Cardiovascular complications after transplantation: treatment options in solid organ recipients

Sex disparities in mortality and cardiovascular outcomes in chronic kidney disease

Sex (biologically determined) and gender (socially constructed) modulate manifestations and prognosis of a vast number of diseases, including cardiovascular disease (CVD) and chronic kidney disease (CKD). CVD remains the leading cause of death in CKD patients. Population-based studies indicate that women present a higher prevalence of CKD and experience less CVD than men in all CKD stages, although this is not as clear in patients on dialysis or transplantation. When compared to the general population of the same sex, CKD has a more negative impact on women on kidney replacement therapy. European women on dialysis or recipients of kidney transplants have life expectancy up to 44.8 and 19.8 years lower, respectively, than their counterparts of similar age in the general population. For men, these figures stand at 37.1 and 16.5 years, representing a 21% to 20% difference, respectively. Hormonal, genetic, societal, and cultural influences may contribute to these sex-based disparities. To gain a more comprehensive understanding of these differences and their implications for patient care, well-designed clinical trials that involve a larger representation of women and focus on sex-related variables are urgently needed. This narrative review emphasizes the importance of acknowledging the epidemiology and prognosis of sex disparities in CVD among CKD patients. Such insights can guide research into the underlying pathophysiological mechanisms, leading to optimized treatment strategies and ultimately, improved clinical outcomes.

Changes over time in the causes of death with a functioning graft in kidney transplantation recipients

INTRODUCTION

Death with a functioning graft (DWFG) is the most frequent cause of loss of kidney transplantation (KT).

OBJECTIVE

To analyze the evolution of the causes of DWFG and the frequency of the types of cancer causing DWFG.

METHODS

Retrospective study of KT in Andalusia from 1984 to 2018. We analyzed the evolution according to eras (1984-1995; 1996-2007; 2008-2018) and according to post-transplant period (early death: first year post-KT; late death: after first year post-KT).

RESULTS

A total of 9905 KT were performed, registering 1861 DWFG. The most frequent causes were cardiovascular disease (25.1%), infections (21.5%) and cancer (19.9%). In early death we did not observe changes, and infections were always the main cause. In late death, cardiovascular death decreased (1984-1995: 35.2%, 1996-2007: 22.6%, 2008-2018: 23.9%), but infections (1984-1995: 12.5%, 1996-2007: 18.3%, 2008-2018: 19.9%) and, above all, cancer-related deaths increased (1984-1995: 21.8%, 1996-2007: 29%, 2008-2018: 26.8%) (P < .001). In the multivariable analysis for late death due to cardiovascular disease, recipient age, retransplantation, diabetes, and the first period were risk factors, while the risk of late death due to cancer and infections was associated with recent eras. In the first year after transplantation, the most frequent neoplasia causing DWFG was post-transplant lymphoproliferative disease, and after the first year, it was lung cancer, without differences when it was analyzed by eras.

CONCLUSIONS

Despite the greater comorbidity of the recipients, cardiovascular deaths have decreased. Cancer has been the main cause of late death in recent years. Lung cancer is the most frequent malignancy that causes DWFG in our transplant patients.

Chances and risks of sodium-glucose cotransporter 2 inhibitors in solid organ transplantation: A review of literatures

Solid organ transplantation offers life-saving treatment for patients with end-organ dysfunction. Patient survival and quality of life have improved over the past few decades as a result of pharmacological development, expansion of the donor pool, technological advances and standardization of practices related to transplantation. Still, transplantation is associated with cardiovascular complications, of which post-transplant diabetes mellitus (PTDM) is one of the most important. PTDM increases mortality, which is best documented in patients who have received kidney and heart transplants. PTDM results from traditional risk factors seen in patients with type 2 diabetes mellitus, but also from specific post-transplant risk factors such as metabolic side effects of immunosuppressive drugs, post-transplant viral infections and hypomagnesemia. Oral hypoglycaemic agents are the first choice for the treatment of type 2 diabetes mellitus in non-transplanted patients. However, the evidence on the safety and efficacy of oral hypoglycaemic agents in transplant recipients is limited. The favourable risk/benefit ratio, which is suggested by large-scale and long-term studies on new glucose-lowering drug classes such as glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, makes studies warranted to assess the potential role of these agents in the management of PTDM.

