Predictive value of dobutamine stress echocardiography for coronary artery disease detection in liver transplant candidates

Evaluation of coronary artery disease in potential liver transplant recipients

Improvements in the management of patients undergoing liver transplantation (LT) have resulted in a significant increase in survival in recent years. Cardiac disease is now the leading cause of early mortality, and the stress of major surgery, hemodynamic shifts, and the possibilities of hemorrhage or reperfusion syndrome require the recipient to have good baseline cardiac function. The prevalence of coronary artery disease (CAD) is increasing in LT candidates, especially in those with nonalcoholic fatty liver disease. In assessing LT recipients, we suggest a management paradigm of "quadruple assessment" to include (1) history, examination, and electrocardiogram; (2) transthoracic echocardiogram; (3) functional testing; and (4) where appropriate, direct assessment of CAD. The added value of functional testing, such as cardiopulmonary exercise testing, has been shown to be able to predict posttransplant complications independently of the presence of CV disease. This approach gives the assessment team the greatest chance of detecting and preventing complications related to CAD. Liver Transplantation 23 386-395 2017 AASLD.

Coronary Computed Tomography Angiography in Combination with Coronary Artery Calcium Scoring for the Preoperative Cardiac Evaluation of Liver Transplant Recipients

Liver transplantation is the best treatment option for early-stage hepatocellular carcinoma, liver cirrhosis, fulminant liver failure, and end-stage liver diseases. Even though advances in surgical techniques and perioperative care have improved postoperative outcomes, perioperative cardiovascular complications are a leading cause of postoperative morbidity and mortality following liver transplantation. Ischemic coronary artery disease (CAD) and cardiomyopathy are the most common cardiovascular diseases and could be negative predictors of postoperative outcomes in liver transplant recipients. Therefore, comprehensive cardiovascular evaluations are required to assess perioperative risks and prevent concomitant cardiovascular complications that would preclude good outcomes in liver transplant recipients. The two major types of cardiac computed tomography are the coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA). CCTA in combination with the CACS is a validated noninvasive alternative to coronary angiography for diagnosing and grading the severity of CAD. A CACS > 400 is associated with significant CAD and a known important predictor of posttransplant cardiovascular complications in liver transplant recipients. In this review article, we discuss the usefulness, advantages, and disadvantages of CCTA combined with CACS as a noninvasive diagnostic tool for preoperative cardiac evaluation and for maximizing the perioperative outcomes of liver transplant recipients.

Non-alcoholic fatty liver disease and liver transplantation

Cirrhosis secondary to non-alcoholic steatohepatitis (NASH) is a common indication for liver transplant. In comparison to other cirrhotic patients, patients with NASH cirrhosis are more likely to be older and have the metabolic syndrome. Pre-transplant, patients require careful evaluation of cardiovascular risk. As the incidence of non-alcoholic fatty liver disease (NAFLD) is rising, a greater proportion of donor grafts have steatosis greater than 30%, which is associated with poor outcomes. Grafts with steatosis greater than 60% are unsuitable for transplant. Overall, post-transplant survival outcomes for patients with NASH cirrhosis are similar to those with cirrhosis without NASH. However, NASH cirrhosis is associated with a higher 30-day mortality, predominantly from an increase in cardiovascular events and infections. Following liver transplant, there is a significant risk of NASH recurrence, although this seldom results in allograft loss. Furthermore, a significant number of patients who had a liver transplant for other reasons develop NASH de novo. When patients with NASH cirrhosis are considered for transplant, one of the major challenges lies in identifying which patients are too high risk for surgery. This review aims to provide information to aid this decision making process, and to provide guidance on the peri-operative care strategies that can modify risk.

Anesthesia Management of Liver Transplantation

Anesthesia for liver transplantation pertains to a continuum of critical care of patients with end-stage liver disease. Hence, anesthesiologists, armed with a comprehensive understanding of pathophysiology and physiologic effects of liver transplantation on recipients, are expected to maintain homeostasis of all organ function. Specifically, patients with fulminant hepatic failure develop significant changes in cerebral function, and cerebral perfusion is maintained by monitoring cerebral blood flow and cerebral metabolic rate of oxygen, and intracranial pressure. Hyperdynamic circulation is challenged by the postreperfusion syndrome, which may lead to cardiovascular collapse. The goal of circulatory support is to maintain tissue perfusion via optimal preload, contractility, and heart rate using the guidance of right-heart catheterization and transesophageal echocardiography. Portopulmonary hypertension and hepatopulmonary syndrome have high morbidity and mortality, and they should be properly evaluated preoperatively. Major bleeding is a common occurrence, and euvolemia is maintained using a rapid infusion device. Pre-existing coagulopathy is compounded by dilution, fibrinolysis, heparin effect, and excessive activation. It is treated using selective component or pharmacologic therapy based on the viscoelastic properties of whole blood. Hypocalcemia and hyperkalemia from massive transfusion, lack of hepatic function, and the postreperfusion syndrome should be aggressively treated. Close communication between all parties involved in liver transplantation is also equally valuable in achieving a successful outcome.

