Predicting coronary heart disease after kidney transplantation: Patient Outcomes in Renal Transplantation (PORT) Study

From Risk Assessment to Management: Cardiovascular Complications in Pre- and Post-Kidney Transplant Recipients: A Narrative Review

Kidney transplantation remains the best treatment for chronic kidney failure, offering better outcomes and quality of life compared with dialysis. Cardiovascular disease (CVD) is a major cause of morbidity and mortality in kidney transplant recipients and is associated with decreased patient survival and worse graft outcomes. Post-transplant CVD results from a complex interaction between traditional cardiovascular risk factors, such as hypertension and diabetes, and risk factors specific to kidney transplant recipients including chronic kidney disease, immunosuppressive drugs, or vascular access. An accurate assessment of cardiovascular risk is now needed to optimize the management of cardiovascular comorbidities through the detection of risk factors and the screening of hidden pretransplant coronary artery disease. Promising new strategies are emerging, such as GLP-1 receptor agonists and SGLT2 inhibitors, with a high potential to mitigate cardiovascular complications, although further research is needed to determine their role in kidney transplant recipients. Despite this progress, a significant gap remains in understanding the optimal management of post-transplant CVD, especially coronary artery disease, stroke, and peripheral artery disease. Addressing these challenges is essential to improve the short- and long-term outcomes in kidney transplant recipients. This narrative review aims to provide a comprehensive overview of cardiovascular risk assessment and post-transplant CVD management.

Prevalence of hypertension and uncontrolled hypertension after solid organ transplantation: a 5-year follow-up of the Swiss Transplant Cohort Study

OBJECTIVE

Hypertension (HTN) increases cardiovascular risk and is a frequent finding across all solid organ transplant recipients. We describe the prevalence of HTN and uncontrolled HTN, as well as details on pharmacologic treatment of HTN across solid organs transplant recipients up to five years after transplantation.

METHODS

This retrospective study is nested in the prospective Swiss Transplant Cohort Study ( www.stcs.ch ) that includes kidney, heart, lung, and liver transplantation. Data extraction from 2008 to 2019 was used for this study and follow-up data at 6, 12 and 60 months was analyzed.

RESULTS

A total of 3865 transplant recipients were included for analysis. The prevalence of HTN at 6 and 60 months was 88.9% and 90.4% in kidney ( P  = 0.21), 61.8% and 76.1% in liver ( P  < 0.01), 72.6% and 84.9% in lung ( P  < 0.01), and 89.3% and 85.8% in heart ( P  = 0.33) transplant recipients, respectively. The prevalence of uncontrolled HTN at 6 and 60 months was 40.3% and 38.9% in kidney ( P  = 0.48), 21.2% and 30.5% in liver ( P  = 0.05), 26.0% and 36.8% in lung ( P  = 0.03) and 38.9% and 18.5% in heart ( P  < 0.01) transplant recipients, respectively. At 12 months, compared to heart transplant recipients, kidney [odds ratio (OR) = 1.6, 95% confidence interval (CI) 1.1-2.1], liver (OR = 1.7, 95% CI 1.1-2.6) and lung (OR = 2.6, 95% CI 1.6-4.0) transplant recipients had a higher likelihood of presenting with uncontrolled HTN.

CONCLUSION

HTN prevalence after solid organ transplantation is high. Uncontrolled and untreated HTN remain a major issue post transplantation, particularly in organ recipients not necessarily suffering from cardiovascular diseases such as liver or lung transplant recipients.

Prognostic impact of post-transplant diabetes mellitus in kidney allograft recipients: a meta-analysis

BACKGROUND

Post-transplant diabetes mellitus (PTDM) is a complex condition arising from various factors including immunosuppressive medications, insulin resistance, impaired insulin secretion and inflammatory processes. Its impact on patient and graft survival is a significant concern in kidney transplant recipients. PTDM's impact on kidney transplant recipients, including patient and graft survival and cardiovascular mortality, is a significant concern, given conflicting findings in previous studies. This meta-analysis was imperative not only to incorporate emerging evidence but also to delve into cause-specific mortality considerations. We aimed to comprehensively evaluate the association between PTDM and clinical outcomes, including all-cause and cardiovascular mortality, sepsis-related mortality, malignancy-related mortality and graft loss, in kidney transplant recipients.

METHODS

PubMed, Ovid/Medline, Web of Science, Scopus and Cochrane Library databases were screened and studies evaluating the effect of PTDM on all-cause mortality, cardiovascular mortality, sepsis-related mortality, malignancy-related mortality and overall graft loss in adult kidney transplant recipients were included.

RESULTS

Fifty-three studies, encompassing a total of 138 917 patients, evaluating the association between PTDM and clinical outcomes were included. Our analysis revealed a significant increase in all-cause mortality [risk ratio (RR) 1.70, 95% confidence interval (CI) 1.53 to 1.89, P < .001] and cardiovascular mortality (RR 1.86, 95% CI 1.36 to 2.54, P < .001) among individuals with PTDM. Moreover, PTDM was associated with a higher risk of sepsis-related mortality (RR 1.96, 95% CI 1.51 to 2.54, P < .001) but showed no significant association with malignancy-related mortality (RR 1.20, 95% CI 0.76 to 1.88). Additionally, PTDM was linked to an increased risk of overall graft failure (RR 1.33, 95% CI 1.16 to 1.54, P < .001).

CONCLUSION

These findings underscore the importance of comprehensive management strategies and the need for research targeting PTDM to improve outcomes in kidney transplant recipients.

Identification of tacrolimus-related genes in familial combined hyperlipidemia and development of a diagnostic model using bioinformatics analysis

Background

Clinical observations have revealed that patients undergoing organ transplantation administered tacrolimus often experience abnormal lipid metabolism with serious consequences. Thus, the intricate interplay between tacrolimus and lipid metabolism must be addressed to develop targeted therapeutic interventions. Our ongoing research aims to develop precision medicine approaches that not only alleviate the immediate repercussions for organ transplant patients but also enhance their long-term outcomes. To this end, we investigated the potential genes associated with tacrolimus metabolism in familial combined hyperlipidemia (FCHL) to identify relevant biomarkers of FCHL, develop predictive diagnostic models for hyperlipidemia, and reveal potential therapeutic targets for FCHL.

Methods

Dataset GSE1010 containing information on patients diagnosed with FCHL was obtained from the Gene Expression Omnibus (GEO), and an ensemble of tacrolimus-related genes (TRGs) was retrieved from the GeneCards, STITCH, and Molecular Signatures Database databases. A thorough weighted gene co-expression network analysis was conducted, including a differential expression analysis of the GSE1010 and TRG datasets, to identify intricate patterns of gene co-expression and provide insights on the underlying molecular dynamics within the datasets. Key genes were screened, diagnostic models were constructed, and all genes associated with logFC values were assessed using gene set variation and enrichment analyses. Upregulated genes were identified by a positive logFC (>0) and P < 0.05, while downregulated genes were characterized by a negative logFC (<0) and P < 0.05. These criteria facilitated a more nuanced categorization of gene expression changes within the analyzed datasets. Given tacrolimus's immunosuppressive impact, the gene expression matrix data obtained from dataset GSE1010 was submitted to CIBERSORT to assess immune cell infiltration outcomes. Finally, we examined the regulatory network of screened key genes that interact with RNA-binding proteins, potential drugs, small-molecule compounds, and transcription factors.