Long-Term Impact of Arteriovenous Fistula Ligation on Cardiac Structure and Function in Kidney Transplant Recipients: A 5-Year Follow-Up Observational Cohort Study

Background

The long-term effects of arteriovenous fistula (AVF) ligation on cardiovascular structure following kidney transplantation remain uncertain. A prospective randomized, controlled trial (RCT) examined the effect of AVF ligation at 6 months on cardiovascular magnetic resonance imaging (CMR)-derived parameters in 27 kidney transplant recipients compared with 27 controls. A mean decrease in left ventricular mass (LVM) of 22.1 g (95% CI, 15.0 to 29.1) was observed compared with an increase of 1.2 g (95% CI, -4.8 to 7.2) in the control group (P<0.001). We conducted a long-term follow-up observational cohort study in the treated cohort to determine the evolution of CMR-derived parameters compared with those documented at 6 months post-AVF ligation.

Methods

We performed CMR at long-term follow-up in the AVF ligation observational cohort from our original RCT published in 2019. Results were compared with CMR at 6 months postintervention. The coprimary end point was the change in CMR-derived LVM and LVM index at long-term follow-up from imaging at 6 months postindex procedure.

Results

At a median of 5.1 years (interquartile range, 4.7-5.5 years), 17 patients in the AVF ligation group were studied with repeat CMR with a median duration to follow-up imaging of 5.1 years (IQR, 4.7-5.5 years). Statistically significant further reductions in LVM (-17.6±23.0 g, P=0.006) and LVM index (-10.0±13.0 g/m², P=0.006) were documented.

Conclusions

The benefit of AVF ligation on LVM and LVM index regression appears to persist long term. This has the potential to lead to a significant reduction in cardiovascular mortality.

Genetic background and transplantation outcomes: insights from genome-wide association studies

PURPOSE OF REVIEW

The current review summarizes recent advances in the genetic studies of transplantation outcomes, including new genome-wide association studies for acute rejection, allograft survival, pharmacogenomics, and common transplant comorbidities.

RECENT FINDINGS

Genetic studies of kidney transplantation outcomes have begun to address the question of genetic compatibility beyond human leukocyte antigens, including the role of genome-wide mismatches in missense variants, and the 'genomic collision' hypothesis under which the risk of rejection may be increased in recipients homozygous for loss-of-function variants with grafts from nonhomozygous donors. In recent pilot studies, missense mismatch scores for transmembrane and secreted proteins were associated with antibodies against the mismatched peptides and reduced allograft survival. A 'genomic collision' at the LIMS1 locus involving a common deletion near LIMS1 gene was associated with anti-LIMS1 antibody response and increased risk of rejection. Additional genetic factors under active investigation include genome-wide polygenic risk scores for renal function and apolipoprotein L1 risk genotypes in African-American kidney donors. Due to the heterogeneity and complexity of clinical outcomes, new genome-wide association studies for rejection, allograft survival, and specific transplant comorbidities will require larger multicenter meta-analyses.

SUMMARY

Genetic compatibilities between donor and recipient represent an important determinant of rejection and long-term allograft survival. Genetic background of transplant donors may be additionally predictive of allograft function, while recipient's genomes are likely determinant of a wide range of transplantation outcomes, from rejection susceptibility to pharmacogenetics and various comorbidities related to prolonged immunosuppression.

Expert consensus on management of metabolic disease in Chinese liver transplant recipients

Metabolic disease, including diabetes mellitus, hypertension, dyslipidemia, obesity, and hyperuricemia, is a common complication after liver transplantation and a risk factor for cardiovascular disease and death. The development of metabolic disease is closely related to the side effects of immunosuppressants. Therefore, optimization of the immunosuppressive regimen is very important for the prevention and treatment of metabolic disease. The Chinese Society of Organ Transplantation has developed an expert consensus on the management of metabolic diseases in Chinese liver transplant recipients based on recent studies. Emphasis is placed on the risk factors of metabolic diseases, the effect of immunosuppressants on metabolic disease, and the prevention and treatment of metabolic diseases.

Complications After Upper Extremity Surgery in Solid Organ Transplant Patients

PURPOSE

To determine the rate of and risk factors for complications in solid organ transplant (SOT) patients who have had surgery of the upper extremity.

METHODS

All SOT recipients who had an upper extremity procedure performed by 1 of 6 surgeons at our institution were identified from 2006 to 2018. Demographic data, transplant date and type, upper extremity surgery procedure and date, antirejection medications, American Society of Anesthesiologists Physical Status Classification System (ASA) score, and complications were recorded. Complications were defined as any surgical complication within 1 year and any medical complication within the first 30 days after surgery. Complications were categorized according to the Clavien-Dindo classification system.

