The outcome of heart transplant recipients following the development of end-stage renal disease: analysis of the Canadian Organ Replacement Register (CORR)

High Rate of Kidney Graft Failure after Simultaneous Heart-Kidney Transplantation

Key Points

Simultaneous heart–kidney transplant is associated with high rates of kidney graft failure which are worse when compared with kidney transplant alone. The major causes of kidney graft failure in simultaneous heart–kidney transplant recipients were patient death and primary nonfunction of kidney graft.

Background

The indications and outcomes of simultaneous heart–kidney transplantation (SHKT) remain suboptimally defined. Risk factors for renal graft failure after SHKT also remain poorly defined.

Methods

We analyzed the renal graft outcomes among SHKT recipients using United Network for Organ Sharing database from 2015 to 2020. To evaluate for factors associated with poor renal outcomes, we compared SHKT and kidney transplantation alone recipients using propensity score matching.

Results

Among SHKT recipients, the rate of primary nonfunction (PNF) of kidney graft was 3%, the 30-day kidney graft failure rate was 7.0%, and the 30-day post-transplant mortality rate was 4.1%. The incidence of kidney delayed graft function was 27.5%. Kidney graft failure was seen early post-SHKT with most common causes of patient death (43.9%) and PNF of kidney graft (41.5%). One- and 2-year patient survival was 89.2% and 86.5%, and 1- and 2-year freedom from kidney graft failure was 85.4% and 82.7%, respectively. In subgroup analysis of SHKT recipients, use of pretransplant mechanical cardiac support (adjusted odds ratio [aOR], 2.57; P = 0.017), higher calculated panel reactive antibody (aOR, 1.76; P = 0.016), and older donor age per 10 years (aOR, 1.94; P = 0.001) were associated with PNF. Pretransplant extracorporeal membrane oxygenation support was associated with the increased risk of 30-day recipient mortality (aOR, 5.55; P = 0.002). Increased 30-day graft failure was seen in SHKT recipients with pretransplant mechanical cardiac support (aOR, 1.77; P = 0.038) and dialysis at the time of transplant (aOR, 1.72; P = 0.044). Multivariable Cox hazard analysis demonstrated that SHKT, when compared with kidney transplantation alone, is associated with increased kidney graft failure (hazard ratio, 2.56; P < 0.001) and recipient mortality (hazard ratio, 2.65; P < 0.001).

Conclusions

SHKT is associated with high rates of kidney graft failure. Identification of risk factors of renal graft failure can help optimize recipient selection for SHKT versus kidney after heart transplantation, especially after introduction of the new safety-net policy.

Safety and tolerability of sodium-glucose cotransporter-2 inhibitors in bridge-to-transplant patients supported with centrifugal-flow left ventricular assist devices

BACKGROUND

The safety and tolerability of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with end-stage heart failure supported with left-ventricular-assist-devices (LVADs), irrespective of diabetes mellitus, is not known.

METHODS

A retrospective analysis of 31 outpatients implanted with LVADs as bridge-to-transplant (BTT) was conducted. Patients with biventricular support, aged under 18 years, who were discharged from the index hospitalisation, or were prescribed SGLT2i prior to their first outpatient clinic were excluded. Patient demographics, laboratory studies, pump haemodynamic and adverse event data was collected.

RESULTS

Sixteen (51.6%) of 31 patients were prescribed SGLT2i over median 101.5 days (37.5-190.8). No patients discontinued SGLT2i use or reported attributable adverse symptoms. No significant differences between patients prescribed SGLT2i compared to those SGLT2i-naïve were seen in: [1] renal function; [2] weight; [3] mean arterial pressure. There were numerically lower infection-related (n = 4 vs 7, HR 0.32 (0.08-1.28), p = 0.11) and haemocompatibility-related (n = 3 vs 4, HR 0.52 (0.09-2.83), p = 0.45) adverse events in the SGLT2i group, albeit non-significant.

CONCLUSIONS

We found SGLT2i to be safe and well-tolerated in the BTT LVAD cohort with no significant difference in rates of infection or haemocompatibility-related adverse events with SGLT2i use. Larger studies will inform further beneficial effects of SGLT2i prescription in this cohort.

Renal Dysfunction After Heart Transplant

BACKGROUND

Moderate or severe renal dysfunction (MSRD) is a frequent complication after heart transplantation. Strategies to delay progression and improve outcomes, such as renoprotective medications and timely referral to nephrology, remain important in providing care to heart transplant recipients with MSRD.

RESEARCH QUESTION

What are chronic renal dysfunction's prevalence, risk factors, and optimal clinical management strategies in heart transplant recipients?

DESIGN

This single-center, cross-sectional study examined patients who received a heart transplant from January 1, 2000, to June 30, 2011, and followed until December 31, 2011. Moderate or severe renal dysfunction was defined as a glomerular filtration rate of <60 mL/min/1.73 m2.

RESULTS

The prevalence of MSRD among 195 heart transplant recipients was 60%. Variables associated with MSRD were female sex (odds ratio [OR]: 4.82; 95% CI, 1.72-13.54), greater age (OR: 1.10 per year; 95% CI, 1.06-1.14), time since transplant (OR: 1.0004 per year; 95% CI, 1.0001-1.0007), and mTOR inhibitor use (OR: 2.89; 95% CI, 1.24-6.71). Tacrolimus use (OR: 0.19; 95% CI, 0.05-0.71) and cyclosporine use (OR: 0.21; 95% CI, 0.05-0.80) were associated with patients without MSRD. Among patients with MSRD, 19.6% were referred to a nephrologist. Median eGFR remained stable at approximately 60 mL/min/1.73 m2 for 3 years after the study.

CONCLUSIONS

Our results suggest that female sex, older age at transplant, and time since transplant are associated with MSRD in heart transplant recipients. Tacrolimus and cyclosporine use seemed renoprotective, but lower usage and increased mTOR inhibitor use may more likely indicate existing treatment patterns for patients with MSRD.

Kidney Re-Transplantation after Simultaneous Heart and Kidney Transplant: Case Study and Literature Review

The kidney is one of most frequent transplants to be performed in multi-organ transplantation. A simultaneous heart and kidney transplant (SHKT) is the best-known treatment method in patients with severe heart failure and end-stage renal disease (ESRD). Here, the authors describe the case of a kidney re-transplantation after SHKT, which is in accordance with the majority of studies, and proves the safety of simultaneous procedures. The article highlights the complex care required after the transplant, followed by the multi-factor qualification for re-transplantation. In conclusion, the case shows that SHKT provides long-term favorable outcomes and enables a repeated kidney transplantation with satisfactory one-year follow-up results.

