Cardiovascular risk, atherosclerosis and metabolic syndrome after liver transplantation: a mini review

Minimizing Metabolic and Cardiac Risk Factors to Maximize Outcomes After Liver Transplantation

Cardiovascular disease (CVD) is a leading complication after liver transplantation and has a significant impact on patients' outcomes posttransplant. The major risk factors for post-liver transplant CVD are age, preexisting CVD, nonalcoholic fatty liver disease, chronic kidney disease, and metabolic syndrome. This review explores the contemporary strategies and approaches to minimizing cardiometabolic disease burden in liver transplant recipients. We highlight areas for potential intervention to reduce the mortality of patients with metabolic syndrome and CVD after liver transplantation.

Risk of Cerebral Aneurysm Rupture After Liver Transplantation: Development and Validation of a Hemorrhagic Stroke Scoring Model

BACKGROUND

Liver transplantation (LT) patients appear to be more prone to neurological events compared to individuals undergoing other types of solid-organ transplantation. The aims of the present study were to analyze the prevalence of unruptured intracranial aneurysms (UIAs) in patients undergoing liver transplantation (LT) and to examine the perioperative occurrence of subarachnoid hemorrhage (SAH). Also, it intended to systematically identify the risk factors of SAH and hemorrhagic stroke (HS) within a year after LT and to develop a scoring system which involves distinct clinical features of LT patients.

METHODS

Patients who underwent LT from January 2012 to March 2022 were analyzed. All included patients underwent neurovascular imaging within 6 months before LT. We conducted an analysis of prevalence and radiological features of UIA and SAH. The clinical factors that may have an impact on HS within one year of LT were also reviewed.

RESULTS

Total of 3,487 patients were enrolled in our study after applying inclusion and exclusion criteria. The prevalence of UIA was 5.4%. The incidence of SAH and HS within one year following LT was 0.5% and 1.6%, respectively. We developed a scoring system based on multivariable analysis to predict the HS within 1-year after LT. The variables were a poor admission mental status, the diagnosis of UIA, serum ammonia levels, and Model for End-stage Liver Disease (MELD) scores. Our model showed good discrimination among the development (C index, 0.727; 95% confidence interval [CI], 0.635-0.820) and validation (C index, 0.719; 95% CI, 0.598-0.801) cohorts.

CONCLUSION

The incidence of UIA and SAH was very low in LT patients. A poor admission mental status, diagnosis of UIA, serum ammonia levels, and MELD scores were significantly associated with the risk of HS within one year after LT. Our scoring system showed a good discrimination to predict the HS in LT patients.

A mixed blessing for liver transplantation patients - Rapamycin

BACKGROUND

Liver transplantation (LT) is an effective treatment option for end-stage liver disease. Mammalian target of rapamycin (mTOR) inhibitors, such as rapamycin, are widely used post LT.

DATA SOURCES

In this review, we focused on the anti-cancer activities and metabolic side effects of rapamycin after LT. The literature available on PubMed for the period of January 1999-September 2022 was reviewed. The key words were rapamycin, sirolimus, liver transplantation, hepatocellular carcinoma, diabetes, and lipid metabolism disorder.

RESULTS

Rapamycin has shown excellent effects and is safer than other immunosuppressive regimens. It has exhibited excellent anti-cancer activity and has the potential in preventing hepatocellular carcinoma (HCC) recurrence post LT. Rapamycin is closely related to two long-term complications after LT, diabetes and lipid metabolism disorders.

CONCLUSIONS

Rapamycin prevents HCC recurrence post LT in some patients, but it also induces metabolic disorders. Reasonable use of rapamycin benefits the liver recipients.