Results

We screened 14 statistically significant key genes, built a reliable risk model, and grouped the dataset into categories at high and low risk for hyperlipidemia development. FCHL was linked to memory B and immature B immune cells. The gene set variation analysis revealed two pathways associated with cholesterol homeostasis and the complement system that were closely associated with the potential functions of FCHL and tacrolimus-related differentially expressed genes.

Conclusions

Our research offers a better understanding of FCHL and the TRGs involved in lipid metabolism. Additionally, it provides research directions for identifying potential targets for clinical therapies.

Burden of atherogenic lipids and association with cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND

Cardiac allograft vasculopathy (CAV) is a leading cause of morbidity and mortality after heart transplantation (HTx). There are limited contemporary studies examining post-transplant lipid management and cardiometabolic health.

OBJECTIVE

We study the burden of cardiometabolic derangements post transplantation and its impact on CAV in a modern cohort of HTx recipients.

METHODS

All HTx recipients between January 2019 and December 2020, with 2 lipid assessments and angiographic surveillance were included. Logistic regression was used to assess association of lipid levels with cardiovascular outcomes and CAV.

RESULTS

Among 87 HTx recipients, atherogenic lipids were significantly elevated after Htx. Median low-density lipoprotein cholesterol increased from a baseline level of 69.5 mg/dL to 86.5 mg/dL, p = .002, non-high-density lipoprotein cholesterol (non-HDL-C) 91.5 mg/dL to 118 mg/dL, p < .001, triglycerides 94.5 mg/dL to 133 mg/dL, p < .001, and remnant cholesterol 19 mg/dL to 27 mg/dL, p < .001. Increases in non-HDL-C, triglycerides, and remnant cholesterol were significantly associated with increased risk of CAV (Stanford Grade 4 and intimal thickness). Increases in triglycerides and remnant cholesterol were associated with increased risk of composite major adverse cardiovascular events (MACE).

CONCLUSION

We demonstrate a significant increase in atherogenic lipids 2 years following transplantation with low use (20%) of high-intensity statin. Increase in atherogenic lipids was associated with increased risk of CAV and increase in triglycerides and remnant cholesterol with increased MACE. Future studies examining cardiometabolic consequences of HTx and optimal treatment strategies to reduce risk of CAV and MACE are needed.

Analysis of the Correlation between Hypercholesterolemia and Increased Cardiovascular Morbidity and Mortality among Adult Kidney Transplant Recipients

INTRODUCTION

The correlation between hypercholesterolemia and cardiovascular disease in kidney transplant recipients (KTRs) remains uncertain. We sought to characterize the association between abnormal cholesterol profiles and cardiovascular morbidity and mortality in this unique population.

METHODS

This retrospective cohort study was conducted at a single center and included all adult KTR, transplanted between January 2005 and April 2014. The primary outcome was major adverse cardiovascular events (MACE) while the secondary outcome was the composite outcome of MACE and all-cause mortality. Exposure to abnormal cholesterol levels was calculated using a time-weighted average calculation. MACE and mortality risk were analyzed using a multivariate time-varying Cox model.

RESULTS

The final cohort comprised 737 KTR, with a median follow-up of 2,920 days. A total of 126 patients (17.1%) experienced MACE. High LDL-C levels and MACE risk were correlated by multivariate analysis (HR 1.008 per mg/dL, 95% CI: 1.001-1.016), while low HDL-C levels were not significantly associated with MACE (HR 0.992 per mg/dL, 95% CI: 0.976-1.009). A higher LDL-C/HDL-C ratio was significantly associated with an increased risk of MACE in multivariate analyses (HR 1.502 per unit, 95% CI: 1.147-1.968), and also correlated with the composite outcome (HR 1.35 per unit, 95% CI: 1.06-1.71).

CONCLUSIONS

A high LDL-C/HDL-C ratio is predictive of an increased risk of cardiovascular morbidity and mortality in KTRs. These findings emphasize the significance of the LDL-C/HDL-C ratio as a valuable marker of cardiovascular risk and support current recommendations to improve hypercholesterolemia in this high-risk group.

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.

Physical Exercise After Solid Organ Transplantation: A Cautionary Tale

An increasing body of randomized controlled trials suggests the safety of engaging in moderate to vigorous intensity exercise training following solid organ transplantation. Fueled by emerging sport events designed for transplant recipients and the ever-growing body of research highlighting the diverse health benefits of physical activity, transplant recipients are now increasingly participating in strenuous and occasionally competitive physical endeavors that largely surpass those evaluated in controlled research settings. This viewpoint article adopts a cautionary stance to counterbalance the prevalent one-sided optimistic perspective regarding posttransplant physical activity. While discussing methodological limitations, we explore plausible adverse impacts on the cardiovascular, immunological, and musculoskeletal systems. We also examine the physiological consequences of exercising in the heat, at high altitude, and in areas with high air pollution. Risks associated with employing performance-enhancing strategies and the conceivable psychological implications regarding physical activity as a tribute to the 'gift of life' are discussed. With a deliberate focus on the potential adverse outcomes of strenuous posttransplant physical activity, this viewpoint aims to restore a balanced dialogue on our comprehension of both beneficial and potentially detrimental outcomes of physical activity that ultimately underscores the imperative of well-informed decision-making and tailored exercise regimens in the realm of posttransplant care.

Choroidal and retinal thinning in chronic kidney disease independently associate with eGFR decline and are modifiable with treatment

In patients with chronic kidney disease (CKD), there is an unmet need for novel biomarkers that reliably track kidney injury, demonstrate treatment-response, and predict outcomes. Here, we investigate the potential of retinal optical coherence tomography (OCT) to achieve these ends in a series of prospective studies of patients with pre-dialysis CKD (including those with a kidney transplant), patients with kidney failure undergoing kidney transplantation, living kidney donors, and healthy volunteers. Compared to health, we observe similar retinal thinning and reduced macular volume in patients with CKD and in those with a kidney transplant. However, the choroidal thinning observed in CKD is not seen in patients with a kidney transplant whose choroids resemble those of healthy volunteers. In CKD, the degree of choroidal thinning relates to falling eGFR and extent of kidney scarring. Following kidney transplantation, choroidal thickness increases rapidly (~10%) and is maintained over 1-year, whereas gradual choroidal thinning is seen during the 12 months following kidney donation. In patients with CKD, retinal and choroidal thickness independently associate with eGFR decline over 2 years. These observations highlight the potential for retinal OCT to act as a non-invasive monitoring and prognostic biomarker of kidney injury.

Impact of timing of rejection episode on cardiovascular events in living donor kidney transplantation: a multicenter retrospective study

BACKGROUND

Cardiovascular diseases are still highly prevalent after kidney transplantation. However, little is known about the impact of the timing of rejection episodes on cardiovascular disease. The study aimed to analyze the influence of the timing of rejection episodes on cardiovascular events in recipients of living donor kidney transplantation.

METHODS

We studied 572 living donor kidney transplant recipients from the Michinoku Renal Transplant Network (MRTN), which includes 6 centers in the Tohoku region of Japan. Fine-Gray proportional hazards regression analysis with time-dependent variables was used to assess the effect of rejection episode on cardiovascular events. Recipients were divided into three groups: those without rejection (non-rejection, 370 patients), rejection within 6 months after transplantation (early rejection, 99 patients), and rejection after 6 months (late rejection, 103 patients). The effect of timing on cardiovascular events was evaluated using Fine-Gray proportional hazards regression analysis.