RESULTS

Fifty-one upper extremity procedures in 32 SOT patients were included. Of the 51 procedures, 21 were complicated, for an overall complication rate of 41%. Surgical complications occurred equally before and after 30 days with infection being the most common. Only 1 of the procedures resulting in surgical site infection had an implant (temporary K-wire fixation). The majority of complications were grade II, and there were no grade IV or V complications. Age, ASA score, type or number of SOT, and immunosuppressive regimens were similar between complicated and noncomplicated procedures. Procedures involving male patients were more likely to be complicated than those involving female patients.

CONCLUSIONS

Complications after upper extremity operations are common in SOT patients, and surgical complications often occur after 30 days. Surgeons should counsel this population that they carry a higher complication risk than the general population and may require longer-term monitoring after surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Comparison of different algorithms for the assessment of cardiovascular risk after kidney transplantation by the time of entering waiting list

BACKGROUND

The prevalence of cardiovascular disease is high among patients with chronic kidney disease and cardiovascular events (CVE) remain the leading cause of death after kidney transplantation (KT). We performed a retrospective analysis of 389 KT recipients to assess if the European Society of Cardiology Score (ESC-Score), Framingham Heart Study Score (FRAMINGHAM), Prospective Cardiovascular Munster Study Score (PROCAM-Score) or Assessing cardiovascular risk using Scottish Intercollegiate Guidelines Network Score (ASSIGN-Score) algorithms can predict cardiovascular risk after KT at the time of entering the waiting list.

METHODS

389 KT candidates were scored by the time of entering the waiting list. Pearsons chi-square test, cox regression analysis and survival estimates were performed to evaluate the reliability of the cardiovascular scoring models after successful KT.

RESULTS

During a follow-up of 8 ± 5.8 years, 96 patients (30%) died due to cardiovascular problems, whereas 13.9% suffered non-fatal CVE. Graft loss occurred in 84 patients (21.6%). Predictors of CVE, survival and graft loss were age and the length of end-stage kidney disease. All scores performed well in assessing the risk for CVE (P < 0.01). Receiver-operating characteristic analysis using the ESC-SCORE, as an example, suggested a cut-off for risk stratification and clinical decisions.

CONCLUSIONS

We found all tested scores were reliable for cardiovascular assessment. We suggest using cardiac scores for risk assessment before KT and then taking further steps according to current guidelines.

High-Performance Liquid Chromatography-Mass Spectrometry-Based Lipid Metabolite Profiling of Acromegaly

CONTEXT

Metabolic disorders, especially dysregulated lipid metabolism, increase the risk of cardiovascular mortality in acromegaly. Previous studies measuring plasma macromolecular lipids have yielded conflicting results.

PURPOSE

To explore the plasma lipid metabolite profiles by metabolomics analysis and identify potential metabolites associated with cardiac function in acromegaly.

METHODS

Plasma was obtained from 80 newly diagnosed, untreated patients with acromegaly and 80 healthy controls. Echocardiography was performed. Based on the results of an oral glucose tolerance test (OGTT), patients were categorized into 2 groups: normal glucose tolerance (NGT, n = 28) and impaired glucose tolerance or diabetes mellitus (IGT/DM, n = 52). High-performance liquid chromatography-mass spectrometry (HPLC-MS)-based metabolomics analysis was conducted. Data were processed by principal components analysis (PCA), orthogonal partial least square-discriminant analysis (OPLS-DA), and MetaboAnalyst 4.0. Associations between metabolic substances and cardiovascular parameters were also explored.

RESULTS

Metabolomics uncovered a distinct metabolic pattern between acromegaly and healthy controls, and perturbed pathways mainly include glycerophospholipid metabolism, sphingolipid metabolism, as well as linoleic acid metabolism. Collective analysis showed that phosphatidylethanolamine (PE) (22:6/16:0) was positively correlated with LV mass, while lysophosphatidylcholine (LysoPC) (16:0) was positively correlated with fractional shortening (FS) and left ventricle ejection fraction (LVEF).

CONCLUSION

Patients with acromegaly have distinct lipid metabolite profiling, while PE (22:6/16:0) and LysoPC (16:0) are correlated with cardiac structure and function, which may contribute to the risk of cardiovascular complications.