Clinical implications of diabetes in chronic liver disease: Diagnosis, outcomes and management, current and future perspectives

Diabetes mellitus (DM) is common in liver cirrhosis (LC). The pathophysiological association is bidirectional. DM is a risk factor of LC and LC is a diabetogenic condition. In the recent years, research on different aspects of the association DM and LC has been intensified. Nevertheless, it has been insufficient and still exist many gaps. The aims of this review are: (1) To discuss the latest understandings of the association of DM and LC in order to identify the strategies of early diagnosis; (2) To evaluate the impact of DM on outcomes of LC patients; and (3) To select the most adequate management benefiting the two conditions. Literature searches were conducted using PubMed, Ovid and Scopus engines for DM and LC, diagnosis, outcomes and management. The authors also provided insight from their own published experience. Based on the published studies, two types of DM associated with LC have emerged: Type 2 DM (T2DM) and hepatogenous diabetes (HD). High-quality evidences have determined that T2DM or HD significantly increase complications and death pre and post-liver transplantation. HD has been poorly studied and has not been recognized as a complication of LC. The management of DM in LC patients continues to be difficult and should be based on drug pharmacokinetics and the degree of liver failure. In conclusion, the clinical impact of DM in outcomes of LC patients has been the most studied item recently. Nevertheless many gaps still exist particularly in the management. These most important gaps were highlighted in order to propose future lines for research.

NEAT1/hsa-miR-372-3p axis participates in rapamycin-induced lipid metabolic disorder

Rapamycin is a crucial immunosuppressive regimen for patients that have undergone liver transplantation (LT). However, one of the major side effects of rapamycin include metabolic disorders such as dyslipidemia, and the mechanism remains unknown. This study aims to explore the biomolecules that are responsible for rapamycin-induced dyslipidemia and the control strategies that can reverse the lipid metabolism disorder. In this study, data collected from LT patients, cell and mouse models treated with rapamycin were analyzed. Results showed an increase of triglycerides (TGs) induced by rapamycin. MicroRNAs (miRNAs) play important roles in many vital biological processes including TG metabolism. hsa-miR-372-3p was filtered using RNA sequencing and identified as a key regulator in rapamycin-induced TGs accumulation. Using bioinformatics and experimental analyses, target genes of hsa-miR-372-3p were predicted. These genes were alkylglycerone phosphate synthase (AGPS) and apolipoprotein C4 (APOC4), which are reported to be involved in TG metabolism. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) was also identified as an upstream regulatory factor of hsa-miR-372-3p. From the results of this study, NEAT1/hsa-miR-372-3p/AGPS/APOC4 axis plays a vital role in rapamycin-disruption of lipid homeostasis. Therefore, targeting this axis is a potential therapeutic target combating rapamycin-induced dyslipidemia after LT.

Combination of liver graft sonographic grading and point shear wave elastography to reduce early allograft dysfunction after liver transplantation

OBJECTIVE

To analyze the performance of a liver graft sonographic grading system and point shear wave elastography (PSWE) in predicting early allograft dysfunction (EAD) after liver transplantation (LT).

METHODS

Successive brain-dead donors and liver recipients in our hospital from March 2017 to May 2018 were retrospectively recruited. All donors underwent PSWE examination, abdominal ultrasonography, and sonographic grading (grade 0 to grade 5). Donors with ≥ 10 valid PSWE examinations and a failure rate of < 60% were included. For all recipients, abdominal ultrasonography and blood tests for biologic parameters were performed preoperatively and daily postoperatively to screen for EAD. The recipients and their grafts were classified into EAD and non-EAD groups. Statistical analyses were performed to analyze the correlations among liver stiffness (LS), liver graft sonographic grading, and EAD.

RESULTS

Thirty-two donors and 32 corresponding liver recipients were enrolled (15 cases in the EAD group; 17 in the non-EAD group). There were no grade 0, 1, or 2 cases in the two groups. For prediction of EAD in recipients after LT, the AUC for PSWE was 0.929 and the AUC for combination of PSWE and sonographic grading system was 0.935.

CONCLUSIONS

Combination of PSWE and sonographic grading system can predict postoperative EAD in LT recipients with high sensitivity. Abnormal results may suggest a need for liver biopsy preoperatively, thus avoiding unnecessary surgical preparation for liver procurement.

KEY POINTS

• Combination of PSWE with new sonographic grading system is useful for preoperative evaluation of liver grafts from brain-dead donors. • EAD is as a criterion for evaluating the diagnostic value of PSWE and sonographic grading system. • Combination of PSWE and sonographic grading system can predict postoperative EAD in LT recipients with high sensitivity.

