Cardiovascular risk factors following renal transplant

Risks of cardiovascular disease and cerebrovascular disease following kidney transplantation: A nationwide, population-based cohort study

Background: Kidney transplant recipients (KTRs) have an increased risk for cardiovascular disease (CVD) and cerebrovascular disease (CBD). This study investigated the risks of CVD and CBD following kidney transplantation. Materials and methods: This retrospective cohort study enrolled 3596 KTRs between 2003 and 2017. Propensity Score Matching (PSM) was performed to select patients without a kidney transplant, who were assigned to the control group. Each KTR was matched with five patients without a kidney transplant by sex, age, insured salary, urbanization level, Charlson comorbidity index (CCI), and year of inclusion in the study. A Cox proportional hazards model was employed to investigate the risks of incident CVD and CBD in KTRs after adjusting for relevant variables. Furthermore, we analyzed for CVD and CBD risk 6 months and 1, 3, and 5 years after transplantation. Results: Among KTRs, the CVD incidence rate per 1,000 person-years was 33.98, which was significantly higher than that among patients without a kidney transplant. After adjusting for confounding variables, KTRs had a significantly higher risk of CVD (adjusted hazard ratio [aHR], 1.74; 95% confidence interval [CI], 1.58-1.93) than did patients without a kidney transplant. Regarding cumulative incidence, the risk of CVD increased over time. Among the four follow-up periods we assessed, the 5-year follow-up period had the highest CVD risk (aHR, 1.35; 95% CI, 1.17-1.56), followed by the 3-year follow-up period (aHR, 1.34; 95% CI, 1.13-1.59). KTRs also had a significantly higher risk of CBD (aHR, 1.43; 95% CI, 1.23-1.68) than did patients without a kidney transplant. Conclusion: CVD risk is higher among KTRs than among those without a kidney transplant, and this risk increases over time. CBD risk was also higher among KTRs. Large, randomized controlled prospective studies are needed to thoroughly evaluate the relationship between kidney transplantation and the risks of CVD and CBD.

Immunosuppressive drugs and diet interact to modify the gut microbiota and cardiovascular risk factors, and to trigger diabetes

BACKGROUND

Kidney transplant recipients are prescribed an immunosuppressive therapy (IST) and some of them follow a high fat diet (HFD) despite medical recommendations. Both are frequently associated with gut microbiota changes and metabolic disorders. We aimed at precisely identifying the effect of the IST and the HFD on metabolic parameters and the gut microbiota in mice, and at establishing correlations between the latters.

METHODS

8-week-old male mice were treated with IST (a combination of prednisone, mycophenolate mofetil and tacrolimus) or not and were fed HFD or standard chow. Metabolic parameters were measured, and the gut microbiota was explored by the quantification of specific bacterial groups by qPCR and by 16S rDNA sequencing.

RESULTS

The HFD increased insulinemia and decreased the fecal proportion of Bacteroidetes and of Bacteroides. The IST increased systolic blood pressure and the fecal proportion of Escherichia coli. The HFD and the IST administered together resulted in an additive effect on glucose intolerance, high fasting blood glucose, homeostasis model assessment of insulin resistance (HOMA-IR), percentage of fat mass, blood triglyceride, blood cholesterol, and endotoxemia. On the opposite, the HFD and the IST had antagonistic effects on body weight, the proportion of Firmicutes, the Firmicutes/Bacteroidetes ratio, and the proportion of Clostridium leptum, Bifidobacterium, and Lactobacillus in the feces. Finally, we found that the correlations between gut bacterial communities and metabolic consequences of the HFD were altered by the IST.

CONCLUSION

The IST and the HFD have specific consequences on the gut microbiota and metabolism. We hypothesize that the metabolic consequences are at least partially mediated by IST/HFD-induced dysbiosis.

Management of heart disease in renal transplant recipients: a national Delphi survey-based SET/SEC/SEN consensus document

Renal transplantation improves the survival and quality of life of patients with end-stage renal disease. Cardiovascular disease is the leading cause of morbidity and mortality in renal transplant recipients. The bidirectional relationship between renal and heart disease creates a unique clinical scenario that demands a comprehensive and personalized approach. This expert consensus, drafted by the Spanish Society of Transplantation, the Spanish Society of Cardiology, and the Spanish Society of Nephrology, aims to assess current practices and propose strategies for the management of heart disease in renal transplant recipients. A panel of Spanish nephrologists and cardiologists with expertise in renal and heart transplantation reviewed the scientific evidence concerning the current management of heart disease in renal transplant recipients. Subsequently, consensus statements were created through a 2-round Delphi methodology, resulting in 30 statements covering key topics such as the identification of renal transplant candidates, the management of heart disease in renal transplant recipients, and eligibility for combined heart-kidney transplantation in patients with both end-stage renal disease and cardiac disease. These consensus statements provide expert guidance for the management of heart disease in renal transplant recipients, an area where published clinical evidence remains limited.

A structured, home-based exercise programme in kidney transplant recipients (ECSERT): A randomised controlled feasibility study

BACKGROUND

Cardiometabolic diseases are a major cause of morbidity and mortality in kidney transplant recipients (KTR) due to clustering of traditional and non-traditional risk factors including poor physical fitness and physical inactivity. Exercise may mitigate the risk of these diseases in this population but evidence is limited, and physical activity levels are low. The ECSERT randomised controlled trial assessed the feasibility of delivering a structured, home-based exercise intervention in KTR at increased cardiometabolic risk.

METHODS

Fifty KTR (>1-year post-transplant) were randomised 1:1 to: intervention (INT: a 12-week home-based combined aerobic and resistance exercise programme) or control (CTR: guideline-directed care). The a-priori thresholds for feasibility were: recruitment of 20% of eligible participants (≥2 participants per month); adherence (an average of ≥ 3 exercise sessions per week); and attrition (≤30%).

RESULTS

One hundred and seventy-one patients were screened and 94 (55%) were eligible and invited to take part in the study. Fifty of those invited (53%) were recruited across 22 months of recruitment. Consented participant characteristics were: age 50 ± 14 years (INT 49 ± 13; CTR 51 ± 15), 23 male (INT 10; CTR 13), eGFR 59 ± 19 ml/min/1.73m2 (INT 60 ± 20; CTR 61 ± 21), 35 White British (WB), 13 South Asian (SA), 1 Caribbean, and 1 Mixed ethnicity (INT 17 WB, 7 SA, 1 Mixed; CTR 18 WB, 6 SA, 1 Caribbean). Intervention participants (n = 22 completed) recorded an average of 4.4 ± 1.4 exercise sessions per week (aerobic 2.8 ± 1.1; strength 1.6 ± 0.5). Three participants withdrew from the intervention group (1 COVID-19 infection, 1 recurrent urine infections unrelated to the trial, 1 time/family circumstances) and one from the control group (lost to follow-up; 8% attrition). There were no serious adverse events reported.

CONCLUSION

Despite previous evidence showing physical fitness and activity levels are low in KTR, the present results support that a structured, home-based exercise programme is feasible in this population. Specifically, a-priory recruitment, adherence, and retention thresholds were all exceeded. The groups were well matched and there was encouraging representation of female participants and participants from a non-white background. Thus, this study supports further development and testing of home-based programmes of exercise and activity for KTR.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04123951.

Long-term outcomes in rapamycin on renal allograft function: a 30-year follow-up from a single-center experience

OBJECTIVES

To evaluate long-term renal graft prognosis and the role of rapamycin from a single-center in China over a 30-year follow-up.

METHODS

This study enrolled a total of 654 patients who underwent kidney transplantation between 1989 and 2020. The basic characteristics of the included patients were collected. Graft survival was described and compared using Kaplan-Meier curves (K-M curves). Both continuous and categorical variables were included in a multivariate Cox proportional-hazards model. Patients were divided into rapamycin-based quadruple immunosuppression regimen group (rapa group, n = 41) and conventional tacrolimus-based triple immunosuppression regimen group (control group, n = 218). The indication biopsy results of the two groups were further reviewed to compare the incidence of rejection, acute rejection, and banff score.

