Evaluation and Management of Pulmonary Hypertension in Kidney Transplant Candidates and Recipients: Concepts and Controversies

Associations Between Type of Hemodialysis Access and Pulmonary Hypertension: A Single-Center Retrospective Cohort

BACKGROUND

Pulmonary hypertension affects patients with hemodialysis-dependent end-stage kidney failure; however, the estimated prevalence varies greatly due to the underutilization of right heart catheterization and the evolving diagnostic criteria of pulmonary hypertension. Pulmonary hypertension in end-stage kidney failure is often attributed to arteriovenous (AV) access; therefore, we hypothesized that patients with AV fistula/graft would have a greater prevalence of pulmonary hypertension on right heart catheterization compared to those with central venous (CV) catheter accesses.

METHODS

In this retrospective single-center cohort study, we identified and randomly sampled patients from July 2012 to August 2022 receiving hemodialysis for ≥ 3 months and who underwent right heart catheterization, using Current Procedural Terminology codes. Pulmonary hypertension was defined as mean pulmonary arterial pressure (mPAP) > 20 mmHg. Our primary outcome was the prevalence of pulmonary hypertension among patients with AV fistula/graft versus CV hemodialysis access, tested with descriptive statistics. We evaluated survival as a secondary outcome using a Cox proportional hazards model.

RESULTS

A total of 3834 patient charts were extracted. Overall, 444 charts were randomly sampled, resulting in 137 subjects meeting the inclusion criteria. The mean age was 63.8 ± 10.5 years, and 62% were male. The most common etiology of end-stage kidney failure was diabetic kidney disease (57.7%). Eighty percent of end-stage kidney failure patients had pulmonary hypertension; however, the type of hemodialysis access was not associated with pulmonary hypertension (85% CV catheter vs. 79.5% AV access, p = 0.59). Patients with pulmonary hypertension had lower hemoglobin (9.6 ± 0.8 vs. 11.2 ± 1.3 g/dL, p < 0.0001) and serum albumin (2.3 ± 0.9 vs. 3.4 ± 0.6 g/dL, p < 0.0001) than those without pulmonary hypertension. Those with pulmonary hypertension had an increased risk of mortality (hazard ratio: 2.2, 95% confidence interval: 1.04-4.61; p = 0.04).

CONCLUSION

Our findings show a high burden of pulmonary hypertension among this heterogeneous cohort of end-stage kidney failure patients, with no association between pulmonary hypertension and the type of hemodialysis access. This study highlights the need for prospective investigations incorporating current strategies for pulmonary hypertension diagnosis and treatment among the dialysis-dependent population.

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

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

Endothelial dysfunction in the kidney transplant population: Current evidence and management strategies

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and vasodilators. Endothelial dysfunction (ED), characterized by impaired vasodilation, inflammation, and thrombosis, triggers future cardiovascular (CV) diseases. Chronic kidney disease, a state of chronic inflammation caused by oxidative stress, metabolic abnormalities, infection, and uremic toxins damages the endothelium. ED is also associated with a decline in estimated glomerular filtration rate. After kidney transplantation, endothelial functions undergo immediate but partial restoration, promising graft longevity and enhanced CV health. However, the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED, culminating in poor CV health and graft survival. ED in kidney transplant recipients is an under-recognized and poorly studied entity. CV diseases are the leading cause of death among kidney transplant candidates with functioning grafts. ED contributes to the pathogenesis of many of the CV diseases. Various biomarkers and vasoreactivity tests are available to study endothelial functions. With an increasing number of transplants happening every year, and improved graft rejection rates due to the availability of effective immunosuppressants, the focus has now shifted to endothelial protection for the prevention, early recognition, and treatment of CV diseases.