RESULTS

During a median follow-up of 77 months, 70 patients experienced cardiovascular events. Rejection episodes were significantly associated with cardiovascular events (hazard ratio [HR]: 2.08, 95% confidence interval [CI]: 1.26-3.43, P = 0.004), along with age and dialysis vintage. The 5-year cumulative incidence of cardiovascular events was significantly higher in the late rejection group than in the early rejection group (15% vs. 3.3%, P = 0.021). However, no significant difference in 5-year cumulative cardiovascular event incidence was observed between the early rejection and non-rejection groups. Late rejection was significantly associated with cardiovascular events (HR: 2.40, 95% CI: 1.38-4.18, P = 0.002), whereas early rejection was not significantly correlated with cardiovascular event risk (HR: 1.18, P = 0.670).

CONCLUSIONS

Rejections occurring more than 6 months after transplantation is significantly associated with risk of cardiovascular events.

TRIAL REGISTRATION NUMBER

2019-099-1, date of registration; 3 Dec. 2019, retrospectively registered.

Survival Benefit of Kidney Transplantation in Patients With End-Stage Kidney Disease and Prior Acute Myocardial Infarction

Patients with end stage kidney disease (ESKD) and a previous acute myocardial infarction (AMI) have less access to KT. Data on ESKD patients with an AMI history who underwent first KT or dialysis between January 2007 and December 2018 were extracted from the Korean National Health Insurance Service. Patients who underwent KT (n = 423) were chronologically matched in a 1:3 ratio with those maintained on dialysis (n = 1,269) at the corresponding dates, based on time-conditional propensity scores. The 1, 5, and 10 years cumulative incidences for all-cause mortality were 12.6%, 39.1%, and 60.1% in the dialysis group and 3.1%, 7.2%, and 14.5% in the KT group. Adjusted hazard ratios (HRs) of KT versus dialysis were 0.17 (95% confidence interval [CI], 0.12-0.24; p < 0.001) for mortality and 0.38 (95% CI, 0.23-0.51; p < 0.001) for major adverse cardiovascular events (MACE). Of the MACE components, KT was most protective against cardiovascular death (HR, 0.23; 95% CI, 0.12-0.42; p < 0.001). Protective effects of KT for all-cause mortality and MACE were consistent across various subgroups, including patients at higher risk (e.g., age >65 years, recent AMI [<6 months], congestive heart failure). KT is associated with lower all-cause mortality and MACE than maintenance dialysis patients with a prior AMI.

Cardiovascular Outcomes in De Novo Kidney Transplant Recipients Receiving Everolimus and Reduced Calcineurin Inhibitor or Standard Triple Therapy: 24-month Post Hoc Analysis From TRANSFORM Study

BACKGROUND

The comparative impact of everolimus (EVR)-based regimens versus standard of care (mycophenolic acid+standard calcineurin inhibitor [MPA+sCNI]) on cardiovascular outcomes in de novo kidney transplant recipients (KTRs) is poorly understood. The incidence of major adverse cardiac events (MACEs) in KTRs receiving EVR+reduced CNI (rCNI) or MPA+sCNI from the TRANSplant eFficacy and safety Outcomes with an eveRolimus-based regiMen study was evaluated.

METHODS

The incidence of MACE was determined for all randomized patients receiving at least 1 dose of the study drug. Factors associated with MACEs were determined by logistic regression. Risk of MACE out to 3 y post-study was calculated using the Patient Outcome in Renal Transplantation equation.

RESULTS

MACE occurred in 81 of 1014 (8.0%; EVR+rCNI) versus 89 of 1012 (8.8%; MPA+sCNI) KTRs (risk ratio, 0.91 [95% confidence interval [CI], 0.68-1.21]). The incidence of circulatory death, myocardial infarction, revascularization, or angina was similar between the arms. Incidence of MACE was similar between EVR+rCNI and MPA+sCNI arms with a higher incidence in prespecified risk groups: older age, pretransplant diabetes (15.1% versus 15.9%), statin use (8.5% versus 10.8%), and low estimated glomerular filtration rate (Month 2 estimated glomerular filtration rate <30 versus >60 mL/min/1.73 m 2 ; odds ratio, 2.23 [95% CI, 1.02-4.86]; P = 0.044), respectively. Predicted risk of MACE within 3 y of follow-up did not differ between the treatment arms.

CONCLUSIONS

Cardiovascular morbidity and mortality were similar between de novo KTRs receiving EVR+rCNI and MPA+sCNI. EVR+rCNI is a viable alternative to the current standard of care in KTRs.

Cardiovascular Risk Following Conversion to Belatacept From a Calcineurin Inhibitor in Kidney Transplant Recipients: A Randomized Clinical Trial

Rationale & Objective

In kidney transplant recipients (KTRs), a belatacept-based immunosuppressive regimen is associated with beneficial effects on cardiovascular (CV) risk factors compared with calcineurin inhibitor (CNI)-based regimens. Our objective was to compare the calculated CV risk between belatacept and CNI (predominantly tacrolimus) treatments using a validated model developed for KTRs.

Study Design

Prospective, randomized, open-label, parallel-group, investigator-initiated, international multicenter trial.

Setting & Participants

KTRs aged 18-80 years with a stable graft function (estimated glomerular filtration rate > 20 mL/min/1.73 m²), 3-60 months after transplantation, treated with tacrolimus or cyclosporine A, were eligible for inclusion.

Intervention

Continuation with a CNI-based regimen or switch to belatacept for 12 months.

Outcomes

Comparison of the change in the estimated 7-year risk of major adverse CV events and all-cause mortality, changes in traditional markers of CV health, as well as measures of arterial stiffness.

Results

Among the 105 KTRs randomized, we found no differences between the treatment groups in the predicted risk for major adverse CV events or mortality. Diastolic blood pressure, measured both centrally by using a SphygmoCor device and peripherally, was lower after the belatacept treatment than after the CNI treatment. The mean changes in traditional cardiovascular (CV) risk factors, including kidney transplant function, were otherwise similar in both the treatment groups. The belatacept group had 4 acute rejection episodes; 2 were severe rejections, of which 1 led to graft loss.

Limitations

The heterogeneous baseline estimated glomerular filtration rate and time from transplantation to trial enrollment in the participants. A limited study duration of 1 year.

Conclusions

We found no effects on the calculated CV risk by switching to the belatacept treatment. Participants in the belatacept group had not only lower central and peripheral diastolic blood pressure but also a higher rejection rate.

Funding

The trial has received a financial grant from Bristol-Myers Squibb.

Trial Registration

EudraCT no. 2013-001178-20.

Dyslipidemia in Transplant Patients: Which Therapy?

Cardiovascular disease is the most important cause of death worldwide in recent years; an increasing trend is also shown in organ transplant patients subjected to immunosuppressive therapies, in which cardiovascular diseases represent one of the most frequent causes of long-term mortality. This is also linked to immunosuppressant-induced dyslipidemia, which occurs in 27 to 71% of organ transplant recipients. The aim of this review is to clarify the pathophysiological mechanisms underlying dyslipidemia in patients treated with immunosuppressants to identify immunosuppressive therapies which do not cause dyslipidemia or therapeutic pathways effective in reducing hypercholesterolemia, hypertriglyceridemia, or both, without further adverse events.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors Use for Atherogenic Dyslipidemia in Solid Organ Transplant Patients

Dyslipidemia is a widespread risk factor in solid organ transplant patients, due to many reasons, such as the use of immunosuppressive drugs, with a consequent increase in cardiovascular diseases in this population. PCSK9 is an enzyme mainly known for its role in altering LDL levels, consequently increasing cardiovascular risk. Monoclonal antibody PCSK9 inhibitors demonstrated remarkable efficacy in the general population in reducing LDL cholesterol levels and preventing cardiovascular disease. In transplant patients, these drugs are still poorly used, despite having comparable efficacy to the general population and giving fewer drug interactions with immunosuppressants. Furthermore, there is enough evidence that PCSK9 also plays a role in other pathways, such as inflammation, which is particularly dangerous for graft survival. In this review, the current evidence on the function of PCSK9 and the use of its inhibitors will be discussed, particularly in transplant patients, in which they may provide additional benefits.