RESULTS

The overall 5, 10, 15, 20-year graft survival rate of our center is 87.5%, 62.4%, 46.4% and 20.9%, respectively. The median survival time after surgery is 14 years. Multiple Cox regression analysis identified BMI (p = 0.035), dialysis type (p < 0.001), immunosuppressants (p < 0.01), urine albumen (p < 0.001), globulin (p = 0.041), and blood glucose (p = 0.002) as risk factors. The 20-year, 10-year and 5-year AUC is 0.78, 0.75 and 0.75. The combination of FK506 and rapamycin was further suggested by the model to effectively improve the graft prognosis (p < 0.01, HR = 0.763). The K-M curve showed that the long-term survival rate of renal grafts in the rapa group was significantly better than that in the conventional group (p < 0.001). In addition, indication biopsy records revealed a lower possibility of immune rejection in the rapa group than that in the conventional group (p < 0.001). Banff score indicated that rapa group had less vascular inflammation in the transplanted kidney.

CONCLUSIONS

In this study, a 30-year follow-up was performed in a single center, and a total graft 20-year survival rate of 20.9% was reported. The prognostic model and subgroup analysis suggested that FK506 combined with rapamycin could effectively improve the prognosis of renal transplantation, which could be explained by reduced acute rejection and less vascular inflammation.

The Role of Angiopoietins in Cardiovascular Outcomes of Kidney Transplant Recipients: An Ancillary Study from the FAVORIT

INTRODUCTION

Kidney transplant recipients (KTRs) have increased risk of cardiovascular disease (CVD) mortality. We investigated vascular biomarkers, angiopoietin-1, and angiopoietin-2 (angpt-1, -2), in CVD development in KTRs.

METHODS

This ancillary study from the FAVORIT evaluates the associations of baseline plasma angpt-1, -2 levels in CVD development (primary outcome) and graft failure (GF) and death (secondary outcomes) in 2000 deceased donor KTRs. We used Cox regression to analyze the association of biomarker quartiles with outcomes. We adjusted for demographic; CVD- and transplant-related variables; medications; urine albumin-to-creatinine ratio; and randomization status. We calculated areas under the curves (AUCs) to predict CVD or death, and GF or death by incorporating biomarkers alongside clinical variables.

RESULTS

Participants' median age was 52 IQR [45, 59] years: with 37% women and 73% identifying as white. Median time from transplantation was 3.99 IQR [1.58, 7.93] years and to CVD development was 2.54 IQR [1.11-3.80] years. Quartiles of angpt-1 were not associated with outcomes. Whereas higher levels of angpt-2 (quartile 4) were associated with about 2 times the risk of CVD, GF, and death (aHR 1.85 [1.25-2.73], p < 0.01; 2.24 [1.36-3.70)], p < 0.01; 2.30 [1.48-3.58], p < 0.01, respectively) as compared to quartile 1. Adding angiopoietins to preexisting clinical variables improved prediction of CVD or death (AUC improved from 0.70 to 0.72, p = 0.005) and GF or death (AUC improved from 0.68 to 0.70, p = 0.005). Angpt-2 may partially explain the increased risk of future CVD in KTRs. Further research is needed to assess the utility of using angiopoietins in the clinical care of KTRs.

CONCLUSION

Angpt-2 may be a useful prognostic tool for future CVD in KTRs. Combining angiopoietins with clinical markers may tailor follow-up to mitigate CVD risk.

Glucagon-like Peptide 1 Receptor Agonists and Cardiovascular Outcomes in Solid Organ Transplant Recipients With Diabetes Mellitus

BACKGROUND

Glucagon-like peptide 1 receptor agonists (GLP1-RAs) reduce cardiovascular events and mortality in type 2 diabetes. Limited data are available on diabetes treatment after solid organ transplantation. We aimed to explore the effect of GLP1-RAs on cardiovascular outcomes in transplanted recipients with diabetes.

METHODS

We extracted data on adult transplant recipients (kidney, lungs, liver, heart) insured in a large health maintenance organization. Death-censored patients with diabetes treated with GLP1-RAs were matched with nonusers. The primary outcome was a composite of major cardiovascular events (MACEs): a nonfatal cardiac event (myocardial infarction, stable/unstable angina, coronary bypass, and coronary angiography), ischemic stroke and all-cause mortality. Secondary outcomes were MACE or peripheral vascular disease (MACE-PVD), and all-cause mortality. Safety outcomes included biliopancreatic adverse events.

RESULTS

We included 318 patients (69% males, average age 58.3 ± 11.0 y) with a 3.1-y median follow-up. The incidence of MACE was 101 of 1000 patient-years in GLP1-RAs users compared with 134 of 1000 in controls (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.27-0.78). GLP1-RAs similarly reduced the risk of MACE-PVD (HR 0.53; 95% CI, 0.33-0.88) and the risk of all-cause mortality (HR 0.39; 95% CI, 0.18-0.84). Biliopancreatic adverse events occurred less in GLP1-RA users.

CONCLUSIONS

Transplant recipients with diabetes who used GLP1-RAs had lower risks for MACE and all-cause mortality. These results may profoundly implicate the daily management of posttransplant recipients with diabetes, a population with a high prevalence of cardiometabolic risk factors and cardiovascular death. Transplant patients are usually excluded from randomized controlled trials and, hence might be undertreated with disease-modifying drugs. Larger prospective studies are needed in this unique population.

Comparison of depression and suicide between dialysis and kidney transplant recipients in Korea: a nationwide population study

Background

Kidney transplantation (KT) improves physical and psychological prognoses for patients with end-stage kidney disease (ESKD). However, few comparative studies have examined depression and suicide rates among patients with ESKD treated with dialysis versus KT.

Methods

Data on 21,809 patients with ESKD were extracted from the Korean National Health Insurance Service database, extending from January 2002 to December 2018. These patients exhibited no history of depression or insomnia before starting renal replacement therapy. Outcomes were compared between dialysis and KT recipients using 1:2 propensity score matching (PSM).

Results

Of the patients, 17,649 received dialysis (hemodialysis, 15,537; peritoneal dialysis, 2,112), while 4,160 underwent KT. Of those on dialysis, 45.04% (7,949) experienced insomnia, compared to 25.72% (1,070) of KT recipients (P<0.001). Depression was more frequent among dialysis recipients (22.77%, 4,019) than KT recipients (8.61%, 358; P<0.001). Additionally, those on dialysis had a higher incidence of suicide (0.19%, 33) than recipients of KT (0.12%, 5; P=0.047). After PSM, the hazard ratio (HR) for depression in patients on dialysis compared to KT recipients was 1.76 (95% confidence interval [CI], 1.56-1.99). In subgroup analysis, the relative likelihood of depression among dialysis recipients was particularly high for residents of urban areas (HR, 2.10; 95% CI, 1.80-2.44) and patients under 65 years old (HR, 1.82; 95% CI, 1.62-2.09).

Conclusions

KT recipients exhibit a lower suicide rate than patients on dialysis. Furthermore, KT is associated with a lower prevalence of depression among Korean patients with ESKD, particularly urban residents and individuals under 65 years old.

The Importance of the FUT2 rs602662 Polymorphism in the Risk of Cardiovascular Complications in Patients after Kidney Transplantation

The FUT2 gene encodes an enzyme called α-1,2-fucosyltransferase, which is involved in the formation of blood group antigens AB0(H) and is also involved in the processes of vitamin B12 absorption and its transport between cells. FUT2 gene polymorphisms are associated with vitamin B12 levels in the body. Vitamin B12 deficiency associated with hyperhomocysteinemia is a major risk factor for cardiovascular diseases (CVDs), which are one of the main causes of death in patients after kidney transplantation. The aim of our study was to determine the impact of the rs602662 (G>A) polymorphism of the FUT2 gene on the functionality of transplanted kidneys and the risk of CVD in patients after kidney transplantation. The study included 402 patients treated with immunosuppression (183 patients taking cyclosporine (CsA) and 219 patients taking tacrolimus (TAC)). The analysis of the FUT2 rs602662 (G>A) polymorphism was performed using real-time PCR. Patients with CsA were more likely to be underweight (1.64% vs. 0.91%) and obese (27.87% vs. 15.98%), while those taking TAC were more likely to be of normal weight (39.27%) or overweight (43.84%). No statistically significant differences were observed comparing the mean blood pressure, both systolic and diastolic. The renal profile showed a higher median urea nitrogen concentration in patients with CsA (26.45 mg/dL (20.60-35.40) vs. 22.95 mg/dL (17.60-33.30), p = 0.004). The observed frequency of rs602662 alleles of the FUT2 gene was similar in the analyzed groups. The A allele was present in 43.7% of patients with CsA and 41.1% of those taking TAC (OR = 0.898; 95% CI: 0.678-1.189; p = 0.453). In the group with CsA, the GG genotype was present in 32.2% of patients, the GA in 48.1% and the AA in 19.7%. A similar distribution was obtained in the TAC group: GG-33.8%, GA-50.2%, and AA-16.0%. An association of genotypes containing the G allele with a higher incidence of hypertension was observed. The G allele was present in 65% of people with hypertension and in 56% of patients with normal blood pressure (p = 0.036). Moreover, the evaluation of the renal parameters showed no effect of the FUT2 polymorphism on the risk of organ rejection because the levels of creatinine, eGFR, potassium, and urea nitrogen were prognostic of successful transplantation. Our results suggest that the rs6022662 FUT2 polymorphism may influence the risk of cardiovascular diseases.