Transient elastography for assessment of fibrosis and steatosis of liver grafts from brain-death donors

BACKGROUND

An objective and accurate evaluation of liver grafts is required to improve the prognosis of liver transplant recipients and to increase the number of available liver grafts.

AIM

To compare outcomes using FibroScan with that of pathology in liver grafts from brain-dead donors (DBD).

METHODS

Liver grafts from 52 DBD were examined using ultrasound (US), FibroScan before liver transplantation (LT). Blood tested before LT and a biopsy was performed pre- or intra-operation to determine pathology. The diagnostic accuracy of the FibroScan results was compared with the pathology results, which is the gold standard for evaluating liver grafts. The donors enrolled were grouped by the stage of liver fibrosis (F0-F4) and steatosis (S0-S3), based on Kleiner's scoring system of nonalcoholic fatty liver disease, respectively.

RESULTS

The liver stiffness (LS) value in group F1 was significantly increased compared with group F0 (8.74±1.32kPa and 5.93±1.64kPa, respectively, P<0.01). The LS value had a significant positive correlation with the liver graft fibrosis stage (r=0.73, P<0.01). The area under receiver operating characteristic curves (AUROC) for F1 stage fibrosis was 0.93 (P<0.01). Significant differences in the controlled attenuation parameter (CAP) were found among groups S0, S1, and S2 (173.30±38.36dB/m, 230.29±23.27dB/m, 250.00±57.01dB/m, respectively; F=12.41, P<0.01). The CAP was associated with the liver graft steatosis stage (r=0.64, P<0.01). The AUROC for S1 and S2 stage steatosis in liver grafts was 0.89 (P=0.002) and 0.83 (P=0.007), respectively.

CONCLUSIONS

Transient elastography quantifies fibrosis and steatosis in liver grafts from 52 DBD with a high diagnostic accuracy and provides further imaging evidence for use in assessing liver grafts.

Obesity, dynapenia and high cardiovascular risk co-exist in post-liver transplant setting: results of a cross-sectional study

BACKGROUND

Cardiovascular disease is a major cause of death in post-liver transplantation (LT). The aim of this study was to evaluate LT patients as to the carotid intima-media thickness (CIMT) and its association with nutritional status, dietary intake, metabolic profile and cardiovascular risk factors.

METHODS

In this cross-sectional study, adult patients with more than 12 months of post-transplant follow-up underwent clinical, laboratory, functional and nutritional evaluation by 3-day-diet-record, anthropometry and dynamometry. CIMT was evaluated by Doppler ultrasonography.

RESULTS

Sixty-nine post-LT patients [males 61%, median of age 59 (51-64) years were included; median time post-liver transplantation 2.8 (1.4-6.3) years]. High prevalence of malnutrition was found (45% of arm muscle area < p15 and 71% of handgrip strength < p30). Excess weight was present in 72% of patients, body mass index ≥ 30 kg/m² in 35% and metabolic syndrome in 51%. Abnormal CIMT was found in 54% of the sample. Patients with abnormal CIMT presented higher cardiovascular risk Score, LDL cholesterol, higher prevalence of high-sensitive C-reactive protein ≥ 1 mg/L and higher intake of saturated and trans fatty acids (P < 0.05 for all).

CONCLUSIONS

Abnormal IMT was commonly found in LT patients presenting at the same time with overweight and dynapemia. These results were associated with higher LDL-cholesterol levels, high-sensitive C-reactive protein ≥ 1 mg/L and higher intake of saturated and trans fatty acids. Preventive measures, including dietary advice, are required for all post-liver transplantation patients to minimize cardiovascular risk.

Evaluation of Liver Graft Recipient Workup in Predicting of Early Cardiovascular Events During Liver Transplantation: A Single-Center Experience

BACKGROUND

Cardiovascular events (CVE) contribute to serious complications and death after liver transplantation (LT). Troponin I (TnI) level >0.07 mg/L and prior cardiac disease are known to be the independent predictors for posttransplant CVE. We evaluated single-center cardiac workup to predict early cardiovascular morbidity and mortality after LT.

