Usefulness of preoperative noninvasive radionuclide testing for detecting coronary artery disease in candidates for liver transplantation

Coronary Computed Tomography Angiography Demonstrates a High Burden of Coronary Artery Disease Despite Low-Risk Nuclear Studies in Pre-Liver Transplant Evaluation

We investigated the presence and severity of coronary artery disease (CAD) in orthotopic liver transplantation (OLT) candidates using coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA) as compared with the prevalence of normal and abnormal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). A total of 140 prospective OLT candidates without known CAD underwent coronary artery calcium (CAC) scans with (n = 77) or without CCTA and coronary computed tomography angiography-derived fractional flow reserve (FFR_CT ; n = 57) using a dual-source computed tomography (CT) and were followed for 2.6 ± 1.4 years. Coronary plaque was quantified using the segment-involvement score (SIS) and segment stenosis score (SSS). The mean age was 59 ± 6 years, and 65.0% of patients were male. Mean Agatston CACS was 367 ± 653, and 15.0% of patients had CACSs of 0; 83.6% received a SPECT MPI, of which 95.7% were interpreted as normal/probably normal. By CCTA, 9.1% had obstructive CAD (≥70% stenosis), 67.5% had nonobstructive CAD, and 23.4% had no CAD. Nonobstructive CAD was diffuse with mean SIS 3.0 ± 2.9 and SSS 4.5 ± 5.4. Only 14 patients had high risk-findings (severe 3v CAD, n = 4, CACS >1000 n = 10) that prompted X-ray angiography in 3 patients who had undergone CCTA, resulting in revascularization of a high-risk obstruction in 1 patient who had a normal SPECT study. Patients with end-stage liver disease have a high prevalence of nonobstructive CAD by CCTA, which is undiagnosed by SPECT MPI, potentially underestimating cardiovascular risk. Deferring X-ray angiography unless high-risk CCTA findings are present is a potential strategy for avoiding unnecessary X-ray angiography.

Pre-operative stress testing in the evaluation of patients undergoing non-cardiac surgery: A systematic review and meta-analysis

Background

Pre-operative stress testing is widely used to evaluate patients for non-cardiac surgeries. However, its value in predicting peri-operative mortality is uncertain. The objective of this study is to assess the type and quality of available evidence in a comprehensive and statistically rigorous evaluation regarding the effectiveness of pre-operative stress testing in reducing 30-day post -operative mortality following non -cardiac surgery.

Methods

The databases of MEDLINE, EMBASE, and CENTRAL databases (from inception to January 27, 2016) were searched for all studies in English. We included studies with pre-operative stress testing prior to 10 different non-cardiac surgery among adults and excluded studies with sample size<15. The data on study characteristics, methodology and outcomes were extracted independently by two observers and checked by two other observers. The primary outcome was 30-day mortality. We performed random effects meta-analysis to estimate relative risk (RR) and 95% confidence intervals (95% CI) in two-group comparison and pooled the rates for stress test alone. Heterogeneity was assessed using I² and methodological quality of studies using Newcastle-Ottawa Quality Assessment Scale. The predefined protocol was registered in PROSPERO #CRD42016049212.

Results

From 1807 abstracts, 79 studies were eligible (297,534 patients): 40 had information on 30-day mortality, of which 6 studies compared stress test versus no stress test. The risk of 30-day mortality was not significant in the comparison of stress testing versus none (RR: 0.79, 95% CI = 0.35–1.80) along with weak evidence for heterogeneity. For the studies that evaluated stress testing without a comparison group, the pooled rates are 1.98% (95% CI = 1.25–2.85) with a high heterogeneity. There was evidence of potential publication bias and small study effects.

Conclusions

Despite substantial interest and research over the past 40 years to predict 30-day mortality risk among patients undergoing non-cardiac surgery, the current body of evidence is insufficient to derive a definitive conclusion as to whether stress testing leads to reduced peri-operative mortality.

Cardiac stress testing and coronary artery disease in liver transplantation candidates: Meta-analysis

AIM

To evaluate the diagnostic value of dobutamine stress echocardiography (DSE) and myocardial perfusion scintigraphy (MPS) in predicting coronary artery disease (CAD) in cirrhotic patients listed for liver transplantation (LT), using invasive coronary angiography (ICA) as gold-standard.

METHODS

Retrieval of studies was based on Medical Subject Headings and Health Sciences Descriptors, which were combined using Boolean operators. Searches were run on the electronic databases Scopus, Web of Science, EMBASE, MEDLINE (PubMed), BIREME (Biblioteca Regional de Medicina), LILACS (Latin American and Caribbean Health Sciences Literature), Cochrane Library for Systematic Reviews and Opengray.eu. There was no language or date of publication restrictions. The reference lists of the studies retrieved were searched manually.