The Impact of ABCC2 -24C>T Gene Polymorphism on Graft Survival in Kidney Transplant Recipients

Personalized medicine in kidney transplantation has the potential to improve outcomes and reduce complications. The aim of this study was to investigate the influence of single nucleotide polymorphisms in genes encoding metabolizing enzymes (CYP3A5) and transporters (ABCC2) on clinical outcomes (acute graft failure and/or acute tubular necrosis (ATN)) in kidney transplant recipients (KTR). This was a multicenter, retrospective cohort study where adult KTR who had undergone kidney transplantation between 2020 and 2021 and received tacrolimus-mycophenolate treatment were enrolled in the study. DNA was extracted from collected blood samples using a commercially available kit. CYP3A5*3, ABCC2 -24C>T and ABCC2 3972C>T SNP were determined by polymerase chain reaction. Of the total 39 patients included, nine (23.1%) KTR had an incidence of acute graft failure and/or ATN. A multiple logistic regression showed wildtype ABCC2 -24C>T C allele had a higher risk of developing acute graft rejection and/or ATN compared to the variant allele carriers (adjusted Odd Ratios [aOR]: 27.675, p = 0.038). Recipients who had delayed graft function (aOR: 49.214, p = 0.012) and a history of CMV infection (aOR: 18.097, p = 0.009) were at 49.2 and 18.1-times increased risk for acute graft failure and/or ATN, respectively. The large aOR was inevitable due to the small sample size and required cautious interpretation. This is the first study to determine the effect of the ABCC2 -24C>T genetic polymorphism on clinical outcomes in Malaysian KTR and forms the basis for further work on ABCC2 -24C>T effects in long-term KTR.

Cerebrovascular Disease Hospitalization Rates in End-Stage Kidney Disease Patients with Kidney Transplant and Peripheral Vascular Disease: Analysis Using the National Inpatient Sample (2005-2019)

Individuals with end-stage kidney disease (ESKD) face higher cerebrovascular risk. Yet, the impact of peripheral vascular disease (PVD) and kidney transplantation (KTx) on hospitalization rates for cerebral infarction and hemorrhage remains underexplored. Analyzing 2,713,194 ESKD hospitalizations (2005-2019) using the National Inpatient Sample, we investigated hospitalization rates for ischemic and hemorrhagic cerebrovascular diseases concerning ESKD, PVD, KTx, or their combinations. Patients hospitalized with cerebral infarction due to thrombosis/embolism/occlusion (CITO) or artery occlusion resulting in cerebral ischemia (AOSI) had higher rates of comorbid ESKD and PVD (4.17% and 7.29%, respectively) versus non-CITO or AOSI hospitalizations (2.34%, p < 0.001; 2.29%, p < 0.001). Conversely, patients hospitalized with nontraumatic intracranial hemorrhage (NIH) had significantly lower rates of ESKD and PVD (1.64%) compared to non-NIH hospitalizations (2.34%, p < 0.001). Furthermore, hospitalizations for CITO or AOSI exhibited higher rates of KTx and PVD (0.17%, 0.09%, respectively) compared to non-CITO or AOSI hospitalizations (0.05%, p = 0.033; 0.05%, p = 0.002). Patients hospitalized with NIH showed similar rates of KTx and PVD (0.04%) versus non-NIH hospitalizations (0.05%, p = 0.34). This nationwide analysis reveals that PVD in ESKD patients is associated with increased hospitalization rates with cerebral ischemic events and reduced NIH events. Among KTx recipients, PVD correlated with increased hospitalizations for ischemic events, without affecting NIH. This highlights management concerns for patients with KTx and PVD.

Standardized risk-stratified cardiac assessment and early posttransplant cardiovascular complications in kidney transplant recipients

Introduction

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in kidney transplant recipient (KTR). There is a dearth of standardized guidelines on optimal cardiovascular evaluation of transplant candidates.

Methods

This single-center cohort study aims to determine the effectiveness of our standardized risk-stratified pretransplant cardiovascular screening protocol, which includes coronary angiography (CAG), in identifying advanced CVD, the proper pretransplant management of which could lead to a reduction in the incidence of major cardiac events (MACE) in the early posttransplant period.

Results

Out of the total 776 KTR transplanted between 2017 and 2019, CAG was performed on 541 patients (69.7%), of whom 22.4% were found to have obstructive coronary artery disease (CAD). Asymptomatic obstructive CAD was observed in 70.2% of cases. In 73.6% of cases, CAG findings resulted in myocardial revascularization. MACE occurred in 5.6% (N = 44) of the 23 KTR with pretransplant CVD and 21 without pretransplant CVD. KTR with posttransplant MACE occurrence had significantly worse kidney graft function at the first year posttransplant (p = 0.00048) and worse patient survival rates (p = 0.0063) during the 3-year follow-up period compared with KTR without MACE. After adjustment, the independent significant factors for MACE were arrhythmia (HR 2.511, p = 0.02, 95% CI 1.158-5.444), pretransplant history of acute myocardial infarction (HR 0.201, p = 0.046, 95% CI 0.042-0.970), and pretransplant myocardial revascularization (HR 0.225, p = 0.045, 95% CI 0.052-0.939).

Conclusion

Asymptomatic CVD is largely prevalent in KTR. Posttransplant MACE has a negative effect on grafts and patient outcomes. Further research is needed to assess the benefits of pretransplant myocardial revascularization in asymptomatic kidney transplant candidates.

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.

Hypertension and cardiomyopathy associated with chronic kidney disease: epidemiology, pathogenesis and treatment considerations

Chronic kidney disease (CKD) is a complex condition with a prevalence of 10-15% worldwide. An inverse-graded relationship exists between cardiovascular events and mortality with kidney function which is independent of age, sex, and other risk factors. The proportion of deaths due to heart failure and sudden cardiac death increase with progression of chronic kidney disease with relatively fewer deaths from atheromatous, vasculo-occlusive processes. This phenomenon can largely be explained by the increased prevalence of CKD-associated cardiomyopathy with worsening kidney function. The key features of CKD-associated cardiomyopathy are increased left ventricular mass and left ventricular hypertrophy, diastolic and systolic left ventricular dysfunction, and profound cardiac fibrosis on histology. While these features have predominantly been described in patients with advanced kidney disease on dialysis treatment, patients with only mild to moderate renal impairment already exhibit structural and functional changes consistent with CKD-associated cardiomyopathy. In this review we discuss the key drivers of CKD-associated cardiomyopathy and the key role of hypertension in its pathogenesis. We also evaluate existing, as well as developing therapies in the treatment of CKD-associated cardiomyopathy.

Associations between Advanced Glycation End Products, Body Composition and Mediterranean Diet Adherence in Kidney Transplant Recipients

There is limited evidence on the associations between dietary patterns, body composition, and nonclassical predictors of worse outcomes such as advanced glycation end products (AGE) in kidney transplant recipients (KTRs). The aim of this cross-sectional study was to determine the level of AGE-determined cardiovascular (CV) risk in Dalmatian KTRs and possible associations between AGE, adherence to the Mediterranean diet (MeDi), and nutritional status. Eighty-five (85) KTRs were enrolled in this study. For each study participant, data were collected on the level of AGE, as measured by skin autofluorescence (SAF), Mediterranean Diet Serving Score (MDSS), body mass composition, anthropometric parameters, and clinical and laboratory parameters. Only 11.76% of the participants were adherent to the MeDi. Sixty-nine percent (69%) of KTRs had severe CV risk based on AGE, while 31% of KTRs had mild to moderate CV risk. The results of the LASSO regression analysis showed that age, dialysis type, dialysis vintage, presence of CV and chronic kidney disease, C- reactive protein level, urate level, percentage of muscle mass, and adherence to recommendations for nuts, meat, and sweets were identified as positive predictors of AGE. The negative predictors for AGE were calcium, phosphate, cereal adherence according to the MeDi, and trunk fat mass. These results demonstrate extremely low adherence to the MeDi and high AGE levels related CV risk in Dalmatian KTRs. Lifestyle interventions in terms of CV risk management and adherence to the MeDi of KTRs should be taken into consideration when taking care of this patient population.