PATIENTS AND METHODS

We recruited 105 consecutive liver transplant recipients (male/female, 59/46; mean age, 51.66 ± 11.67 years). The cardiological assessment at evaluation for LT included medical history, electrocardiogram, echocardiography, Holter monitoring, and exercise test. We collected data regarding CVE including hypotonia with catecholamine usage, arrhythmia, sudden cardiac death, pulmonary edema, and myocardial infarction within 7 days after LT.

RESULTS

CVE during LT occurred in 42 recipients (40%) and after LT in 9 patients (8.57%). Proposed cutoff level of TnI >0.07 mg/L did not correlate with CVE during operation (P = .73) or after LT (P = .47). CVE during LT was associated with arterial hypertension in medical history (P <.001), right ventricular systolic pressure (P< .05), and clinical scores: Child-Pugh (P = .04), Model for End-Stage Liver Disease (MELD) (P = .04), MELD incorporating serum sodium (P<.03), and integrated MELD score (P = .01). CVE after LT correlated only with arrhythmia (P<.001) and catecholamine usage (P < .05) perioperatively. Of interest, catecholamine usage during LT was associated with prolonged stay at the intensive care unit (P < .05).

CONCLUSION

The single-center algorithm with noninvasive cardiac procedures without TnI assessment is optimal in evaluation before LT; however, medical history and severity of the liver disease are crucial for short-term cardiovascular morbidity after LT.

Prevalence of hypertension after living-donor liver transplantation: a prospective study

BACKGROUND

Hypertension is common among patients who have undergone liver transplantation and is a major contributor to cardiovascular events. Few studies have studied the risk factors associated with post-liver transplantation (LT) hypertension. This prospective study assessed the prevalence of post-LT hypertension and associated preoperative risk factors.

METHODS

From May 2008 to December 2009, 79 normotensive adult patients (≥ 18 years old) who underwent living-donor LT with a median follow up of 4.79 ± 0.88 years were enrolled. Patients' pre-LT demographics, clinical data, pre-LT diabetes, and immunosuppressive agents used after LT were studied for their association with post-LT hypertension.

RESULTS

The prevalence of post-LT hypertension was 49.4%. The independent risk factors for post-living-donor LT hypertension were pre-LT systolic blood pressure (SBP; odds ratio [OR], 1.04; 95% confidence interval [CI], 1.00-1.09; P = .039) and post-LT administration of mammalian target of rapamycin (mTOR) inhibitors (OR, 4.08; 95% CI, 1.40-11.94; P = .010). Pre-LT diabetes had a negative predictive value (OR, 0.15; 95% CI, 0.03-0.74; P = .019). Neither age, male sex, smoking, pre-LT serum cholesterol and triglyceride levels, tacrolimus, nor glucocorticoid was associated with post-LT hypertension.

CONCLUSIONS

The prevalence of hypertension is high after LT. Higher pre-LT SBP and post-LT mTOR inhibitor administration predispose patients to post-LT hypertension.

Is minimal, [almost] steroid-free immunosuppression a safe approach in adult liver transplantation? Long-term outcome of a prospective, double blind, placebo-controlled, randomized, investigator-driven study

OBJECTIVE

To investigate the safety of minimal immunosuppression (IS) in liver transplantation (LT).

BACKGROUND

The lack of long-term follow-up studies, including pathologic data, has led to a protean handling of IS in LT.

METHODS

Between February 2000 and September 2004, 156 adults were enrolled in a prospective, randomized, double-blind, placebo-controlled minimization trial comparing tacrolimus placebo (TAC-PLAC) and TAC short-term steroid (TAC-STER) IS. All patients had a minimum clinical, biochemical, and histological follow-up of 5 years.

RESULTS

Five-year actual patient and graft survival rates in TAC-PLAC and TAC-STER groups were 78.1% and 82.1% (P=0.89) and 74.2% and 76.9% (P=0.90), respectively. Five-year biopsies were available in 112 (89.6%) of 125 survivors. Twelve patients refused a biopsy because of their excellent evolution; tissue material was insufficient in 1 patient; 11 had normal liver tests; and 2 patients had developed alcoholic and secondary biliary cirrhosis. Histology was normal in 44 (39.3%) patients; 35 (31.3%) had disease recurrence. The remaining biopsies showed nonspecific chronic hepatitis (14.3%), mild inflammatory infiltrates (10.7%), and steatosis (3.5%). All findings were equally distributed between both groups. In each group, 3 patients (4.8%) presented with acute cellular rejection after the first year and only 1 (0.9%) TAC-PLAC patient developed chronic rejection after IS withdrawal because of pneumonitis. Arterial hypertension, diabetes mellitus, renal insufficiency, hypercholesterolemia, gout, and obesity were equally low in both groups.