Management of Kidney Disease in Heart Transplant Patients: A National Delphi Survey-based Consensus Expert Paper

Kidney disease is a common complication in heart transplant recipients and requires a comprehensive and personalized approach. The interplay between preexisting kidney disease, perioperative factors, immunosuppression, and cardiovascular complications makes the management of kidney dysfunction challenging in these patients. The objective of this expert consensus was to look for agreements for the management of chronic kidney disease in heart transplant recipients. A panel of Spanish cardiologists and nephrologists with expertise in heart and kidney transplantation reviewed the evidence related to the current management of chronic kidney disease in heart transplant recipients and consensus statements were developed using a 2-round Delphi methodology. Consensus statements were proposed covering key topics, including the identification and management of kidney disease in heart transplant recipients and the indications for kidney transplantation. These statements provide additional expert guidance for the management of kidney disease in patients undergoing heart transplantation where published clinical evidence is scarce.

Cardiac evaluation of renal transplant candidates with heart failure

Patients with advanced kidney disease are at elevated risk of developing heart failure and appropriate risk stratification is important to permit them to receive kidney transplantation. The American Heart Association and American College of Cardiology joint statement provides guidance on risk stratification for the major cause of heart failure for these patients in its recommendations for coronary heart disease. Herein we provide an overview of the available literature on risk stratification for nonischemic heart failure and functional heart disease states such as pulmonary hypertension. Many of these options for optimizing these patients before transplant include optimizing their volume status, often with more aggressive ultrafiltration. Kidney transplantation remains the treatment of choice for patients with advanced kidney disease and cardiac disease, the correction of the azotemic substances with kidney transplantation has been associated with improved survival than remaining on dialysis long-term. The findings in the studies reviewed here are expected to help clinicians refine current strategies for evaluating potential kidney transplant recipients.

Association of Cardiopulmonary Hemodynamics and Outcomes in Pulmonary Hypertension Following Kidney Transplantation: A Multicenter Retrospective Cohort Study

BACKGROUND

Pulmonary hypertension (PH) frequently complicates the evaluation of kidney transplantation (KT) candidates, and is associated with increased adverse outcomes (mortality, delayed graft function [DGF], and major adverse cardiovascular event) following KT.

RESEARCH QUESTION

What is the relationship between cardiopulmonary hemodynamics and post-KT outcomes?

STUDY DESIGN AND METHODS

We conducted a multicenter retrospective cohort study of adults undergoing KT between October 1, 2011 and October 1, 2021, who underwent right heart catheterization (RHC) to assess cardiopulmonary hemodynamics within 1 year of transplantation. Frailty models and logistic regression models were used to evaluate the association between cardiopulmonary hemodynamics and outcomes (mortality, DGF, major adverse cardiovascular event) following KT.

RESULTS

A total of 117 patients were included in the final analysis, predominantly male (72%), with a median age of 57 years. PH, defined as mean pulmonary artery pressure (mPAP) > 20 mm Hg, was present in most of the cohort (n = 93; 79%). The cohort was monitored for a median of 29.9 months post-KT, during which about one-fourth experienced mortality (23%) or DGF (25%) events, and approximately one-third (34%) experienced major adverse cardiovascular event. Although echocardiographic measures of pulmonary artery pressure failed to identify post-KT outcomes, a mPAP of ≥ 30 mm Hg on RHC was associated with post-KT major adverse cardiovascular event (hazard ratio, 2.60; 95% CI, 1.10-6.10) and more prevalent in those experiencing post-KT mortality (63% vs 32%; P = .001). Precapillary pulmonary hypertension was also associated with post-KT mortality (hazard ratio, 3.71; 95% CI, 1.07-12.90).

INTERPRETATION

Precapillary pulmonary hypertension and an mPAP of ≥ 30 mm Hg on RHC, but not echocardiographic evidence of PH, was associated with mortality and major adverse cardiovascular event following KT. These data suggest that RHC hemodynamics are superior to echocardiographic measures of PH in association with outcomes following KT, and RHC-derived mPAP in particular may have value in predicting major adverse cardiovascular event and mortality post-KT.

