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

Screening Modalities for Coronary Artery Disease in Liver Transplant Candidates: A Review of the Literature

Patients with cirrhosis undergoing liver transplant (LT) are at high risk of postoperative cardiopulmonary complications. It is known that patients with coronary artery disease (CAD) have greater rates of post-LT morbidity and mortality than patients without CAD. Thus, identifying significant CAD in LT candidates is of the utmost importance to optimize survival posttransplant. Consensus is lacking on the ideal screening test for CAD in LT candidates. Traditional exercise and many pharmacologic stress tests are impractical and inaccurate in patients with cirrhosis due to their unique physiology. The purpose of this review is to describe different screening modalities for CAD among LT candidates. The background, diagnostic accuracy, and limitations of each screening modality are described to achieve this goal.

Percutaneous Coronary Intervention Outcomes in Patients with Liver Cirrhosis: A Systematic Review and Meta-Analysis

There is a paucity of data and minimal literature on outcomes of percutaneous coronary intervention (PCI) among liver cirrhosis patients. Therefore, we conducted a systematic review and meta-analysis to evaluate the clinical outcomes among liver cirrhosis patients post-PCI. We conducted a comprehensive literature search in the PubMed, Embase, Cochrane, and Scopus databases for relevant studies. Effect sizes were pooled using the DerSimonian and Laird random-effects model as an odds ratio (OR) with 95% confidence intervals (CI). A total of 3 studies met the inclusion criteria, providing data from 10,705,976 patients. A total of 28,100 patients were in the PCI + Cirrhosis group and 10,677,876 patients were in the PCI-only group. The mean age of patients with PCI + Cirrhosis and PCI alone was 63.45 and 64.35 years. The most common comorbidity was hypertension among the PCI + Cirrhosis group compared with PCI alone (68.15% vs. 73.6%). Cirrhosis patients post-PCI were had higher rates of in-hospital mortality (OR, 4.78 (95%CI: 3.39–6.75), p < 0.001), GI bleeding (OR, 1.91 (95%CI:1.83–1.99), p < 0.001, I2 = 0%), stroke (OR, 2.48 (95%CI:1.68–3.66), p < 0.001), AKI (OR, 3.66 (95%CI: 2.33–6.02), p < 0.001), and vascular complications (OR, 1.50 (95%CI: 1.13–1.98), p < 0.001) compared with the PCI group without cirrhosis. Patients with cirrhosis are at a high risk for mortality and adverse outcomes post-PCI procedure compared to the PCI-only group of patients.

Impact of cardiac and noncardiac cirrhosis on coronary revascularization outcomes from the National Inpatient Sample, 2016 to 2018

Data on coronary revascularization in patients with cirrhosis are scarce because it is often deferred in the setting of significant comorbidities and coagulopathies. It is unknown whether patients with cardiac cirrhosis have a worse prognosis. The National Inpatient Sample was surveyed to identify patients who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for acute coronary syndrome (ACS) from 2016 to 2018. Those with and without liver cirrhosis were propensity score-matched and compared within the PCI and CABG cohorts. Primary outcome was in-hospital mortality. Patients with cirrhosis were further classified into cardiac and noncardiac cirrhosis and their in-hospital mortalities were compared. A total of 1,069,730 PCIs and 273,715 CABGs were performed for ACS, of which 0.6% and 0.7%, respectively, were performed in patients with cirrhosis. In both the PCI cohort (odds ratio = 1.56; 95% confidence interval, 1.10-2.25; P = 0.01) and the CABG cohort (odds ratio = 2.34; 95% confidence interval, 1.19-4.62; P = 0.01), cirrhosis was associated with higher in-hospital mortality. In-hospital mortality was greatest in cardiac cirrhosis (8.4% and 7.1%), followed by noncardiac cirrhosis (5.5% and 5.0%) and no cirrhosis (2.6% and 2.3%) in PCI and CABG cohorts, respectively. Higher in-hospital mortality and periprocedural morbidities should be considered when performing coronary revascularization in patients with cirrhosis.

