Risk factors for cardiovascular disease in renal transplant recipients and strategies to minimize risk

Left ventricular remodeling and its association with mineral and bone disorder in kidney transplant recipients

BACKGROUND

The assessment of left ventricular (LV) remodeling and its association with mineral and bone disorder (MBD) in kidney transplant recipients (KTRs) have not been systematically studied. We aimed to evaluate LV remodeling changes one year after kidney transplantation (KT) and identify their influencing factors.

METHODS

Ninety-five KTRs (68 males; ages 40.2 ± 10.8 years) were followed before and one year after KT. Traditional risk factors and bone metabolism indicators were assessed. Left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF) and left ventricular diastolic dysfunction (LVDD) were measured using two-dimensional transthoracic echocardiography. The relationship between MBD and LV remodeling and the factors influencing LV remodeling were analyzed.

RESULTS

One year after KT, MBD was partially improved, mainly characterized by hypercalcemia, hypophosphatemia, hyperparathyroidism, 25-(OH) vitamin D deficiency, elevated bone turnover markers, and bone loss. LVMI, the prevalence of left ventricular hypertrophy (LVH), and the prevalence of LVDD decreased, while LVEF increased. LVH was positively associated with postoperative intact parathyroid hormone (iPTH) and iPTH nonnormalization. △LVMI was positively associated with preoperative type-I collagen N-terminal peptide and postoperative iPTH. LVEF was negatively associated with postoperative phosphorous. △LVEF was negatively associated with postoperative iPTH. LVDD was positively associated with postoperative lumbar spine osteoporosis. Preoperative LVMI was negatively associated with △LVMI and positively associated with △LVEF. Advanced age, increased BMI, diabetes, longer dialysis time, lower albumin level, and higher total cholesterol and low-density lipoprotein levels were associated with LV remodeling.

CONCLUSIONS

LV remodeling partially improved after KT, showing a close relationship with MBD.

Impact of Immunosenescence in Older Kidney Transplant Recipients: Associated Clinical Outcomes and Possible Risk Stratification for Immunosuppression Reduction

The number of older individuals receiving a kidney transplant as replacement therapy has significantly increased in the past decades and this increase is expected to continue. Older patients have a lower rate of acute rejection but an increased incidence of death with a functioning graft. Several factors, including an increased incidence of infections, post-transplant malignancy and cardiovascular comorbidity and mortality, contribute to this increased risk. Notwithstanding, kidney transplantation is still the best form of kidney replacement therapy in all patients with chronic kidney disease, including in older individuals. The best form of immunosuppression and the optimal dose of these medications in older recipients remains a topic of discussion. Pharmacological studies have usually excluded older patients and when included, patients were highly selected and their numbers insignificant to draw a reasonable conclusion. The reduced incidence of acute rejection in older recipients has largely been attributed to immunosenescence. Immunosenescence refers to the aging of the innate and adaptive immunity, accumulating in phenotypic and functional changes. These changes influences the response of the immune system to new challenges. In older individuals, immunosenescence is associated with increased susceptibility to infectious pathogens, a decreased response after vaccinations, increased risk of malignancies and cardiovascular morbidity and mortality. Chronic kidney disease is associated with premature immunosenescent changes, and these are independent of aging. The immunosenescent state is associated with low-grade sterile inflammation termed inflammaging. This chronic low-grade inflammation triggers a compensatory immunosuppressive state to avoid further tissue damage, leaving older individuals with chronic kidney disease in an immune-impaired state before kidney transplantation. Immunosuppression after transplantation may further enhance progression of this immunosenescent state. This review covers the role of immunosenescence in older kidney transplant recipients and it details present knowledge of the changes in chronic kidney disease and after transplantation. The impact of immunosuppression on the progression and complications of an immunosenescent state are discussed, and the future direction of a possible clinical implementation of immunosenescence to individualize/reduce immunosuppression in older recipients is laid out.

Risk factors and current state of therapy for anemia after kidney transplantation

Post-transplant anemia is one of the most common complications in kidney transplant recipients, severely affecting patient prognosis and quality of life, and is an independent predictor of graft kidney loss and patient mortality. However, our clinical understanding and the attention given to post-transplant anemia are currently insufficient. This paper reviews the current status, risk factors, and therapeutic progress in anemia after transplantation in kidney transplant recipients. We recommend that clinical staff pay attention to anemia and its complications in kidney transplant recipients and intervene early for anemia.

Circulating Omentin-1, Sustained Inflammation and Hyperphosphatemia at the Interface of Subclinical Atherosclerosis in Chronic Kidney Disease Patients on Chronic Renal Replacement Therapy

Background and Objectives: Subclinical atherosclerosis, reflected by abnormal carotid intima–media thickness (cIMT), is pervasive among chronic kidney disease patients on chronic renal replacement therapy (RRT), being mostly influenced by uremia-related rather than traditional risk factors. Materials and Methods: In this pilot study, we measured circulating levels of Omentin-1, a recently discovered adipokine with strong anti-atherogenic properties, in a heterogeneous cohort of 77 asymptomatic RRT individuals (40 chronic kidney transplant recipients, Ktx; and 37 chronic hemodialysis patients, HD) and in 30 age-matched controls. Results: Omentin-1 was increased in RRT individuals as compared with controls (p = 0.03). When stratifying for renal replacement modality, we found Ktx patients to have significantly lower Omentin-1 than HD patients (p = 0.01). Lower Omentin-1 levels were also found among RRT individuals with pathological cIMT (168.7 [51.1–457.8] vs. 474.9 [197.2–1432.1]; p = 0.004). Our multivariate correlations analysis revealed Omentin-1 as the most robust independent predictor of carotid atherosclerosis (β-0.687; p = 0.03), even more than total cholesterol, diastolic BP and age, and this adipokine was at the crossroad of a complex interplay with sustained inflammation (high CRP and ferritin) and hyperphosphatemia in predicting higher cIMT values. Conclusion: The findings reported extend to renal patients with advanced disease, with the possible involvement of Omentin-1 in the pathogenesis of atherosclerosis. This may set the stage for future interventional studies of Omentin-1 replacement to retard atherosclerosis progression, as it is currently being investigated in other disease settings.