Metabolic and functional effects of exercise training in diabetic kidney transplant recipients

BACKGROUND

Physical activity levels are significantly lower in kidney transplant (KT) recipients compared to the general population. The effects of exercise training in KT recipients with diabetes mellitus remain unclear, and so little is known about the role of increased exercise on cardiovascular risk and metabolic profile of KT patients.

AIM

To investigate the effects of a 6-mo home-based exercise training program on functional capacity, glucose levels and lipid profile of diabetic KT patients.

METHODS

In total, 21 type II diabetic KT recipients were randomly assigned into two groups: Exercise (n = 11, aged 52.9 ± 10.1 years) and control (n = 10, aged 53.01 ± 9.5 years). All participants at baseline and the end of the study underwent biochemical tests for fasting plasma glucose levels, glycated hemoglobin and lipid profile and cardiopulmonary exercise testing for maximum oxygen uptake [(VO₂)_peak] estimation. The exercise group followed a 6-mo supervised home-based aerobic and progressive resistance exercise program of moderate intensity 3 times per week, while the control group continued to receive usual care.

RESULTS

At the end of the 6-mo study, the exercise group had significantly lower values in fasting plasma glucose by 13.4% (from 120.6 ± 28.9 mg/dL to 104.8 ± 21.9 mg/dL, P = 0.01), glycated hemoglobin by 1.5% (from 6.7% ± 0.4 to 6.6% ± 0.4, P = 0.01) and triglycerides by 8.5% (from 164.7 ± 14.8 mg/dL to 150.8 ± 11.6 mg/dL, P < 0.05) and higher values in high-density lipoprotein by 10.2% (from 51.4 ± 8.8 mg/dL to 57.2 ± 8.7 mg/dL, P < 0.05) and (VO₂)_peak by 4.7% (from 22.7 ± 3.3 to 23.8 ± 4.2, P = 0.02) than the control group. There were statistically significant differences between the two groups at the end of the study for fasting plasma glucose (decreased by 9.6%, P < 0.05), triglycerides (decreased by 4.5%, P = 0.04) and (VO₂)_peak (increased by 4.4%, P = 0.01). Finally, after training, there was a moderate, positive linear relationship between (VO₂)_peak and glycated hemoglobin in the exercise group (r = 0.408, P = 0.03).

CONCLUSION

The results demonstrated that a 6-mo home-based mixed type exercise training program can improve the functional capacity, levels of glucose and lipid profile of diabetic KT recipients.

Perioperative outcomes and readmissions following cardiac operations in kidney transplant recipients

OBJECTIVE

Although kidney transplant (KTx) recipients are at significant risk for cardiovascular disease, outcomes following cardiac operations have been examined in limited series. The present study thus aimed to assess the impact of KTx on in-hospital perioperative outcomes and readmissions in a nationally representative cohort.

METHODS

All adults undergoing elective coronary artery bypass grafting, valve repair/replacement or a combination thereof were identified from the 2010-2018 Nationwide Readmissions Database. Patients were stratified by history of KTx. Transplant-capable centres were defined as hospitals performing at least one KTx annually. To perform risk-adjustment in assessing outcomes, multivariable regression models were developed.

RESULTS

Of an estimated 1 407 351 patients included for analysis, 0.2% (n=2849) were KTx recipients. Compared with the general cardiac surgical population, patients with prior KTx experienced higher adjusted odds of in-hospital mortality (adjusted OR (AOR) 2.44, 95% CI 1.72 to 3.47, p<0.001) and perioperative complication (AOR 1.67, 95% CI 1.44 to 1.94, p<0.001). Additionally, KTx was independently associated with greater readmission rates within 30 days (AOR 1.96, 95% CI 1.65 to 2.34, p<0.001) with kidney injury contributing significantly to the burden of rehospitalisation (4.6 vs 1.8%, p=0.005). In a subpopulation comprised of only KTx recipients, treatment at a transplant-capable centre reduced odds of kidney injury with non-transplant hospitals as reference (AOR 0.65, 95% CI 0.43 to 0.98, p=0.037).

CONCLUSIONS

Kidney transplant recipients undergoing cardiac operations encounter significant risks compared with the general surgical population. Referral to transplant-capable centres should be explored to improve outcomes and to preserve allograft function in this population.

Protocol for the IMPACT Trial: Improving Healthcare Outcomes in American Transplant Recipients Using Culturally-Tailored Novel Technology

Kidney transplant (KT) recipients face post-transplant health issues. Immunosuppressive agents can cause hyperlipidemia, hypertension, post-transplant diabetes, and glomerulopathy. Post-transplant weight gain and decreased activity are associated with poor quality of life, sleep, and cardiometabolic outcomes. This study will test the feasibility and acceptability of a culturally tailored diet and exercise intervention for KT patients delivered immediately post-transplant using novel technology. A registered dietitian nutritionist (RDN) and physical rehabilitation therapist will examine participants' cultural background, preferences, and health-related obstacles (with consultation from the transplant team) to create an individualized exercise and meal plan. The RDN will provide medical nutrition therapy via the nutrition care process throughout the course of the intervention. The Twistle Patient Engagement Platform will be used to deliver and collect survey data, communicate with participants, and promote retention. Outcomes to be assessed include intervention feasibility and acceptability and intervention efficacy on patients' adherence, medical, quality of life, and occupational outcomes.

Nutritional Predictors of Cardiovascular Risk in Patients after Kidney Transplantation-Pilot Study

Asymmetric dimethylarginine (ADMA) is a marker of endothelial damage. Research confirms the association of ADMA with an increased cardiovascular risk (CVR) among kidney transplant recipients (KTRs). Additionally, increased circulating levels of fibroblast growth factor 23 (FGF-23) are associated with pathological cardiac remodeling and vascular alterations. The aim of the study is the analysis of the relationship between ADMA, FGF-23, nutritional, biochemical parameters in healthy subjects and KTRs. 46 KTRs and 23 healthy volunteers at mean age of 50.8 ± 15.4 and 62.5 ± 10.7 years were enrolled. The anthropometric and biochemical parameters such as ADMA, FGF-23, albumin, prealbumin were assessed. Fat tissue mass among KTRs was 30.28 ± 9.73%, lean body mass 64.5 ± 14.8%. Overweight and obesity was presented by 65.2% of recipients. Albumin level was 38.54 ± 3.80 g/L, prealbumin 27.83 ± 7.30 mg/dL and were significantly lower than in the control (p < 0.05). Patients with ADMA > 0.66 µmol/L had a lower concentration of prealbumin, albumin and increased concentration of oxidized low density lipoprotein (oxLDL), high sensitive C-reactive protein (hsCRP) and FGF-23. FGF-23 was significantly higher in patients with higher hsCRP (p < 0.05). KTRs with elevated ADMA had a longer transplantation vintage, lower eGFR and higher albuminuria. Diabetes mellitus (DM) was associated with higher levels of ADMA and FGF-23. Even in stable KTRs a relationship between inflammatory state, nutritional status, graft function and endothelial dysfunction biomarkers was observed.

Coronary artery calcification progression and long-term cardiovascular outcomes in renal transplant recipients: an analysis by the joint model

Background

Compared with the general population, the risk of death is substantially higher in renal transplant recipients than in age- and sex-matched individuals in the general population. In the general population, coronary artery calcification (CAC) predicts all-cause and cardiovascular mortality. In this study we aimed to analyse these relationships in renal transplant recipients.

Methods

We examined 178 renal transplant patients in this prospective observational cohort study. We measured CAC with multidetector spiral computed tomography using the Agatston score at multiple time points. Overall, 411 scans were performed in 178 patients over an average 12.8 years follow-up. The clinical endpoint was a composite including all-cause death and non-fatal cardiovascular events. Data analysis was performed by the joint model.

Results

During a follow-up of 12.8 ± 2.4 years, coronary calcification progressed over time (P < 0.001) and the clinical endpoint occurred in 54 patients. In the analysis by the joint model, both the baseline CAC score and the CAC score progression were strongly associated with the incidence rate of the composite event [hazard ratio 1.261 (95% confidence interval 1.119–1.420), P = 0.0001].

Conclusions

CAC at baseline and coronary calcification progression robustly predict the risk of death and cardiovascular events in renal transplant recipients. These findings support the hypothesis that the link between the calcifying arteriopathy of renal transplant patients and clinical end points in these patients is causal in nature.