Two is better than one: when to consider multiorgan transplant

PURPOSE OF REVIEW

Patients with end-stage heart failure often present with concomitant end-stage renal or end-stage liver disease requiring transplantation. There are limited data regarding the risks, benefits and long-term outcomes of heart-kidney (HKT) and heart-liver transplantation (HLT), and guidelines are mainly limited to expert consensus statements.

RECENT FINDINGS

The incidence of HKT and HLT has steadily increased in recent years with favourable outcomes. Both single-centre and large database studies have shown benefits of HKT/HLT through improved survival, freedom from dialysis and lower rates of rejection and coronary allograft vasculopathy. Current guidelines are institution dependent and controversial due to the ethical considerations surrounding multiorgan transplantation (MOT).

SUMMARY

MOT is an effective and necessary option for patients with end-stage heart and kidney/liver failure. MOT is ethically permissible, and efforts should be made to consider eligible patients as early as possible to limit morbidity and mortality. Further research is needed regarding appropriate listing criteria and long-term outcomes.

Assessment of kidney function: clinical indications for measured GFR

In the vast majority of cases, glomerular filtration rate (GFR) is estimated using serum creatinine, which is highly influenced by age, sex, muscle mass, body composition, severe chronic illness and many other factors. This often leads to misclassification of patients or potentially puts patients at risk for inappropriate clinical decisions. Possible solutions are the use of cystatin C as an alternative endogenous marker or performing direct measurement of GFR using an exogenous marker such as iohexol. The purpose of this review is to highlight clinical scenarios and conditions such as extreme body composition, Black race, disagreement between creatinine- and cystatin C-based estimated GFR (eGFR), drug dosing, liver cirrhosis, advanced chronic kidney disease and the transition to kidney replacement therapy, non-kidney solid organ transplant recipients and living kidney donors where creatinine-based GFR estimation may be invalid. In contrast to the majority of literature on measured GFR (mGFR), this review does not include aspects of mGFR for research or public health settings but aims to reach practicing clinicians and raise their understanding of the substantial limitations of creatinine. While including cystatin C as a renal biomarker in GFR estimating equations has been shown to increase the accuracy of the GFR estimate, there are also limitations to eGFR based on cystatin C alone or the combination of creatinine and cystatin C in the clinical scenarios described above that can be overcome by measuring GFR with an exogenous marker. We acknowledge that mGFR is not readily available in many centres but hope that this review will highlight and promote the expansion of kidney function diagnostics using standardized mGFR procedures as an important milestone towards more accurate and personalized medicine.

Long-Term Outcomes and Risk Factors of Renal Failure Requiring Dialysis after Heart Transplantation: A Nationwide Cohort Study

Acute kidney injury and renal failure are common after heart transplantation. We retrospectively reviewed a national cohort and identified 1129 heart transplant patients. Patients receiving renal replacement therapy after heart transplantation were grouped into the dialysis cohort. The long-term survival and risk factors of dialysis were investigated. Patients who had undergone dialysis were stratified to early or late dialysis for subgroup analysis. The mean follow-up was five years, the incidence of dialysis was 28.4% (21% early dialysis and 7.4% late dialysis). The dialysis cohort had higher overall mortality compared with the non-dialysis cohort. The hazard ratios of mortality in patients with dialysis were 3.44 (95% confidence interval (CI), 2.73–4.33) for all dialysis patients, 3.58 (95% CI, 2.74–4.67) for early dialysis patients, and 3.27 (95% CI, 2.44–4.36; all p < 0.001) for late dialysis patients. Patients with diabetes mellitus, chronic kidney disease, acute kidney injury, and coronary artery disease were at higher risk of renal failure requiring dialysis. Cardiomyopathy, hepatitis B virus infection, and hyperlipidemia treated with statins were associated with a lower risk of renal dysfunction requiring early dialysis. The use of Sirolimus and Mycophenolate mofetil was associated with a lower incidence of late dialysis. Renal dysfunction requiring dialysis after heart transplantation is common in Taiwan. Early and late dialysis were both associated with an increased risk of mortality in heart transplant recipients.

Heart and kidney transplant: should they be combined or subsequent?

AIMS

End-stage heart failure patients often present with severe kidney failure and have limited treatment options. We compared the clinical characteristics and outcomes among end-stage heart and kidney failure patients who underwent combined heart and kidney transplant (HKTx) with those who underwent kidney transplant after heart transplant (KAH).

METHODS AND RESULTS

All patients from 2007-2016 who underwent combined HKTx (n = 715) and those who underwent KAH (n = 130) using the United Network for Organ Sharing database were included. Kaplan-Meier curves and Cox models compared survivals and identified predictors of death. Number of combined HKTx performed annually in United States increased from 59 in 2007 to 146 in 2016 whereas KAH decreased from 34 in 2007 to 6 in 2016. Among KAH patients, average wait time for kidney transplant was 3.0 years, time to dialysis or to kidney transplant after heart transplant did not differ with varying severity of kidney disease at baseline (P for both >0.05). Upon follow-up (mean 3.5 ± 2.7 years), 151 patients died. In multivariable models, patients who underwent combined HKTx had 4.7-fold greater risk of death [95% confidence interval (CI) 2.4-9.4) than KAH patients upon follow up. A secondary analysis using calculation of survival only after kidney transplant for KAH patients still conferred higher risk for combined HKTx patients [hazard ratio (HR) 2.6 95% CI 1.33-5.15]. In subgroup analyses after excluding patients on dialysis (HR 3.99 95% CI 1.98-8.04) and analysis after propensity matching for age, gender, and glomerular filtration rate (HR 3.01 95% CI 1.40-6.43) showed similar and significantly higher risk for combined HKTx patients compared with KAH patients. Lastly, these results also remained unchanged after excluding transplant centres who performed only one type of procedure preferentially, i.e. HKTx or KAH (HR 4.70 95% CI 2.35-9.42).

CONCLUSIONS

National registry data show continual increase in combined HKTx performed annually in the United States but inferior survival compared with KAH patients. Differences in patient characteristics or level of kidney dysfunction at baseline do not explain these poor outcomes among HKTx patients compared with KAH patients. Consensus guidelines are greatly needed to identify patients who may benefit more from dual organ transplants.