CONCLUSIONS

Excellent long-term results can be obtained under minimal IS and absence of steroids. TAC-based monotherapy is feasible in most adult liver recipients until 5 years of follow-up.

Pro-atherosclerotic markers and cardiovascular risk factors one year after liver transplantation

AIM: To investigate pro-atherosclerotic markers (endothelial dysfunction and inflammation) in patients one year after liver transplantation.

METHODS: Forty-four consecutive liver transplant (LT) outpatients who were admitted between August 2009 and July 2010, were followed-up by for 1 year, exhibited no evidences of infection or rejection, all of them underwent tacrolimus-based immunosuppressive regimens were consecutively enrolled. Inflammatory cytokines (TNFα, IFNγ, IL-8, and IL-10), endothelial biomarkers (sVCAM-1, sICAM-1, MPO, adiponectin, PAI-1, SAP, SAA, E-selectin, and MMP-9), high sensitive C-reactive protein, and Framingham risk score (FRS) were assessed. The anthropometric data, aminotransferases, metabolic syndrome features, glucose and lipid profiles, and insulin resistance data were also collected. The LT recipients were compared to 22 biopsy-proven non-alcoholic steatohepatitis (NASH) patients and 20 healthy controls (non-obese, non-diabetics, and non-dyslipidemic).

RESULTS: The LT recipients had significantly younger ages and lower body mass indices, aminotransferases, fasting glucose and insulin levels, glucose homeostasis model and metabolic syndrome features than the NASH patients. Classic cardiovascular risk markers, such as Hs-CRP and FRS [2.0 (1.0-8.75)], were lower in the LT patients compared to those observed in the NASH patients (P = 0.009). In contrast, the LT recipients and NASH patients had similar inflammatory and endothelial serum markers compared to the controls (pg/mL): lower IL-10 levels (32.3 and 32.3 vs 62.5, respectively, P = 0.019) and higher IFNγ (626.1 and 411.9 vs 67.9, respectively, P < 0.001), E-selectin (48.5 and 90.03 vs 35.7, respectively, P < 0.001), sVCAM-1 (1820.6 and 1692.4 vs 1167.2, respectively, P < 0.001), and sICAM-1 (230.3 and 259.7 vs 152.9, respectively, P = 0.015) levels.

CONCLUSION: Non-obese LT recipients have similar pro-atherosclerotic serum profiles after a short 1-year follow-up period compared to NASH patients, suggesting a high risk of atherosclerosis in this population.

Risk of sudden cardiac death in chronic kidney disease

The review discusses the epidemiology and the possible underlying mechanisms of sudden cardiac death (SCD) in chronic kidney disease (CKD), and highlights the unmet clinical need for noninvasive risk stratification strategies in these patients. Although renal dysfunction shares common risk factors and often coexists with atherosclerotic cardiovascular disease, the presence of renal impairment increases the risk of arrhythmic complications to an extent that cannot be explained by the severity of the atherosclerotic process. Renal impairment is an independent risk factor for SCD from the early stages of CKD; the risk increases as renal function declines and reaches very high levels in patients with end-stage renal disease on dialysis. Autonomic imbalance, uremic cardiomyopathy, and electrolyte disturbances likely play a role in increasing the arrhythmic risk and can be potential targets for treatment. Cardioverter defibrillator treatment could be offered as lifesaving treatment in selected patients, although selection strategies for this treatment mode are presently problematic in dialyzed patients. The review also examines the current experience with risk stratification tools in renal patients and suggests that noninvasive electrophysiological testing during dialysis may be of clinical value as it provides the necessary standardized environment for reproducible measurements for risk stratification purposes.