Association of arteriovenous fistulae with precapillary pulmonary hypertension - A single center retrospective analysis of invasive hemodynamic parameters

BACKGROUND

Pulmonary hypertension (pH) is a well-known complication among patients with chronic kidney disease (CKD). Arteriovenous fistulae (AVF) have been associated with pH mainly by increasing cardiac output. However, the burden of precapillary pH in individuals with CKD and an AVF is unclear.

OBJECTIVES

To better and more fully understand the mechanism and development of precapillary pH in patients with AVF, as well as the consequences of precapillary pH in these patients.

METHODS

This was a large retrospective study of patients with CKD stage 4 or 5 who underwent right heart catheterization (RHC) from 2018 to 2023. The data were stratified according to the presence of AVF. To determine if AVF was independently associated with precapillary pH, we used a multivariable logistic regression analysis adjusting for demographics and potential comorbidities associated with precapillary pH, including diagnosis of chronic lung disease, obstructive sleep apnea, connective tissue disease, history of venous thromboembolism, chronic anemia, and heart failure.

RESULTS

Of 651 patients with CKD4 or CKD5, 145 (22 %) had AVF and 506 (78 %) did not have AVF. Within the AVF group, the median age was 64 years (IQR 54-71), and they were predominantly males (61 %, n = 88) and African American (77 %, n = 111). A total of 31 % (n = 45) had evidence of precapillary pH, 30 % (n = 43) of combined pH, and 14 % (n = 20) of isolated postcapillary pH. Compared to the non-AVF group, precapillary pH was more likely in the AVF group (31% vs 17 %, p < 0.0001). On multivariable analysis, AVF was independently associated with precapillary pH (OR 2.47, CI 1.56-3.89; p < 0.0001). The median time from dialysis initiation to RHC date (and precapillary pH diagnosis) was 6 years (IQR 3-8).

CONCLUSION

Based on RHC findings, almost one-third of patients with CKD and AVF had precapillary pH. The presence of AVF was independently associated with precapillary pH.

Kidney transplantation in the presence of pulmonary hypertension: A clinical dilemma

End-stage renal disease (ESRD) is a progressive chronic condition that is strongly associated with cardiovascular mortality. ESRD patients usually benefit significantly from kidney transplantation. Pulmonary hypertension (PH) is a common finding in ESRD patients that adversely affects their survival. It has also been associated with adverse increased mortality and morbidity following kidney transplantation. However, PH has also been thought to improve following kidney transplantation. The exact underlying pathophysiology of PH in ESRD patients is unknown. However, it has been believed to be multifactorial, involving endothelial dysfunction, volume overload, and arteriovenous fistula. Management of PH in kidney transplant candidates and ESRD patients is remarkably understudied. Several treatment options are available for the treatment of PH. However, studies conducted on treating PH in ESRD patients are scarce. There is an increased need for studies on ESRD patients with PH.

The Effect of Kidney Transplantation on Pulmonary Hypertension in End-stage Kidney Disease Patients on Hemodialysis

Introduction:

Pulmonary hypertension (PH) is highly prevalent in chronic kidney disease (CKD) patients, especially those undergoing hemodialysis. PH is a strong independent predictor of mortality in dialysis patients. Kidney transplantation (KT) is the best treatment modality for reversing adverse cardiac effects of CKD.

Methods:

A prospective cohort study was done in end-stage kidney disease (ESKD) patients on hemodialysis with PH (defined as pulmonary artery systolic pressure [PASP] of 35 mmHg or above) who subsequently underwent KT. Follow-up echocardiogram was done at an average of 15 months post KT.