Genetic markers associated with long-term cardiovascular outcome in kidney transplant recipients

There is a clear genetic contribution to the risk of cardiovascular diseases, and a composite genetic risk score (GRS) based on 27 single nucleotide polymorphisms (SNPs) was reported to predict risk of cardiovascular events in the general population. We aimed to evaluate this risk score in renal transplant recipients, a population with heightened cardiovascular risk, with a yet unknown genetic contribution. A total of 1640 participants from the ALERT trial (Assessment of Lescol in Renal Transplantation), a study comparing fluvastatin with placebo in stable renal transplant recipients, were genotyped for all SNPs making up the GRS. Risk alleles were weighted by the log of odds ratios reported in genome wide association studies and summed. Associations between GRS and time from study inclusion to first major cardiovascular event (MACE) were analyzed by Cox regression. In analyses adjusted for cardiovascular risk factors, GRS was significantly associated with MACE (hazard ratio [HR] 1.81, P = .006) when comparing genetic high-risk patients (quartile 4) with genetic low-risk participants (quartile 1). A 27-SNP GRS, which predicted cardiovascular events in the nontransplant population, appears to have predictive value also in kidney allograft recipients. Refining the score to better fit the transplant population seems feasible.

Complications of Solid Organ Transplantation: Cardiovascular, Neurologic, Renal, and Gastrointestinal

Despite improvements in overall graft function and patient survival rates after solid organ transplantation, complications can lead to significant morbidity and mortality. Cardiovascular complications include heart failure, arrhythmias leading to sudden death, hypertension, left ventricular hypertrophy, and allograft vasculopathy in heart transplantation. Neurologic complications include stroke, posterior reversible encephalopathy syndrome, infections, neuromuscular disease, seizure disorders, and neoplastic disease. Acute kidney injury occurs from immunosuppression with calcineurin inhibitors or as a result of graft failure after kidney transplantation. Gastrointestinal complications include infections, malignancy, mucosal ulceration, perforation, biliary tract disease, pancreatitis, and diverticular disease. Immunosuppression can predispose to infections and malignancy.

Physical Activity, Sedentary Time, and Associated Factors in Recipients of Solid-Organ Transplantation

BACKGROUND

Short-term survival after solid-organ transplantation has substantially improved, and the focus has shifted to long-term survival, including the role of physical activity (PA). Knowledge about PA and sedentary time in recipients of solid-organ transplantation is limited, and identification of the levels and associated factors is necessary for intervention development.

OBJECTIVE

The objectives of this study were to investigate the level of PA and sedentary time in recipients of solid-organ transplantation and to identify factors associated with these behaviors.

DESIGN

The design consisted of a cross-sectional survey.

METHODS

Questionnaires on PA level, sedentary time, and potential associated factors were used for recipients of solid-organ transplantation (kidney, liver, lung, and heart [N = 656]). Multiple regression analyses with a variable selection procedure were used.

RESULTS

Fewer than 60% of the recipients fulfilled the PA guideline. Factors significantly associated with a lower level of PA included being a woman, younger age (nonlinear), not actively working or being retired, physical limitations, and low expectations and self-confidence. Factors significantly associated with less sedentary time included exercise self-efficacy and not actively working or being retired. Significantly associated with more sedentary time were a high education level, fear of negative effects, physical limitations, and the motivator "health and physical outcomes." The type of transplantation did not significantly influence either of the outcome measures.

LIMITATIONS

The design did not allow for causal inferences to be made. The studied associated factors were limited to individual and interpersonal factors. Self-reported measures of PA and sedentary time were used.

CONCLUSIONS

In intervention development directed at increasing the level of PA and reducing sedentary time in recipients of solid-organ transplantation, attention should be paid to physical limitations, fear of negative effects, low expectations and self-confidence, health and physical outcomes, and exercise self-efficacy.

Does Histopathology of Implanted Kidney According to Banff 07 Help Predict Long-term Transplantation Outcome?

Analyses of peritransplant biopsies of deceased-donor kidneys show high incidence of chronic abnormalities. The question arises whether chronic abnormalities present at implantation determine engrafted kidney fate regardless of other concomitant variables. The aim of this study was to identify risk factors of graft loss considering histopathological changes present at implantation scored according to Banff 07 criteria.

PATIENTS AND METHODS

Inclusion criteria (n = 300) was engraftment between years 2000 and 2008 and availability of implantation biopsy. Analyzed abnormalities present in donor biopsy were arteriolar hyalinization, interstitial fibrosis, intimal sclerotization, tubular atrophy, total inflammation, and percentage of sclerotic glomeruli (Banff classification). Allograft function was estimated by abbreviated Modification of Diet in Renal Disease formula and proteinuria semi-quantitatively by standard dip-stick test. Kaplan-Meier estimate was used to assess graft survival. Searching for independent risk factors of graft survival was performed by means of Cox proportional hazards models (SAS System, SAS Institute Inc, Cary, NC, United States).