RESULTS

The search strategy retrieved 322 references for DSE and 90 for MPS. In the final analysis, 10 references for DSE and 10 for MPS were included. Pooled sensitivity was 28% and 61% for DSE and MPS and specificity was 82% and 74%, for diagnosis of CAD using ICA as gold-standard, respectively.

CONCLUSION

DSE and MPS do not have adequate sensitivity for determination of whether CAD is present, despite having significant specificity.

Dobutamine stress echocardiography, myocardial perfusion scintigraphy, invasive coronary angiography, and post-liver transplantation events: Systematic review and meta-analysis

The impact of coronary artery disease on the clinical course of patients enrolled for liver transplantation (LT) has changed over the years as these patients become older and sicker. The purpose of this systematic review and meta-analysis was to investigate the value of dobutamine stress echocardiography (DSE), myocardial perfusion scintigraphy (MPS), and invasive coronary angiography (ICA) in predicting cardiac events post-LT in cirrhotic patients. A literature search was conducted using Scopus, Web of Science, EMBASE, MEDLINE (via PubMed), BIREME (regional medical library of the Pan American Health Organization), LILACS (Latin American and Caribbean Health Sciences Literature), Cochrane Library for Systematic Reviews, and OpenGrey Repository (www.opengrey.eu) electronic databases. A total of 322 records were retrieved for DSE, 90 for MPS, and 149 for ICA. In the final analysis, 11 records for DSE, 7 for MPS, and 8 for ICA were included. The relative risk and confidence interval for major adverse cardiac events were 30.2 (2.8-325.4) for DSE, 2.6 (1.09-6.1) for MPS, and 2.1 (1.0-2.3) for ICA, while the relative risk and confidence interval for all-cause mortality was 4.7 for DSE (1.8-12.0), 2.7 (1.25-5.9) for MPS, and 1.5 (0.89-3.2) for ICA. In conclusion, this meta-analysis found that DSE, MPS, and ICA do not satisfactorily predict increased risk of perioperative MACE or all-cause mortality among cirrhotic patients listed for LT, among small and heterogenous studies.

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.

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.

Clinical value of preoperative coronary risk assessment by computed tomographic arteriography prior to adult living donor liver transplantation

PURPOSE

Patients with advanced liver diseases are at increased risk of cardiovascular events, resulting in a higher incidence of cardiac complications following liver transplantation (OLT). We assessed the clinical value of computed tomographic coronary arteriography (CTCAG) as a routine preoperative cardiac evaluation test in adult patients scheduled for living donor OLT (LDLT).

METHODS

This single-center, prospective, observational study evaluated 247 adult patients being assessed for LDLT from April 2010 to March 2011. CTCAG was performed in patients with all-negative findings on routine cardiac workup, including thallium single photon emission computed tomography (SPECT).

RESULTS

Of the 247 patients evaluated, 27 (10.9%) showed abnormal findings on CTCAG, with 18 (7.3%) showing mild to moderate involvement of one vessel; 7 (2.8%), two-vessel; and 2 (0.8%), three-vessel involvement. Coronary artery calcification was identified in patients with significant coronary artery stenosis. No adverse events occurred after CTCAG. Noticeable hypotensive episodes during LDLT surgery occurred in 5% of patients, mostly related to massive bleeding or postperfusion syndrome. During the first 3 months after LDLT, 3% of patients showed stress cardiomyopathy, but all recovered with supportive care.

CONCLUSIONS

The poor general medical condition of LDLT candidates and the diagnostic accuracy of CTCAG suggest that this test should be included in the routine pretransplant cardiac workup, along with thallium SPECT, for these patients.

Update in liver transplantation

PURPOSE OF REVIEW

Successful transplant outcomes require optimal patient selection and timing. This review will update clinicians with current status and challenges in liver transplantation. Currently, the major limitation facing liver transplant centers is the shortage of organs. The limited availability of organs has led to long waiting periods for liver transplantation and consequently many patients become seriously ill or die while on the waiting list.

RECENT FINDINGS

This has major implications in the selection of patients, as well as the timing of transplant, for optimal use of these scarce organs. Indications and contraindications have changed slightly over the years and will be reviewed in this article.

SUMMARY

Timing for transplantation has changed more dramatically in the recent years because major changes to organ allocation systems have been undertaken to provide clinicians with a better way to prioritize patients for liver transplant.