De Ritis ratio and long-term major cardiovascular adverse events in patients undergoing elective percutaneous coronary intervention

BACKGROUND

The association of aspartate aminotransferase to alanine aminotransferase ratio (De Ritis ratio) with clinical outcomes in patients with chronic coronary syndromes (CCS) remains unclear. This study aims to assess the association of De Ritis ratio with adverse cardiovascular events in patients with CCS.

MATERIALS AND METHODS

The study included 5020 patients with CCS undergoing percutaneous coronary intervention. Patients were categorized into groups according to tertiles of the De Ritis ratio: tertile 1 (De Ritis ratio: <.75; n = 1688 patients), tertile 2 (De Ritis ratio: .75-1.08; n = 1666 patients) and tertile 3 (De Ritis ratio: >1.08; n = 1666 patients). The primary endpoint was 3-year mortality.

RESULTS

At 3 years, there were 384 deaths, 176 myocardial infarctions and 61 strokes. In groups with De Ritis in the 1st, 2nd and 3rd tertiles, deaths occurred in 5.0%, 7.5% and 14.5% of the patients, respectively (adjusted hazard ratio = 1.09, 95% confidence interval [1.06-1.12], p < .001); myocardial infarctions occurred in 2.6%, 3.5% and 5.1% of the patients, respectively (p < .001); strokes occurred in 1.0%, 1.2% and 1.9% of the patients, respectively (p = .030); bleeding at 30 days (n = 112) occurred in 1.4%, 1.6% and 3.7% of the patients, respectively (p < .001). The C-statistic of the Cox proportional hazards model for all-cause mortality with baseline data without the De Ritis ratio was .815 [.794-.836] and .818 [.797-.838] after the inclusion of the De Ritis ratio (delta C-statistic = .003; p = .005).

CONCLUSIONS

In patients with CCS undergoing percutaneous coronary intervention, an elevated De Ritis ratio was associated with long-term major adverse cardiovascular events.

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

Cardiac risk assessment prior to liver transplantation has become widely accepted. With the emergence of nonalcoholic steatohepatitis among the leading causes of end-stage liver disease and the steady rise of the age of liver transplant recipients, the burden of cardiovascular diseases has markedly increased in this population. Selecting appropriate liver transplant candidates is crucial due to the increasing demand for scarce donor organs. The use of noninvasive cardiac imaging for pre-operative assessment of the cardiovascular status of liver transplant recipients has been on the rise, yet the optimal assessment strategy remains an area of active debate. In this review, we examine the relevant literature pertaining to the diagnostic and prognostic applications of noninvasive cardiac imaging in this population. We also propose a simple literature-based evaluation algorithm for CAD surveillance in liver transplant candidates.

Prognostic value of coronary risk factors, exercise capacity and single photon emission computed tomography in liver transplantation candidates: A 5-year follow-up study

BACKGROUND

Although consensus-based guidelines support noninvasive stress testing prior to orthotopic liver transplantation (OLT), the optimal screening strategy for assessment of coronary artery disease in patients with end-stage liver disease (ESLD) is unclear. This study sought to determine the relative predictive value of coronary risk factors, functional capacity, and single photon emission computed tomography (SPECT) on major adverse cardiovascular events and all-cause mortality in liver transplantation candidates.

METHODS

Prior to listing for transplantation, 404 consecutive ESLD patients were referred to a University hospital for cardiovascular (CV) risk stratification. All subjects met at least one of the following criteria: inability to perform > 4 METs by history (62%), insulin-treated diabetes mellitus (53%), serum creatinine > 1.72 mg/dL (8%), history of MI, PCI or CABG (5%), stable angina (3%), cerebrovascular disease (1%), peripheral vascular disease (1%). Subjects underwent Technetium-99m SPECT with multislice coronary artery calcium scoring (CACS) using exercise treadmill or standard adenosine stress in those unable to achieve 85% maximal heart rate (Siemens Symbia T16). Abnormal perfusion was defined as a summed stress score (SSS) ≥ 4.