New Approaches to Cardiovascular Disease and Its Management in Kidney Transplant Recipients

Cardiovascular events, including ischemic heart disease, heart failure, and arrhythmia, are common complications after kidney transplantation and continue to be leading causes of graft loss. Kidney transplant recipients have both traditional and transplant-specific risk factors for cardiovascular disease. In the general population, modification of cardiovascular risk factors is the best strategy to reduce cardiovascular events; however, studies evaluating the impact of risk modification strategies on cardiovascular outcomes among kidney transplant recipients are limited. Furthermore, there is only minimal guidance on appropriate cardiovascular screening and monitoring in this unique patient population. This review focuses on the limited scientific evidence that addresses cardiovascular events in kidney transplant recipients. Additionally, we focus on clinical management of specific cardiovascular entities that are more prevalent among kidney transplant recipients (ie, pulmonary hypertension, valvular diseases, diastolic dysfunction) and the use of newer evolving drug classes for treatment of heart failure within this cohort of patients. We note that there are no consensus documents describing optimal diagnostic, monitoring, or management strategies to reduce cardiovascular events after kidney transplantation; however, we outline quality initiatives and research recommendations for the assessment and management of cardiovascular-specific risk factors that could improve outcomes.

Rationale for Surrogate Endpoints and Conditional Marketing Authorization of New Therapies for Kidney Transplantation

Conditional marketing authorization (CMA) facilitates timely access to new drugs for illnesses with unmet clinical needs, such as late graft failure after kidney transplantation. Late graft failure remains a serious, burdensome, and life-threatening condition for recipients. This article has been developed from content prepared by members of a working group within the European Society for Organ Transplantation (ESOT) for a Broad Scientific Advice request, submitted by ESOT to the European Medicines Agency (EMA), and reviewed by the EMA in 2020. The article presents the rationale for using surrogate endpoints in clinical trials aiming at improving late graft failure rates, to enable novel kidney transplantation therapies to be considered for CMA and improve access to medicines. The paper also provides background data to illustrate the relationship between primary and surrogate endpoints. Developing surrogate endpoints and a CMA strategy could be particularly beneficial for studies where the use of primary endpoints would yield insufficient statistical power or insufficient indication of long-term benefit following transplantation.

Surrogate Endpoints for Late Kidney Transplantation Failure

In kidney transplant recipients, late graft failure is often multifactorial. In addition, primary endpoints in kidney transplantation studies seek to demonstrate the short-term efficacy and safety of clinical interventions. Although such endpoints might demonstrate short-term improvement in specific aspects of graft function or incidence of rejection, such findings do not automatically translate into meaningful long-term graft survival benefits. Combining many factors into a well-validated model is therefore more likely to predict long-term outcome and better reflect the complexity of late graft failure than using single endpoints. If conditional marketing authorization could be considered for therapies that aim to improve long-term outcomes following kidney transplantation, then the surrogate endpoint for graft failure in clinical trial settings needs clearer definition. This Consensus Report considers the potential benefits and drawbacks of several candidate surrogate endpoints (including estimated glomerular filtration rate, proteinuria, histological lesions, and donor-specific anti-human leukocyte antigen antibodies) and composite scoring systems. The content was created from information prepared by a working group within the European Society for Organ Transplantation (ESOT). The group submitted a Broad Scientific Advice request to the European Medicines Agency (EMA), June 2020: the request focused on clinical trial design and endpoints in kidney transplantation. Following discussion and refinement, the EMA made final recommendations to ESOT in December 2020 regarding the potential to use surrogate endpoints in clinical studies that aim to improving late graft failure.

Influence of Belatacept- vs. CNI-Based Immunosuppression on Vascular Stiffness and Body Composition

Background: Arterial stiffness and phase angle (PhA) have gained importance as a diagnostic and prognostic parameter in the management of cardiovascular disease. There are few studies regarding the differences in arterial stiffness and body composition between renal transplant recipients (RTRs) receiving belatacept (BELA) vs. calcineurin inhibitors (CNI). Therefore, we investigated the differences in arterial stiffness and body composition between RTRs treated with different immunosuppressants, including BELA. Methods: In total, 325 RTRs were enrolled in the study (mean age 52.2 years, M −62.7%). Arterial stiffness was determined with an automated oscillometric device. All body composition parameters were assessed, based on bioelectrical impedance analysis (BIA), and laboratory parameters were obtained from the medical files of the patients. Results: We did not detect any significant difference in terms of arterial stiffness and PhA in RTRs undergoing different immunosuppressive regimens, based on CsA, Tac, or BELA. Age was an essential risk factor for greater arterial stiffness. The PhA was associated with age, BMI, time of dialysis before transplantation, and kidney graft function. Conclusion: No significant differences in arterial stiffness and PhA were observed in RTRs under different immunosuppressive regimens. While our data provide additional evidence for arterial stiffness and PhA in RTRs, more research is needed to fully explore these cardiovascular risk factors and the impact of different immunosuppressive regimens.

Follow-Up of Blood Pressure, Arterial Stiffness, and GFR in Pediatric Kidney Transplant Recipients

Pediatric renal transplant recipients (RTx) were studied for longitudinal changes in blood pressure (BP), arterial stiffness by pulse wave velocity (PWV), and graft function.

Patients and Methods: 52 RTx patients (22 males) were included; office BP (OBP) and 24 h BP monitoring (ABPM) as well as PWV were assessed together with glycemic and lipid parameters and glomerular filtration rate (GFR) at 2.4[1.0–4.7] (T₁) and 9.3[6.3–11.8] years (T₂) after transplantation (median [range]).