Height-adjusted lean body mass and its associations with physical activity and kidney function in pediatric kidney transplantation

BACKGROUND

Although LBM is positively associated with health outcomes, studies assessing determinants for the accrual of ht-LBM, such as physical activity, are limited. This study aimed to assess ht-LBM levels in pediatric kidney transplant recipients and test its association with baseline and contemporaneous variables, including physical activity.

METHODS

A retrospective cross-sectional review was performed on 46 pediatric kidney transplant recipients, and a longitudinal review was performed on a subset of recipients with serial post-transplant (n = 21) and pre/post-transplant (n = 11) ht-LBM measurements. Ht-LBM measurements were obtained using DXA scans.

RESULTS

This cohort was 16.0 (IQR 12.3, 17.7) years old, 56.5% male and 46 ± 45 months post-transplant with a mean ht-LBM of 15.1 ± 2.5 kg/m² . A median ht-LBM increase of 1.6 kg/m² (IQR - 0.1, 2.6 kg/m² ; p < .01) was observed, over 29.2 ± 12.0 months from the earliest post-transplant scan obtained at 46 ± 25 months post-transplant until the most recent post-transplant scan. A 1.7 ± 1.4 kg/m² (p < .01) increase was observed between pre- and post-transplant DXA scans which were taken at 12 ± 11 months pre-transplant and 13 ± 6 months post-transplant, respectively. In separate adjusted models, lower physical activity questionnaire scores (n = 17, beta = 1.55, p = .02), faster rate of estimated glomerular filtration rate decline (beta = 0.05, p < .048) adjusted for annualized change in BSA, and younger age at scan (beta = 0.32, p < .01) were each significant predictors of lower ht-LBM.

CONCLUSIONS

Physical activity and kidney function may influence ht-LBM in the pediatric kidney transplant population.

Mitral and Aortic Regurgitation in Patients Undergoing Kidney Transplantation: The Natural Course and Factors Associated With Progression

Background

Valve regurgitation can decrease with resolution of hemodynamic loads on the left ventricle (LV) after kidney transplantation (KT). We aimed to investigate the natural course of left-side valve regurgitation after KT and factors associated with progression.

Methods

Among patients who underwent KT in two tertiary centers, 430 (224 men, mean age 50 ± 13 years) were examined by echocardiography within 3 months before KT and between 6 and 36 months after KT. Mitral regurgitation (MR) and aortic regurgitation (AR) were graded according to the current guidelines. Regression was defined as a decrease in regurgitation by one or more steps, and progression was an increase in one or more steps after KT. Clinical and echocardiographic factors associated with progression of MR and AR were analyzed.

Results

Mild or greater MR was observed in 216 (50%) patients before KT, and mild or greater AR was observed in 99 (23%). During the follow-up period of 23.4 ± 9.9 months, most patients experienced regression or no change in regurgitation after KT, but 34 patients (7.9%) showed MR progression and 37 (8.6%) revealed AR progression. Patients who showed MR progression were more likely to receive a second KT, have mitral annular calcifications, and show a smaller decrease in LV end-systolic dimension. Patients who showed AR progression were more likely to have persistent hypertension after KT, aortic valve calcifications, and a smaller reduction of LV end-systolic dimension.

Conclusions

Risk factors for progression of MR after KT include a second KT, MAC and a smaller decrease in LV end-systolic dimension after KT. Risk factors for progression of AR include valve calcification, persistent hypertension and a smaller decrease in LV end-systolic dimension after KT. Further echocardiographic surveillance and risk factor management after KT are warranted in these patients.

Time-Varying Proteinuria and the Risk of Cardiovascular Disease and Graft Failure in Kidney Transplant Recipients

Introduction: Proteinuria is recognized as an independent risk factor for cardiovascular disease in kidney transplant recipients, but previous studies have not considered the impact of changes in urine protein over time. Research Question and Design: We used time-dependent, multivariable Cox proportional hazards models in this observational cohort study of adult kidney transplant recipients to evaluate whether proteinuria measured by dipstick on random spot urine samples starting from 1-month post-transplant was associated with the risk of major adverse cardiac events and graft loss. Results: A total of 144 major adverse cardiac events, defined as acute myocardial infarction, cerebrovascular accident, revascularization, or all-cause mortality, were observed in 1106 patients over 5728.7 person-years. Any level of proteinuria greater or equal to trace resulted in a two-fold increase in the risk of major adverse cardiac events (hazard ratio 2.00 [95% confidence interval 1.41, 2.84]). This relationship was not found to be dose-dependent (hazard ratios of 2.98, 1.76, 1.63, and 1.54 for trace, 1+, 2+, and 3+ urine protein, respectively). There was an increased risk of graft failure with greater urine protein concentration (hazard ratios 2.22, 2.85, 6.41, and 19.71 for trace, 1+, 2+, and 3+, respectively). Conclusion: Urine protein is associated with major adverse cardiac events and graft loss in kidney transplant recipients. The role of interventions to reduce proteinuria on decreasing the risk of adverse cardiovascular and graft outcomes in kidney transplant recipients requires further study.

Advanced Genomics-Based Approaches for Defining Allograft Rejection With Single Cell Resolution

Solid organ transplant recipients require long-term immunosuppression for prevention of rejection. Calcineurin inhibitor (CNI)-based immunosuppressive regimens have remained the primary means for immunosuppression for four decades now, yet little is known about their effects on graft resident and infiltrating immune cell populations. Similarly, the understanding of rejection biology under specific types of immunosuppression remains to be defined. Furthermore, development of innovative, rationally designed targeted therapeutics for mitigating or preventing rejection requires a fundamental understanding of the immunobiology that underlies the rejection process. The established use of microarray technologies in transplantation has provided great insight into gene transcripts associated with allograft rejection but does not characterize rejection on a single cell level. Therefore, the development of novel genomics tools, such as single cell sequencing techniques, combined with powerful bioinformatics approaches, has enabled characterization of immune processes at the single cell level. This can provide profound insights into the rejection process, including identification of resident and infiltrating cell transcriptomes, cell-cell interactions, and T cell receptor α/β repertoires. In this review, we discuss genomic analysis techniques, including microarray, bulk RNAseq (bulkSeq), single-cell RNAseq (scRNAseq), and spatial transcriptomic (ST) techniques, including considerations of their benefits and limitations. Further, other techniques, such as chromatin analysis via assay for transposase-accessible chromatin sequencing (ATACseq), bioinformatic regulatory network analyses, and protein-based approaches are also examined. Application of these tools will play a crucial role in redefining transplant rejection with single cell resolution and likely aid in the development of future immunomodulatory therapies in solid organ transplantation.

Role of hypertension in kidney transplant recipients

Cardiovascular events are one of the leading causes of mortality in kidney transplant recipients. Hypertension is the most common comorbidity accompanying chronic kidney disease, with prevalence remaining as high as 90% even after kidney transplantation. It is often poorly controlled. Abnormal blood pressure profiles, such as masked or white-coat hypertension, are also extremely common in these patients. The pathophysiology of blood pressure elevation in kidney transplant recipients is complex and includes transplantation-specific risk factors, which are added to the traditional or chronic kidney disease-related factors. Despite these observations, hypertension management has been an under-researched area in kidney transplantation. Thus, relevant evidence derives either from studies in the general population or from small trials in kidney transplant recipients. Based on the relevant guidelines in the general population, lifestyle modifications should probably be applied as the first step of hypertension management in kidney transplant recipients. The optimal pharmacological management of hypertension in kidney transplant recipients is also not clear. Dihydropyridine calcium channel blockers are commonly used as first line agents because of their lack of adverse effects on the kidney, while other antihypertensive drug classes are under-utilised due to fear of the possible haemodynamic consequences on renal function. This review summarizes the existing data on the pathophysiology, diagnosis, prognostic significance and management of hypertension in kidney transplantation.

Home-based exercise program improves normal Right Ventricle function in Renal Transplant Recipients

BACKGROUND

Right ventricular function is strongly associated with clinical outcomes in populations at high cardiovascular risk. Renal Transplant Recipients have multiple coexisting comorbidities potentially involved in the biventricular dysfunction including the right ventricular chamber. Speckle tracking echocardiography is recently used to investigate the normal function of this chamber. The study aims to verify whether global longitudinal strain carries clinical and prognosis implications in the renal transplant recipients during 1 year of regular unsupervised physical activity and compared to a control group.

METHODS

a group of 50 transplant recipients, aged 49.6±11.5 was submitted for 1 year to a moderate intensity of mixed exercise. All the subjects were followed by echocardiographic exam every 6 months, only 25 subjects with a high quality of image were investigated by 2D Speckle tracking strain analysis with the measurement calculated at T0, T6, and T12 months.