Nonalcoholic Fatty Liver Disease and Liver Transplantation

Nonalcoholic fatty liver disease (NAFLD) is prevalent in the general population and a growing indication for liver transplant. Longer wait times and challenges with pretransplant survivorship are expected, underscoring the need for improved management of attendant comorbidities. Recognition with potential modification of obesity, sarcopenia, chronic kidney disease, and cardiovascular disease in patients with NAFLD may have important implications in the pretransplant and posttransplant periods. Although patients with NAFLD have generally favorable postoperative outcomes, they are at risk for developing recurrent disease in their allograft, driving the need for pharmacotherapies and dietary innovations appropriate for use in the posttransplant period.

Preoperative cardiovascular investigations in liver transplant candidate: An update

Cardiovascular complications are a major cause of morbidity and mortality in patients with end-stage liver disease (ESLD) undergoing liver transplantation. Identifying candidates at the highest risk of postoperative cardiovascular complications is the cornerstone for optimizing the outcome. Ischaemic heart disease contributes to major portion of cardiovascular complications and therefore warrants evaluation in the preoperative period. Patients of ESLD usually demonstrate increased cardiac output, compromised ventricular response to stress, low systemic vascular resistance and occasionally bradycardia. Despite various recommendations for preoperative evaluation of cardiovascular disease in liver transplant candidates, a considerable controversy on screening methodology persists. This review critically focuses on the rapidly expanding body of evidence for diagnosis and risk stratification of cardiovascular disorder in liver transplant candidates.

Coronary Interventions before Liver Transplantation Might Not Avert Postoperative Cardiovascular Events

Percutaneous coronary intervention and coronary artery bypass grafting may be performed before orthotopic liver transplantation (OLT) to try to improve the condition of patients who have severe ischemic heart disease. However, data supporting improved outcomes are lacking. We reviewed the medical records of 2,010 patients who underwent OLT at our hospital from 2000 through 2010. The 51 patients who underwent coronary artery angiography within 6 months of transplantation were included in this study: 28 had mild coronary artery disease, 10 had moderate disease, and 13 had severe disease. We compared all-cause and cardiac-cause mortality rates. We found a significant difference in cardiac deaths between the groups (P <0.001), but none in all-cause death (P=0.624). Of the 10 patients who had moderate coronary artery disease, one underwent pre-transplant coronary artery bypass grafting. Of 13 patients with severe disease, 3 underwent percutaneous coronary intervention, and 6 underwent coronary artery bypass grafting. Overall, 50% of patients who underwent either intervention died of cardiac-related causes, whereas no patient died of a cardiac-related cause after undergoing neither intervention (P <0.0001). We conclude that, despite coronary intervention, mortality rates remain high in OLT patients who have severe coronary artery disease.

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.

Myocardial perfusion imaging is an effective screening test for coronary artery disease in liver transplant candidates

A reliable screening test for coronary artery disease (CAD) in liver transplant (LT) candidates with end-stage liver disease is essential because a high percentage of perioperative mortality and morbidity is CAD-related. In this study, the effectiveness of myocardial perfusion imaging (MPI) for identification of significant CAD in LT candidates was evaluated. Records of 244 patients meeting criteria for MPI were evaluated: 74 met inclusion criteria; 40 had a positive MPI and cardiology follow-up; 27 had a negative MPI and underwent LT; and seven had a negative MPI and then had coronary angiography or a significant cardiac event. A selective MPI interpretation strategy was established where MPI-positive patients were divided into high, intermediate, and low CAD risk groups. The overall incidence of CAD in this study population was 5.1% and our strategy resulted in PPV 20%, NPV 94%, sensitivity 80%, and specificity 50% for categorizing CAD risk. When applied only to the subset of patients categorized as high CAD risk, the strategy was more effective, with PPV 67%, NPV 97%, sensitivity 80%, and specificity 94%. We determined that renal dysfunction was an independent predictive factor for CAD (p < 0.0001, odds ratio = 8.1), and grades of coronary occlusion correlated significantly with chronic renal dysfunction (p = 0.0079).

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.

Coronary Computed Tomographic Angiography in the Evaluation of Liver Transplant Candidates

The feasibility, safety, and value of coronary computed tomographic angiography (CCTA) in evaluating orthotopic liver transplant (OLT) candidates are unknown. We studied a cohort of consecutive OLT candidates with intermediate-to-high risk of coronary artery disease (CAD). Intermediate risk candidates received CCTA, and those at high risk or with abnormal noninvasive testing underwent invasive coronary angiography (ICA). One hundred consecutive patients were evaluated. Fifty patients underwent a CCTA, 71.4% were β-blocked, the image quality was "good" or "excellent" in 71.4% of cases, and there was no event of significant contrast-induced nephropathy. Twenty (20%) patients were found to have severe CAD (≥70% stenosis) by CCTA and/or ICA. Independent predictors of severe CAD were age (odds ratio [OR] = 5.4 per 10-year increment, 95% confidence interval [CI] = 1.7-17.0; P = .004), dyslipidemia (OR = 12.3, 95% CI = 2.6-57.6; P = .001), and chest pain (OR = 6.0, 95% CI = 1.2-29.1; P = .03). Implementing CCTA in the evaluation of intermediate/high CAD risk OLT candidates is challenging but feasible and seems safe.