Results: Hypertension was present in 67 and 75% of patients at T₁ and T₂, respectively. Controlled hypertension was documented in 37 and 44% by OBP and 40 and 43% by ABPM. Nocturnal hypertension was present in 35 and 30% at T₁ and T₂; 24 and 32% of the patients had masked hypertension, while white coat hypertension was present in 16 and 21% at T₁ and T₂, respectively. Blood pressure by ABPM correlated significantly with GFR and PWV at T₂, while PWV also correlated significantly with T₂ cholesterol levels. Patients with uncontrolled hypertension by ABPM had a significant decrease in GFR, although not significant with OBP. Anemia and increased HOMAi were present in ~20% of patients at T₁ and T₂.

Conclusion: Pediatric RTx patients harbor risk factors that may affect their cardiovascular health. While we were unable to predict the evolution of renal function based on PWV and ABPM at T₁, these risk factors correlated closely with GFR at follow-up suggesting that control of hypertension may have an impact on the evolution of GFR.

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.

Arterial Stiffness in Renal Transplant Recipients: 5-Year Follow-up

BACKGROUND

Chronic kidney disease is a risk factor for cardiovascular diseases. After renal transplant, some traditional and chronic kidney disease-specific risk factors vanish, but new risk factors emerge. This retrospective study aimed to define the long-term impact of renal transplant and diabetes mellitus on arterial stiffness, evaluated by measuring pulse wave velocity (PWV) and augmentation index (AI) and on myocardial perfusion, evaluated by subendocardial viability ratio (SEVR).

METHODS

PWV, AI, and SEVR were evaluated noninvasively by applanation tonometry using SphygmoCor in the first 4 weeks after kidney transplant and 4 to 5 years thereafter.

RESULTS

A total of 48 graft recipients (18 women, 30 men; mean ± standard deviation age, 47.9 ± 11.8 years) were included. The follow-up period was 57.4 ± 8.0 months. PWV did not change significantly during the follow-up period (9.1 ± 1.8m/s and 8.7 ± 1.8m/s, respectively; P = .137). In the subgroup of patients without diabetes mellitus, we observed a trend of PWV reduction, whereas in the subgroup of patients with diabetes we observed the trend of PWV increase. The duration of smoking before transplant correlated significantly with PWV (P = .012). AI in the whole group increased significantly during the study period (from 18.3% ±10.3% to 25.9% ±9.4%; P < .01) as well as SEVR (from 134.9 ± 23.1 to 155.4 ± 28.6; P = .001).

CONCLUSIONS

PWV, reflecting the central vessel stiffness, did not change significantly in the whole group during the follow-up period. The AI, which indicates systemic stiffness, increased significantly within 5 years after transplant, indicating the progression of vascular processes of elastic and muscular arteries. Significant increases in the SEVR values in both diabetics and nondiabetics indicate the long-term favorable effect of kidney transplant on myocardial perfusion.

Statin use and incident cardiovascular events in renal transplant recipients

BACKGROUND

Statins achieve potent LDL lowering in the general population leading to a significant cardiovascular (CV) risk reduction. In renal transplant recipients (RTR) statins are included in treatment guidelines, however, conclusive evidence of improved cardiovascular outcomes has not been uniformly provided and concerns have been raised about simultaneous use of statins and the immunosuppressant cyclosporine. This study aimed to elucidate the effect of statins on a compound CV endpoint, comprised of ischaemic CV events and CV mortality in RTR, with subgroup analysis focussing on cyclosporine users.

METHOD

622 included RTR (follow-up 5.4 years) were matched based on propensity scores and dichotomized by statin use. Survival analysis was conducted.

RESULTS

Cox regression showed that statin use was not significantly associated with the compound CV endpoint in a fully adjusted model (HR = 0.81, 95% CI = 0.53-1.24, P = .33). Subgroup analyses in RTR using cyclosporine revealed a strong positive association of statin use with the CV compound outcome in a fully adjusted model (HR = 6.60, 95% CI 1.75-24.9, P = .005). Furthermore, statin use was positively correlated with cyclosporine trough levels (correlation coefficient 0.11, P = .04).

CONCLUSION

In conclusion, statin use does not significantly decrease incident CV events in an overall RTR cohort, but is independently associated with CV-specific mortality and events in cyclosporine using RTR, possibly due to a bilateral pharmacological interaction.

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.

Breathlessness and Respiratory Disability After Kidney Transplantation

BACKGROUND

Dyspnea is a common symptom in patients with end-stage kidney disease being treated with dialysis. This study aimed to ascertain the level of respiratory disability in patients after kidney transplantation through assessing a cohort of kidney allograft recipients for respiratory compromise and thereby identifying a potential target for therapeutic intervention.

METHODS

Kidney transplant recipients who were under active observation in a single tertiary referral center were invited to take part in this prevalence study at the time of clinic follow-up. All patients agreed to take part in the study, which involved completing a Medical Research Council (MRC) dyspnea scale, completing the St George's Respiratory Questionnaire, and performing basic spirometry. An MRC score of ≥2 and/or a forced expiratory volume in 1 second <90% predicted prompted formal clinical assessment by a respiratory physician.

RESULTS

This study enrolled 103 patients; 35% of all patients reported breathlessness, and 56% of all patients warranted formal respiratory medicine review. After completion of their investigations, 33 patients were found to have an underlying condition accounting for their symptoms.

CONCLUSION

Our study highlights the issues of respiratory disability and breathlessness in patients who have undergone kidney transplantation. Although extensive cardiologic evaluation is performed routinely and can rule out many causes of dyspnea, respiratory assessment is not a preoperative prerequisite. This study could suggest that a formal pulmonological evaluation and basic spirometry should be part of the pretransplant evaluation of the kidney transplant recipient.

