict trismus outcome for post-operative oral cavity cancer patients who received adjuvant intensity-modulated radiation therapy (IMRT), 22 patients with oral cancer treated with IMRT were studied over a two-year period. Signal abnormality scores (SA scores) were computed from Likert-type ratings of the abnormalities of nine masticator structures and compared with the Mann-Whitney U-test and Kruskal-Wallis one-way ANOVA test between groups. Seventeen patients (77.3%) experienced different degrees of trismus during the two-year follow-up period. The SA score correlated with the trismus grade (r = 0.52, p<0.005). Patients having progressive trismus had higher mean doses of radiation to multiple structures, including the masticator and lateral pterygoid muscles, and the parotid gland (p<0.05). In addition, this group also had higher SA-masticator muscle dose product at 6 months and SA scores at 12 months (p<0.05). At the optimum cut-off points of 0.38 for the propensity score, the sensitivity was 100% and the specificity was 93% for predicting the prognosis of the trismus patients. The SA score, as determined using MRI, can reflect the radiation injury and correlate to trismus severity. Together with the radiation dose, it could serve as a useful biomarker to predict the outcome and guide the management of trismus following radiation therapy.

Echocardiography in liver transplant candidates

Involvement of the cardiovascular system in patients with end-stage liver disease (ESLD) is well recognized and may be seen in several scenarios in adult liver transplantation (LT) candidates. The hemodynamic effects of ESLD may result in apparent heart disease, or in some instances may mask cardiac disease. Alternatively, cardiac disease can occasionally be the underlying etiology of ESLD. LT imposes significant hemodynamic stresses, with cardiovascular complications accounting for considerable perioperative mortality and morbidity. Pre-operative assessment of the cardiac status of LT candidates is thus critically important for risk stratification and management. Cardiac imaging plays an integral role in the assessment of LT candidates. In this review, we discuss the role of cardiac imaging, including transthoracic echocardiography with Doppler and contrast enhancement, noninvasive functional assessment for routine pre-operative assessment of coronary artery disease, and transesophageal echocardiography in select cases to aid in intra-operative fluid management and monitoring in LT candidates.

Accuracy of stress myocardial perfusion imaging to diagnose coronary artery disease in end stage liver disease patients

Patients with end-stage liver disease (ESLD) who also have underlying coronary artery disease (CAD) may be at increased risk for undergoing hemodynamically challenging orthotopic liver transplantation. Noninvasive single-photon emission computed tomographic (SPECT) imaging is often used to determine whether a patient with ESLD has unsuspected CAD. The objective of this study was to determine the accuracy of SPECT imaging for detection of CAD in patients with ESLD. Patients with ESLD who underwent coronary angiography and SPECT imaging before orthotopic liver transplantation were analyzed retrospectively. The predictive accuracy of clinical risk factors was calculated and compared to the results of SPECT imaging. There were 473 SPECT imaging studies. Adenosine SPECT imaging had a sensitivity of 62%, specificity of 82%, positive predictive value of 30%, and negative predictive value of 95% for diagnosing severe CAD. Regadenoson SPECT imaging had a sensitivity of 35%, specificity of 88%, positive predictive value of 23%, and negative predictive value of 93% for diagnosing severe CAD. The accuracy of a standard risk factor analysis showed no statistical difference in predicting CAD compared with adenosine (sensitivity McNemar's p = 0.48, specificity McNemar's p = 1.00) or regadenoson (sensitivity McNemar's p = 0.77, specificity McNemar's p = 1.00) SPECT studies. In conclusion, the 2 pharmaceutical agents had low sensitivity but high specificity for diagnosing CAD. However, because the sensitivity of the test is low, the chances of missing patients with ESLD with CAD is high, making SPECT imaging an inaccurate screening test. A standard risk factor analysis as a predictor for CAD in patients with ESLD is less expensive, has no radiation exposure, and is as accurate as SPECT imaging.

Anesthesia for Liver Transplantation

Orthotopic liver transplantation is the only definitive treatment for end-stage liver disease. More than 6000 procedures are performed in the United States annually with excellent survival rates. The shortage of donor organs leads to continued interest in techniques to enlarge the potential donor pool. Patients presenting for liver transplant suffer from important cardiovascular, respiratory, renal, neurological, and gastroenterological comorbidity. In the Western world, liver failure is increasingly caused by steatohepatitis, and transplant candidates are thus becoming older and more comorbid. The role of the transplant anesthesiologist is highly important in the preoperative assessment, intraoperative management, and postoperative care of these complex and sick patients. Appropriate investigation and management of comorbidities such as coronary artery disease and portopulmonary hypertension is controversial and differs between programs. The transplant procedure is a major surgery, and although massive transfusion is no longer commonplace, there is potential for significant hemodynamic instability, coagulopathy, and metabolic disturbance. Liver transplant surgery can be divided into the preanhepatic phase, the anhepatic phase, and the reperfusion phase, with important anesthetic considerations at each point.  An understanding of the surgical techniques used for vascular exclusion of the liver and the role of venovenous bypass is crucial for the anesthesiologist. Recent trends in perioperative care include the use of antifibrinolytic drugs and point-of-care coagulation tests, intraoperative renal replacement therapy, and “fast-track” extubation and postoperative care. Care of patients with fulminant hepatic failure or those receiving split-liver grafts requires special consideration.