RESULTS

renal transplant recipients started with low values of right ventricle global longitudinal strain compared to health controls; it increased significantly (p<0.01) after 12 months of exercise, restoring the normal range.

CONCLUSIONS

moderate intensity of physical exercise, despite unsupervised, support a normal RV ventricular performance in renal transplant recipients. strain analysis contribute to plan a correct follow-up, with prognostic impact in these patients practicing physical exercise.

A pilot randomised controlled trial of a structured, home-based exercise programme on cardiovascular structure and function in kidney transplant recipients: the ECSERT study design and methods

BACKGROUND

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in kidney transplant recipients (KTRs). CVD risk scores underestimate risk in this population as CVD is driven by clustering of traditional and non-traditional risk factors, which lead to prognostic pathological changes in cardiovascular structure and function. While exercise may mitigate CVD in this population, evidence is limited, and physical activity levels and patient activation towards exercise and self-management are low. This pilot study will assess the feasibility of delivering a structured, home-based exercise intervention in a population of KTRs at increased cardiometabolic risk and evaluate the putative effects on cardiovascular structural and functional changes, cardiorespiratory fitness, quality of life, patient activation, healthcare utilisation and engagement with the prescribed exercise programme.

METHODS AND ANALYSIS

Fifty KTRs will be randomised 1:1 to: (1) the intervention; a 12week, home-based combined resistance and aerobic exercise intervention; or (2) the control; usual care. Intervention participants will have one introductory session for instruction and practice of the recommended exercises prior to receiving an exercise diary, dumbbells, resistance bands and access to instructional videos. The study will evaluate the feasibility of recruitment, randomisation, retention, assessment procedures and the intervention implementation. Outcomes, to be assessed prior to randomisation and postintervention, include: cardiac structure and function with stress perfusion cardiac MRI, cardiorespiratory fitness, physical function, blood biomarkers of cardiometabolic health, quality of life and patient activation. These data will be used to inform the power calculations for future definitive trials.

ETHICS AND DISSEMINATION

The protocol was reviewed and given favourable opinion by the East Midlands-Nottingham 2 Research Ethics Committee (reference: 19/EM/0209; 14 October 2019). Results will be published in peer-reviewed academic journals and will be disseminated to the patient and public community via social media, newsletter articles and presentations at conferences.

TRIAL REGISTRATION NUMBER

NCT04123951.

Obesity in Renal Transplantation

BACKGROUND

Data from the WHO show an increasing rate of overweight and obesity in general population in the last decades. This increase in obesity also affects population with end-stage renal disease (ESRD) and kidney transplant (KT) candidates.

SUMMARY

In this review, we focused on how obesity impacts on KT stages: access to KT and outcomes of KT candidates; how to reduce weight and its consequences; short and long-term outcomes in obese recipients and the impact of weight variations; and the implications of obesity in living donor KT. We searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials until November 30, 2020. We selected systematic reviews and meta-analyses and randomized clinical trials. When no such reports were found for a topic, observational studies were included in the assessment. Key Messages: Although obesity is a risk factor to present worst outcomes after KT, several studies have demonstrated a survival benefit compared to patients who continue on dialysis. There is a need for a public health campaign to raise awareness in KT candidates and to highlight the importance of self-care, increasing exercise, healthy diet, and weight loss.

Combined Liver Kidney Transplant in Adult Patient With Alagille Syndrome and Pulmonary Hypertension

In this article, we describe a case of a 33-year-old female with Alagille syndrome complicated by bilateral branch pulmonary artery stenosis resulting in moderate pulmonary hypertension, end-stage liver disease complicated by portal hypertension, and chronic renal disease who presented for combined liver-kidney transplant. Alagille syndrome is an autosomal dominant disease affecting the liver, heart, and kidneys. Multidisciplinary preoperative evaluation was performed with a team consisting of a congenital heart disease cardiologist, a cardiac anesthesiologist, a nephrologist, and a transplant surgeon. We describe Alagille syndrome and our intraoperative management. To our knowledge, this is the first description of a combined liver-kidney transplant in an adult patient with Alagille syndrome.

Metabolic syndrome-related dietary pattern and risk of mortality in kidney transplant recipients

BACKGROUND AND AIMS

Presence of the metabolic syndrome (MetS) importantly contributes to excess mortality in kidney transplant recipients (KTRs). However, it is unclear which dietary factors drive the adverse role of MetS in KTRs. We aimed to define a dietary pattern that maximally explained the variation in MetS components, and to investigate the association between this MetS-related dietary pattern (MetS-DP) and all-cause mortality in KTRs.

METHODS AND RESULTS

We included 429 adult KTRs who had a functioning graft ⩾1 year. A MetS-DP was constructed using habitual dietary intake derived from a 177-item food frequency questionnaire. We used reduced rank regression (RRR), and defined the six components of MetS (waist circumference, systolic blood pressure, diastolic blood pressure, serum triglycerides, HbA1c, and HDL cholesterol) as response variables and 48 food groups as predictor variables. We evaluated the association between the MetS-DP and all-cause mortality using multivariable Cox regression analysis. The MetS-DP was characterized by high intakes of processed meat and desserts, and low intakes of vegetables, tea, rice, fruits, milk, and meat substitutes. During a mean follow-up of 5.3 ± 1.2 years, 63 KTRs (14.7%) died. Compared to the lowest tertile of the Mets-DP score, those with the greatest adherence had a more than 3-fold higher risk of all-cause mortality (hazard ratio [HR] = 3.63; 95% confidence interval [CI], 1.70-7.74, P < 0.001), independent of potential confounders.

CONCLUSIONS

We identified a MetS-related dietary pattern which was independently associated with all-cause mortality in KTRs. The association between this dietary pattern and all-cause mortality was mediated by MetS. Clinical trial reg. no. NCT02811835.

Diabetes and Cardiovascular Risk in Renal Transplant Patients

End-stage kidney disease (ESKD) is a main public health problem, the prevalence of which is continuously increasing worldwide. Due to adverse effects of renal replacement therapies, kidney transplantation seems to be the optimal form of therapy with significantly improved survival, quality of life and diminished overall costs compared with dialysis. However, post-transplant patients frequently suffer from post-transplant diabetes mellitus (PTDM) which an important risk factor for cardiovascular and cardiovascular-related deaths after transplantation. The management of post-transplant diabetes resembles that of diabetes in the general population as it is based on strict glycemic control as well as screening and treatment of common complications. Lifestyle interventions accompanied by the tailoring of immunosuppressive regimen may be of key importance to mitigate PTDM-associated complications in kidney transplant patients. More transplant-specific approach can include the exchange of tacrolimus with an alternative immunosuppressant (cyclosporine or mammalian target of rapamycin (mTOR) inhibitor), the decrease or cessation of corticosteroid therapy and caution in the prescribing of diuretics since they are independently connected with post-transplant diabetes. Early identification of high-risk patients for cardiovascular diseases enables timely introduction of appropriate therapeutic strategy and results in higher survival rates for patients with a transplanted kidney.

Changes in left ventricular structure and function associated with renal transplantation: a systematic review and meta-analysis

Aims

This study aimed to examine if the cardiac changes associated with uraemic cardiomyopathy are reversed by renal transplantation.

Methods and results

MEDLINE, Embase, OpenGrey, and the Cochrane Library databases were searched from 1950 to March 2020. The primary outcome measure was left ventricular mass index. Secondary outcome measures included left ventricular dimensions and measures of diastolic and systolic function. Studies were included if they used any imaging modality both before and after successful renal transplantation. Data were analysed through meta‐analysis approaches. Weight of evidence was assessed through the Grading of Recommendations Assessment, Development and Evaluation system. Twenty‐three studies used echocardiography, and three used cardiac magnetic resonance imaging as their imaging modality. The methodological quality of the evidence was generally poor. Four studies followed up control groups, two using cardiac magnetic resonance imaging and two using echocardiography. Meta‐analysis of these studies indicated that there was no difference in left ventricular mass index between groups following transplantation {standardized mean difference −0.07 [95% confidence interval (CI) −0.41 to 0.26]; P = 0.67}. There was also no difference observed in left ventricular ejection fraction [mean difference 0.39% (95% CI −4.09% to 4.87%); P = 0.86] or left ventricular end‐diastolic volume [standardized mean difference −0.24 (95% CI −0.94 to 0.45); P = 0.49]. Inconsistent reporting of changes in diastolic dysfunction did not allow for any meaningful analysis or interpretation.