The impact of severe acute kidney injury requiring renal replacement therapy on survival and renal function of heart transplant recipients - a UK cohort study

Severe acute kidney injury (AKI), defined as requiring renal replacement therapy (RRT), is associated with higher mortality postheart transplantation, but its long-term renal consequences are not known. Anonymized data of 3365 patients, who underwent heart transplantation between 1995 and 2017, were retrieved from the UK Transplant Registry. Multivariable binary logistic regression was performed to identify risk factors for severe AKI requiring RRT, Kaplan-Meier analysis to compare survival and renal function deterioration of the RRT and non-RRT groups, and multivariable Cox regression model to identify predicting factors of mortality and end-stage renal disease (ESRD). 26.0% of heart recipients received RRT post-transplant. The RRT group has lower survival rates at all time points, especially in the immediate post-transplant period. However, conditional on 3 months survival, older age, diabetes and coronary heart disease, but not post-transplant RRT, were the risk factors for long-term survival. The predicting factors for ESRD were insulin-dependent diabetes, renal function at transplantation, eGFR decline in the first 3 months post-transplant, post-transplant severe AKI and transplantation era. Severe AKI requiring RRT post-transplant is associated with worse short-term survival, but has no impact on long-term mortality. It also accelerates recipients' renal function deterioration in the long term.

Incidence of end-stage renal disease after heart transplantation and effect of its treatment on survival

Aims

Many heart transplant recipients will develop end‐stage renal disease in the post‐operative course. The aim of this study was to identify the long‐term incidence of end‐stage renal disease, determine its risk factors, and investigate what subsequent therapy was associated with the best survival.

Methods and results

A retrospective, single‐centre study was performed in all adult heart transplant patients from 1984 to 2016. Risk factors for end‐stage renal disease were analysed by means of multivariable regression analysis and survival by means of Kaplan–Meier. Of 685 heart transplant recipients, 71 were excluded: 64 were under 18 years of age and seven were re‐transplantations. During a median follow‐up of 8.6 years, 121 (19.7%) patients developed end‐stage renal disease: 22 received conservative therapy, 80 were treated with dialysis (46 haemodialysis and 34 peritoneal dialysis), and 19 received a kidney transplant. Development of end‐stage renal disease (examined as a time‐dependent variable) inferred a hazard ratio of 6.45 (95% confidence interval 4.87–8.54, P < 0.001) for mortality. Tacrolimus‐based therapy decreased, and acute kidney injury requiring renal replacement therapy increased the risk for end‐stage renal disease development (hazard ratio 0.40, 95% confidence interval 0.26–0.62, P < 0.001, and hazard ratio 4.18, 95% confidence interval 2.30–7.59, P < 0.001, respectively). Kidney transplantation was associated with the best median survival compared with dialysis or conservative therapy: 6.4 vs. 2.2 vs. 0.3 years (P < 0.0001), respectively, after end‐stage renal disease development.

Conclusions

End‐stage renal disease is a frequent complication after heart transplant and is associated with poor survival. Kidney transplantation resulted in the longest survival of patients with end‐stage renal disease.

Kidney transplantation and cardiomyopathy: Concepts and controversies in clinical decision-making

Increasing comorbidities and an aging population have led to a tremendous increase in the burden of both kidney and cardiac dysfunction. Concomitant cardiomyopathy exposes the patients with kidney disease to further physiological, hemodynamic, and pathologic alterations. Kidney transplantation imposes lesser anesthetic and surgical complexities compared to another solid organ transplant. The surgical decision-making remains an unsettled issue in these conditions. The surgical choices, techniques, and sequences in kidney transplant and cardiac surgery depend on the pathophysiological perturbations and perioperative outcomes. The absence of randomized controlled trials eludes us from suggesting definite management protocol in patients with end-stage kidney disease with cardiomyopathy. Nevertheless, in this review, we extracted data from published literature to understand the pathophysiologic interactions between end-stage renal diseases with cardiomyopathy and also proposed the management algorithm in this challenging scenario. The proposed management algorithm would ensure consensus across all stakeholders involved in decision-making. Our simplistic evidence-based approach would augur future randomized trials and would further ensure refinement in our management approach after the emergence of more definitive evidence.

Acute Kidney Injury in Patients Undergoing Cardiac Transplantation: A Meta-Analysis

Background: Acute kidney injury (AKI) is a common complication following solid-organ transplantation. However, the epidemiology of AKI and mortality risk of AKI among patients undergoing cardiac transplantation is not uniformly described. We conducted this study to assess the incidence of AKI and mortality risk of AKI in adult patients after cardiac transplantation. Methods: A systematic review of EMBASE, MEDLINE, and Cochrane Databases was performed until June 2019 to identify studies evaluating the incidence of AKI (by standard AKI definitions), AKI requiring renal replacement therapy (RRT), and mortality risk of AKI in patients undergoing cardiac transplantation. Pooled AKI incidence and mortality risk from the included studies were consolidated by random-effects model. The protocol for this study is registered with PROSPERO (no. CRD42019134577). Results: 27 cohort studies with 137,201 patients undergoing cardiac transplantation were identified. Pooled estimated incidence of AKI and AKI requiring RRT was 47.1% (95% CI: 37.6-56.7%) and 11.8% (95% CI: 7.2-18.8%), respectively. The pooled ORs of hospital mortality and/or 90-day mortality among patients undergoing cardiac transplantation with AKI and AKI requiring RRT were 3.46 (95% CI, 2.40-4.97) and 13.05 (95% CI, 6.89-24.70), respectively. The pooled ORs of 1-year mortality among patients with AKI and AKI requiring RRT were 2.26 (95% CI, 1.56-3.26) and 3.89 (95% CI, 2.49-6.08), respectively. Conclusion: Among patients undergoing cardiac transplantation, the incidence of AKI and severe AKI requiring RRT are 47.1% and 11.8%, respectively. AKI post cardiac transplantation is associated with reduced short term and 1-year patient survival.

Use of durable mechanical circulatory support on outcomes of heart-kidney transplantation

OBJECTIVES

Previous studies have demonstrated that preheart transplant mechanical circulatory support (MCS) can lead to a small but significant increase in mortality. However, data on outcomes of patients with MCS who require simultaneous heart-kidney transplant are limited.

METHODS

A retrospective review of simultaneous heart-kidney transplantations (HKTxs) performed at a single institution over a 5-year period was performed. Patients were divided based on the preoperative use of durable MCS. Renal graft-related end points were evaluated, including glomerular filtration rate following transplantation, prevalence of delayed renal graft function and freedom from antibody and cellular-mediated graft rejection. Patient-specific outcomes, including survival and frequency of non-fatal major adverse cardiac events at 1 year, were additionally assessed.

RESULTS

During the study period, 50 HKTxs were performed, 14 of which had preoperative MCS. HKTx patients with and without MCS implantations had a similar prevalence of delayed graft function (57.1% vs 50.0%; P = 0.757). A numerical trend was observed towards a reduced glomerular filtration rate 1-month post-transplant in patients without an MCS device (81.2 ± 32.8 vs 64.4 ± 27.5; P = 0.072), but no significant difference was observed at 6 and 12 months. No significant difference was observed on the need for post-transplant renal replacement therapy, non-fatal major adverse cardiac events, freedom from graft rejection and overall survival at 1 year.