Dietary Nutrients and Cardiovascular Risk Factors among Renal Transplant Recipients

Cardiovascular disease (CVD) is the leading cause of mortality in post-renal transplant recipients (RTRs). Adequate nutrient intake is a protective factor for CVD. We examined the associations of macronutrients and micronutrients with traditional and nontraditional CVD risk factors. Conducted from September 2016 to June 2018, this cross-sectional study included 106 RTRs aged ≥18 years with a functioning allograft. Dietary intake data from 3-day dietary records were collected. Nutrient intake adequacy was defined using various instruments, including the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines. CVD risk factors were defined according to the K/DOQI guidelines. Bivariate and multivariate logistic regression models were used to analyze the associations. CVD risk was present in all patients; the lowest proportions of adequate intake were 2.8% for dietary fiber and 0.9% for calcium. Adequate nutrient intake was associated with a lower likelihood of the occurrence of traditional CVD risk factors (specifically, 1.9-31.3% for hyperlipidemia and 94.6% for diabetes mellitus). It was also associated with a lower likelihood of the occurrence of nontraditional CVD risk by 0.8% for hypophosphatemia and 34% for hyperuricemia. Adherence to dietary guidelines should be promoted among RTRs to decrease CVD risk.

Racial Difference in the Association of Long-Term Exposure to Fine Particulate Matter (PM2.5) and Cardiovascular Disease Mortality among Renal Transplant Recipients

Ambient air pollutants are known risk factors for cardiovascular disease (CVD) morbidity and mortality with significant racial disparities. However, few studies have explored racial differences among highly susceptible subpopulations, such as renal transplant recipients (RTRs). Despite improvements in quality of life after transplantation, CVD remains the major cause of mortality, especially among Black recipients. This study aimed to evaluate potential racial differences in the association between long-term levels of PM2.5 and the risk of all-cause, total CVD, and coronary heart disease (CHD) mortality among RTRs. This retrospective study consists of 93,857 non-smoking adults who received a renal transplant between 2001 and 2015. Time-dependent Cox regression was used to assess the association between annual concentrations of PM2.5 and mortality risk. In the multivariable-adjusted models, a 10 μg/m3 increase in ambient PM2.5 levels found increased risk of all-cause (HR = 3.45, 95% CI: 3.08-3.78), CVD (HR = 2.38, 95% CI: 1.94-2.92), and CHD mortality (HR = 3.10, 95% CI: 1.96-4.90). Black recipients had higher risks of all-cause (HR = 4.09, 95% CI: 3.43-4.88) and CHD mortality (HR = 6.73, 95% CI: 2.96-15.32). High levels of ambient PM2.5 were associated with all-cause, CVD, and CHD mortality. The association tended to be higher among Black recipients than non-Blacks.

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.

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.

Long-Term Treatment of Azathioprine in Rats Induces Vessel Mineralization

Medial vascular calcification (mVC) is closely related to cardiovascular disease, especially in patients suffering from chronic kidney disease (CKD). Even after successful kidney transplantation, cardiovascular mortality remains increased. There is evidence that immunosuppressive drugs might influence pathophysiological mechanisms in the vessel wall. Previously, we have shown in vitro that mVC is induced in vascular smooth muscle cells (VSMCs) upon treatment with azathioprine (AZA). This effect was confirmed in the current study in an in vivo rat model treated with AZA for 24 weeks. The calcium content increased in the aortic tissue upon AZA treatment. The pathophysiologic mechanisms involve AZA catabolism to 6-thiouracil via xanthine oxidase (XO) with subsequent induction of oxidative stress. Proinflammatory cytokines, such as interleukin (IL)-1ß and IL-6, increase upon AZA treatment, both systemically and in the aortic tissue. Further, VSMCs show an increased expression of core-binding factor α-1, alkaline phosphatase and osteopontin. As the AZA effect could be decreased in NLRP3^−/− aortic rings in an ex vivo experiment, the signaling pathway might be, at least in part, dependent on the NLRP3 inflammasome. Although human studies are necessary to confirm the harmful effects of AZA on vascular stiffening, these results provide further evidence of induction of VSMC calcification under AZA treatment and its effects on vessel structure.

Cardiac Mortality in Kidney Transplant Patients: A Population-based Cohort Study 1988-2013 in Australia and New Zealand

BACKGROUND

Transplant recipients experience excess cardiac mortality. We compared circulatory death rates in Australian and New Zealand kidney transplant recipients to the general population and identified risk factors for circulatory death in kidney transplant recipients.

METHODS

The primary cause of death for kidney transplant recipients aged ≥18 was established through ICD-10-AM codes using data linkage between the Australia and New Zealand dialysis and transplant registry and national death registers. We estimated standardized mortality ratios (SMRs) and developed a Fine-Gray competing risks model to determine risk factors for cardiac mortality.

RESULTS

Of 5089 deaths in 16 329 kidney transplant recipients (158 325 person-years), 918 (18%) were cardiac. An increased risk of circulatory death was associated with older age (P < 0.001), male sex (P < 0.001), longer dialysis duration (P = 0.004), earlier era of transplantation (P < 0.001), ever graft failure (P < 0.001), known coronary artery disease (P = 0.002), and kidney failure from diabetes or hypertension (P < 0.001). The cardiac SMR was 5.4 [95% confidence interval (CI): 5.0-5.8], falling from 8.0 (95% CI: 4.9-13.1) in 1988 to 5.3 (95% CI: 4.0-7.0) in 2013 (P < 0.001). Females, particularly young ones, had significantly higher relative cardiac mortality than men. In recipients aged 40 years, the cardiac SMR was 26.5 (95% CI: 15.0-46.6) in females and 7.5 (95% CI: 5.0-11.1) for males.

CONCLUSIONS

Cardiac risks remain elevated in kidney transplant recipients and may be under-recognized, and prevention and treatment interventions less accessed, less effective or even harmful in female recipients.