RESULTS

Of the 404 patients, 158 (age 59 ± 9 years; male 68%) subsequently underwent transplantation and were included in the primary analysis. Of those, 50 (32%) died after a mean duration follow-up of 5.4 years (maximal 10.9 years). Most deaths (78%) were attributed to noncardiovascular causes (malignancy, sepsis, renal failure). Of the 32 subjects with abnormal perfusion (20%), nine (6%) had a high-risk perfusion abnormality defined as a total perfusion defect size (PDS) ≥ 15% and/or an ischemic PDS ≥ 10%. Kaplan-Meier survival curves demonstrated abnormal perfusion was associated with increased CV mortality (generalized Wilcoxon, P = 0.014) but not all-cause death. Subjects with both abnormal perfusion and an inability to exercise > 4 METs had the lowest survival from all-cause death (P = 0.038). Abnormal perfusion was a strong independent predictor of CV death (adjusted HR 4.2; 95% CI 1.4 to 12.3; P = 0.019) and MACE (adjusted HR 7.7; 95% CI 1.4 to 42.4; P = 0.018) in a multivariate Cox regression model that included age, sex, diabetes, smoking and the ability to exercise > 4 METs. There was no association between CACS and the extent of perfusion abnormality, nor with outcomes.

CONCLUSIONS

Most deaths following OLT are noncardiovascular. Nonetheless, abnormal perfusion is prevalent in this high-risk population and a stronger predictor of cardiovascular morbidity and mortality than functional status. A combined assessment of functional status and myocardial perfusion identifies those at highest risk of all-cause death. (Exercise Capacity and Single Photon Emission Computed Tomography in Liver Transplantation Candidates [ExSPECT]; ClinicalTrials.gov Identifier: NCT03864497).

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

Background

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

Methods

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

Results

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

Conclusions

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

Preoperative Evaluation of Coronary Artery Disease in Liver Transplant Candidates: Many Unanswered Questions in Clinical Practice

Cardiovascular (CV) complications represent the first non-graft-related cause of death and the third overall cause of death among patients undergoing liver transplantation (LT). History of coronary artery disease is related to increased CV mortality following LT. Although it is of paramount importance to stratify CV risk in pre-LT patients, there is no consensus regarding the choice of the optimal non-invasive cardiac imaging test. Algorithms proposed by scientific associations include non-traditional risk factors, which are associated with increased cardiac risk profiles. Thus, an individualized pre-LT evaluation protocol should be followed. As the average age of patients undergoing LT and the number of candidates continue to rise, the “3 W” questions still remain unanswered, Who, Which and When? Who should be screened for coronary artery disease (CAD), which screening modality should be used and when should the asymptomatic waitlisted patients repeat cardiac evaluation? Prospective studies with large sample sizes are warranted to define an algorithm that can provide better risk stratification and more reliable survival prediction.

SPECT myocardial perfusion imaging in liver transplantation candidates

BACKGROUND

The optimal cardiovascular evaluation prior to liver transplantation remains controversial and includes stress echocardiography, stress MPI, cardiac CTA, and coronary angiography. This study summarizes our experience of the past decade using SPECT MPI in patients with end-stage liver disease, including patient characteristics, stress testing protocols, test results, the need for repeat testing, and downstream testing.

METHODS

All patients who underwent a clinically indicated stress SPECT MPI study as part of their pre-liver transplant evaluation from 2004 to 2014 were reviewed from the Nuclear Cardiology database. Results of perfusion imaging, repeat testing, subsequent angiography, and need for revascularization were reviewed.