CONCLUSIONS

The use of preoperative MCS in patients undergoing combined HKTx was not found to affect renal graft function post-transplantation and does not seem to be associated with increase in morbidity or mortality.

Changes in Renal Function After Heart Transplantation

Renal function after heart transplantation (HTx) typically follows a biphasic pattern and an initial decay within 1 to 2 years. Trajectory of renal function after HTx is less reported, especially in Asia. The aims of this cohort study were to describe the changes in HTx recipients' serum creatinine and estimated glomerular filtration rate (eGFR) levels 5 years following HTx in Taiwan.

METHODS

We retrospectively reviewed 5 years of 440 consecutive adult patients (≥ 18 years) who underwent first HTx from June 1987 to December 2014 at the National Taiwan University Hospital.

RESULTS

Among 422 participants, they received induction therapy consisting of intravenous rabbit antithymocyte globulin. Here, we illustrated the trends over the years by dividing the subjects into 2 groups based on their immunosuppressive regimen of transplantation (1987-2002 and 2003-2014) The pretransplantation median serum creatinine concentration level was 1.2 mg/dL, rose to 1.4 mg/dL at 3 months after surgery, and remained steady over 5 years after HTx. Pretransplant median eGFR was 67 mL/min/1.73 m².The median serum creatinine concentration level and eGFR at baseline were all significantly difference than pretransplantation (P > .05). This result has showed that an initial steep decline within 3 months after transplant remained stable 5 years after HTx.

CONCLUSION

As renal function deteriorates after HTx, we observed a steep decline in serum creatinine level and glomerular filtration rate within the 3 months after HTx, followed by a slow rate of deterioration over the following months. We found a time-related progressive deterioration in renal function during the 5 years after HTx.

Longitudinal changes in kidney function following heart transplantation: Stanford experience

Many heart transplant recipients experience declining kidney function following transplantation. We aimed to quantify change in kidney function in heart transplant recipients stratified by pre-transplant kidney function. A total of 230 adult heart transplant recipients between May 1, 2008, and December 31, 2014, were evaluated for up to 5 years post-transplant (median 1 year). Using 19 398 total estimated glomerular filtration rate (eGFR) assessments, we evaluated trends in eGFR in recipients with normal/near-normal (eGFR ≥45 mL/min/1.73 m2 ) vs impaired (eGFR <45 mL/min/1.73 m2 ) kidney function and the likelihood of reaching an eGFR of 20 mL/min/1.73 m2 after heart transplant. Baseline characteristics were similar. Immediately following heart transplant, the impaired pre-transplant kidney function group showed a mean eGFR gain of 9.5 mL/min/1.73 m2 (n = 193) vs a mean decline of 4.9 mL/min/1.73 m2 (n = 37) in the normal/near-normal group. Subsequent rates of eGFR decline were 2.2 mL/min/1.73 m2 /y vs 2.9 mL/min/1.73 m2 /y, respectively. The probability of reaching an eGFR of 20 mL/min/1.73 m2 or less at 1, 5, and 10 years following heart transplant was 1%, 4%, and 30% in the impaired group, and <1%, <1%, and 10% in the normal/near-normal group. Estimates of expected recovery in kidney function and its decline over time will help inform decision making about kidney care after heart transplantation.

Renal Complications Following Lung Transplantation and Heart Transplantation

Renal complications are common following heart and/or lung transplantation and lead to increased morbidity and mortality. Renal dysfunction is also associated with increased mortality for patients on the transplant wait list. Dialysis dependence is a relative contraindication for heart or lung transplantation at most centers, and such patients are often listed for a simultaneous kidney transplant. Several factors contribute to the impaired renal function in patients undergoing heart and/or lung transplantation, including the interplay between cardiopulmonary and renal hemodynamics, complex perioperative issues, and exposure to nephrotoxic medications, mainly calcineurin inhibitors.

Life-Saving Combined Heart-Kidney Transplantation in a Previous Sequential Heart and Kidney Transplant Recipient

Purpose

Solid organ re-transplantation in the context of allograft failure is a challenging clinical and ethical problem. Ideally, solid organ re-transplantation after initial allograft failure should be performed in all recipients, but this is often not clinically or logistically feasible.

Methods

This report details what we believe is the first combined heart–kidney transplant in a recipient of a previous sequential heart and kidney transplant.

Results

Eight years after a combined heart and kidney transplant after initially receiving a sequential heart and kidney transplant, a 31-year-old man is doing extremely well, with no rejection episodes or significant complications after transplantation.

Summary

This case confirms that combined heart and kidney transplantation is a viable option for tackling the complex issue of graft failure in recipients of previous cardiac and renal grafts.

LEARNING POINTS

Outcomes of Adult Intestinal Transplant Recipients Requiring Dialysis and Renal Transplantation

Supplemental digital content is available in the text.

Background

Data on dialysis and renal transplantation (RT) after intestinal transplantation (IT) are sparse. Whether changes in immunosuppression and surgical techniques have modified these outcomes is unknown.

Methods

Two hundred eighty-eight adult intestinal transplants performed between 1990 and 2014 at the University of Pittsburgh were analyzed for incidence, risk factors and outcomes after dialysis and RT. Cohort was divided into 3 eras based on immunosuppression and surgical technique (1990-1994, 1995-2001, and 2001-2014). Receiving RT, or dialysis for 90 days or longer was considered as end-stage renal disease (ESRD).

Results

During a median follow-up of 5.7 years, 71 (24.7%) patients required dialysis, 38 (13.2%) required long-term dialysis and 17 (6%) received RT after IT. One-, 3-, and 5-year ESRD risk was 2%, 7%, and 14%, respectively. No significant era-based differences were noted. Higher baseline creatinine (hazard ratio [HR], 3.40 per unit increase, P < 0.01) and use of liver containing grafts (HR, 2.01; P = 0.04) had an increased ESRD risk. Median patient survival after dialysis initiation was 6 months, with a 3-year survival of 21%. Any dialysis (HR, 12.74; 95% CI 8.46-19.20; P < 0.01) and ESRD (HR, 9.53; 95% CI, 5.87-15.49; P < 0.01) had higher mortality after adjusting for covariates. For renal after IT, 1- and 3-year kidney and patient survivals were 70% and 49%, respectively. All graft losses were from death with a functioning graft, primarily related to infectious complications (55%).

Conclusions

In intestinal transplant recipients, renal failure requiring dialysis or RT is high and is associated with increased mortality. Additionally, the outcomes for kidney after IT are suboptimal due to death with a functioning graft.