Fear of Movement and Physical Self-Efficacy Partially Mediate the Association Between Fatigue and Physical Activity Among Kidney Transplant Recipients

Fatigue is one of the most distressing symptoms in renal transplant patients, causing functional impairment and worsening their quality of life. However, the mechanism by which fatigue affects physical activity is unclear. A cross-sectional study using a convenient sampling approach was utilized to investigate 665 kidney transplant recipients recruited from the transplantation centers of six general hospitals from July and September 2019. Structural equation modeling was used to examine the interaction among fatigue, fear of movement, physical self-efficacy, and physical activity. Our study found fatigue was directly negatively associated with physical activity and had an indirect impact on physical activity through the mediating effects of physical self-efficacy and fear of movement. These variables accounted for 44.4% of the variation in physical activity. Our findings alert healthcare providers for the importance of fatigue management for physical activity and focused attention on fear of movement and physical self-efficacy in renal transplant recipients.

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.

Associations between High Serum Adipocyte Fatty Acid Binding Protein and First Hospitalization in Kidney Transplantation Patients: A 5-Year Follow-up Study

Adipocyte fatty acid binding protein (A-FABP) is predictive of type 2 diabetes mellitus incidences and metabolic syndrome and is independently associated with atherosclerosis. The present study aimed to assess the association between serum A-FABP levels and future first hospitalization events in kidney transplantation (KT). We enrolled 72 KT patients from January through April 2012 and followed up on these subjects until June 2017. The first hospitalization events incidence was the primary endpoint. Using a commercially available enzyme immunoassay, serum A-FABP levels were measured from the patient's fasting blood samples. During a median 65-month follow-up, 49 first hospitalization events occurred. KT patients with first hospitalization events had greater incidences of hypertension, diabetes, and higher serum blood urea nitrogen, creatinine, triglyceride, and A-FABP levels than those without the events. Kaplan-Meier analysis showed that the cumulative incidence of first hospitalization events was greater in the high A-FABP group than in the low A-FABP group. Multivariate Cox analysis with significant variables showed that serum A-FABP (hazard ratio = 1.012; 95% confidence interval = 1.000-1.025; p = 0.044) was independently associated with first hospitalization events among KT patients. The results revealed that serum A-FABP is associated with first hospitalization events in KT patients. However, further prospective studies are needed to determine the mechanisms underlying this association.

Mortality from cancer is not increased in elderly kidney transplant recipients compared to the general population: a competing risk analysis

BACKGROUND

The impact of cancer on death of elderly kidney transplant recipients has been extensively investigated, but with conflicting results. Unlike their younger counterparts, in elderly kidney transplant recipients cardiovascular and infectious disease may outweigh cancer in causing the patient's death.

METHODS

Using competing risk analysis on a large retrospective cohort of kidney transplant recipients, we estimated the cause-specific cumulative incidence and hazard of death in different age categories and calculated standardized mortality ratios (SMRs) to compare mortality rates with the general population.

RESULTS

Six thousand seven hundred eighty-nine kidney transplant recipients were followed-up for a median of 9 years. Ten years after transplantation, in transplant recipients aged 20-39, 40-59, and 60+, the cumulative incidence of cancer-related death was 0.6 (95% confidence interval [CI]: 0.3-1.0), 2.9 (2.3-3.6) and 5.3% (3.5-7.5), whereas the SMR was 9.1 (5.5-15.0), 2.0 (1.6-2.5), and 0.8 (0.6-1.0), respectively. At variance with young recipients, the hazard and the cumulative incidence of cardiovascular-related death in elderly recipients was well above that of cancer-related death.

CONCLUSIONS

Relative to the general population, cancer-related death is increased in young but not in elderly kidney transplant recipients because of the more marked increased incidence of competing cause of death in the latter category.

Changes in Body Mass Index and Outcomes After Kidney Transplant: A Single-Center, Retrospective, Observational Study

OBJECTIVES

We aimed to describe changes in body mass index after kidney transplant and to assess how these changes influence long-term outcomes.

MATERIALS AND METHODS

Data were collected from kidney transplant recipients seen at our center between January 2007 and July 2016. Changes in body mass index over the posttransplant period were modeled using a generalized estimating equation, with changes calculated for each patient from pretransplant to 6 months posttransplant. Calculations were then categorized into 3 body mass index groups: stable (change of ± 1.5 kg/m² or less), reduced (reduction of > 1.5 kg/m²), and increased (increase of > 1.5 kg/m²). Outcomes among groups were compared.

RESULTS

Among 1344 total patients, the geometric mean pretransplant body mass index was 27.3 kg/m². This declined significantly (P < .001) to a geometric mean of 25.6 kg/m² at 1 month posttransplant, before increasing and stabilizing to pretransplant levels by 36 months (geometric mean body mass index of 27.2 kg/m² ; P = .522). Of 822 patients with body mass index measurements at 6 months, 303 had reduced, 388 had stable, and 131 had increased levels relative to pretransplant levels. On multivariate analyses, 12-month creatinine levels were significantly higher in the reduced cohort, with adjusted levels of 160.6 versus 135.0 μmol/L for the stable cohort. However, no significant associations were detected between 6-month body mass index changes and patient survival, graft survival, incidences of posttransplant diabetes and cancer, and a range of other clinical and histologic outcomes (all P > .05).

CONCLUSIONS

Our data demonstrated that body mass index was significantly reduced in the first month after kidney transplant before increasing to pretransplant levels during years 3 to 5. Furthermore, patients who retained decreased levels at 6 months had impaired graft function in long-term follow-up. These observations conflict with the existing literature and warrant further investigations.