Cardiometabolic and Kidney Protection in Kidney Transplant Recipients With Diabetes: Mechanisms, Clinical Applications, and Summary of Clinical Trials

Kidney transplantation is the therapy of choice for patients with end-stage renal disease. Preexisting diabetes is highly prevalent in kidney transplant recipients (KTR), and the development of posttransplant diabetes is common because of a number of transplant-specific risk factors such as the use of diabetogenic immunosuppressive medications and posttransplant weight gain. The presence of pretransplant and posttransplant diabetes in KTR significantly and variably affect the risk of graft failure, cardiovascular disease (CVD), and death. Among the many available therapies for diabetes, there are little data to determine the glucose-lowering agent(s) of choice in KTR. Furthermore, despite the high burden of graft loss and CVD among KTR with diabetes, evidence for strategies offering cardiovascular and kidney protection is lacking. Recent accumulating evidence convincingly shows glucose-independent cardiorenal protective effects in non-KTR with glucose-lowering agents, such as sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists. Therefore, our aim was to review cardiorenal protective strategies, including the evidence, mechanisms, and rationale for the use of these glucose-lowering agents in KTR with diabetes.

KDOQI US Commentary on the KDIGO 2020 Clinical Practice Guideline for Diabetes Management in CKD

In October 2020, KDIGO (Kidney Disease: Improving Global Outcomes) published its first clinical practice guideline directed specifically to the care of patients with diabetes and chronic kidney disease (CKD). This commentary presents the views of the KDOQI (Kidney Disease Outcomes Quality Initiative) work group for diabetes in CKD, convened by the National Kidney Foundation to provide an independent expert perspective on the new guideline. The KDOQI work group believes that the KDIGO guideline takes a major step forward in clarifying glycemic targets and use of specific antihyperglycemic agents in diabetes and CKD. The purpose of this commentary is to carry forward the conversation regarding optimization of care for patients with diabetes and CKD. Recent developments for prevention of CKD progression and cardiovascular events in people with diabetes and CKD, particularly related to sodium/glucose cotransporter 2 (SGLT2) inhibitors, have filled a longstanding gap in nephrology's approach to the care of persons with diabetes and CKD. The multifaceted benefits of SGLT2 inhibitors have facilitated interactions between nephrology, cardiology, endocrinology, and primary care, underscoring the need for innovative approaches to multidisciplinary care in these patients. We now have more interventions to slow kidney disease progression and prevent or delay kidney failure in patients with diabetes and kidney disease, but methods to streamline their implementation and overcome barriers in access to care, particularly cost, are essential to ensuring all patients may benefit.

Clonal myelopoiesis promotes adverse outcomes in chronic kidney disease

We sought to determine the relationship between age-related clonal hematopoiesis (CH) and chronic kidney disease (CKD). CH, defined as mosaic chromosome abnormalities (mCA) and/or driver mutations was identified in 5449 (2.9%) eligible UK Biobank participants (n = 190,487 median age = 58 years). CH was negatively associated with glomerular filtration rate estimated from cystatin-C (eGFR.cys; β = -0.75, P = 2.37 × 10-4), but not with eGFR estimated from creatinine, and was specifically associated with CKD defined by eGFR.cys < 60 (OR = 1.02, P = 8.44 × 10-8). In participants without prevalent myeloid neoplasms, eGFR.cys was associated with myeloid mCA (n = 148, β = -3.36, P = 0.01) and somatic driver mutations (n = 3241, β = -1.08, P = 6.25 × 10-5) associated with myeloid neoplasia (myeloid CH), specifically mutations in CBL, TET2, JAK2, PPM1D and GNB1 but not DNMT3A or ASXL1. In participants with no history of cardiovascular disease or myeloid neoplasms, myeloid CH increased the risk of adverse outcomes in CKD (HR = 1.6, P = 0.002) compared to those without myeloid CH. Mendelian randomisation analysis provided suggestive evidence for a causal relationship between CH and CKD (P = 0.03). We conclude that CH, and specifically myeloid CH, is associated with CKD defined by eGFR.cys. Myeloid CH promotes adverse outcomes in CKD, highlighting the importance of the interaction between intrinsic and extrinsic factors to define the health risk associated with CH.

A Statistical Prediction Model for Survival After Kidney Transplantation from Deceased Donors

Background

In an environment of limited kidney donation resources, patient recovery and survival after kidney transplantation (KT) are highly important. We used pre-operative data of kidney recipients to build a statistical model for predicting survivability after kidney transplantation.

Material/Methods

A dataset was constructed from a pool of patients who received a first KT in our hospital. For allogeneic transplantation, all donated kidneys were collected from deceased donors. Logistic regression analysis was used to change continuous variables into dichotomous ones through the creation of appropriate cut-off values. A regression model based on the least absolute shrinkage and selection operator (LASSO) algorithm was used for dimensionality reduction, feature selection, and survivability prediction. We used receiver operating characteristic (ROC) analysis, calibration, and decision curve analysis (DCA) to evaluate the performance and clinical impact of the proposed model. Finally, a 10-fold cross-validation scheme was implemented to verify the model robustness.

Results

We identified 22 potential variables from which 30 features were selected as survivability predictors. The model established based on the LASSO regression algorithm had shown discrimination with an area under curve (AUC) value of 0.690 (95% confidence interval: 0.557–0.823) and good calibration result. DCA demonstrated clinical applicability of the prognostic model when the intervention progressed to the possibility threshold of 2%. An average AUC value of 0.691 was obtained on the validation data.

Conclusions

Our results suggest that the proposed model can predict the mortality risk for patients after kidney transplants and could help kidney specialists choose kidney recipients with better prognosis.

The ViKTORIES trial: A randomized, double-blind, placebo-controlled trial of vitamin K supplementation to improve vascular health in kidney transplant recipients

Premature cardiovascular disease and death with a functioning graft are leading causes of death and graft loss, respectively, in kidney transplant recipients (KTRs). Vascular stiffness and calcification are markers of cardiovascular disease that are prevalent in KTR and associated with subclinical vitamin K deficiency. We performed a single-center, phase II, parallel-group, randomized, double-blind, placebo-controlled trial (ISRCTN22012044) to test whether vitamin K supplementation reduced vascular stiffness (MRI-based aortic distensibility) or calcification (coronary artery calcium score on computed tomography) in KTR over 1 year of treatment. The primary outcome was between-group difference in vascular stiffness (ascending aortic distensibility). KTRs were recruited between September 2017 and June 2018, and randomized 1:1 to vitamin K (menadiol diphosphate 5 mg; n = 45) or placebo (n = 45) thrice weekly. Baseline demographics, clinical history, and immunosuppression regimens were similar between groups. There was no impact of vitamin K on vascular stiffness (treatment effect -0.23 [95% CI -0.75 to 0.29] × 10^-3  mmHg^-1 ; p = .377), vascular calcification (treatment effect -141 [95% CI - 320 to 38] units; p = .124), nor any other outcome measure. In this heterogeneous cohort of prevalent KTR, vitamin K supplementation did not reduce vascular stiffness or calcification over 1 year. Improving vascular health in KTR is likely to require a multifaceted approach.