Conclusions

The evidence does not support the notion that uraemic cardiomyopathy is reversible by renal transplantation. However, the evidence is limited by methodological weaknesses, which should be considered when interpreting these findings.

Kidney-Pancreas Transplant Recipients Experience Higher Risk of Complications Compared to the General Population after Undergoing Coronary Artery Bypass Grafting

This retrospective analysis aims to identify differences in surgical outcomes between pancreas and/or kidney transplant recipients compared with the general population undergoing coronary artery bypass grafting (CABG). Using Nationwide Inpatient Sample (NIS) data from 2005 to 2014, patients who underwent CABG were stratified by either no history of transplant, or history of pancreas and/or kidney transplant. Multivariate analysis was used to calculate odds ratio (OR) to evaluate in-hospital mortality, morbidity, length of stay (LOS), and total hospital charge in all centers. The analysis was performed for both nonemergency and emergency CABG. Overall, 2,678 KTx (kidney transplant alone), 184 PTx (pancreas transplant alone), 254 KPTx (kidney-pancreas transplant recipients), and 1,796,186 Non-Tx (nontransplant) met inclusion criteria. KPTx experienced higher complication rates compared with Non-Tx (78.3 vs. 47.8%, p  < 0.01). Those with PTx incurred greater total hospital charge and LOS. On weighted multivariate analysis, KPTx was associated with an increased risk for developing any complication following CABG (OR 3.512, p  < 0.01) and emergency CABG (3.707, p  < 0.01). This risk was even higher at transplant centers (CABG OR 4.302, p  < 0.01; emergency CABG OR 10.072, p  < 0.001). KTx was associated with increased in-hospital mortality following emergency CABG, while PTx and KPTx had no mortality to analyze. KPTx experienced a significantly higher risk of complications compared with the general population after undergoing CABG, in both transplant and nontransplant centers. These outcomes should be considered when providing perioperative care.

Cardiac evaluation of the kidney or liver transplant candidate

PURPOSE OF REVIEW

As the field of transplant has advanced, cardiac events have become the leading cause of morbidity and mortality after liver and kidney transplantation ahead of graft failure and infection. This trend has been bolstered by the transplantation of older and sicker patients who have a higher burden of cardiovascular risk factors, accentuating the need to determine which patients should undergo more extensive cardiac evaluation prior to transplantation.

RECENT FINDINGS

Computed tomography coronary angiography with or without coronary artery calcium scoring is now preferred over stress imaging in most transplant candidates for assessment of coronary artery disease. Assessment of cardiac structure and function using transthoracic echocardiography with tissue doppler imaging and strain imaging is recommended, particularly in liver transplant candidates who are at high risk of cirrhotic cardiomyopathy, for which new diagnostic criteria were recently published in 2019.

SUMMARY

Cardiac evaluation of liver and kidney transplant candidates requires a global assessment for both short and long-term risk for cardiac events. Imaging of cardiac structure and function using transthoracic echocardiography with tissue doppler imaging and strain imaging is recommended. Risk stratification should consider both the anatomic and functional consequences of coronary artery disease in transplant candidates.

VIDEO ABSTRACT

http://links.lww.com/MOT/A27.

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.

Physical activity and risk of cardiovascular events and all-cause mortality among kidney transplant recipients

BACKGROUND

Insufficient physical activity (PA) may increase the risk of all-cause mortality and cardiovascular disease (CVD) morbidity and mortality among kidney transplant recipients (KTRs), but limited research is available. We examine the relationship between PA and the development of CVD events, CVD death and all-cause mortality among KTRs.

METHODS

A total of 3050 KTRs enrolled in an international homocysteine-lowering randomized controlled trial were examined (38% female; mean age 51.8 ± 9.4 years; 75% white; 20% with prevalent CVD). PA was measured at baseline using a modified Yale Physical Activity Survey, divided into tertiles (T1, T2 and T3) from lowest to highest PA. Kaplan-Meier survival curves were used to graph the risk of events; Cox proportional hazards regression models examined the association of baseline PA levels with CVD events (e.g. stroke, myocardial infarction), CVD mortality and all-cause mortality over time.

RESULTS

Participants were followed up to 2500 days (mean 3.7 ± 1.6 years). The cohort experienced 426 CVD events and 357 deaths. Fully adjusted models revealed that, compared to the lowest tertile of PA, the highest tertile experienced a significantly lower risk of CVD events {hazard ratio [HR] 0.76 [95% confidence interval (CI) 0.59-0.98]}, CVD mortality [HR 0.58 (95% CI 0.35-0.96)] and all-cause mortality [HR 0.76 (95% CI 0.59-0.98)]. Results were similar in unadjusted models.

CONCLUSIONS

PA was associated with a reduced risk of CVD events and all-cause mortality among KTRs. These observed associations in a large, international sample, even when controlling for traditional CVD risk factors, indicate the potential importance of PA in reducing CVD and death among KTRs.

To compare intraoperative goal directed fluid therapy by trans-oesophageal Doppler vis-à-vis FloTrac™ in patients undergoing living related renal transplantation-a prospective randomised controlled study

Background:

Optimal intra-operative fluid therapy in renal transplantation (RT) is essential to ensure adequate graft function while preventing fluid overload related complications. This RCT was to compare the intraoperative goal directed fluid therapy (GDFT) based either on corrected flow time (CFT), measured by trans oesophageal Doppler (TED) or on the stroke volume variation (SVV), by FloTrac in patients undergoing living donor RT.

Methods:

This prospective, randomised controlled trial (RCT) was done on 60 end stage renal disease (ESRD) patients, American Society of Anaesthesiologists(ASA) grade III–IV, age 18 to 65 years of either sex, scheduled for living donor RT under general anaesthesia. They were randomly divided into two groups: TED group (n = 30) and FloTrac™ group (n = 30) and administered GDFT, based upon CFT (TED) and SVV (FloTrac™). The primary outcome was to compare the total fluid and number of fluid boluses administered intraoperatively, while the secondary outcomes were to compare any postoperative complications due to fluid overload and allograft function, assessed by serial serum creatinine levels up to 90 days postoperatively.

Results:

The mean total intra-operative fluid [3991.67 ± 856.32 vs. 3543.33 ± 1131.35, P = 0.089] and the amount of fluid administered per kg body weight per hour [13.32 ± 4.67 vs. 11.82 ± 4.76, P = 0.222] were lesser in the FloTrac compared to TED group, though not statistically significant. However, the postoperative incidence of allograft dysfunction, including rejection (P = 0.743) and acute tubular necrosis (ATN) (P = 0.999), and other complications (P = 0.643) were comparable.

Conclusions:

Both TED and FloTrac devices can be used effectively to guide GDFT in RT, However, lesser total fluid was required in the FloTrac group, which may lead to a lesser number of fluid-related postoperative complications.

The care of kidney transplant recipients during a global pandemic: Challenges and strategies for success

The global pandemic of severe acute respiratory coronavirus 2 (SARS-CoV-2), which causes the novel beta coronavirus 2019 disease (COVID-19), has become an unprecedented medical, economic, and psychosocial crisis. The pandemic and its management strategies have resulted in immense challenges for health systems, not only in caring for those with COVID-19 but also in the ongoing management of chronic medical conditions. Kidney transplant recipients present a unique challenge given their need for ongoing monitoring and management as well as their higher risk of COVID-19 infection. In the absence of clear guidelines, it is unclear how to best provide routine care to this unique patient population during the pandemic. Rigorous medical and psychosocial patient-centered risk stratification strategies are needed to avoid adverse outcomes in stable solid organ transplant recipients. This review will focus on the challenges faced by kidney transplant recipients and health care providers and provides strategies to address these issues.

A Pilot Randomized Controlled Trial Using SystemCHANGE™ Approach to Increase Physical Activity in Older Kidney Transplant Recipients

BACKGROUND

Cardiovascular disease is the leading cause of death in kidney transplant recipients. Physical activity after transplant is the most modifiable nonpharmacological factor for improving cardiovascular outcomes. Few studies have tested walking interventions to enhance daily steps and health outcomes in older kidney recipients.

METHODS

Using a pilot feasibility randomized clinical trial design, we tested the feasibility and efficacy of a 6-month SystemCHANGE™ (Change Habits by Applying New Goals and Experience) + Activity Tracker intervention for recruitment, retention, daily steps, and health outcomes (blood pressure, heart rate, body mass index, waist circumference, and physical function). The SystemCHANGE™ + Activity Tracker intervention taught participants to use a multicomponent intervention that connects person-centered systems solutions combined with visual feedback from a mobile activity tracker to achieve daily step goals.