Safety of Peritoneal Dialysis after Nonrenal Solid-Organ Transplantation

BACKGROUND

End-stage renal disease is a well-known complication after solid-organ transplantation, mostly as a result of calcineurin-inhibitor therapy. Among recipients of solid-organ transplants other than kidneys, peritoneal dialysis (PD) has been considered an accessory technique as an increased risk of infectious complications has been reported. The aim of our study was to evaluate the outcome of patients with a liver, heart, or lung transplant who underwent PD for replacement therapy.

METHODS

This was a retrospective, monocentric study. Every adult patient starting PD between January 1, 2001, and December 31, 2016, at our center was included. The history of previous solid-organ transplantation was determined. For the statistical analysis, we considered 2 groups of patients: 1 group having a history of transplantation of an organ other than the kidney (lung, heart, liver), and 1 group that was starting dialysis without any prior history of organ transplantation. Patients who had previously undergone kidney transplantation were excluded. The events of interest were the first peritonitis episode, death, and PD failure, defined as transfer to hemodialysis.

RESULTS

A total of 383 patients started PD during this period, 13 of whom had a history of organ transplantation. We found no significant difference between the solid-organ transplantation patients and those without a history of transplantation in terms of the occurrence of peritonitis (HR [hazard ratio] 0.91 [0.37 - 2.22]), death (HR 0.83 [0.26 - 2.63]), and PD failure (HR 1.01 [0.32 - 3.22]).

CONCLUSION

Peritoneal dialysis appears to be an effective replacement therapy for patients with a previous history of solid-organ transplantation.

Effect of Calcineurin Inhibitor-Free, Everolimus-Based Immunosuppressive Regimen on Albuminuria and Glomerular Filtration Rate After Heart Transplantation

BACKGROUND

Albuminuria in maintenance heart transplantation (HTx) is associated with poor renal response when switching to a calcineurin inhibitor (CNI)-lowered or CNI-free immunosuppressive regimen using everolimus (EVR), but the significance of albuminuria associated with EVR treatment after early CNI withdrawal in de novo HTx is unknown.

METHODS

We tested if measured glomerular filtration rate (mGFR, by chrome-ethylenediaminetetraacetic acid clearance) was associated with urine albumin/creatinine ratio (UACR) post-HTx in a subgroup of patients included in the Scandinavian Heart Transplant Everolimus De Novo Study With Early Calcineurin Inhibitor Avoidance trial, where de novo HTx patients (n = 115) were randomized to EVR with complete CNI elimination 7 to 11 weeks post-HTx or standard CNI immunosuppression.

RESULTS

In 66 patients, UACR measures were available at 1 year. In 7 patients in the EVR group, a CNI was reintroduced within 12 months. Median mGFR was significantly higher in the EVR group both 1 and 3 years post-HTx (P = 0.0004 and P = 0.03, respectively). Median UACR at 1 year was significantly higher in the EVR group (P = 0.002). There was no correlation between log(UACR) at 1 year and mGFR at 1 or 3 years (r = -0.01, P = 0.9 and r = 0.15, P = 0.26, respectively) and in the EVR group between log(UACR) at 1 year and change in mGFR (Δ1-3 years) (r = 0.27, P = 0.14). Excluding patients in the EVR group in whom a CNI was reintroduced did not significantly change the results.

CONCLUSIONS

The effects of EVR with early CNI withdrawal after HTx on albuminuria and renal function seem dissociated; hence, the clinical significance of albuminuria in this setting is uncertain and should not necessarily rule out EVR-based immunosuppression.

Heart failure therapies: new strategies for old treatments and new treatments for old strategies

Heart failure, whether acute or chronic, remains a major health care crisis affecting almost 6 million Americans and over 23 million people worldwide. Roughly half of those affected will die within 5 years, and the annual cost exceeds $30 billion in the US alone. Although medical therapy has made some modest inroads in partially stemming the heart failure tsunami, there remains a significant population for whom medication is unsuccessful or has ceased being effective; such patients can benefit from heart transplantation or mechanical circulatory support. Indeed, in the past quarter century (and as covered in Cardiovascular Pathology over those years), significant improvements in pathologic understanding and in engineering design have materially enhanced the toolkit of options for such refractory patients. Mechanical devices, whether total artificial hearts or ventricular assist devices, have been reengineered to reduce complications and basic wear and tear. Transplant survival has also been extended through a better comprehension of and improved therapies for transplant vasculopathy and antibody-mediated rejection. Here we review the ideas and treatments from the last 25 years and highlight some of the new directions in nonpharmacologic heart failure therapy.

Kidney transplantation as a therapeutic option for end-stage renal disease developing after heart transplantation

BACKGROUND

Progressive renal failure is a frequent complication after heart transplantation (HTx). It may result in end-stage renal disease (ESRD), prompting consideration of kidney Tx after HTx (KAH).

METHODS

We performed a retrospective single-center study of 268 HTx recipients to evaluate outcomes after KAH compared with HTx recipients with and without ESRD.

RESULTS

During a median follow-up of 76 months, ESRD developed in 51 patients (19), and 39 of them (76%) underwent KAH. The mean time from HTx to ESRD was 83 months. The incidence of switching to a calcineurin inhibitor (CNI)-free regimen based on sirolimus was significantly lower among recipients with ESRD (6% vs 57%, p = 0.0001), and prolonged exposure to CNI significantly increased the risk for ESRD (hazard ratio, 1.09; 95% confidence interval, 1.03-1.15; p < 0.005). Death-censored renal graft survival after KAH was 95%, 95%, and 83% at 1, 5, and 10 years, respectively. Median long-term survival of KAH patients was comparable to HTx recipients without ESRD (17.5 vs 17.1 years, p = 0.27) and significantly better compared with HTx recipients with ESRD (17.5 vs 7.3 years, p < 0.001).

CONCLUSIONS

Prolonged exposure to CNI immunosuppression medications significantly increases the risk for ESRD among HTx recipients. KAH is a good therapeutic option for HTx recipients with ESRD, with survival benefit comparable to HTx without ESRD.

Multiorgan transplantation

Kidney transplantation has proven to be the gold standard therapy for severe chronic kidney disease (CKD) due to multiple etiologies in individuals deemed eligible from a surgical standpoint. While kidney transplantation is traditionally considered in conditions of native kidney disease such as diabetes and immunological or inherited causes of kidney disease, an increasing indication for kidney transplantation is kidney dysfunction in the setting of other severe organ dysfunction that requires transplant, such as severe liver or heart disease. In these settings, multiorgan transplantation is now commonly performed, with controversy regarding the appropriate utilization of kidneys transplanted both from a physiological perspective (distinguishing those who require a kidney transplant) and also from an ethical perspective (allocation of a scarce resource to a more morbid population). These issues persist in the setting of simultaneous pancreas-kidney transplant (SPK), in which utilization for patients with type 1 diabetes has been historically accepted. Questions of physiological benefit persist, and utilization is waning despite broader allocation policies that encourage SPK, including consideration for patients with type 2 diabetes. The purpose of this review will be to summarize the physiological data regarding multiorgan transplantation and place these into context while reviewing current allocation policy in the United States.