Evaluation of solid organ transplant candidates for coronary artery disease

Solid organ transplantation has increased in frequency in the United States, having evolved from an area of experimentation into accepted therapy for end-organ failure. As organ transplantation has become more common, the average age of transplant recipients has increased, thus increasing the potential for multiple comorbidities including coronary artery disease (CAD). CAD has been shown to be a major cause of morbidity and mortality in kidney, lung and liver transplant recipients. Identification of CAD in solid organ transplant candidates allows for stratification of short- and long-term risk, ensuring proper use of valuable allograft resources while guiding further patient management. Assessment of asymptomatic transplant candidates for CAD is difficult. Many patients undergo stress echocardiography or nuclear imaging, which have demonstrated inconsistent rates of sensitivity and specificity for the detection of CAD in these patient populations. Cardiac computed tomography is a potential tool for detecting CAD in these populations, but has questionable utility at this time. Coronary angiography has an important role in detecting CAD in high-risk transplant candidates, affecting their long-term management and risk.

Chronotropic incompetence on dobutamine stress echocardiography in candidates for a liver transplant

OBJECTIVES

We evaluated dobutamine stress echocardiography as an initial screening test for a cardiac evaluation before a liver transplant.

MATERIALS AND METHODS

We retrospectively examined 111 liver transplant candidates who had undergone previous cardiac evaluation; 30 of whom had undergone a liver transplant.

RESULTS

Eighty patients (72.1%) completed a dobutamine stress echocardiography (41 chronotropically competent, 39 incompetent), while 31 patients (27.9%) required us to terminate early. Overall, 68 patients (61%) were on β-blockers (21 required early dobutamine stress echocardiography termination, 30 chronotropically incompetent, and 17 competent). Patient results were normal. Thirty patients underwent a liver transplant. Among candidates requiring termination of early dobutamine stress echocardiography, posttransplant cardiac events included 1 fatal acute myocardial infarction, 1 nonfatal acute myocardial infarction, and 1 idiopathic cardiomyopathy. Among chronotropically incompetent patients, 2 patients had transient bradycardia, and among those who were chronotropically competent, 1 had refractory atrial fibrillation, and 1 had transient bradycardia.

CONCLUSIONS

Nearly 50% of patients with end-stage liver disease may not reach the target heart rate. Early termination of dobutamine stress echocardiography because of cardiac symptoms or significant echocardiographic changes have more effect in predicting postoperative cardiac events, but further evaluation is required even if their target heart rate is close to that desired. Lower target heart rate may be acceptable in chronotropically incompetent individuals provided they are asymptomatic, have no echocardiographic changes, or cardiovascular risk factors, especially if they are on β-blockers.

Impaired functional capacity in potential liver transplant candidates predicts short-term mortality before transplantation

Liver transplantation (LT) is a lifesaving treatment. Because of the shortage of donor organs, some patients will not survive long enough to receive a transplant. The identification of LT candidates at increased risk of short-term mortality without transplantation may affect listing decisions. Functional capacity, determined with cardiopulmonary exercise testing (CPET), is a measure of cardiorespiratory reserve and predicts perioperative outcomes. This study examined the association between functional capacity and short-term survival before LT and the potential for CPET to predict 90-day mortality without transplantation. A total of 176 patients who were assessed for nonacute LT underwent CPET. Ninety days after the assessment, 10 of the 164 patients who had not undergone transplantation were deceased (mortality rate = 6.1%). According to a comparison of survivors and nonsurvivors, the Model for End-Stage Liver Disease score, UK Model for End-Stage Liver Disease (UKELD) score, age, anaerobic threshold, and peak oxygen uptake (VO(2)) were significant univariate predictors of 90-day mortality without transplantation, but only the UKELD score and peak VO(2) retained significance in a multivariate analysis. The mean peak VO(2) was significantly lower for nonsurvivors versus survivors (15.2 ± 3.3 versus 21.2 ± 5.3 mL/minute/kg, P < 0.001). According to a receiver operating characteristic (ROC) curve analysis, peak VO(2) performed well as a diagnostic test (area under the ROC curve = 0.84, 95% confidence interval = 0.76-0.92, sensitivity = 0.90, specificity = 0.74, P < 0.001). The optimal cutoff value for predicting mortality was ≤17.6 mL/minute/kg. The positive predictive value of a peak VO(2)  ≤ 17.6 mL/minute/kg for 90-day mortality was greatest for patients with high UKELD scores: 38% of the patients with a UKELD score ≥ 57 and a peak VO(2)  ≤ 17.6 mL/minute/kg died, whereas only 6% of the patients with a UKELD score ≥ 57 and a peak VO(2)  > 17.6 mL/minute/kg died (P = 0.03). In conclusion, patients assessed for LT with an impaired functional capacity have poorer short-term survival; this is particularly true for individuals with worse liver disease severity.

Role of cardiovascular intervention as a bridge to liver transplantation

End stage liver disease (ESLD) is associated with many specific derangements in cardiovascular physiology, which influence perioperative outcomes and may profoundly influence diagnostic and management strategies in the preoperative period. This review focuses on evidence-based diagnosis and management of coronary, hemodynamic and pulmonary vascular disease in this population with an emphasis on specific strategies that may provide a bridge to transplantation. Specifically, we address the underlying prevalence of cardiovascular disease states in the ESLD population, and relevant diagnostic criteria thereof. We highlight traditional and non-traditional predictors of cardiovascular outcomes following liver transplant, as well as data to guide risk-factor based diagnostic strategies. We go on to discuss the alterations in cardiovascular physiology which influence positive- and negative-predictive values of standard noninvasive testing modalities in the ESLD population, and review the data regarding the safety and efficacy of invasive testing in the face of ESLD and its co-morbidities. Finally, based upon the totality of available data, we outline an evidence-based approach for the management of ischemia, heart failure and pulmonary vascular disease in this population. It is our hope that such evidence-driven strategies can be employed to more safely bridge appropriate candidates to liver transplant, and to improve their cardiovascular health and outcomes in the peri-operative period.