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.

Adult liver transplantation in the USA

PURPOSE OF REVIEW

To provide the nontransplant clinician with a basic understanding of the liver transplant process.

RECENT FINDINGS

Since its inception, the technique of liver transplantation and patient management has evolved considerably. We present an up-to-date overview of the evaluation of the transplant recipient and the listing and timing of transplant. We conclude with a brief summary of long-term complications, which should be considered when caring for the posttransplant patient.

SUMMARY

Liver transplantation is the only definitive treatment option for patients dying of liver failure. The growing population of patients with liver disease means that more transplants will be performed. As these patients now live longer lives, it is crucial that clinicians have a basic understanding of the process and outcomes.

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.

Clinical value of myocardial perfusion scintigraphy as a screening tool in liver transplant candidates

A cardiac evaluation before orthotopic liver transplantation (OLT) is imperative. Previous investigations have demonstrated that mild to moderate reversible perfusion defects on myocardial perfusion scintigraphy (MPS) in general are associated with a low risk for perioperative cardiac events. The objective of this study was to assess any perfusion defects in consecutive patients with chronic liver disease who were undergoing OLT. OLT candidates underwent extensive cardiovascular screening that included, among other methods, MPS. Patients who had no contraindications for surgery and underwent OLT were followed up. The occurrence and risk of complications and mortality were compared in 3 groups of patients: patients with normal MPS results, patients with any reversible defect, and patients with a fixed perfusion defect on MPS. In all, 156 subsequent patients underwent OLT. One or more reversible segmental perfusion defects on MPS were present in 14 patients (<3 segments, n = 12; 3 segments without obstructive coronary artery disease, n = 2). The risk of complications did not differ significantly between patients with normal MPS findings and patients with a reversible perfusion defect (odds ratio = 3.04, 95% confidence interval = 0.65-14.26, P = 0.16), although the study was not sufficiently powered to show a difference. The presence of 1 or more reversible defects on MPS was significantly associated with an increased incidence of all-cause 1-year mortality (hazard ratio = 3.17, 95% confidence interval = 1.02-9.83, P = 0.046). No significant difference in the outcomes of patients with normal MPS findings and patients with a fixed defect on MPS was found; the study was, however, not adequately powered to do so. In conclusion, the results of this small cohort study indicate that patients with mild to moderate reversible perfusion defects on MPS may have inferior survival characteristics in comparison with patients with normal MPS results. A prospective, adequately powered study is required to confirm the results of this study.

Safety of regadenoson in patients with end-stage liver disease

BACKGROUND

Regadenoson is a selective A(2A) receptor agonist that is used for vasodilator stress myocardial perfusion imaging (MPI). Since the drug is partially metabolized by the liver, its safety in patients with end-stage liver disease (ESLD) needs to be determined.

METHODS AND RESULTS

We studied 168 consecutive patients with ESLD who had regadenoson stress gated single photon emission computed tomography MPI between January 2008 and March 2010 before planned orthotopic liver transplantation and compared the hemodynamic responses and safety profile to 168 control patients. There were 72 women (43%) in ESLD versus 87 (52%) in the control group (P = .1). The patients with ESLD were younger (58 ± 7 vs 62 ± 12 years, P = .0002), but more likely to be Caucasians (P = .002). The MPI images were normal in 161 patients (96%) in each group. The left ventricular ejection fraction was 72 ± 10% in ESLD and 66 ± 11% in the control patients (P = .0001). The heart rate increase in response to regadenoson was lower in patients with ESLD than in the control group (16 ± 11 vs 23 ± 16 bpm, P = .0001), but the changes in systolic and diastolic blood pressures were similar (-9 ± 12 vs -11 ± 14 mmHg and -6 ± 8 vs -7 ± 10 mmHg, respectively, P = NS). There were no deaths or medication-related adverse events that required hospitalization in either group within 30 days of the study.

CONCLUSION

This is the first study to document the tolerability and safety profile of regadenoson in patients with ESLD.