RESULTS

A total of 2500 patients were referred for SPECT MPI, of those 111 had known CAD and 271 underwent more than one MPI study. Compared to other patients undergoing stress MPI, pre-liver transplant patients were younger, had fewer cardiac risk factors and lower prevalence of prior cardiac history, and used pharmacologic stress more often. During the study decade, patient age increased, prevalence of hypertension increased and smoking decreased, prevalence of known CAD increased, and the number of abnormal studies decreased. Abnormal perfusion results were present in 7.8% of pre-liver transplant patients compared to 34.3% of all other patients. In a multivariate model, age and lower ejection fraction were associated with an abnormal MPI result. Of the 64 patients who underwent subsequent invasive or non-invasive coronary angiography after an abnormal MPI, obstructive CAD was diagnosed in 25 patients (1.0%), non-obstructive CAD was diagnosed in 23 patients (0.9%), and normal coronaries found in 16 patients (0.6%); a total of 18 (0.7%) of these underwent coronary revascularization. The average time to repeat testing was 27.2 ± 17.9 months. In a multivariate model, younger age and exercise stress were associated with repeat testing. In only 17 patients out of 271 with a normal initial perfusion, the repeat study became abnormal. The use of stress-first imaging was successful in 80% of patients with a reduction in Tc-99m dose from 39.1 to 18.3 mCi.

CONCLUSION

Abnormal SPECT MPI results in candidates for liver transplantation are infrequent compared to non-liver transplant patients and the incidence of obstructive CAD on subsequent angiography even less. Repeat testing in those on the transplant waiting list after initial normal test results appears to be of limited value. Stress-first protocols may be considered for the majority of these patients to reduce testing time and radiation exposure.

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.

Cardiac diseases among liver transplant candidates

Improvements in early survival after liver transplant (LT) have allowed for the selection of LT candidates with multiple comorbidities. Cardiovascular disease is a major contributor to post-LT complications. We performed a literature search to identify the causes of cardiac disease in the LT population and to describe techniques for diagnosis and perioperative management. As no definite guidelines for preoperative assessment (except for pulmonary heart disease) are currently available, we recommend an algorithm for preoperative cardiac work-up.

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.

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.

Perioperative Cardiovascular Evaluation for Orthotopic Liver Transplantation

Patients with advanced liver disease have a high prevalence of cardiovascular risk factors, but many of them are asymptomatic. Cardiovascular risk stratification prior to liver transplant can be done by dobutamine stress echocardiography, stress myocardial perfusion imaging, cardiac computer tomography, and coronary angiography, but there are no clear recommendations regarding what method should be used and who should be screened. Because of this and because of inherent risk profile in this population, the variations in practice are significant. Careful screening and rigorous management of cardiovascular risk factors are important to ensure optimal cardiovascular outcomes in the immediate post-transplantation period and in the long term as well.

Percutaneous Coronary Intervention in Patients With End-Stage Liver Disease

The objective of our study was to assess patients with end-stage liver disease undergoing percutaneous coronary intervention (PCI) and determine the rates and trend of complications and in-hospital outcomes. Data were obtained from the Nationwide Inpatient Sample 2005 to 2012. We identified all PCIs performed in patients with diagnosis of cirrhosis during the study period by the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Preventable procedural complications were identified by Patient Safety Indicators. Propensity scoring method was used to establish matched cohorts to control for imbalances and account for differences that may have influenced treatment outcomes. A total of 1,051,242 PCIs were performed during the study period, of these, 122,342 were done on subjects with a formal diagnosis of cirrhosis. Bare-metal stents (BMS) were more likely to be used in patients who presented with ST-elevation myocardial infarction (19.73 vs 13.58, p <0.001), in cardiogenic shock (5.58, vs 2.81, p <0.001), or required intraaortic balloon pump (4.73 vs 2.38, p <0.001). The overall rate of complications was 7.1%, whereas the overall mortality rate over these years was 3.63%. On a propensity-matched analysis the mortality rate was 2 times higher for BMS (5.18 vs 2.35, p <0.001) compared with drug-eluting stents. PCI remains a safe and plausible option for patients with cirrhosis albeit riskier than for the general population. The use of BMS is associated with increased mortality and bleeding complications compared with drug-eluting stents which likely is representative of preferential use of BMS in patients with more advanced end-stage liver disease who are also likely to experience higher postprocedural complications.