Outcomes of Recipients With Pancreas Transplant Alone Who Develop End-Stage Renal Disease

Recipients of pancreas transplant alone (PTA) may be at increased risk for developing end-stage renal disease (ESRD). The survival experience of PTA recipients developing ESRD has not been described. Furthermore, the relative survival of these patients as compared to diabetics on chronic dialysis is unknown. We studied all adult PTA recipients from January 1, 1990 to September 1, 2008 using the Scientific Registry of Transplant Recipients. Each PTA recipient developing ESRD was matched to 10 diabetics on chronic dialysis from the United States Renal Data System. Cox proportional hazards models were fitted to determine the relation between ESRD and mortality among PTA recipients, and the relation between PTA and mortality among diabetics on chronic dialysis. There were 1597 PTA recipients in the study, of which 207 developed ESRD. Those with ESRD had a threefold increase in mortality versus those without (adjusted hazard ratio 3.28 [95% confidence interval: 2.27, 4.76]). There was no significant difference in the risk of death among PTA recipients with ESRD versus diabetics on dialysis. PTA recipients developing ESRD are three times more likely to die than PTA recipients without ESRD; however, the risk of death in these patients was similar to diabetics on chronic dialysis without PTA.

Measured and not estimated glomerular filtration rate should be used to assess renal function in heart transplant recipients

BACKGROUND

In organ transplanted patients, impaired renal function is of major prognostic importance and influences therapeutic decisions. Therefore, monitoring of renal function with glomerular filtration rate (GFR) is of importance, both before and after heart transplantation (HTx). The GFR can be measured directly (mGFR) or estimated (eGFR) with equations based on circulating creatinine or cystatin C levels. However, these equations have not been thoroughly validated in the HTx population.

METHODS

We investigated the correlation, agreement and accuracy between mGFR (using (51)Cr-ethylenediaminetetraacetic acid or iohexol clearance) and three commonly used eGFR equations (Modification of Diet in Renal Disease, Cockcroft-Gault and Chronic Kidney Disease Epidemiology Collaboration) in a retrospective analysis of 416 HTx recipients followed between 1988 and 2012. Comparisons were performed prior to transplantation and at 1, 5 and 10 years of follow-up.

RESULTS

The correlations between eGFR and mGFR were only moderate, with r-values ranging from 0.55 preoperatively to 0.82 during follow-up. Most importantly, the level of agreement between eGFR and mGFR was very low for all three estimates, with percentage errors ranging from 93.3 to 157.3%. Also, the percentage of patients with eGFR within 30% of mGFR (P30) rarely reached the National Kidney Foundation recommended minimum level of 75%.

CONCLUSION

We argue that the accuracy and the precision of the most commonly used estimation equations for assessment of kidney function are unacceptably low and we believe that mGFR should be used liberally as the basis for clinical decision-making both before and after HTx when eGFR is subnormal.

Chronic renal insufficiency in heart transplant recipients: risk factors and management options

Renal dysfunction after heart transplantation is a frequently observed complication, in some cases resulting in significant limitation of quality of life and reduced survival. Since the pathophysiology of renal failure (RF) is multifactorial, the current etiologic paradigm for chronic kidney disease after heart transplantation relies on the concept of calcineurin inhibitor (CNI)-related nephrotoxicity acting on a predisposed recipient. Until recently, the management of RF has been restricted to the minimization of CNI dosage and general avoidance of classic nephrotoxic risk factors, with somewhat limited success. The recent introduction of proliferation signal inhibitors (PSIs) (sirolimus and everolimus), a new class of immunosuppressive drugs lacking intrinsic nephrotoxicity, has provided a completely new alternative in this clinical setting. As clinical experience with these new drugs increases, new renal-sparing strategies are becoming available. PSIs can be used in combination with reduced doses of CNIs and even in complete CNI-free protocols. Different strategies have been devised, including de novo use to avoid acute renal toxicity in high-risk patients immediately after transplantation, or more delayed introduction in those patients developing chronic RF after prolonged CNI exposure. In this review, the main information on the clinical relevance and pathophysiology of RF after heart transplantation, as well as the currently available experience with renal-sparing immunosuppressive regimens, particularly focused on the use of PSIs, is reviewed and summarized, including the key practical points for their appropriate clinical usage.

Advantageous effects of immunosuppression with tacrolimus in comparison with cyclosporine A regarding renal function in patients after heart transplantation

BACKGROUND

Nephrotoxicity is a serious adverse effect of calcineurin inhibitor therapy in patients after heart transplantation (HTX).

AIM

In this retrospective registry study, renal function within the first 2 years after HTX in patients receiving de novo calcineurin inhibitor treatment, that is, cyclosporine A (CSA) or tacrolimus (TAC), was analyzed. In a consecutive subgroup analysis, renal function in patients receiving conventional tacrolimus (CTAC) was compared with that of patients receiving extended-release tacrolimus (ETAC).

METHODS

Data from 150 HTX patients at Heidelberg Heart Transplantation Center were retrospectively analyzed. All patients were continuously receiving the primarily applied calcineurin inhibitor during the first 2 years after HTX and received follow-up care according to center practice.

RESULTS

Within the first 2 years after HTX, serum creatinine increased significantly in patients receiving CSA (P<0.0001), whereas in patients receiving TAC, change of serum creatinine was not statistically significant (P=not statistically significant [ns]). McNemar's test detected a significant accumulation of patients with deterioration of renal function in the first half year after HTX among patients receiving CSA (P=0.0004). In patients receiving TAC, no significant accumulation of patients with deterioration of renal function during the first 2 years after HTX was detectable (all P=ns). Direct comparison of patients receiving CTAC versus those receiving ETAC detected no significant differences regarding renal function between patients primarily receiving CTAC or ETAC treatment during study period (all P=ns).

CONCLUSION

CSA is associated with a more pronounced deterioration of renal function, especially in the first 6 months after HTX, in comparison with patients receiving TAC as baseline immunosuppressive therapy.

Organ donation and transplantation in Canada: insights from the Canadian Organ Replacement Register

PURPOSE OF REVIEW

To provide an overview of the transplant component of the Canadian Organ Replacement Register (CORR).

FINDINGS

CORR is the national registry of organ failure in Canada. It has existed in some form since 1972 and currently houses data on patients with end-stage renal disease and solid organ transplants (kidney and/or non-kidney). The transplant component of CORR receives data on a voluntary basis from individual transplant centres and organ procurement organizations across the country. Coverage for transplant procedures is comprehensive and complete. Long-term outcomes are tracked based on follow-up reports from participating transplant centres. The longitudinal nature of CORR provides an opportunity to observe the trajectory of a patient's journey with organ failure over their life span. Research studies conducted using CORR data inform both practitioners and health policy makers alike.