Role of cardiac catheterization and percutaneous coronary intervention in the preoperative assessment and management of patients before orthotopic liver transplantation

Limited data regarding the optimal risk assessment strategy for evaluating candidates for orthotopic liver transplantation (OLT) exist. Our center has adopted a policy of performing cardiac catheterization (CATH) in patients with predefined risk factors, and this is followed by percutaneous coronary intervention (PCI) when it is indicated, even in the presence of negative stress test findings. The aim of this single-center, retrospective study of all patients who underwent OLT between 2000 and 2010 was to assess the effect of our policy on cardiovascular (CV) complications and survival rates after OLT. Data, including 1-year all-cause and CV mortality, postoperative myocardial infarctions (MIs), and frequencies of CATH and PCI, were abstracted. The study was divided into 3 subperiods to reflect the changes in policy over this period: (A) 2000-2004, (B) 2005-2008, and (C) 2009-2010. One thousand two hundred twenty-one patients underwent OLT between 2000 and 2010. The rate of catheterization increased during the 3 time periods (P < 0.001), as did the rate of PCI (P < 0.05). All-cause mortality decreased over the periods (P < 0.001), as did the MI rate (P < 0.001). Thirty-five of the 57 patients requiring PCI had normal stress tests. The mortality rate associated with postoperative MIs was significantly higher than the overall all-cause mortality rate. In conclusion, a significant improvement in the overall survival rate over the 3 analyzed time periods was noted. Increases in the frequencies of CATH and PCI corresponded to significant reductions in postoperative MIs and 1-year all-cause mortality rates. The increased use of CATH and PCI was associated with reduced overall all-cause mortality through reductions in the incidence of both fatal and nonfatal MIs. Further analyses of the role of stress testing and CATH in evaluating and treating patients before OLT are required to optimize this process.

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.

Utility of dobutamine stress echocardiography as part of the pre-liver transplant evaluation: an evaluation of its efficacy

BACKGROUND

Dobutamine stress echocardiography (DSE) is commonly used to risk stratify patients in the cardiac evaluation prior to orthotopic liver transplantation (OLT). Data remain limited regarding the accuracy to predict obstructive coronary artery disease (CAD) using this approach.

HYPOTHESIS

We hypothesize that DSE may have limitations in the investigation of underlying CAD in patients with end-stage liver disease.

METHODS

A retrospective chart review of all patients who underwent OLT at Mayo Clinic in Florida between 1998 and 2010 was performed. Sixty-six underwent invasive coronary angiography (ICA) within 1 year of DSE and were included in our study. Based on DSE results, patients were stratified into 1 of 3 groups: nonischemic, ischemic, and indeterminate. The relationship between DSE, ICA, and death from all cause and cardiac-related cause with a minimum 3-year follow-up period were analyzed.

RESULTS

A total of 66 patients were included in our cohort. There was no difference in age, gender, severity of liver disease, and echocardiographic findings among the groups. Forty-three percent of patients (n = 12) with an abnormal result on DSE were found to have moderate or severe obstructive CAD on cardiac catheterization, whereas 49% of patients (n = 17) with a normal finding on DSE had moderate or severe CAD. Of 5 patients who died from a documented cardiac etiology, 3 had normal stress test results, 1 had abnormal findings, and 1 had an indeterminate DSE result. When compared with ICA, our study demonstrated that DSE has a sensitivity of 41.4% (95% confidence interval [CI]: 0.24-0.61), specificity of 47.1% (95% CI: 0.30-0.65), positive predictive value of 40.0% (95% CI: 0.23-0.59), and negative predictive value of 48.0% (95% CI: 0.31-0.66) in identification of underlying CAD.

CONCLUSIONS

Although widely used, DSE may not always accurately reflect the severity of obstructive CAD in patients undergoing OLT.

Dobutamine stress echocardiography in patients undergoing orthotopic liver transplantation: a pooled analysis of accuracy, perioperative and long term cardiovascular prognosis

Pre-transplant evaluation for orthotopic liver transplantation (OLT) commonly includes a cardiac evaluation using dobutamine stress echocardiography (DSE). We performed a quantitative systematic review assessing DSE's use in detecting coronary artery disease (CAD) and predicting perioperative and long term cardiac events in patients undergoing OLT. Published studies in pubmed were accessed using keyword searches and bibliographic review. Included studies evaluated the use of DSE in patients undergoing OLT, including its accuracy for detection of CAD, and in predicting perioperative and long term cardiac prognosis for both hard (myocardial infarction, cardiac death, cardiac arrest, and asystole) and soft cardiac events (all other events that were cardiovascular in nature). We calculated DSE's sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) in the above areas. We identified 7 studies, including a total of 580 patients, which included 4 accuracy studies (n = 110 patients), 4 perioperative studies, and 3 long term studies. Accuracy for CAD included a sensitivity of 0.32, specificity of 0.78, PPV of 0.37, and NPV of 0.75. Accuracy for prediction of perioperative hard and soft cardiac events was a sensitivity of 0.20 and 0, specificity of 0.99 and 0.99, PPV of 0.33 and 0, and NPV of 0.98 and 0.89, respectively. For long term hard and soft cardiac events, sensitivity was 0.5 and 0, specificity 0.99 and 0.98, PPV 0.33 and 0, and NPV 0.99 and 0.96, respectively. DSE has a limited accuracy for the detection of CAD in candidates for OLT. However, among those patients selected for OLT, the negative predictive value of DSE for both perioperative and long term cardiac events is high.