ST elevation myocardial infarction and kidney transplant: A large cohort study: STEMI and renal transplant

BACKGROUND

The literature on outcomes of ST-elevation myocardial infarction (STEMI) amongst kidney transplant recipients (KTR) is limited.

OBJECTIVE

To study the outcomes of STEMI among KTR.

METHODS

Data from the national readmissions database (NRD) sample that constitutes 49.1% of the stratified sample of all hospitals in the USA were analyzed for hospitalizations with STEMI among KTR for the years 2012-2018. Complications associated with STEMI were extracted using International Classification of Diseases codes.

RESULTS

A total of 588,668 index KTR hospitalizations (mean age 57.67±14.22 years; female 44.5%) of which 3,496 (0.59%) had STEMI were recorded in the NRD for the years 2012-2018. A total of 11,676 (1.98%) patients died during the hospitalization. In-hospital mortality among STEMI was higher, 465 (13.3%), than without-STEMI 11,211 (1.92%). Among the complications, mechanical complications occurred among 1.0% vs 0.02%, cardiogenic shock 10.6 vs 0.3%, ventricular arrythmias 8.3% vs 0.8%, conduction block 6.9% vs 2%, stroke 4.1% vs 1.9%, and acute kidney injury 31.6% vs 28.3% among STEMI and without-STEMI respectively. Among coronary procedures, coronary angiography was performed among 1,999 (57.2%) of which 1,777 (50.8%) had percutaneous coronary intervention (PCI). On coarsened exact matching of baseline characteristics, PCI was less likely associated with mortality, odds ratio 0.39 (95% confidence interval 0.24-0.64; p=0.0002). The trends of mortality among STEMI were steady (p-trend 0.11). PCI trend increased (p-trend 0.008) and incidence of STEMI decreased over the study years 2012 (0.66%)-2018(0.474%). A total of 84,810 (14.4%) patients were readmitted in 30 days of which 696 (20%) patients were among the STEMI subgroup.

CONCLUSION

STEMI is not an uncommon complication among KTR and is associated with significant mechanical complications. Improvement in cardiovascular risk factors might improve the STEMI rates among KTR.

Overall of kidney transplant recipients with a pretransplantation cancer history

No significant morbidity from recurrence cancer and no development of secondary type of cancers in pre-existing malignancies. We must be careful about risk of rejection.

Peripheral Vascular Disease and Kidney Transplant Outcomes: Rethinking an Important Ongoing Complication

Peripheral vascular disease (PVD) is highly prevalent in patients on the waiting list for kidney transplantation (KT) and after transplantation and is associated with impaired transplant outcomes. Multiple traditional and nontraditional risk factors, as well as uremia- and transplant-related factors, affect 2 processes that can coexist, atherosclerosis and arteriosclerosis, leading to PVD. Some pathogenic mechanisms, such as inflammation-related endothelial dysfunction, mineral metabolism disorders, lipid alterations, or diabetic status, may contribute to the development and progression of PVD. Early detection of PVD before and after KT, better understanding of the mechanisms of vascular damage, and application of suitable therapeutic approaches could all minimize the impact of PVD on transplant outcomes. This review focuses on the following issues: (1) definition, epidemiological data, diagnosis, risk factors, and pathogenic mechanisms in KT candidates and recipients; (2) adverse clinical consequences and outcomes; and (3) classical and new therapeutic approaches.

The Impact of Atherosclerotic Cardiovascular Risk on Graft Failure in Deceased-Donor Renal Transplantation

INTRODUCTION

Pretransplant cardiovascular risk may be amplified after renal transplant, but little is known about its impact on graft outcomes.

RESEARCH QUESTION

The purpose of this study was to determine if pretransplant cardiovascular risk was associated with graft outcomes.

DESIGN

This retrospective study included deceased-donor renal transplant recipients from 2010-2015. Atherosclerotic cardiovascular disease risk for patients without prior disease was calculated and patients were categorized into high (score >20%), intermediate (7.5-20%), and low risk (<7.5%). Patients with and without prior cardiovascular disease were also compared. The main endpoint was graft failure at 3-years post-transplant. Other outcomes included major adverse cardiovascular events, biopsy-proven rejection, and mortality.

RESULTS

In patients without prior atherosclerotic cardiovascular disease (N = 115), graft failure rates (4.5% vs 11.3% vs 12.5%; (P = 0.64) and major adverse cardiovascular events (9.1% vs 13.2% vs 5.0%; P = 0.52) were similar in the high, intermediate, and low risk groups. In those with prior disease (N = 220), rates of primary nonfunction (6.8% vs 1.7%; P = 0.04), major adverse cardiovascular events (7.3% vs 2.6%; P = 0.01), and heart failure (10.9% vs 3.5%; P = 0.02) were higher than those without cardiovascular; rates of major adverse cardiovascular events and heart failure were insignificant after adjusting for age, gender, and race. Other outcomes were not different. Outcomes did not differ based on pretransplant cardiovascular risk.

DISCUSSION

Pretransplant atherosclerotic cardiovascular disease was associated with increased early graft failure but similar outcomes at 3-years, suggesting cardiac risk alone should not exclude transplantation.

Performance versus Risk Factor-Based Approaches to Coronary Artery Disease Screening in Waitlisted Kidney Transplant Candidates

INTRODUCTION

Current screening algorithms for coronary artery disease (CAD) before kidney transplantation result in many tests but few interventions.

OBJECTIVE

The aim of this study was to study the utility of 6-minute walk test (6MWT), an office-based test of cardiorespiratory fitness, for risk stratification in this setting.

METHODS

We enrolled 360 patients who are near the top of the kidney transplant waitlist at our institution. All patients underwent CAD evaluation irrespective of 6MWT results. We examined the association between 6MWT and time to CAD-related events (defined as cardiac death, revascularization, nonfatal myocardial infarction, and removal from the waitlist for CAD), treating noncardiac death and waitlist removal for non-CAD reasons as competing events.

RESULTS

The 6MWT-based approach designated approximately 45% of patients as "low risk," whereas a risk factor- or symptom-based approach designated 14 and 81% of patients as "low risk," respectively. The 6MWT-based approach was not significantly associated with CAD-related events within 1 year (subproportional hazard ratio [sHR] 1.00 [0.90-1.11] per 50 m) but was significantly associated with competing events (sHR 0.70 [0.66-0.75] per 50 m). In a companion analysis, removing waitlist status from consideration, 6MWT result was associated with the development of CAD-related events (sHR 0.92 [0.84-1.00] per 50 m).

CONCLUSIONS

The 6MWT designates fewer patients as high risk and in need of further testing (compared to risk factor-based approaches), but its utility as a pure CAD risk stratification tool is modulated by the background waitlist removal rate. CAD screening before kidney transplant should be tailored according to a patient's actual chance of receiving a transplant.