Coronary plaque quantification and composition in asymptomatic patients with type II diabetes mellitus

OBJECTIVE

The aim of this study was to characterize the extent and morphology of coronary lesions in asymptomatic patients with type II diabetes mellitus.

METHODS

We enrolled 102 asymptomatic patients with type II diabetes mellitus and 97 patients without diabetes as controls. All individuals had no history of ischemic heart disease. They underwent multidetector computed tomography (MDCT). Plaque density and plaque volume were calculated using specific software on axial images. Arterial remodeling was evaluated with semiquantitative assessment on image reconstructions.

RESULTS

MDCT angiography revealed the presence of 124 coronary plaques in 46 patients with type II diabetes mellitus and 59 plaques in 21 controls (P<0.01). Diabetic patients had a significantly higher proportion of lesions with impaired adaptive remodeling (56.5 versus 35.6%, P<0.01), as compared with nondiabetic individuals. The volume of fibrofatty component was 0.1 cm (0.01-0.72) in diabetic patients and 0.08 cm (0.01-0.33) in controls (P=0.14). The calcium volume was 0.082 cm (0-0.558) in diabetic patients and 0.12 cm (0-0.669) in controls (P=0.21). Plaques with fibrofatty components had a significantly higher density in the diabetic cohort (58.76  ±  9.55  Hounsfield Units), as compared with the control group (47.31  ±  5.42 Hounsfield Units, P<0.001). Plaque density correlated with the duration of type II diabetes mellitus (r=0.37, P=0.044), but was independent of age, sex, hypertension and metabolic profile. In the control group, plaque density was independent of any covariate.

CONCLUSION

Coronary plaques in type II diabetes mellitus show a tendency to develop impaired adaptive remodeling and to have a higher tissue density.

Prognostic value of preoperative coronary computed tomography angiography in patients treated by orthotopic liver transplantation

OBJECTIVES

The aim of this study was to assess the feasibility of 64-slice coronary computed tomography (CT) angiography in patients treated by orthotopic liver transplantation, and to compare prognostic values of CT angiography and dobutamine stress echocardiography in the same population.

METHODS

Eighty-two consecutive patients, without known coronary artery disease, who underwent orthotopic liver transplantation, were included in this study. A CT angiography was performed along with usual explorations including dobutamine stress echography. A one-year minimal follow-up was performed to seek cardiac events.

RESULTS

Fifty-two (65.8%) patients underwent a CT angiography. Thirty-seven (71%) were totally normal or showed nonobstructive coronary plaque, six (12%) showed at least one obstructive coronary plaque greater than 50%. Nine (17%) of the examined patients had at least one nonassessable segment. A total of six (7.6%) major cardiac events occurred in a mean-time follow-up of 17.8 ± 12.7 months.

CONCLUSION

CT angiography that is normal or with a nonobstructive coronary plaque has a negative predicting value of 95% [0.82-0.99] for major cardiac adverse events, and of 100% [0.91-1] for clinical coronary events in patients undergoing orthotopic liver transplantation. The prognostic value of CT angiography was comparable with that of dobutamine stress echography.

Cardiovascular risk assessment of the liver transplant candidate

Liver transplantation (LT) candidates today are increasingly older, have greater medical acuity, and have more cardiovascular comorbidities than ever before. Steadily rising model for end-stage liver disease (MELD) scores at the time of transplant, resulting from high organ demand, reflect the escalating risk profiles of LT candidates. In addition to advanced age and the presence of comorbidities, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Patients with cirrhosis requiring LT usually demonstrate increased cardiac output and a compromised ventricular response to stress, a condition termed cirrhotic cardiomyopathy. These cardiac disturbances are likely mediated by decreased beta-agonist transduction, increased circulating inflammatory mediators with cardiodepressant properties, and repolarization changes. Low systemic vascular resistance and bradycardia are also commonly seen in cirrhosis and can be aggravated by beta-blocker use. These physiologic changes all contribute to the potential for cardiovascular complications, particularly with the altered hemodynamic stresses that LT patients face in the immediate post-operative period. Post-transplant reperfusion may result in cardiac death due to a multitude of causes, including arrhythmia, acute heart failure, and myocardial infarction. Recognizing the hemodynamic challenges encountered by LT patients in the perioperative period and how these responses can be exacerbated by underlying cardiac pathology is critical in developing recommendations for the pre-operative risk assessment and management of these patients. The following provides a review of the cardiovascular challenges in LT candidates, as well as evidence-based recommendations for their evaluation and management.