RESULTS

Fifty-three participants (mean age 65 years, 66% male, and 57% white) participated with 27 in the intervention and 26 in the control group. The study protocol was feasible to deliver with high adherence to the protocol in both groups. The intervention group increased daily steps at 3 months (mean difference, 608; standard error = 283, P = .03) compared to the control group. The secondary outcome of heart rate decreased for the intervention group (baseline [mean] 74.4+ 10.8 [standard deviation, SD;] vs 6 months [mean] 67.6+ 11.3 [SD]; P = .002) compared to the control group (baseline [mean] 70.67+ 10.4 [SD]; vs 6 months [mean] 70.2 + 11.1 [SD]; P = .83).

CONCLUSIONS

SystemCHANGE™ + Activity Tracker intervention appears to be feasible and efficacious for increasing daily steps in older kidney recipients.

Prevalence of primary aldosteronism in hypertensive kidney transplant recipients: A cross-sectional study

Due to high prevalence of primary aldosteronism (PA) in the general hypertensive population, and its association with worse cardiovascular and renal outcomes, the 2016 Endocrine Society Guidelines explicitly recognize PA as a major public health issue requiring urgent attention. Its prevalence in hypertensive kidney transplant recipients (KTRs) is unknown. In this cross-sectional study, we screened KTRs with hypertension who were on ≥4 antihypertensive medications, on 3 antihypertensive medications with BP ≥ 140/90, and on potassium supplements, or were hypokalemic. 172 of 280 eligible patients successfully completed the testing. A positive screen for PA defined by an aldosterone-to-renin ratio of ≥20 and a plasma aldosterone concentration of >15 ng/dL yielded a prevalence of 15.7%. Potassium supplement requirement (52% vs 27%, P = .01) and hypokalemia (25.9% vs 4.8%, P < .01) were more common in patients who screened positive compared with those who screened negative. 67% of patients who screened positive were on potassium supplements and/or were hypokalemic. Our study is the first to systematically explore the prevalence of PA among the hypertensive KTR population, which has inherently high cardiovascular risk. Further studies are needed to determine the cardiovascular and renal risk attributable to PA, and define optimal therapy for KTRs with PA.

Long-Term Changes in Sleep Disordered Breathing in Renal Transplant Patients: Relevance of the BMI

Sleep disordered breathing (SDB), as defined by the Apnea Hypopnea Index (AHI), is a highly prevalent disturbance in end stage kidney disease. SDB improves early on after renal transplantation but long-term changes in AHI in these patients have not been studied. We studied the long-term changes in AHI in a series of 221 renal transplant patients (mean age: 47 ± 12 years; 70% males) over a median follow up of 35 months. Data analysis was made by the generalized estimating equations method (GEE). On longitudinal observation, the median AHI rose from 1.8 (Interquartile range: 0.6-5.0) to 2.9 (IQR: 1.0-6.6) and to 3.6 (IQR: 1.7-10.4) at the second and third visit, respectively (p = 0.009 by the GEE model and the proportion of patients with moderate to severe SDB rose from 8% to 20%. Longitudinal changes in minimum oxygen saturation (minSaO2) mirrored those in the AHI. In adjusted analyses, repeated measurements of BMI (p < 0.009) emerged as the strongest independent longitudinal correlate of AHI and MinSaO2. The AHI worsens over time in renal transplant patients and longitudinal changes of this biomarker are directly related to simultaneous changes in BMI. Overweight/obesity, a potentially modifiable risk factor, is an important factor underlying the risk of SDB in this population.

Calcium and phosphate levels after kidney transplantation and long-term patient and allograft survival

Background

Non-traditional cardiovascular risk factors, including calcium and phosphate derangement, may play a role in mortality in renal transplant. The data regarding this effect are conflicting. Our aim was to assess the impact of calcium and phosphate derangements in the first 90 days post-transplant on allograft and recipient outcomes.

Methods

We performed a retrospective cohort review of all-adult, first renal transplants in the Republic of Ireland between 1999 and 2015. We divided patients into tertiles based on serum phosphate and calcium levels post-transplant. We assessed their effect on death-censored graft survival and all-cause mortality. We used Stata for statistical analysis and did survival analysis and spline curves to assess the association.

Results

We included 1525 renal transplant recipients. Of the total, 86.3% had hypophosphataemia and 36.1% hypercalcaemia. Patients in the lowest phosphate tertile were younger, more likely female, had lower weight, more time on dialysis, received a kidney from a younger donor, had less delayed graft function and better transplant function compared with other tertiles. Patients in the highest calcium tertile were younger, more likely male, had higher body mass index, more time on dialysis and better transplant function. Adjusting for differences between groups, we were unable to show any difference in death-censored graft failure [phosphate = 1.14, 95% confidence interval (CI) 0.92–1.41; calcium = 0.98, 95% CI 0.80–1.20] or all-cause mortality (phosphate = 1.10, 95% CI 0.91–1.32; calcium = 0.96, 95% CI 0.81–1.13) based on tertiles of calcium or phosphate in the initial 90 days.

Conclusions

Hypophosphataemia and hypercalcaemia are common occurrences post-kidney transplant. We have identified different risk factors for these metabolic derangements. The calcium and phosphate levels exhibit no independent association with death-censored graft failure and mortality.

Postcontrast Acute Kidney Injury after Peripheral Vascular Interventions in Kidney Transplant Recipients

BACKGROUND

Postcontrast acute kidney injury (PC-AKI) is a feared complication of peripheral vascular interventions (PVIs), associated with increased mortality. Whether kidney transplant recipients (KTRs) are at increased risk of PC-AKI after PVI is unknown. This study analyzes the perioperative outcomes of KTR following PVI, with emphasis on the incidence and risk factors for PC-AKI.

METHODS

The Vascular Quality Initiative files for PVI (2010-2018) were reviewed. Patients on dialysis were excluded. PC-AKI was defined by Vascular Quality Initiative as creatinine increase ≥0.5 mg/dL or new dialysis requirement. Characteristics of KTR and patients without kidney transplant were compared, and propensity score matching used to control for differences in baseline features. Multivariable logistic regression was used to define risk factors for PC-AKI, and survival was compared using Kaplan-Meier analysis.

RESULTS

A total of 58,014 procedures were analyzed, including 641 (1%) procedures for KTR. The incidence of PC-AKI in KTR was 2.8% compared with 0.9% in patients without kidney transplants. Baseline warfarin use (odds ratio [OR] = 4.7) and poor allograft function (OR = 4.0) were significantly associated with increased risk for PC-AKI in KTR. Compared with a matched group of patients without kidney transplant, KTR had similar risk of PC-AKI and were more likely to develop postop myocardial infarction (OR = 4.3) but had lower in-hospital mortality (OR = 0.22).

CONCLUSIONS

The incidence of PC-AKI in KTR is higher than the overall population undergoing PVI but is not elevated compared with propensity-matched patients without kidney transplant. PVI for peripheral artery disease in KTR is safe and associated with acceptable perioperative and long-term survival.

Bioelectrical impedance vector analysis (BIVA) in renal transplant recipients during an unsupervised physical exercise program

BACKGROUND

Muscle weakness, incorrect body water distribution and reduced exercise tolerance are the main characteristics found in renal transplant recipients after surgical treatment. Regular physical supervised exercise programs, at moderate intensity, have been promoted to contrast these aspects, while few data are available for long-term unsupervised mixed exercise plans. Bioelectrical impedance vector analysis (BIVA) provides a semi-quantitative evaluation of body cell mass and body water. This study aims to approach the role of the BIVA analysis in the follow-up of Renal Transplant Group (RTG) and analyze the impact of unsupervised exercise program.

METHODS

Thirteen male RTG and ten healthy subjects, adherent to a tailored exercise program, at moderate intensity and prescribed in an unsupervised way, have been followed up for one year. Every six months all the subjects have been submitted to the ergometric test, echocardiographic exam and an analysis of body composition by bioimpedance. They were compared to a healthy control group (HG).

RESULTS

A significant reduction of the BMI was observed at the end of the study in the RTG group (T0 24.8±3.2, T12 24.2±3.2 kg/m2; P<0.05). BIVA has shown a lower right quadrant for RTG. All echocardiographic parameters were in a normal range, and no differences were found over time.

CONCLUSIONS

Unsupervised tailored and mixed exercise intervention reduces some cardiovascular risks factors. However, it does not modify the frailty of RTG. BIVA analysis seems to have appropriate sensitivity to highlight this aspect.