Detection of pro angiogenic and inflammatory biomarkers in patients with CKD

Cardiovascular disease (CVD) is the most common cause of death in patients with native and post-transplant chronic kidney disease (CKD). To identify new biomarkers of vascular injury and inflammation, we analyzed the proteome of plasma and circulating extracellular vesicles (EVs) in native and post-transplant CKD patients utilizing an aptamer-based assay. Proteins of angiogenesis were significantly higher in native and post-transplant CKD patients versus healthy controls. Ingenuity pathway analysis (IPA) indicated Ephrin receptor signaling, serine biosynthesis, and transforming growth factor-β as the top pathways activated in both CKD groups. Pro-inflammatory proteins were significantly higher only in the EVs of native CKD patients. IPA indicated acute phase response signaling, insulin-like growth factor-1, tumor necrosis factor-α, and interleukin-6 pathway activation. These data indicate that pathways of angiogenesis and inflammation are activated in CKD patients' plasma and EVs, respectively. The pathways common in both native and post-transplant CKD may signal similar mechanisms of CVD.

mTOR inhibition improves mitochondria function/biogenesis and delays cardiovascular aging in kidney transplant recipients with chronic graft dysfunction

CVD remains the major cause of mortality with graft functioning in Kidney transplant recipients (KTRs), with an estimated risk of CV events about 50-fold higher than in the general population. Many strategies have been considered to reduce the CV risk such as the use of mTOR inhibitors. We evaluate whether chronic mTOR inhibition might influence CV aging in KTRs studying the molecular mechanisms involved in this effect. We retrospectively analyzed 210 KTRs with stable graft function on therapy with CNI and mycophenolic acid (Group A, 105 pts.), or with CNI and mTORi (Everolimus, Group B, 105 pts.). The presence of mTOR inhibitor in immunosuppressive therapy was associated to increase serum levels of Klotho with concomitant reduction in FGF-23, with a significant decrease in left ventricular mass. In addition, KTRs with mTORi improved mitochondrial function/biogenesis in PBMC with more efficient oxidative phosphorylation, antioxidant capacity and glutathione peroxidase activity. Finally, group B KTRs presented reduced levels of inflammaging markers such as reduced serum pentraxin-3 and p21ink expression in PBMC. In conclusion, we demonstrated that mTOR inhibition in immunosuppressive protocols prevents the occurrence and signs of CV aging in KTRs.

Cardiovascular calcifications in kidney transplant recipients

Vascular and valvular calcifications are highly prevalent in kidney transplant recipients and are associated with an increased risk of cardiovascular events, which represent the leading cause of long-term mortality in these patients. However, cardiovascular calcification has been traditionally considered as a condition mostly associated with advanced chronic kidney disease stages and dialysis, and comparatively fewer studies have assessed its impact after kidney transplantation. Despite partial or complete resolution of uremia-associated metabolic derangements, kidney transplant recipients are still exposed to several pro-calcifying stimuli that favour the progression of pre-existing vascular calcifications or their de novo development. Traditional risk factors, bone mineral disorders, inflammation, immunosuppressive drugs and deficiency of calcification inhibitors may all play a role, and strategies to correct or minimize their effects are urgently needed. The aim of this work is to provide an overview of established and putative mediators involved in the pathogenesis of cardiovascular calcification in kidney transplantation, and to describe the clinical and radiological features of these forms. We also discuss current evidence on preventive strategies to delay the progression of cardiovascular calcifications in kidney transplant recipients, as well as novel therapeutic candidates to potentially prevent their long-term deleterious effects.

Early cardiovascular events and cardiovascular death after renal transplantation: role of pretransplant risk factors

BACKGROUND

The purpose of this study was to verify the risk factors present in patients on the kidney transplant waiting list that may interfere with the incidence of cardiovascular (CV) events and death during the first 12 months after transplantation.

METHODS

Based on the data collected prospectively during pretransplant workups, a retrospective study was conducted including 665 patients followed up until death or completing 12 months posttransplantation. Endpoints were the composite incidence of CV events and death.

RESULTS

The prevalence of diabetes, LV hypertrophy, and CV disease at baseline was high; 14% of patients had angina, 26% an abnormal myocardial scan, and 47% coronary artery disease. CV events occurred in 53 patients (8.4%) and in 29 (55%) caused death. The independent predictors of events were age ≥ 50 years (HR 2.292; CI% 1.093-4.806), angina (HR 1.969; CI% 1.039-3.732), and altered myocardial scan (HR 1.905, CI% 1.059-3.428). Altered myocardial scan (HR 2.822, 95% CI 1.095-6.660) was also one of the independent predictor of CV death.

CONCLUSION

The incidence of CV events and death were predicted by variables associated with myocardial ischemia, a potentially modifiable risk factor. Patients with pretransplantation myocardial ischemia should be considered at a higher risk of developing early CV complications and managed accordingly before, during, and after kidney transplantation.

Sex Differences in Subclinical Cardiovascular Organ Damage After Renal Transplantation: A Single-Center Cohort Study

Background: Cardiovascular disease (CVD) is the leading cause of death after renal transplantation (RT). Sex-specific differences in CVD in the general population are well known. The aim of this study was to evaluate sex-specific differences in prevalence and course of subclinical cardiovascular (CV) organ damage in RT recipients during the first year after RT. Methods: In a prospective longitudinal study, we enrolled 121 patients (male 64%, age 51 ± 15 years). CV risk factors, left ventricular mass index (LVMI), and pulse wave velocity (PWV) were assessed at time of RT and 1 year later. Results: Women showed less prediagnosed CVD and better blood pressure (BP) control, and were less likely to be treated with calcium channel blockers (CCBs). Despite similar transplant function, LVMI increased in women and decreased in men (p = 0.027). In multivariable analysis, changes in LVMI were independently associated with female sex and systolic BP. Importantly, women receiving CCBs showed a decrease in LVMI and PWV. Conclusions: Our findings indicate a sex-specific association between RT and changes in LVMI. CCBs seem to have a positive impact on CV risk after RT, especially in women. Further studies on the effect of sex and CCB use in RT recipients are warranted.

A propensity score-matched analysis indicates screening for asymptomatic coronary artery disease does not predict cardiac events in kidney transplant recipients

Screening for asymptomatic coronary artery disease prior to kidney transplantation aims to reduce peri- and post-operative cardiac events. It is uncertain if this is achieved. Here, we investigated whether pre-transplant screening with a stress test or coronary angiogram associated with any difference in major adverse cardiac events (MACE) up to five years post-transplantation. We examined a national prospective cohort recruited to the Access to Transplant and Transplant Outcome Measures study who received a kidney transplant between 2011-2017, and linked patient demographics and details of cardiac screening investigations to outcome data extracted from the Hospital Episode Statistics dataset and United Kingdom Renal Registry. Propensity score matched groups were analyzed using Kaplan-Meier and Cox survival analyses. Overall, 2572 individuals were transplanted in 18 centers; 51% underwent screening and the proportion undergoing screening by center ranged from 5-100%. The incidence of MACE at 90 days, one and five years was 0.9%, 2.1% and 9.4% respectively. After propensity score matching based on the presence or absence of screening, 1760 individuals were examined (880 each in screened and unscreened groups). There was no statistically significant association between screening and MACE at 90 days (hazard ratio 0.80, 95% Confidence Interval 0.31-2.05), one year (1.12, 0.51-2.47) or five years (1.31, 0.86-1.99). Age, male sex and history of ischemic heart disease were associated with MACE. Thus, there is no association between screening for asymptomatic coronary artery disease and MACE up to five years post-transplant. Practices involving unselected screening of transplant recipients should be reviewed.

Myocardial Infarction after Kidney Transplantation: A Risk and Specific Profile Analysis from a Nationwide French Medical Information Database

INTRODUCTION

Renal transplant recipients have a high peri-operative risk for cardiovascular events. The post-transplantation period also carries a risk of myocardial infarction (MI). Coronary artery disease (CAD) is a leading cause of death in these patients. We aimed to assess the risk of MI, the specific morbidity profile of MI after transplantation as well as the long-term prognosis after MI in renal transplantation (RT) patients regarding cardiovascular (CV) death and all-cause death.