Results:

A total of 277 patients underwent KT, out of which 95 had PH (prevalence 34.3%). Our study included 65 patients with PH who consented for the study. There was a significant improvement in PH as evidenced by a reduction in PASP (PASP pre KT 44.8 [±9.91] post KT 32.77 [±6.33], P = 0.001). 72.3% of patients achieved normal pulmonary pressures. There was also a significant improvement in ejection fraction (63.01 [±7.4] vs. 65.06 [±5.61], P = 0.04) and left atrial diameter (3.9 [±0.45] vs. 3.52 [±0.51], P = 0.001) post KT. There was an improvement in mean hemoglobin level (10.4 [±2.17] vs. 13.5 [±2.13], P = 0.001), serum calcium levels (serum Ca 8.76 [±0.72] vs. 9.19 [±0.82], P = 0.001) and improvement in the New York Heart Association (NYHA) class.

Conclusions:

KT significantly improves PH in ESKD patients on hemodialysis and can potentially normalize it. There is also improvement in overall cardiac functions, serum hemoglobin, and calcium levels. This translates to better physical endurance as evidenced by improvement in NYHA class post KT.

Approach to Late Noninfectious Post-Transplant Complications

The management of noninfectious complications in kidney transplant recipients includes a broad spectrum of conditions, including metabolic issues, cardiovascular diseases, and malignancies, each presenting unique challenges for nephrologists managing these patients. Unlike infectious complications, these noninfectious issues require nuanced, multidisciplinary approaches for prevention, diagnosis, and management, emphasizing the need for personalized care plans. Cardiovascular disease is particularly significant, standing as the primary cause of death post-transplantation, with recent data indicating an overtaking of cancer death rates over infections among kidney transplant recipients. The intricacies of managing these patients, influenced by the burden of kidney disease and immunosuppression, highlight the importance of a collaborative care model. Although nephrologists may not directly treat all these conditions, their understanding of the unique aspects of transplant recipients is crucial. They play a pivotal role in coordinating care with specialists such as cardiologists, endocrinologists, hematologists, and oncologists, ensuring comprehensive management that addresses these specific post-transplant complications. This review discusses the epidemiology, underlying mechanisms, clinical manifestations, and management strategies of various noninfectious complications post-kidney transplant, with a focus on cardiovascular, metabolic, oncologic, and hematologic complications.

Evaluation of the effect of kidney transplantation on left ventricular myocardial work by noninvasive pressure-strain loops

Purpose

Kidney transplantation (KT) has the potential to reverse the cardiac changes caused by end-stage renal disease, and it may be inaccurate to analysis the left ventricular function by conventional echocardiography due to afterload. This study aimed to investigate the utility of pressure strain loops (PSLs) in evaluating left ventricular performance in patients underwent KT.

Methods

We enrolled 60 patients with end-stage renal disease who underwent KT between January 2022 and July 2023, and 60 healthy controls with a similar distribution of gender and age to the patients. All participants underwent conventional echocardiography and three-dimensional speckle tracking echocardiography (3D-STE). Long axis, short axis, and four cavity images were collected and cardiac parameters were measured. The echocardiographic changes of cardiac structure and function of all patients before KT and about 12 months after KT were recorded. Left ventricular myocardial work parameters were acquired by PSLs, including the global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE) and global longitudinal strain (GLS). In addition, the correlation between PSLs and clinical data were explored.

Results

Compared with controls, the conventional echocardiographic parameters, myocardial function indicators GWI and GCW appeared no difference in post-KT group, while the GWE and GLS decreased (p < 0.05), and the GWW increased (p < 0.05). Compared with pre-KT, the GLS, GWI, GCW and GWE increased in post-KT group, while the GWW decreased (all p < 0.05). The above indicators were correlated with left ventricular GLS and left ventricular ejection fraction.

Conclusion

PSLs were more sensitive than traditional echocardiographic indicators in detecting changes in myocardial work and predicting left ventricular myocardial damage. This indicator could quantitatively evaluate myocardial work and provide a new and reliable non-invasive reference for clinical diagnosis and treatment of patients underwent KT.