Patient selection and preoperative evaluation for transplant surgery

Candidates for abdominal transplant undergo a pretransplant evaluation to identify associated conditions that may require intervention or that may influence a patient's candidacy for transplant. Coronary artery disease is prevalent in candidates for abdominal organ transplantation. The optimal approach to identify and manage coronary artery disease in the peri-transplant period is currently unclear. In liver transplant candidates portopulmonary hypertension and hepatopulmonary syndrome should be screened for. Identification of the patient who is too sick to benefit from transplant is problematic; with no good evidence available decisions should be individualized and made after multidisciplinary discussion.

Interactions of the heart and the liver

There is a mutual interaction between the function of the heart and the liver and a broad spectrum of acute and chronic entities that affect both the heart and the liver. These can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. In chronic and acute cardiac hepatopathy, owing to cardiac failure, a combination of reduced arterial perfusion and passive congestion leads to cardiac cirrhosis and cardiogenic hypoxic hepatitis. These conditions may impair the liver function and treatment should be directed towards the primary heart disease and seek to secure perfusion of vital organs. In patients with advanced cirrhosis, physical and/or pharmacological stress may reveal a reduced cardiac performance with systolic and diastolic dysfunction and electrophysical abnormalities termed cirrhotic cardiomyopathy. Electrophysiological abnormalities include prolonged QT interval, chronotropic incompetance, and electromechanical uncoupling. No specific therapy can be recommended, but it should be supportive and directed against the heart failure. Numerous conditions affect both the heart and the liver such as infections, inflammatory and systemic diseases, and chronic alcoholism. The risk and prevalence of coronary artery disease are increasing in cirrhotic patients and since the perioperative mortality is high, a careful cardiac evaluation of such patients is required prior to orthotopic liver transplantation.

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.

Response to exercise in patients with liver cirrhosis: implications for liver transplantation

End-stage liver cirrhosis is a systemic disease carrying a short-term desperate prognosis without liver transplantation. Given the discrepancy between the growing number of candidates and the limited available liver grafts, the pre-transplantation screening process has become a challenging task. Cardiopulmonary exercise testing, by measuring maximal oxygen consumption at peak exercise, provides a global integrative approach of the health status of an individual. In the setting of liver cirrhosis, decreased oxygen consumption at peak exercise may result from a combination of multiple extra-hepatic complications, including deconditioning, malnutrition-associated muscle weakness, anaemia, cirrhotic cardiomyopathy, and hepato-pulmonary syndrome for instance. In addition, oxygen consumption at peak exercise not only correlated with the severity of the liver disease, but it is also independently associated with survival following liver transplantation. The present article aims to review the numerous determinants of impaired aerobic capacity in patients with severe liver disease, and to discuss how useful is cardiopulmonary exercise testing as a critical tool in the pre-transplantation assessment of these patients.

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.

Liver transplantation outcome in patients with angiographically proven coronary artery disease: a multi-institutional study

Over the last decade the age of liver transplant (LT) recipients and the likelihood of coronary artery disease (CAD) in this population have increased. There are no multicenter studies that have examined the impact of CAD on LT outcomes. In this historical cohort study, we identified adult LT recipients who underwent angiography prior to transplantation at seven institutions over a 12-year period. For each patient we recorded demographic data, recipient and donor risk factors, duration of follow-up, the presence of angiographically proven obstructive CAD (≥50% stenosis) and post-LT survival. Obstructive CAD was present in 151 of 630 patients, the CAD(+) group. Nonobstructive CAD was found in 479 patients, the CAD(-) group. Patient survival was similar for the CAD(+) group (adjusted HR 1.13, CI = [0.79, 1.62], p = 0.493) compared to the CAD(-) group. The CAD(+) patients were further stratified into severe (CADsev, >70% stenosis, n = 96), and moderate CAD (CADmod, 50-70% stenosis, n = 55) groups. Survival for the CADsev (adjusted HR = 1.26, CI = [0.83, 1.91], p = 0.277) and CADmod (adjusted HR = 0.93, CI = [0.52, 1.66], p = 0.797) groups were similar to the CAD(-) group. We conclude that when current CAD treatment strategies are employed prior to transplant, post-LT survival is not significantly different between patients with and without obstructive CAD.

Reducing the load: the evolution and management of obesity and nonalcoholic steatohepatitis before liver transplantation

1. Obesity is common in patients with end-stage liver disease of any cause. 2. Obesity is associated with comorbidities that can affect liver transplant candidacy, such as metabolic syndrome (diabetes, hyperlipidemia, and hypertension), cardiovascular disease, pulmonary disorders (related to obstructive sleep apnea), renal dysfunction, and malignancies. 3. Nonalcoholic steatohepatitis is the only indication for transplantation that is increasing in frequency, and it may soon become the leading indication. 4. There is no set body mass index above which liver transplantation is contraindicated. Transplant candidacy and outcomes depend on the cumulative comorbidities of the individual patient. 5. Weight loss is an important component of metabolic syndrome management and is recommended before liver transplantation. 6. Bariatric surgery may be considered in carefully selected patients with well-compensated cirrhosis but is not recommended in patients with decompensated cirrhosis.