Cardiovascular disease in the kidney transplant recipient: epidemiology, diagnosis and management strategies

Kidney transplantation (KT) is the optimal therapy for end-stage kidney disease (ESKD), resulting in significant improvement in survival as well as quality of life when compared with maintenance dialysis. The burden of cardiovascular disease (CVD) in ESKD is reduced after KT; however, it still remains the leading cause of premature patient and allograft loss, as well as a source of significant morbidity and healthcare costs. All major phenotypes of CVD including coronary artery disease, heart failure, valvular heart disease, arrhythmias and pulmonary hypertension are represented in the KT recipient population. Pre-existing risk factors for CVD in the KT recipient are amplified by superimposed cardio-metabolic derangements after transplantation such as the metabolic effects of immunosuppressive regimens, obesity, posttransplant diabetes, hypertension, dyslipidemia and allograft dysfunction. This review summarizes the major risk factors for CVD in KT recipients and describes the individual phenotypes of overt CVD in this population. It highlights gaps in the existing literature to emphasize the need for future studies in those areas and optimize cardiovascular outcomes after KT. Finally, it outlines the need for a joint 'cardio-nephrology' clinical care model to ensure continuity, multidisciplinary collaboration and implementation of best clinical practices toward reducing CVD after KT.

Transplanting the Elderly: Mandatory Age- and Minimal Histocompatibility Matching

Worldwide over 40% of patients receiving renal replacement therapy (RRT) are aged 65 years or older, a number that is still increasing. Renal transplantation is the preferred RRT, providing substantial survival benefit over those remaining on dialysis, including the elderly. Only 3% of patients aged 65 years or older accepted on the waiting list actually received a kidney transplant offer within the Eurotransplant allocation region. To increase the chance for elderly to receive a timely kidney transplant, the Eurotransplant Senior Program was introduced. The ESP supports local allocation of older kidneys to older donors in order to decrease cold ischemia time, while disregarding former exchange principles based on matching for HLA antigens. As a consequence, more elderly received a kidney transplant and a relative higher incidence of acute rejection resulted in additional courses of high steroids and/or depleting antibody therapy. Since death with a functioning graft due to infections is the dominant reason of graft loss in elderly, more intense clinical immunosuppression to prevent or treat acute rejection is not a very attractive option. Therefore in elderly kidney transplant candidates, we advocate reintroduction of minimal histocompatibility criteria (i.e., HLA-DR matching) followed by age-matching with mandatory local/regional allocation to also facilitate short cold ischemia.

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 Risk of Stroke in Kidney Transplant Recipients with End-Stage Kidney Disease

Background: The incidence of stroke after kidney transplantation is poorly understood. Our study aimed to determine the incidence and predictors of stroke as well as mortality from stroke in kidney transplant recipients (KTRs). Methods: This retrospective cohort study used the National Health Insurance Research Database in Taiwan to study KTRs (N = 4635), patients with end-stage renal disease (ESRD; N = 69,297), and patients from the general population who were chronic kidney disease (CKD)-free and matched by comorbidities (N = 69,297) for the years 2000 through 2010. The risk of stroke was analyzed using univariate and multivariate Cox regression models and compared between study cohorts. Findings: Compared with the ESRD subgroup, KTRs had a significantly lower risk of overall stroke (adjusted hazard ratio (aHR) = 0.37, 95% confidence interval (CI) = 0.31⁻0.44), ischemic stroke (aHR = 0.45, 95% CI = 0.37⁻0.55), and hemorrhagic stroke (aHR = 0.20, 95% CI = 0.14⁻0.29). The risk patterns for each type of stroke in the KTR group were not significantly different than those of the CKD-free control subgroup. The predictors of stroke were age and diabetes in KTRs. All forms of stroke after transplantation independently predicted an increased risk of subsequent mortality, and the strongest risk was related to hemorrhagic events. Interpretation: KTRs had a lower risk of stroke than ESRD patients, but this risk was not significantly different from that of the CKD-free comorbidities-matched general population group. Although stroke was relatively uncommon among cardiovascular events, it predicted unfavorable outcome in KTRs.

Renal Function, Albuminuria, and the Risk of Cardiovascular Events After Kidney Transplantation

BACKGROUND

The risk of mortality and graft loss is higher in kidney transplant recipients with reduced estimated glomerular filtration rate (eGFR) and albuminuria. It is unclear whether these markers are also associated with cardiovascular events.

METHODS

We examined linked healthcare databases in Alberta, Canada to identify kidney transplant recipients between 2002 and 2013 who had at least 1 outpatient serum creatinine and albuminuria measurement at 1-year posttransplant. We determined the relationship between categories of eGFR and albuminuria and the risk of subsequent cardiovascular events.

RESULTS

Among 1069 eligible kidney transplant recipients, the median age was 52 years, 37% were female, and 52% had eGFR ≥60 mL/min per 1.73 m2. Over a median follow-up of 6 years, the adjusted rate of all-cause mortality and cardiovascular events was 2.7-fold higher for recipients with eGFR 15-29 mL/min per 1.73 m2 and heavy albuminuria compared to recipients with eGFR ≥60 mL/min per 1.73 m2 and normal albuminuria (rate ratio, 2.7; 95% confidence interval, 1.3-5.7). Similarly, recipients with heavy albuminuria had a threefold increased risk of all-cause mortality and heart failure compared with recipients with eGFR ≥60 mL/min per 1.73 m2 and normal albuminuria.

CONCLUSIONS

These findings suggest that eGFR and albuminuria should be used together to determine the risk of cardiovascular outcomes in transplant recipients.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials

Background

Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes.

Methods

PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497).

Results

There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes).

Conclusions

Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes.

Trial registration

clinicaltrials.gov, NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT (2006-007021-32 and 2004-004346-40).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1031-1) contains supplementary material, which is available to authorized users.

An improvement of carotid intima-media thickness and pulse wave velocity in renal transplant recipients

Background

Renal transplantation can significantly improve the quality of life of patients with end stage renal disease (ESRD) who would otherwise require dialysis. Renal transplant (RT) recipients have higher risks of cardiovascular disease compared with general population. The carotid intima-media thickness (CIMT) and pulse wave velocity (PWV) have been used as the important predicting factor of vascular arteriosclerosis. Therefore, this study was to investigate the improvement of carotid intima-media thickness and pulse wave velocity in renal transplant recipients.