Management and Outcomes of Kidney Transplant Candidates With Severe Pulmonary Hypertension: A Single-center Strategy and Experience

Background

Severe pulmonary hypertension (PH) is associated with high mortality posttransplant and thus is considered a contraindication to kidney transplantation. In this study, we describe the pretransplant management and posttransplant outcomes in patients with severe PH using a multidisciplinary approach.

Methods

Between 11 of 2013 and 8 of 2022, we identified all patients with severe PH on initial pretransplant workup who underwent ultrafiltration (UF) or medical therapy for PH before transplant. Posttransplant we evaluated the perioperative course, renal function, graft, and patient survival. We compared survival to those who remained waitlisted or were delisted.

Results

Three-two patients (mean age = 55.03 ± 10.22 y) diagnosed with severe PH on pretransplant screening echocardiogram. Thirty patients (94%) were subjected to a median of 4 (range, 3-8) UF sessions with an average weight loss of 4.33 ± 2.6 kg. Repeat assessment of PH revealed a decline in mean pulmonary artery systolic pressure from 67 ± 12 mm Hg to 43 ± 13 mm Hg (P < 0.0001). Seventeen patients (53%) received a kidney transplant. The mean estimated Glomerular Filtration Rate at 3, 6, 9, and 12 mo was 72 ± 27, 72 ± 28, 75 ± 29, and 75 ± 29 mL/min/1.73 m2. Among, those who underwent transplantation both graft and patient survival was 100% at 1-y posttransplant. Overall, since the UF intervention, at a median follow-up of 88 ± 12 mo those transplanted had a patient survival of 88% while those who remained on dialysis had a survival of 53% (P = 0.0003).

Conclusion

In this single-center study, we report postcapillary PH can be a significant contributor to elevations in pulmonary artery systolic pressure. Using a multidisciplinary approach, PH can improve with volume removal and phosphodiesterase 5 inhibitors therapy leading to a successful posttransplant outcome.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Intensive ultrafiltration strategy restores kidney transplant candidacy for patients with echocardiographic evidence of pulmonary hypertension

INTRODUCTION

Pulmonary hypertension (PH) is prevalent in those with end-stage kidney disease (ESKD) and poses a barrier to kidney transplant due to its association with poor outcomes. Studies examining these adverse outcomes are limited and often utilize echocardiographic measurements of pulmonary artery systolic pressure (PASP) instead of the gold standard right heart catheterization (RHC). We hypothesized that in ESKD patients deemed ineligible for kidney transplant because of an echocardiographic diagnosis of PH the predominant cause of PH is hypervolemia and is potentially reversible.

METHODS

We conducted a prospective study of 16 patients with ESKD who were denied transplant candidacy. Prior echocardiograms and RHCs were reviewed for confirmation of PH. Patients were admitted for daily sessions of ultrafiltration for volume removal and repeat RHCs were performed following intervention. RHC parameters and body weight were compared before and after intervention. Statistical analysis was performed using PRISM GraphPad software. A p-value <.05 was considered statistically significant.

RESULTS

Following intervention, the mean pulmonary artery pressure (mPAP) and pulmonary arterial wedge pressure decreased from 45.0 ± 3.06 to 29.1 ± 7.77 mmHg (p < .0001) and 22.2 ± 5.06 to 13.1 ± 7.25 mmHg (p = .003), respectively. The pulmonary vascular resistance decreased from 4.73 ± 1.99 to 4.28 ± 2.07 WU (p = .30). Eleven patients from the initial cohort underwent successful kidney transplantation post-intervention with 100% survival at 1-year.

CONCLUSIONS

In ESKD patients, diagnoses of PH made by echocardiography may be largely due to hypervolemia and may be optimized using an intensive ultrafiltration strategy to restore transplant candidacy.