The end-organ impairment in liver cirrhosis: appointments for critical care

Liver cirrhosis (LC) can lead to a clinical state of liver failure, which can exacerbate through the course of the disease. New therapies aimed to control the diverse etiologies are now more effective, although the disease may result in advanced stages of liver failure, where liver transplantation (LT) remains the most effective treatment. The extended lifespan of these patients and the extended possibilities of liver support devices make their admission to an intensive care unit (ICU) more probable. In this paper the LC is approached from the point of view of the pathophysiological alterations present in LC patients previous to ICU admission, particularly cardiovascular, but also renal, coagulopathic, and encephalopathic. Infections and available liver detoxifications devices also deserve mentioning. We intend to contribute towards ICU physician readiness to the care for this particular type of patients, possibly in dedicated ICUs.

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.

New index for assessing the chronotropic response in patients with end-stage liver disease who are undergoing dobutamine stress echocardiography

The inability to achieve 85% of the maximum predicted heart rate (MPHR) on dobutamine stress echocardiography (DSE) is defined as chronotropic incompetence and is a predictor of major cardiac events after orthotopic liver transplantation (OLT). The majority of patients with end-stage liver disease (ESLD) receive beta-blockers for the prevention of variceal bleeding. In these patients, it is impossible to determine whether chronotropic incompetence is secondary to cirrhosis-related autonomic dysfunction or is merely a beta-blocker effect. We evaluated the usefulness of the maximum achieved heart rate (MAHR) and the heart rate reserve (HRR) in the detection of chronotropic incompetence in ESLD patients on beta-blocker therapy before DSE. We also evaluated the usefulness of a new index, the modified heart rate reserve (MHRR), in diagnosing chronotropic incompetence and predicting major cardiovascular adverse events after OLT. The study population consisted of 284 ESLD patients. The mean values of MAHR (expressed as a percentage of 85% of MPHR) and HRR were significantly lower for patients on beta-blockers versus patients off beta-blockers [97.1% versus 101.6% (t = 5.01, P < 0.001) and 71.7% versus 77.3% (t = 4.03, P < 0.001), respectively], whereas the values of MHRR were similar in patients on beta-blockers and patients off beta-blockers [102.3% versus 102.1% (t = 0.04, P = 0.97)]. A regression analysis showed a significant association of MAHR (P < 0.001) and HRR (P < 0.001) with beta-blockers, whereas MHRR was not associated with beta-blocker treatment (P = 0.92). MAHR and HRR were found to have no value for diagnosing chronotropic incompetence in ESLD patients. MHRR was not affected by beta-blocker therapy. Patients who developed heart failure (HF) and myocardial infarction (MI) after OLT had significantly lower MHRR values according to pretransplant DSE. MHRR was significantly associated with the subsequent development of HF (P = 0.01) and MI (P = 0.01) after OLT. MHRR may be useful for the determination of the target heart rate for stress testing, the diagnosis of chronotropic incompetence, and the prediction of adverse cardiac events after OLT.

[Anesthesia in the patient with impaired liver function]

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.

Comparison of the frequency of coronary artery disease in alcohol-related versus non-alcohol-related endstage liver disease

There are conflicting data as to the prevalence of coronary artery disease (CAD) in patients with end-stage liver disease (ESLD) being assessed for liver transplantation (LT). The aims of this study were to compare the prevalence of CAD in patients with alcohol-related versus non-alcohol-related ESLD and to assess the diagnostic utility of dobutamine stress echocardiography (DSE) in predicting angiographically important CAD. Consecutive patients with ESLD being assessed for LT (n = 420, mean age 56 ± 8 years) were identified and divided into groups of those with alcohol-related ESLD (n = 125) and non-alcohol-related ESLD (n = 295). Demographic characteristics, CAD risk factors, results of DSE, and coronary angiographic characteristics were recorded. There were no significant differences in age or CAD risk factors between groups. The incidence of severe CAD (>70% diameter stenosis) was 2% in the alcohol-related ESLD group and 13% in the non-alcohol-related ESLD group (p <0.005). In the 2 groups, the presence of ≥1 CAD risk factor was associated with significant CAD (p <0.05 for all). Absence of cardiac risk factors was highly predictive in ruling out angiographically significant disease (negative predictive value 100% for alcohol-related ESLD and 97% for non-alcohol-related ESLD). DSE was performed in 205 patients. In the 2 groups, DSE had poor predictive value for diagnosing significant CAD but was useful in ruling out patients without significant disease (negative predictive value 89% for alcohol-related ESLD and 80% for non-alcohol-related ESLD). In conclusion, there was a significantly lower prevalence of severe CAD in patients with alcohol-related ESLD. These findings suggest that invasive coronary angiography may not be necessary in this subgroup, particularly in the absence of CAD risk factors and negative results on DSE.

Cardiovascular and renal complications in patients receiving a solid-organ transplant

PURPOSE OF REVIEW

Cardiovascular and renal complications among solid-organ transplant recipients are a frequent source of morbidity. Appropriate management of these complications throughout the perioperative period significantly affects long-term recipient survival. This review details the identification, management, and potential preventive strategies for perioperative cardiovascular and renal complications among solid-organ transplant recipients.