Liver transplantation for alcoholic liver disease

Alcoholic liver disease (ALD) is the second commonest indication for liver transplantation after viral hepatitis in the United States and Europe. Controversies surround the indications and allocation of scarce and expensive resource for this so called self inflicted disease. Controversies stem from the apprehension that alcoholic recipients are likely to relapse and cause damage to the graft. There is a need to select those candidates with lower risk for relapse with the available predictive factors and scores. Substance abuse specialist and psychiatrists are mandatory in the pre-transplant evaluation and in the post-transplant follow-up. There is conflicting evidence to support a fixed period of pretransplant abstinence, although most units do follow this. Alcoholic hepatitis (AH) continues to be a contraindication for transplantation, however there is a need for further research in this field as a subset of patients with AH who do not respond to medical treatment, have high early mortality and could benefit from transplantation. One year, 3-year, and 5-year survival post-transplant is similar for both ALD and non-ALD recipients. The incidence of post-transplant rejection and retransplantation is also similar to other recipients. ALD with viral hepatitis especially hepatitis C virus leads to a more aggressive liver disease with early presentation for transplantation. ALD patients are more prone to develop de-novo malignancy; this is attributed to the long term effect of alcohol, tobacco combined with immunosuppression. Post-transplant surveillance is important to detect early relapse to alcoholism, presence of de-novo malignancy and treat the same adequately.

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.

Value of stress myocardial perfusion scanning in diagnosis of severe coronary artery disease in liver transplantation candidates

BACKGROUND

The significant potential for perioperative and late cardiovascular complications makes careful preoperative cardiac risk assessment imperative in liver transplantation candidates.

OBJECTIVE

To determine the sensitivity and specificity of myocardial perfusion scanning for detection of coronary artery disease (CAD) in liver transplantation candidates.

PATIENTS AND METHODS

We prospectively evaluated 93 liver transplantation candidates. Patients with known CAD were excluded. All patients, regardless of symptoms and risk factors, underwent myocardial perfusion scanning and coronary angiography.

RESULTS

Results of myocardial perfusion scanning were abnormal in 64 patients (68.8%) and normal in 29 patients (31.2%). Of patients with abnormal scans, only 6 (9.4%) had severe CAD at coronary angiography. None of the 29 patients with normal perfusion scans and the 24 patients with fixed defects had severe CAD; however, 6 of 40 patients (15.0%) with reversible perfusion defects had severe CAD at coronary angiography (P = .005). Alcoholic liver disease, reversible perfusion defects at myocardial perfusion scanning, left ventricular systolic dysfunction, and higher low-density lipoprotein (LDL) cholesterol and triglyceride levels were significantly associated with CAD. Defining reversible perfusion defects as a sign of ischemia, and fixed defects and normal perfusion as nonischemic, myocardial perfusion scanning had 100% sensitivity but 61% specificity for severe CAD. The test's accuracy was low (38%).

CONCLUSIONS

The results of reversible perfusion defects on myocardial perfusion scanning were sensitive but not specific for CAD in liver transplantation candidates. The high number of false-positive results decreased the test's accuracy.

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

Patients with obstructive coronary artery disease (CAD) undergoing orthotopic liver transplantation (OLT) are at increased risk of poor outcomes. The accuracy of dobutamine stress echocardiography (DSE) to detect obstructive CAD is not well established in this population. We retrospectively identified patients with end-stage liver disease who underwent both DSE and coronary angiography as part of risk stratification prior to OLT. One hundred and five patients had both DSE and angiography, of whom 14 had known CAD and 27 failed to reach target heart rate during DSE. Among the remaining 64 patients (45 men; average age 61 +/- 8 years) DSE had a low sensitivity (13%), high specificity (85%), low positive predictive value (PPV) (22%) and intermediate negative predictive value (NPV) (75%) for obstructive CAD. DSE as a screening test for obstructive CAD in OLT candidates has a poor sensitivity. The frequent chronotropic incompetence and low sensitivity in patients who achieve target heart rate, even in those with multiple cardiovascular disease risk factors, suggest that alternative or additional methods of risk stratification are necessary.

Cardiac evaluation of liver transplant candidates

Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Cardiomyopathy also occurs in greater frequency. While all patients with advanced cardiac disease have defects in cardiac performance, a larger than expected number of patients have classical findings of dilated, restrictive and hypertrophic cardiomyopathy. This may explain why up to 56% of patients suffer from hypoxemia due to pulmonary edema following transplant surgery. There is considerable controversy on how to screen transplant candidates for the presence of heart disease. Questions focus upon, which patients should be screened and what tests should be used. This review examines screening strategies for transplant candidates and details the prognostic value of common tests used to identify ischemic heart disease. We also review the physiological consequences of cardiomyopathy in transplant candidates and explore the specific syndrome of “cirrhotic cardiomyopathy”.