Use of Peripheral Insertion Central Venous Catheter in Kidney Transplant Patients: An Alternative

Kidney transplantation continues to be the treatment of choice in patients with end-stage chronic kidney disease. Unfortunately, most patients in the adult population have coexisting diseases. Anemia, platelet dysfunction, and changes to the cardiovascular system are not the exception in the evolution of the disease. This group of patients has an increased risk of intraoperative and postoperative complications associated with the general conditions of their body and other complications related to the surgical procedure. For this reason, adequate control of fluids and electrolytes under adequate monitoring and hemodynamic support are essential; these can optimize the patient's vital signs and improve the conditions of the implant to guarantee proper functioning. In this series, 18 kidney transplant recipients with peripheral insertion central venous catheter were reviewed. There was an acceptable rate of success with proper placement. No complications inherent to the installation technique were found. In all patients, the installation was successful.

Incidence, Clinical Correlates, and Outcomes of Pulmonary Hypertension After Kidney Transplantation: Analysis of Linked US Registry and Medicare Billing Claims

BACKGROUND

The incidence, risks, and outcomes associated with pulmonary hypertension (P-HTN) in the kidney transplant (KTx) population are not well described.

METHODS

We linked US transplant registry data with Medicare claims (2006-2016) to investigate P-HTN diagnoses among Medicare-insured KTx recipients (N = 35 512) using billing claims. Cox regression was applied to identify independent correlates and outcomes of P-HTN (adjusted hazard ratio [aHR] 95%LCLaHR95%UCL) and to examine P-HTN diagnoses as time-dependent mortality predictors.

RESULTS

Overall, 8.2% of recipients had a diagnostic code for P-HTN within 2 y preceding transplant. By 3 y posttransplant, P-HTN was diagnosed in 10.310.6%11.0 of the study cohort. After adjustment, posttransplant P-HTN was more likely in KTx recipients who were older (age ≥60 versus 18-30 y a HR, 1.912.403.01) or female (aHR, 1.151.241.34), who had pretransplant P-HTN (aHR, 4.384.795.24), coronary artery disease (aHR, 1.051.151.27), valvular heart disease (aHR, 1.221.321.43), peripheral vascular disease (aHR, 1.051.181.33), chronic pulmonary disease (aHR, 1.201.311.43), obstructive sleep apnea (aHR, 1.151.281.43), longer dialysis duration, pretransplant hemodialysis (aHR, 1.171.371.59), or who underwent transplant in the more recent era (2012-2016 versus 2006-2011: aHR, 1.291.391.51). Posttransplant P-HTN was associated with >2.5-fold increased risk of mortality (aHR, 2.572.843.14) and all-cause graft failure (aHR, 2.422.642.88) within 3 y posttransplant. Outcome associations of newly diagnosed posttransplant P-HTN were similar.

CONCLUSIONS

Posttransplant P-HTN is diagnosed in 1 in 10 KTx recipients and is associated with an increased risk of death and graft failure. Future research is needed to refine diagnostic, classification, and management strategies to improve outcomes in KTx recipients who develop P-HTN.

Cardiovascular risk stratification in the noncardiac solid organ transplant candidate

PURPOSE OF REVIEW

Solid organ transplantation (SOT) has become a widely accepted therapy for end-stage disease across the spectrum of thoracic and abdominal organs. With contemporary advances in medical and surgical therapies in transplantation, candidates for SOT are increasingly older with a larger burden of comorbidities, including cardiovascular disease (CVD). CVD, in particular, is a leading cause of morbidity and mortality in SOT candidates with end-stage disease of noncardiac organs [1].

RECENT FINDINGS

Identification of coronary artery disease (CAD), heart failure, and valvular disease are important in noncardiac SOT to ensure both appropriate peri-transplant management and equitable organ allocation. Although the American College of Cardiology (ACC) and the American Heart Association (AHA) have published guidelines and recommendations for the perioperative cardiovascular evaluation of patients undergoing noncardiac surgery, the implications of both symptomatic and asymptomatic CVD differ in patients with end-stage organ failure being considered for SOT when compared to the general population.