Methods

Thirty-one patients with chronic kidney disease being treated with hemodialysis, 31 renal transplant recipients and 84 healthy control subjects were included to have the clinical evaluations and ultrasonography of bilateral carotid arteries. CIMT and PWV were independently measured by two ultrasonographers using the technique of ultrasonic radiofrequency tracking and correlated with arteriosclerosis risk factors. The progression of CIMT and PWV with age were analyzed by linear regression models, and the slopes of curves were compared using Z test.

Results

Compared with the patients on hemodialysis, the CIMT was significantly lower in renal transplant recipients and healthy control. The PWV were higher in hemodialysis patients and renal transplant recipients than that of the subjects in control group. The progression is CIMT positively corelated with age and cumulative duration in renal transplant recipients and hemodialysis patients. In both hemodialysis patients and renal transplant recipients, age and cumulative time on dialysis were all positively correlated with the increase of PWV as well.

Conclusions

Carotid intima-media thickness and pulse wave velocity is the predicting factors of developing arteriosclerosis, which were improved in renal transplant recipients.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0263-7) contains supplementary material, which is available to authorized users.

High molecular weight adiponectin inhibits vascular calcification in renal allograft recipients

BACKGROUND

Adiponectin (ADPN) prevents the development/recurrence of cardiovascular events via its anti-atherogenic effects. However, few long-term studies have examined the changes in serum ADPN levels and arterial calcification seen in renal allograft recipients.

SUBJECTS AND METHODS

The effects of the serum ADPN level on arterial calcification were examined in 51 Japanese renal allograft recipients. Abdominal aorta calcification was evaluated on computed tomography using the aortic calcification area index (ACAI). The change in the ACAI and serum high-molecular-weight (HMW)-ADPN fractions were studied over an 8-year period. The arterial expression of ADPN, ADPN receptors (AdipoR)1 and 2, and T-cadherin (cadherin-13) were also examined by immunohistochemistry.

RESULTS

The change in the ACAI were grouped into quartiles and compared with the alterations in the serum levels of each ADPN fraction over an 8-year period. The change in the ACAI was much lower in the patients with highly elevated HMW-ADPN levels.Multiple regression analysis demonstrated that an advanced age at transplant and a history of cardiovascular complications were associated with an increased change in the ACAI, while higher HMW-ADPN concentrations were associated with improvements in the ACAI. Serum HDL-C level was also identified as a positive factor to increase serum HMW-ADPN level.In immunohistochemical examinations, ADPN was detected on CD31-positive arterial endothelial cells from renal allograft biopsy samples. ADPN co-localized with T-cadherin and AdipoR1, but only partially co-localized with AdipoR2.

CONCLUSION

Both HMW-ADPN and HDL-C might inhibit the progression of vascular calcification by promoting ADPN binding to vascular endothelial cells via T-cadherin and AdipoR in Japanese renal allograft recipients.

[Focusing on kidney transplantation in the elderly]

Due to the increase in life expectancy and the ageing of end-stage renal disease patients, the number of patients older than 65 years receiving a kidney transplant has been continuously growing over the last fifteen years. The benefits of renal transplantation compared to dialysis in terms of survival and quality of life have been shown in selected recipients over 65, or 70 years. However, the age remains the main limiting factor for the access to the waiting list, and the reluctance of the clinicians can be explained by the multiple comorbidities of these candidates, their limited life expectancy or the shortage of grafts. The challenge is to select the candidates who can benefit from renal transplantation, thanks to rigorous cardiovascular and neoplastic evaluation before enrolment and by taking into account the specific characteristics of elderly patients. The living donor appears to be the ideal option for elderly recipients, the alternative being the extended criteria donor, allowing waiting times to be limited. The choice of immunosuppressive therapy is also crucial in these patients at high risk of infectious and cardiovascular complications in whom the occurrence of acute rejection can have severe consequences. There are currently no specific recommendations for immunosuppression in elderly recipients, and we would need large-scale randomized studies to improve the prognosis of renal transplantation in this population.

A rapid and sustained improvement of calcification propensity score (serum T50 ) after successful kidney transplantation: Reanalysis of a randomized controlled trial of ibandronate

A serum test called T₅₀ assesses the overall propensity for calcification of the blood and is associated with cardiovascular outcomes. We aimed to examine T₅₀ over time in kidney transplant recipients and also address any effects of ibandronate. Serum samples taken from kidney transplant patients included in a prospective, randomized placebo controlled study of ibandronate were analyzed in retrospect. Adequate analyses were performed at baseline (approximately 3 weeks after transplantation) in 129 patients, at 10 weeks in 127 patients and at 1 year in 123 patients. There were no statistical differences between ibandronate and placebo treatment in terms of T₅₀ at 10 weeks (P = .094) or at 1 year (P = .116). Baseline T₅₀ was a significant covariate (P < .0001) for T₅₀ scores at 10 weeks and 1 year. In the total cohort, there was a highly significant (P < .0001) increase in T₅₀ of 26.6% after 10 weeks and T₅₀ remained stable after 1 year. T₅₀ change was inversely correlated to phosphate of -0.515 (P < .0001) and to change in serum albumin (P < .03). We found that T₅₀ increased from baseline to 10 weeks after transplantation with no further change after 1 year. Ibandronate had no effect on T₅₀ .

Cardiovascular Parameters to 2 years After Kidney Transplantation Following Early Switch to Everolimus Without Calcineurin Inhibitor Therapy: An Analysis of the Randomized ELEVATE Study

BACKGROUND

Mammalian target of rapamycin inhibitors may confer cardioprotective advantages, but clinical data are limited.

METHODS

In the open-label ELEVATE trial, kidney transplant patients were randomized at 10 to 14 weeks after transplant to convert from calcineurin inhibitor (CNI) to everolimus or remain on standard CNI therapy. Prespecified end points included left ventricular mass index and, in a subpopulation of patients, arterial stiffness as measured by pulse wave velocity.