RECENT FINDINGS

Abdominal transplant candidates have a significantly higher prevalence of risk factors for obstructive coronary artery disease than the general population. There is no consensus on pretransplant screening for coronary artery disease or determination of perioperative risk in candidates awaiting transplantation. Limitations of noninvasive cardiac screening tests such as dobutamine stress echocardiography and myocardial perfusion scintigraphy complicate preoperative evaluation and cardiac risk stratification. Coronary angiography remains the definitive mechanism for determining the presence and severity of coronary artery disease prior to transplantation; however, the relationship between angiographically documented coronary artery disease and cardiovascular morbidity after transplantation is inconsistent. This has raised speculation that perioperative adverse cardiac events are not principally caused by obstructive coronary artery disease but other acute events related to surgical intervention and allograft function. Current data indicate coronary angiography is safe even with patients demonstrating renal insufficiency. A cardiac screening program should reflect the patient population, dynamics of the transplant program, and institutional expertise. The development of classification schemes for defining and categorizing acute kidney injury reflects the importance of preserved renal function in long-term recipient survival. The potential of serum markers as indicators of acute kidney injury has provided a foundation for understanding the global influence of surgical intervention and allograft function upon recipient survival.

SUMMARY

Meticulous attention to all aspects of the transplant process, including operative events and early allograft function, is necessary to minimize morbidity. Further research is necessary to identify mechanisms that support and improve early allograft function to optimize recipient long-term survival.

Optimizing cost-effectiveness in perioperative care for liver transplantation: a model for low- to medium-income countries

Although liver transplantation (LT) is a highly effective treatment, it has been considered too costly for publicly funded health systems in many countries with low to medium average incomes. However, with economic growth and improving results, some governments are reconsidering this position. Cost-effectiveness data for LT are limited, especially in perioperative care, and the techniques and costs vary widely between centers without overt differences in outcomes. Anesthesiologists working in new programs find it difficult to determine which modalities are essential, which are needed only in exceptional circumstances, and which may be omitted without effects on outcomes. We investigated key elements of preoperative evaluations, intraoperative management, and early postoperative care that might significantly affect costs in order to develop a best-value approach for new programs in resource-limited health systems. We identified all modalities of care commonly used in anesthesia and perioperative care for adult LT along with their costs. Those considered to be universally accepted as minimum requirements for safe care were excluded from the analysis, and so were those considered to be safe and low-cost, even when evidence of efficacy was lacking. The remaining items were, therefore, those with uncertain or context-restricted value and significant costs. A systematic review of the published evidence, practice surveys, and institutional guidelines was performed, and the evidence was graded and summarized. With respect to costs and benefits, each modality was then cited as strongly recommended, recommended or optional, or no recommendation was made because of insufficient evidence. Sixteen modalities, which included preoperative cardiovascular imaging, venovenous bypass, pulmonary artery catheterization, high-flow fluid warming devices, drug therapies for hemostasis, albumin, cell salvage, anesthetic drugs, personnel (staffing) requirements, and early extubation, were assessed. Only high-flow fluid warming was strongly recommended. The recommended modalities included preoperative echocardiography, cell salvage, tranexamic acid and early extubation. Six others were rated optional, and there was insufficient evidence for 5 modalities. We conclude that some costly techniques and treatments can be omitted without adverse effects on outcomes.

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

AIMS

In patients undergoing orthotopic liver transplantation (OLT), coronary artery disease (CAD), obstructive and nonobstructive, is associated with high morbidity and mortality. In OLT candidates, stress testing for detecting ischemia is often inaccurate, and this patient population often has relative contraindications for cardiac catheterization. The objective of this study was to describe the methods, assess the feasibility and determine the extent and severity of CAD in OLT candidates without a prior history of CAD using coronary multidetector computer tomographic angiography (MDCTA).

METHODS

Sixty-five OLT candidates without known CAD underwent coronary MDCTA with dual source cardiac computed tomography (Siemens Definition). Coronary arteries were divided into 17 segments based on American Heart Association guidelines and evaluated independently by two blinded reviewers. Image quality of coronary MDCTA was assessed on a four-point Likert scale (0 = poor, 1 = fair, 2 = good, and 3 = excellent). Atherosclerotic lesions were evaluated for severity [mild (0-50%), moderate (51-70%), and severe (71-100%)], morphology, extent, location and consistency.

RESULTS

Image quality was graded as good or excellent in 73.8%. In this cohort of OLT candidates without known CAD, 9% had normal coronary arteries, 58% had mild CAD and 34% had moderate to severe CAD. Plaque severity and burden scores were high.

CONCLUSION

The prevalence of asymptomatic CAD is high in OLT candidates. Coronary MDCTA is feasible in OLT candidates and appears to be a useful technique to diagnose occult CAD in this patient population.

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.

Critical care of the end-stage liver disease patient awaiting liver transplantation

Patients with end-stage liver disease awaiting liver transplantation frequently require intensive care admission and management due to either complications of liver failure or to intercurrent illness, particularly infection. Mortality in such patients is high and the development of an illness necessitating intensive care unit management can influence transplant candidacy. Specialized support frequently requires hemodynamic support, mechanical ventilation, and renal support. In this review, areas of management of particular importance to patients with end-stage liver disease in the intensive care unit are discussed. These areas are hepatic encephalopathy, infectious diseases, cardiovascular support, mechanical ventilation, renal support and combined transplantation, and decisions regarding delisting. Current knowledge specific to these patients, when available, is discussed, current practice is described, and areas of uncertainty in the evidence are discussed.