IMPLICATIONS

The importance of registry data in monitoring and improving care for Canadian transplant candidates/recipients cannot be over-stated. This paper provides an overview of the transplant data in CORR including its history, data considerations, recent findings, new initiatives, and future directions.

Difficulty of patient selection in a combined heart-kidney transplant: a case report

Combined heart-kidney transplant has become an alternative for heart transplant candidates with significant chronic kidney disease. However, it is not clear which patients will benefit most from such intervention, and in whom cardiac transplant alone will be sufficient to restore adequate renal function. We report the case of a man with ischemic cardiomyopathy and chronic kidney disease who was wait-listed for heart-kidney transplant after acute decompensated heart failure and renal failure requiring hemodialysis. Because of unexpected circumstances, the kidney transplant was cancelled, and only a heart transplant was performed. Nonetheless, the kidney function rapidly improved beyond the levels before hospitalization and remains stable months after transplant. This case illustrates the difficulties in assessing the reversibility of kidney damage in the context of heart failure requiring transplant. This issue is primordial to improve selection of patients who will benefit most from combined heart-kidney transplant in a context of scarce organ allocation resources.

Plasma NGAL and glomerular filtration rate in cardiac transplant recipients treated with standard or reduced calcineurin inhibitor levels

AIM

Predictors of renal recovery following conversion from calcineurin inhibitor- to proliferation signal inhibitor-based therapy are lacking. We hypothesized that plasma NGAL (P-NGAL) could predict improvement in glomerular filtration rate (GFR) after conversion to everolimus.

PATIENTS & METHODS

P-NGAL was measured in 88 cardiac transplantation patients (median 5 years post-transplant) with renal dysfunction randomized to continuation of conventional calcineurin inhibitor-based immunosuppression or switching to an everolimus-based regimen.

RESULTS

P-NGAL correlated with measured GFR (mGFR) at baseline (R(2) = 0.21; p < 0.001). Randomization to everolimus improved mGFR after 1 year (median [25-75 % percentiles]: ΔmGFR 5.5 [-0.5-11.5] vs -1 [-7-4] ml/min/1.73 m(2); p = 0.006). Baseline P-NGAL predicted mGFR after 1 year (R(2) = 0.18; p < 0.001), but this association disappeared after controlling for baseline mGFR.

CONCLUSION

P-NGAL and GFR correlate with renal dysfunction in long-term heart transplantation recipients. P-NGAL did not predict improvement of renal function after conversion to everolimus-based immunosuppression.

Heart and combined heart-kidney transplantation in patients with concomitant renal insufficiency and end-stage heart failure

In patients with end-stage heart failure (ESHF) who are candidates for isolated heart transplant (HRT), dialysis dependence (DD) is considered an indication for combined heart-kidney transplantation (HKT). HKT remains controversial in ESHF transplant candidates with nondialysis-dependent renal insufficiency (NDDRI). Using United Network for Organ Sharing data, we examined the cumulative incidences of transplant and mortality in patients with DD and NDDRI waitlisted for HKT or HRT. In all groups, 3-month waitlist mortality was dismal: 31% and 21% for HRT- and HKT-listed patients with DD and 12% and 7% for HRT- and HKT-listed patients with NDDRI. Five-year posttransplant survival was improved in HKT recipients compared with HRT recipients for both patients with DD (73% vs. 51%, p<0.001) and NDDRI (80% vs. 69%, p<0.001). Likewise, multivariable analysis associated HKT with better outcomes than HRT in HKT-listed patients, although both improved survival. These data argue strongly for HKT in ESHF transplant candidates with DD. However, in patients with NDDRI, HKT must be weighed against the possibility of renal recovery with isolated HRT. Whether HRT (followed by a staged kidney transplant in patients who do not recover renal function after HRT), as opposed to HKT, maximizes organ benefit for patients with NDDRI and ESHF requires assessment. Nevertheless, given their dismal waitlist outcomes and excellent posttransplant results, we suggest that patients with DD and NDDRI with ESHF be considered for early listing and transplant.

Incidence, risk factor, and prognosis of end-stage renal disease after heart transplantation in Chinese recipients

BACKGROUND/PURPOSE

End-stage renal disease (ESRD) is an important complication arising after heart transplantation. At least 3-10% of recipients reach ESRD within 10 years after transplant. The incidence of ESRD in Chinese recipients has not been reported. Here we sought to assess the incidence, prognosis, and risk factors for ESRD in Chinese recipients.

METHODS

We conducted a retrospective analysis of 248 heart recipients who survived >1 year from 1998 through 2007. ESRD was defined as the requirement of maintenance dialysis.

RESULTS

Renal dysfunction was present in 20 patients (8%) prior to transplant. With a follow-up duration of 5.8 ± 3.9 years, 30 patients developed ESRD. The cumulative incidence of ESRD after heart transplantation was 2.1% ± 0.9%, 6.5% ± 1.8%, 16.8% ± 3.3%, and 36.5% ± 9.5% at 2, 5, 10, and 15 years after transplant, respectively. Median onset of ESRD was 6.9 years after transplant. Actuarial survival after dialysis was 74.8% ± 8.3%, 66.6% ± 9.2%, and 43.6% ± 12.6% at 1, 2, and 5 years, respectively. Independent risk factors for ESRD included pretransplant serum creatinine (hazard ratio, 1.84; p = 0.001), presence of diabetes prior to transplant (hazard ratio, 2.51; p = 0.017), and old age at transplant (hazard ratio, 1.05; p = 0.008).

CONCLUSION

There was a high incidence of ESRD in Chinese heart recipients. Patients with ESRD had poor prognosis after dialysis.

Early changes in kidney function predict long-term chronic kidney disease and mortality in patients after liver transplantation

BACKGROUND

Chronic kidney disease (CKD) is a well-known complication after liver transplantation (LT) and is associated with increased mortality. The purpose of this study was to determine risk factors of advanced CKD and mortality after LT.

METHODS

Four hundred forty-five adult patients underwent LT between June 1990 and September 2007 and survived more than 1 month. Multivariate Cox regression analyses were performed for time to CKD stage 4 (glomerular filtration rate [GFR] ≤30 mL/min), time to chronic dialysis, and all-cause mortality. Several patient and disease characteristics were used as independent pre- and posttransplant variables. We specifically analyzed a drop more than or equal to 30% in the estimated GFR (eGFR) during the first year posttransplant.