RESULTS

The mean change in left ventricular mass index from randomization was similar with everolimus versus CNI (month 24, -4.37 g/m versus -5.26 g/m; mean difference, 0.89 [p = 0.392]). At month 24, left ventricular hypertrophy was present in 41.7% versus 37.7% of everolimus and CNI patients, respectively. Mean pulse wave velocity remained stable with both everolimus (mean change from randomization to month 12, -0.24 m/s; month 24, -0.03 m/s) and CNI (month 12, 0.11 m/s; month 24, 0.16 m/s). The change in mean ambulatory nighttime blood pressure from randomization showed a benefit for diastolic pressure at month 12 (P = 0.039) but not at month 24. Major adverse cardiac events occurred in 1.1% and 4.2% of everolimus-treated and CNI-treated patients, respectively, by month 12 (P = 0.018) and 2.3% (8/353) and 4.5% by month 24 (P = 0.145).

CONCLUSIONS

Overall, these data do not suggest a clinically relevant effect on cardiac end points after early conversion from CNI to a CNI-free everolimus-based regimen.

Immunosuppression in Solid-Organ Transplantation: Essentials and Practical Tips

A multidisciplinary team approach is essential for successful management of patients with solid-organ transplant. Transplant nursing encompasses care and support of transplant recipients as well as caregivers and organ donors through all phases of transplantation, from pretransplant evaluation to posttransplant recovery and maintenance. The field of solid-organ transplantation has advanced rapidly, and new treatments continue to emerge. Nurses who are responsible for the care of transplant recipients should have a knowledge base in transplant immunology and pharmacology. This review discusses mechanism of action, indication, side effects, and drug interactions of commonly used immunosuppressive medications in solid-organ transplantation. Nonoral routes of drug administration, therapeutic drug monitoring, and patient monitoring strategies are also included as practical tips for bedside nurses who are responsible for delivery of direct patient care and education of patients and their caregivers. This review focuses on the following medications: antithymocyte globulins, basiliximab, alemtuzumab, corticosteroids, tacrolimus, cyclosporine, azathioprine, mycophenolate mofetil/mycophenolate sodium, sirolimus, everolimus, belatacept, intravenous immunoglobulin, and rituximab.

Prognostic impact of SPECT-MPI after renal transplantation

BACKGROUND

While renal transplantation is increasingly performed for end-stage renal disease, there is a paucity of data on cardiac screening and prognostication post-transplant. We determined the prognostic value of SPECT-MPI in a cohort who underwent renal transplantation.

METHODS

Among 4933 renal transplant recipients identified from the Canadian Organ Replacement Register, we examined outcomes of patients who underwent SPECT-MPI in Ontario, Canada. We determined morbidity and mortality using hospitalization and vital statistics registries, according to SPECT-MPI findings.

RESULTS

We studied 282 renal transplant recipients (median age 46 years [25th, 75th percentile 37, 58]) with detailed SPECT-MPI results available, followed for a median of 5.7 (3.3, 7.7) years. Among those undergoing SPECT-MPI (66% pharmacologic stress), 41% had an abnormal summed stress score (SSS > 0) and 31% demonstrated abnormal summed difference score (SDS > 0). Rates of cardiovascular death were 0.4 per 100 person-years among those with normal stress perfusion (SSS = 0) and 0.4 per 100 person-years with SDS = 0. After adjusting for age, sex, prior myocardial infarction (MI), and cardiac risk factors, an SSS ≥ 4 conferred increased risk of cardiovascular death or cardiovascular hospitalization with adjusted hazard ratios of 2.52 (95% CI 1.41, 4.52, P = .002) for SSS 4-6 and 2.61 (95% CI 1.52, 4.49, P < .001) for SSS ≥ 7. SDS was a significant predictor of cardiovascular death or hospitalization, with adjusted hazard ratios of 2.96 (95% CI 1.72, 5.09, P < .001) for SDS 4-6 and 3.26 (95% CI 1.64, 6.50, P < .001) for SDS ≥ 7.

CONCLUSION

Among renal transplant recipients, SPECT-MPI predicted risk of cardiovascular death and cardiovascular hospitalization events.

Patterns of Care and Outcomes in Cardiovascular Disease After Kidney Transplantation in the United States

Background

Cardiovascular disease (CVD) is an important driver of mortality after kidney transplantation. Its broader impact on posttransplant health care utilization in US hospitals is unknown.

Methods

We used administrative claims data from the Nationwide Inpatient Sample and the American Hospital Association Annual Survey to identify hospitalizations for kidney transplant patients with a cardiovascular diagnosis from 2005 to 2011. CVD hospitalizations were stratified by transplant hospital status to characterize patterns in inpatient health care utilization and outcomes. Based on these analyses, the domestic burden of treatment for posttransplant CVD (myocardial infarction, stroke, congestive heart failure, dysrhythmia, cardiac arrest, malignant hypertension) was estimated.

Results

The total domestic burden of post-kidney transplant hospitalization between 2005 and 2011 is estimated at 389 138 of which 26.5% of episodes were related to CVD (n = 103 118). CVD was responsible for a growing proportion of post-transplant hospitalizations over time (24.4%-30.4%, P < 0.001). Compared with nontransplant hospitals, transplant hospitals had similar length of stay (median length of stay, 3.7 days), higher median costs per hospitalization (US $10 364 vs US $8606, overall US $9324), and lower adjusted mortality (3.2% vs 3.9%, overall 3.6%; P = 0.003).

Conclusions

Inpatient CVD care is increasing over time for kidney transplant patients, accounting for 30% of all post-transplant hospitalizations. Variation exists in the inpatient care, outcomes, and costs between by hospital type. Further studies are needed to better understand the mechanisms behind these phenomena.