The heart in liver transplantation

The heart and liver are organs that are closely related in both health and disease. Patients who undergo liver transplantation may suffer from heart disease that is: (a) related to the original cause of the liver disease such as hemochromatosis, (b) related to the liver disease itself, or (c) related to other associated conditions. Furthermore, liver transplantation is one of the most cardiovascular stressful events that a patient with cirrhosis may undergo. After liver transplantation, the progression of pre-existing or the development of new-onset cardiac disease may occur. This article reviews the relationship between the heart and liver transplantation in the pre-transplant, intra-operative, and post-transplant periods.

Perioperative considerations in patients with cirrhotic cardiomyopathy

PURPOSE OF REVIEW

This review aims to identify specific criteria for cirrhotic cardiomyopathy, examine the correlation with perioperative adverse outcomes and explore options for hemodynamic monitoring.

RECENT FINDINGS

Cirrhotic cardiomyopathy is characterized by an increase in cardiac output, blunted systolic contractile response to stress, diastolic dysfunction and electrophysiological abnormalities. Adverse events due to cirrhotic cardiomyopathy are not as well characterized, but evidence suggests that some cardiovascular complications during surgery and in the postoperative period are caused by an impaired response to physiological stress. New developments in hemodynamic monitoring using not only thermodilution technology provide more reliable information about cardiac performance than pressure-derived measures. Transesophogeal echocardiography also offers the physician new information including the ability to visualize heart structures, shape, and function.

SUMMARY

To detect cirrhotic cardiomyopathy, physicians must conduct a systematic examination of the patient. Overt manifestations of cirrhotic cardiomyopathy often only become evident after a patient is exposed to physiological or drug-induced stress. Appropriate hemodynamic monitoring is a cornerstone in the perioperative management of cirrhotic patients.

Coronary artery disease in orthotopic liver transplantation: pretransplant assessment and management

The prevalence of coronary artery disease in end-stage liver disease is only now being recognized. Liver transplant patients are a high risk subgroup for coronary artery disease, even if asymptomatic. Coronary artery disease is a predictor of poor outcomes; therefore, identification of those at risk must be a key clinical priority. However, risk assessment is particularly difficult as many of the available diagnostic tools have either proven to be unhelpful or remain to be validated. Risk factor profiling has been unable to identify those at risk and commonly underestimates risk. The high negative predictive value of Dobutamine stress echo, when target heart rates are achieved, allows it to be used to identify a low risk group. For all other patients, proceeding to invasive coronary angiography is often necessary, and the risks of the procedure can be reduced by a transradial approach. Pharmacological reduction of the consequences of coronary artery disease can be limited by the underlying liver disease. Revascularization pre-transplantation is recommended in international guidelines but has demonstrated little evidence of benefit. Surgical revascularization carries an increased risk in these patients and is commonly performed pre-transplantation, although combined liver and cardiac surgery has been described. Percutaneous coronary intervention is increasingly used with patients requiring anti-platelet medication for up to one year after intervention. We present a review of all these issues and the evidence for assessing and managing these high-risk patients.

Perioperative risk predictors of cardiac outcomes in patients undergoing liver transplantation surgery

BACKGROUND

Cardiac risk assessment for perioperative outcomes of liver transplantation patients is limited. We examined the outcomes of an older intermediate-cardiac-risk group of patients undergoing liver transplantation surgery.

METHODS AND RESULTS

Patients who had liver transplantation surgery between 2001 and 2005 were studied. The 3 outcomes analyzed were nonfatal myocardial infarction, death, and either outcome within the first 30 days after the liver transplantation surgery. Of 403 patients (mean age, 52+/-9 years; 67% male), 106 (26%) were diabetic, 84 (21%) were hypertensive, and 173 (43%) had a history of smoking. There were 48 total events (12%), 25 myocardial infarctions (7%), and 38 deaths (9%) recorded during the perioperative period. From the final multivariate model, history of coronary artery disease, prior stroke, and postoperative sepsis predicted greater risk (P=0.014; odds ratio [OR], 4.0; 95% confidence interval [CI], 1.3 to 11.8; P=0.025; OR, 6.6; 95% CI, 1.3 to 33.8; and P<0.001; OR, 7.5; 95% CI, 3.3 to 17.1, respectively). Use of perioperative beta-blockers was protective (P=0.004; OR, 0.20; 95% CI, 0.1 to 0.6) for combined cardiac outcomes. For the outcome of death on multivariate analysis, postoperative sepsis and increased interventricular septal thickness predicted risk (P<0.001; OR, 8.6; 95% CI, 3.5 to 20.9; and P=0.027; OR, 2.8; 95% CI, 1.1 to 7.2, respectively), whereas the use of perioperative beta-blockers was again protective (P=0.012; OR, 0.07; 95% CI, 0.01 to 0.56).

CONCLUSIONS

In our study of cardiac risk assessment for liver transplantation surgery, history of stroke, coronary artery disease, postoperative sepsis, and increased interventricular septal thickness were markers of adverse perioperative cardiac outcomes, whereas use of perioperative beta-blockers was significantly protective.