RESULTS

Diabetes mellitus pretransplant and a drop more than or equal to 30% in the eGFR between 3 and 12 months predicted CKD stage 4 (odds ratio [OR] 4.1, 95% confidence interval [CI] 1.9-5.4, P<0.001 and OR 16.1, 95% CI 5.9-44.5, P<0.0001, respectively), the need for chronic dialysis (OR 3.8, 95% CI 1.1-13.2, P=0.03 and OR 14.6, 95% CI 3.0-71.4, P<0.001, respectively), and all-cause mortality (OR 1.9, 95% CI 1.2-2.9, P=0.004 and OR 2.6, 95% CI 1.6-4.4, P<0.001, respectively), more than 1 year after LT.

CONCLUSIONS

Diabetes mellitus pretransplant and a drop more than or equal to 30% in the eGFR within the first year are strong predictors of advanced CKD, chronic dialysis, and death more than 1 year after LT. These easily determined clinical variables define a population at risk for CKD who should be targeted for renal protection strategies.

The influence of induction therapy for kidney transplantation after a non-renal transplant

BACKGROUND AND OBJECTIVES

Non-renal transplant recipients who subsequently develop ESRD and undergo kidney transplantation are medically and immunologically complex due to comorbidities, high cumulative exposure to immunosuppressants, and sensitization to alloantigen from the prior transplant. Although prior non-renal transplant recipients are one of the fastest growing segments of the kidney wait list, minimal data exist to guide the use of antibody induction therapy (IT+) at the time of kidney after lung (KALu), heart (KAH), and liver (KALi) transplant.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study used national registry data to examine IT use and survival after kidney transplantation. Separate multivariate Cox regression models were constructed to assess patient survival for IT+ and IT- KALu (n=232), KAH (n=588), and KALi (n=736) recipients.

RESULTS

Use of IT increased during the study period. The percentage of patients considered highly sensitized (panel reactive antibody ≥20%) was not statistically significant between IT+ and IT- groups. IT+ was not associated with improvement in 1- and 10-year patient survival for KALu (P=0.20 and P=0.22, respectively) or for KAH (P=0.90 and P=0.14, respectively). However, IT+ among KALi was associated with inferior patient survival at 1 and 10 years (P=0.04 and P=0.02, respectively).

CONCLUSIONS

Use of IT for kidney transplantation among prior non-renal transplant recipients may not offer a survival advantage in KALu or KAH. However, due to limited power, these findings should be interpreted cautiously. IT+ was associated with inferior outcomes for KALi. Use of IT should be judicially reconsidered in this complex group of recipients.

Peritoneal dialysis in transplant recipient patients: outcomes and management

Transplant recipient patients performing dialysis represent a growing population in the integrated model of renal replacement therapy. This includes both patients with kidney allograft loss and non-renal organ transplant recipients requiring dialysis. Although a number of possible advantages of peritoneal dialysis over haemodialysis could hypothetically favour its choice when starting dialysis, peritoneal dialysis penetration is relatively residual in this population. Questions about its safety and adequacy in these patients can explain this fact. The purpose of this review is to address unfounded fears and document evidence that peritoneal dialysis should be considered a viable and safe choice in patients returning to dialysis. Specific issues that still need further investigation are also discussed.

Peritoneal dialysis after nonrenal solid organ transplantation: clinical outcomes and practical considerations

The incidence of end-stage renal disease following nonrenal solid organ transplantation (NRSOT) is increasing and is associated with a poor prognosis. The etiology of end-stage renal disease is multifactorial, with calcineurin inhibitor (CNI) nephrotoxicity being primarily responsible. The impact of dialysis modality on the survival of these patients remains unclear. Peritoneal dialysis appears to be a feasible and safe option for renal replacement therapy in NRSOT patients. Concerns that NRSOT patients are at a higher risk of infectious and noninfectious complications necessitate practical considerations when prescribing and planning for peritoneal dialysis in these patients. While nephrotoxicity is a well-recognized complication of long-term CNI use, "peritoneotoxic" effects with significant alterations in peritoneal membrane structure and function have recently been described. Further study including the role of CNI-free immunotherapy protocols to optimize the outcomes of NRSOT recipients is needed.

Wait list death and survival benefit of kidney transplantation among nonrenal transplant recipients

The disparity between the number of patients waiting for kidney transplantation and the limited supply of kidney allografts has renewed interest in the benefit from kidney transplantation experienced by different groups. This study evaluated kidney transplant survival benefit in prior nonrenal transplant recipients (kidney after liver, KALi; lung, KALu; heart, KAH) compared to primary isolated (KA1) or repeat isolated kidney (KA2) transplant. Multivariable Cox regression models were fit using UNOS data for patients wait listed and transplanted from 1995 to 2008. Compared to KA1, the risk of death on the wait list was lower for KA2 (p < 0.001;HR = 0.84;CI = 0.81-0.88), but substantially higher for KALu (p < 0.001; HR = 3.80;CI = 3.08-4.69), KAH (p < 0.001; HR = 1.92; CI = 1.66-2.22), and KALi (p < 0.001; HR = 2.69; CI = 2.46-2.95). Following kidney transplant, patient survival was greatest for KA1, similar among KA2, KALi, KAH, and inferior for KALu. Compared to the entire wait list, renal transplantation was associated with a survival benefit among all groups except KALu (p = 0.017; HR = 1.61; CI = 1.09-2.38), where posttransplant survival was inferior to the wait list population. Recipients of KA1 kidney transplantation have the greatest posttransplant survival and compared to the overall kidney wait list, the greatest survival benefit.

Biopsy-diagnosed renal disease in patients after transplantation of other organs and tissues

Renal function deteriorates in about half of patients undergoing other transplants. We report the results of 105 renal biopsies from 101 nonrenal transplant recipients (bone marrow 14, liver 41, lung 30, heart 20). Biopsy indications were protracted acute renal failure (9%), creatinine increases (83%), heavy proteinuria (22%), or renal insufficiency before re-transplantation (9%). Histological findings other than nonspecific chronic changes, hypertension-related damage, and signs of chronic CNI toxicity included primary glomerular disease (17%), mostly after liver transplantation (21%) or after bone marrow transplantation (29%), and thrombotic microangiopathy (TMA) namely (10%). TMA had the most serious impact on the clinical course. Besides severe hypertension, one TMA patient died of cerebral hemorrhage, 5 had hemolytic-uremic syndrome, and 6 rapidly developed end-stage renal failure. TMA patients had the shortest kidney survival post-biopsy and, together with patients with acute tubular injury, the shortest kidney and patient survival since transplantation. Nine TMA patients had received CNI, 3 of them concomitantly received an mTOR-inhibitor. CNI toxicity is implicated in most patients with renal failure after transplant of other organs and may play a role in the development of TMA, the most serious complication. However, decreased renal function should not be routinely ascribed to CNI.