RESULTS

In one-factor analyses, predictors of kidney allograft loss were donor age, donor history of diabetes, kidney allograft dysfunction within first posttransplant year, and recipient chronic hepatitis C. In terms of chronic abnormalities, arteriolar hyalinization of any intensity nearly doubled the risk of allograft loss. Independent risk factors of kidney allograft loss in multivariate analysis were donor age, posttransplant diabetes mellitus, proteinuria after engraftment, and recipient hepatitis C.

CONCLUSION

The effect of arteriolar hyalinization on renal transplant survival is probably interwoven with other predictors of graft loss. Recognizing the negative impact of recipient chronic hepatitis C on graft survival, hepatitis C virus treatment should be provided to patients with advanced chronic kidney disease, patients on wait lists, or patients already transplanted.

Study of Cardiovascular Outcomes in Renal Transplantation: A Prospective, Multicenter Study to Determine the Incidence of Cardiovascular Events in Renal Transplant Recipients in Ontario, Canada

Background:

Renal transplant recipients (RTRs) are at significantly higher risk for morbidity and mortality compared with the general population, largely attributed to cardiovascular disease (CVD). Previous estimates of CVD events have come from health care databases and retrospective studies.

Objective:

The objective of this study was to prospectively determine the prevalence of risk factors and incidence of CVD events in a Canadian cohort of RTRs.

Design:

Study of Cardiovascular Outcomes in Renal Transplantation (SCORe) was a prospective, longitudinal, multicenter observational study.

Setting:

Adult RTRs were recruited from 6 participating transplant sites in Ontario, Canada.

Patients:

Eligible patients were those receiving a living or deceased donor renal transplant. Patients who received simultaneous transplant of any other organ were excluded.

Measurements:

Primary outcomes included myocardial infarction (MI) defined by American College of Cardiology (ACC-MI) criteria, and major adverse cardiac events (MACE), defined as cardiovascular (CV) death, ACC-MI, coronary revascularization, and nonhemorrhagic stroke. CV events were adjudicated by a single, independent cardiologist.

Methods:

CV and transplant-specific risk factors that predict MACE and ACC-MI were identified by stepwise regression analysis using the Cox proportional hazards model.

Results:

A total of 1303 patients enrolled across 6 transplant centers were followed for 4.5 ± 1.6 years (mean ± SD). Incidence of MACE was 7.0%, with significant independent predictors/risk factors including age, diabetes, coronary revascularization, nonhemorrhagic stroke, and renal replacement therapy (RRT). ACC-MI incidence was 4.0%, with significant independent predictors/risk factors including age, coronary revascularization, and duration of RRT in excess of the median value (2.91 years).

Limitations:

Patients were recruited from a single province, so may not reflect the experience of RTRs in other areas of Canada.

Conclusions:

Using a prospective design and rigorous methodology, this study found that the incidence of CV events after renal transplantation was elevated relative to the general Canadian population and was comparable with that reported in patient registries, thus helping validate the utility of retrospective analysis in this field. SCORe highlights the importance of monitoring RTRs for traditional cardiac and transplant-specific CV risk factors to help prevent CV morbidity and mortality. Further research is needed to investigate a broader range of potential risk factors and their combined effects on incident CV events.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.

Current state of clinical end-points assessment in transplant: Key points

Solid organ transplantation is the treatment of choice for patients with end-stage organ disease. However, organ transplantation can stress the cardiovascular system and decrease immune surveillance, leading to early mortality and graft loss due to multiple underlying comorbidities. Clinical end-points in transplant include death and graft failure. Thus, generating accurate predictive models through regression models is crucial to test for definitive clinical post-transplantation end-points. Survival predictive models should assemble efficient surrogate markers or prognostic factors to generate a minimal set of variables derived from a proper modeling strategy through regression models. However, a few critical points should be considered when reporting survival analyses and regression models to achieve proper discrimination and calibration of the predictive models. Additionally, population-based risk scores may underestimate risk prediction in transplant. The application of predictive models in these patients should therefore incorporate both classical and non-classical risk factors, as well as community-based health indicators and transplant-specific factors to quantify the outcomes in terms of survival properly. This review focuses on assessment of clinical end-points in transplant through regression models by combining predictive and surrogate variables, and considering key points in these analyses to accurately predict definitive end-points, which could aid clinicians in decision making.