METHODS

From a French national medical information database, all of the patients seen in French hospitals in 2013 with at least 5-years follow-up were retrospectively identified and patients without transplantation but with previous dialysis at baseline were excluded. There were 17,526 patients with RT and 3,288,857 with no RT.

RESULTS

Among these patients, 1020 in the RT group (5.8%), and 93,320 in the non-RT group (2.8%) suffered acute MI during a median follow-up of 5.4 years. After multivariable adjustment, risk of MI was higher in RT patients than in non-RT patients (HR 1.45, IC 95% 1.35-1.55). The mean age was 59.5 years for transplant patients with MI, and 70.6 years for the reference population with MI (p < 0.0001). MI patients with RT (vs. non RT patients) were more likely to have hypertension, diabetes dyslipidemia, and peripheral artery disease (76.0% vs. 48.1%, 38.7% vs. 25.2%, 33.2% vs. 23.2%, and 31.2% vs. 17.3%, respectively, p < 0.0001). Incidence of non ST-elevation MI (NSTEMI) was higher in RT patients while incidence of ST-elevation MI (STEMI) was higher in patients without RT. In unadjusted analysis, risk of all-cause death and CV death within the first month after MI were higher in patients without RT (18% vs. 11.1% p < 0.0001 and 12.3% vs. 7.8%, p < 0.0001, respectively). However, multivariable analysis indicated that risk of all-cause death was higher in patients with RT than in those with no RT (adjusted HR 1.15 IC 95% 1.03-1.28).

CONCLUSIONS

MI is not an uncommon complication after RT (incidence of around 5.8% after 5 years). RT is independently associated with a 45% higher risk of MI than in patients without RT, with a predominance of NSTEMI. MI in patients with RT is independently associated with a 15% higher risk of all-cause death than that in patients with MI and no RT.

Kidney retransplantation after anti-programmed cell death-1 (PD-1)-related allograft rejection

In this report, we describe the first kidney retransplantation performed after anti-programmed cell death-1 (PD-1)-related allograft rejection. In 2014, we administered pembrolizumab (anti-PD-1) for ~9 months to a 57-year-old kidney transplant recipient with metastatic cutaneous squamous cell carcinoma (CSCC). The patient experienced both a complete antitumor response and T cell-mediated allograft rejection requiring reinitiation of hemodialysis. Four-and-a-half years after initiating pembrolizumab, the patient remained without evidence of CSCC relapse and received a kidney transplant from a living-unrelated donor. Ten-and-a-half months after kidney retransplantation, the allograft is functioning well and the patient's CSCC remains in remission. This case illustrates the potential for PD-1 blockade to bring about durable immune-mediated tumor control in chronically immunosuppressed patients, and begins to address the feasibility of kidney retransplantation in patients who have previously received immune checkpoint inhibitor therapy for cancer. Results from this and future cases may help elucidate mechanisms of antitumor immunity and allograft tolerance, and inform updates to transplant decision models. Our report also underscores the need for clinical trials testing novel immunotherapy combinations in solid organ transplant recipients designed to uncouple antitumor and anti-allograft immunity.

Myocardial ischemia by radionuclide imaging and long-term outcomes after kidney transplantation

PURPOSE

We examined the incidence of myocardial ischemia (MI) in kidney transplant recipients (KTR) using myocardial perfusion imaging (MPI), and its association with long-term outcomes after transplantation.

METHODS

A retrospective observational study was conducted of asymptomatic KTRs who underwent post-transplant MPI screening for MI, as defined by moderate to severe myocardial perfusion defects, post-stress myocardial stunning or balanced ischemia. A composite outcome of all-cause mortality, graft loss, and major adverse cardiovascular events (MACE) was examined over minimum 5 years.

RESULTS

We studied 135 KTRs who underwent 226 MPIs, with follow-up duration of 10 (7-13) years. 110 (81%) patients had normal MPIs, 11 (8%) had mild perfusion defects, and 14 (10%) had MI. Correspondingly, composite outcome developed in 6%, 27%, and 43% (p = 0.04), and MACE occurred in 7%, 0%, and 21% (p = 0.11), of the respective subgroups. Twenty-six patients developed the composite outcome after 5 (3-7) years post-transplantation, including 11 patients with MACE. On multivariate analysis, MI, higher low-density lipoprotein levels, and proteinuria > 0.3 g/day independently predicted the composite outcome; only MI predicted MACE (all p < 0.05). Ninety-one patients had two serial MPIs, which increased the positive predictive value for MACE from 17 to 25%. Absence of MI had negative predictive value of 83% for MACE and 93% for the composite outcome.

CONCLUSION

MI that is detected early post-kidney transplantation predicts long-term mortality, graft loss, and MACE in KTRs, with excellent negative but poor positive predictive values.

Vitamin K for kidney transplant organ recipients: investigating vessel stiffness (ViKTORIES): study rationale and protocol of a randomised controlled trial

BACKGROUND

Renal transplant recipients (RTRs) exhibit increased vascular stiffness and calcification; these parameters are associated with increased cardiovascular risk. Activity of endogenous calcification inhibitors such as matrix gla protein (MGP) is dependent on vitamin K. RTRs commonly have subclinical vitamin K deficiency. The Vitamin K in kidney Transplant Organ Recipients: Investigating vEssel Stiffness (ViKTORIES) study assesses whether vitamin K supplementation reduces vascular stiffness and calcification in a diverse population of RTR.

METHODS AND ANALYSIS

ViKTORIES (ISRCTN22012044) is a single-centre, phase II, parallel-group, randomised, double-blind, placebo-controlled trial of the effect of vitamin K supplementation in 90 prevalent RTR. Participants are eligible if they have a functioning renal transplant for >1 year. Those on warfarin, with atrial fibrillation, estimated glomerular filtration rate <15 mL/min/1.73 m2 or contraindications to MRI are excluded. Treatment is with vitamin K (menadiol diphosphate) 5 mg three times per week for 1 year or matching placebo. All participants have primary and secondary endpoint measures at 0 and 12 months. The primary endpoint is ascending aortic distensibility on cardiac MR imaging. Secondary endpoints include vascular calcification (coronary artery calcium score by CT), cardiac structure and function on MR, carotid-femoral pulse wave velocity, serum uncarboxylated MGP, transplant function, proteinuria and quality of life. The study is powered to detect 1.0×10-3 mm Hg-1 improvement in ascending aortic distensibility in the vitamin K group relative to placebo at 12 months. Analyses will be conducted as between-group differences at 12 months by intention to treat.

DISCUSSION

This trial may identify a novel, inexpensive and low-risk treatment to improve surrogate markers of cardiovascular risk in RTR.

Risk of Graft Failure in Kidney Recipients with Cured Post-Transplant Cancer

BACKGROUND

Post-transplant cancer (PTC) is a critical complication after kidney transplantation. However, whether successfully cured PTC affects the long-term graft outcome remains unclear.

METHODS

We retrospectively reviewed 1,629 kidney transplant recipients from 1995 to 2017 after excluding patients with post-transplant hematologic or advanced non-curable cancers and who underwent allograft nephrectomy because of cancer. Cured PTCs were defined as cancers treated with curative methods and/or adjuvant therapy without recurrence during ≥ 2 years. Propensity score matching was performed to match cured PTC patients with cancer-naïve patients (i.e., non-PTC group).