Value of dobutamine stress myocardial contrast perfusion echocardiography in patients with advanced liver disease

Although dobutamine stress echocardiography has been used for the preoperative evaluation of patients with advanced liver disease (ALD), no data exist regarding the value of myocardial perfusion imaging (MPI) with real-time myocardial contrast echocardiography (RTMCE) in this patient population. We sought to determine the value of MPI during dobutamine stress RTMCE for predicting prognosis in patients with ALD. We examined both wall motion and MPI in 230 patients with ALD who underwent dobutamine stress RTMCE using intravenous commercially available contrast agents (Optison, GE-Amersham, Princeton, NJ; or Definity, Bristol-Myers Squibb Medical Imaging, North Billerica, MA). The prognostic value of clinical variables, including the Model for End-Stage Liver Disease (MELD) score, and echocardiographic data were examined using a Cox Hazard model. The primary endpoint was mortality of all causes. Among the 85 patients who underwent orthotopic liver transplantation, 4 had abnormal MPI and 81 had normal perfusion. The hospital mortality rate was 50% (2/4) in patients with abnormal MPI and 2% (2/81) in patients with normal MPI (P = 0.01). Among patients with abnormal MPI, 1 died from myocardial infarction in the first postoperative day and the second 1 from hemorrhagic shock. During a median follow-up of 15 months, 53 (23%) patients died. The independent predictors of death were an age of > or = 65 yr (RR = 2.2; 95% confidence interval (CI) = 1.1-4.4; P = 0.03), MELD score of > or = 25 (RR = 3.2; 95% CI = 1.8-5.5; P < 0.0001), and abnormal MPI (RR = 2.4; 95% CI = 1.1-5.2; P = 0.02). The 2-yr mortality was 24% for patients with normal MPI and 45% for those with inducible MPI abnormalities (P = 0.003). In conclusion, MPI obtained by RTMCE appears to be a useful tool in predicting mortality in patients with ALD. Further studies are required to verify its independent value.

Older age and liver transplantation: a review

Patients older than 60 are undergoing transplantation with increasing frequency. Reports from several transplant centers document that overall short-term patient survival rates in seniors undergoing liver transplantation are comparable to survival rates of younger adults. However, specific subgroups of older patients may not fare as well. Seniors with far-advanced end-stage liver disease are high-risk for liver transplantation and have poor survival rates. In addition, seniors older than 65 have worse outcomes than those who are 60 to 65, and studies have shown increased mortality with increasing age as a continuous variable. On the other hand, the majority of seniors who survive liver transplantation have full or only minimally limited functional status. Preoperative evaluation of older patients for transplantation requires careful screening to exclude cardiopulmonary disease, malignancy, and other diseases of the aged. Paradoxically, seniors may benefit from a senescent immune system, which results in decreased requirements for immunosuppressive drugs, and possibly a lower rate of acute allograft rejection. Despite good overall short-term survival in the elderly, long-term survival may be worse because of an increased rate of long-term complications, such as malignancy and heart disease. In conclusion, although advanced age is a negative risk factor, advanced age alone should not exclude a patient from liver transplantation; however, it mandates thorough pretransplant evaluation and careful long-term follow-up with attention to usual health maintenance issues in the elderly.

Usefulness of preoperative stress perfusion imaging in predicting prognosis after liver transplantation

The role of preoperative stress single-photon emission computed tomographic (SPECT) imaging in patients with end-stage liver disease who underwent liver transplantation is not well established. We reviewed medical records of patients who had liver transplantation at our institution between January 1998 and November 2001. During this time, 339 patients (213 men, aged 51 +/- 11 years) underwent liver transplantation. Of these, 87 patients had preoperative stress SPECT imaging. Diabetes mellitus (30% vs 11%), hypertension (26% vs 12%), and coronary artery disease (15% vs 7%) were more prevalent in those with than without SPECT (p <0.01 each). The stress SPECT perfusion images were normal in 78 patients (91%) and the left ventricular ejection fraction was 72 +/- 10%. SPECT images revealed ascites in 66% and splenomegaly in 83% of patients. There were 35 total deaths (10%) and 5 nonfatal myocardial infarctions over a mean follow-up of 21 +/- 13 months. Most deaths (32 of 35) were noncardiac and sepsis was the most common cause of death. A normal SPECT study had a 99% negative predictive value for perioperative cardiac events. Kaplan-Meier survival curves showed an 87% 2-year cumulative survival rate in the total group. Thus, in patients undergoing liver transplantation, 2-year survival depends on early noncardiac events. A normal stress SPECT study identified patients at a very low risk for early and late cardiac events despite a higher risk profile. SPECT images also revealed unique findings, such as ascites and splenomegaly, which could produce image artifacts and may interfere with accurate image interpretation.