RESULTS

During the median period of 7 years (maximum, 23 years), 70 patients (4.3%) had cured PTCs. The PTC group showed significantly higher risks of death-censored graft failure (adjusted hazard ratio [HR], 2.56 [1.05-6.23]), class II donor-specific antibodies (adjusted HRs, 3.37 [1.30-8.71]), estimated glomerular filtration rate < 30 mL/min/1.73 m² (adjusted HR, 2.68 [1.43-5.02]) and random urine protein/creatinine ratio > 1 g (adjusted HR, 3.61 [1.92-6.79]) compared to non-PTC group. However, the risk of mortality was not different between the PTC and non-PTC groups. According to the cancer type, only urogenital cancer had a significant association with graft failure (adjusted HR, 4.26 [1.19-15.22]) and the gastrointestinal cancer showed elevated risk of T cell mediated rejection compared to non-PTC (adjusted HR, 20.44 [6.02-69.39]).

CONCLUSION

Appropriate monitoring of graft function is necessary in patients with cured PTCs.

Chronic Kidney Disease and Coronary Artery Disease: JACC State-of-the-Art Review

Chronic kidney disease (CKD) is a major risk factor for coronary artery disease (CAD). As well as their high prevalence of traditional CAD risk factors, such as diabetes and hypertension, persons with CKD are also exposed to other nontraditional, uremia-related cardiovascular disease risk factors, including inflammation, oxidative stress, and abnormal calcium-phosphorus metabolism. CKD and end-stage kidney disease not only increase the risk of CAD, but they also modify its clinical presentation and cardinal symptoms. Management of CAD is complicated in CKD patients, due to their likelihood of comorbid conditions and potential for side effects during interventions. This summary of the Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference on CAD and CKD (including end-stage kidney disease and transplant recipients) seeks to improve understanding of the epidemiology, pathophysiology, diagnosis, and treatment of CAD in CKD and to identify knowledge gaps, areas of controversy, and priorities for research.

Recent Advances and Clinical Outcomes of Kidney Transplantation

Recent advances in surgical, immunosuppressive and monitoring protocols have led to the significant improvement of overall one-year kidney allograft outcomes. Nonetheless, there has not been a significant change in long-term kidney allograft outcomes. In fact, chronic and acute antibody-mediated rejection (ABMR) and non-immunological complications following kidney transplantation, including multiple incidences of primary kidney disease, as well as complications such as cardiovascular diseases, infections, and malignancy are the major factors that have contributed to the failure of kidney allografts. The use of molecular techniques to enhance histological diagnostics and noninvasive surveillance are what the latest studies in the field of clinical kidney transplant seem to mainly focus upon. Increasingly innovative approaches are being used to discover immunosuppressive methods to overcome critical sensitization, prevent the development of anti-human leukocyte antigen (HLA) antibodies, treat chronic active ABMR, and reduce non-immunological complications following kidney transplantation, such as the recurrence of primary kidney disease and other complications, such as cardiovascular diseases, infections, and malignancy. In the present era of utilizing electronic health records (EHRs), it is strongly believed that big data and artificial intelligence will reshape the research done on kidney transplantation in the near future. In addition, the utilization of telemedicine is increasing, providing benefits such as reaching out to kidney transplant patients in remote areas and helping to make scarce healthcare resources more accessible for kidney transplantation. In this article, we discuss the recent research developments in kidney transplants that may affect long-term allografts, as well as the survival of the patient. The latest developments in living kidney donation are also explored.

High-Density Lipoprotein Particles and Their Relationship to Posttransplantation Diabetes Mellitus in Renal Transplant Recipients

High concentrations of high-density lipoprotein (HDL) cholesterol are likely associated with a lower risk of posttransplantation diabetes mellitus (PTDM). However, HDL particles vary in size and density with yet unestablished associations with PTDM risk. The aim of our study was to determine the association between different HDL particles and development of PTDM in renal transplant recipients (RTRs). We included 351 stable outpatient adult RTRs without diabetes at baseline evaluation. HDL particle characteristics and size were measured by nuclear magnetic resonance (NMR) spectroscopy. During 5.2 (IQR, 4.1‒5.8) years of follow-up, 39 (11%) RTRs developed PTDM. In multivariable Cox regression analysis, levels of HDL cholesterol (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.40-0.94 per 1SD increase; p = 0.024) and of large HDL particles (HR 0.68, 95% CI 0.50-0.93 per log 1SD increase; p = 0.017), as well as larger HDL size (HR 0.58, 95% CI 0.36-0.93 per 1SD increase; p = 0.025) were inversely associated with PTDM development, independently of relevant covariates including, age, sex, body mass index, medication use, transplantation-specific parameters, blood pressure, triglycerides, and glucose. In conclusion, higher concentrations of HDL cholesterol and of large HDL particles and greater HDL size were associated with a lower risk of PTDM development in RTRs, independently of established risk factors for PTDM development.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

The Effect of Marine n-3 Polyunsaturated Fatty Acids on Heart Rate Variability in Renal Transplant Recipients: A Randomized Controlled Trial

Resting heart rate (rHR) and heart rate variability (HRV) are non-invasive measurements that predict the risk of sudden cardiac death (SCD). Marine n-3 polyunsaturated fatty acid (PUFA) supplementation may decrease rHR, increase HRV, and reduce the risk of SCD. To date, no studies have investigated the effect of marine n-3 PUFA on HRV in renal transplant recipients. In a randomized controlled trial, 132 renal transplant recipients were randomized to receive either three 1 g capsules of marine n-3 PUFA, each containing 460 mg/g EPA and 380 mg/g DHA, or control (olive oil) for 44 weeks. HRV was calculated in the time and frequency domains during a conventional cardiovascular reflex test (response to standing, deep breathing, and Valsalva maneuver) and during 2 min of resting in the supine position. There was no significant effect of marine n-3 PUFA supplementation on time-domain HRV compared with controls. rHR decreased 3.1 bpm (± 13.1) for patients receiving marine n-3 PUFA compared to 0.8 (± 11.0) in controls (p = 0.28). In the frequency domain HRV analyses, there was a significant change in response to standing in both high and low frequency measures, 2.9 (p = 0.04, 95% CI (1.1;8)) and 2.7 (p = 0.04, 95% CI (1.1;6.5)), respectively. In conclusion, 44 weeks of supplemental marine n-3 PUFAs in renal transplant recipients significantly improved the cardiac autonomic function, assessed by measuring HRV during conventional cardiovascular reflex tests.

Rituximab protects against development of atherosclerotic cardiovascular disease after kidney transplantation: a propensity-matched study

Recent studies have implicated B cells in atherosclerosis and have verified the atheroprotective effect of rituximab. Rituximab is widely used for desensitization in ABO-incompatible or crossmatch-positive kidney transplantation (KT). Using a single-center KT database, we performed propensity-matched analysis to investigate the association between rituximab and posttransplant atherosclerotic cardiovascular disease (ASCVD). Among 1299 eligible patients, 239 given rituximab induction were matched with 401 controls in a 1:2 propensity score matching process. The cumulative rate of ASCVD during 8 years of follow-up was significantly lower in rituximab-treated patients, compared with matched controls (3.7% vs. 11.2%; P = 0.012). However, all-cause mortality did not differ by group (2.9% vs. 4%; P = 0.943). In multivariable Cox analysis, rituximab proved independently protective of ASCVD (hazard ratio = 0.34, 95% confidence interval: 0.14–0.83). The lower risk of ASCVD seen with rituximab induction reached significance only in patient subsets of diabetes mellitus, pretransplant dialysis, or older age (>50 years). Rituximab induction confers a lower risk of ASCVD during the posttransplant period. This atheroprotective effect appears particularly beneficial in patients whose risk of ASCVD is heightened.