SUMMARY

Herein, we review the epidemiology, diagnosis, and evidence for the management of CVD in kidney and liver transplantation, combining current guidelines from the 2012 ACC/AHA scientific statement on cardiac disease evaluation in SOT with more contemporary evidenced-based algorithms.

The echocardiographic course of pretransplant pulmonary hypertension following kidney transplantation and associated outcomes

The post 3 kidney transplant course of pretransplant echocardiographically‐defined pulmonary hypertension (PH) was reviewed in 115 patients. Of these 61 patients (the largest cohort reported to date), underwent 160 “for indication” echocardiograms posttransplant (mean echocardiograms per patient: 2.6 ± 2.3). Patients undergoing posttransplant echocardiograms demonstrated greater risks for worse outcomes than those without posttransplant echocardiograms; however, there was no difference in mortality, death‐censored graft failure or the composite of death or graft failure between these two groups. Of patients tested, 36 (59%) showed resolution of PH at a median of 37.5 months. Six patients (16.7%) in whom PH resolved (at a median of 29 months), experienced recurrence of PH after an interval of 48 months. No pretransplant demographic or echocardiographic characteristics distinguished those in whom PH persisted versus resolved. Though there was no difference in the risk for mortality or death‐censored graft loss between the two groups at 3 and 5 years, there was a higher risk for the composite of mortality or graft loss at three but not at five years in the group with persistent PH. In conclusion, echocardiographically defined PH resolved in 59% of patients following kidney transplantation; but irrespective of resolution there was no clear association with worse outcome.

Post-Transplant Cardiovascular Disease

Cardiovascular disease remains a leading cause of death and morbidity in kidney transplant recipients and a common reason for post-transplant hospitalization. Several traditional and nontraditional cardiovascular risk factors exist, and many of them present pretransplant and worsened, in part, due to the addition of immunosuppression post-transplant. We discuss optimal strategies for identification and treatment of these risk factors, including the emerging role of sodium-glucose cotransporter 2 inhibitors in post-transplant diabetes and cardiovascular disease. We present common types of cardiovascular disease observed after kidney transplant, including coronary artery disease, heart failure, pulmonary hypertension, arrhythmia, and valvular disease. We also discuss screening, treatment, and prevention of post-transplant cardiac disease. We highlight areas of future research, including the need for goals and best medications for risk factors, the role of biomarkers, and the role of screening and intervention.

Vasodilator use in precapillary pulmonary hypertension with end stage kidney disease: A single center experience

BACKGROUND AND OBJECTIVES

Pulmonary hypertension is commonly seen in end stage kidney disease and is most commonly due to elevated left heart pressures. There is limited data about vasodilator use during the management of Group 1 pulmonary arterial hypertension in the context of those who also have or later developed end stage kidney disease. The objective of this study was to determine safety and efficacy of vasodilator therapy in precapillary pulmonary hypertension requiring renal replacement therapy.

DESIGN

This was a single-center retrospective case series. Patients were identified from our Pulmonary Hypertension Clinic using a historical roster from 2012 to 2020. Patients were included if they >18 years of age, had Group 1 or Group 4 (precapillary) pulmonary hypertension on right heart catheterization, and also had end stage kidney disease requiring either intermittent hemodialysis or peritoneal dialysis.

RESULTS

18 patients were identified with invasively confirmed Group 1 or Group 4 pulmonary hypertension and end stage kidney disease on renal replacement therapy. Scleroderma was the most common etiology for renal failure. 17 patients were treated with vasodilator therapy. Fifteen patients had paired right heart catheterizations that showed a significant decrease in mean pulmonary artery pressure and pulmonary vascular resistance. Therapy was relatively well tolerated but hypotension was common and midodrine was often helpful. Two patients had successful renal transplantation after starting vasodilator therapy.

CONCLUSION

We found vasodilator therapy was reasonably well tolerated and associated with a drop in mean pressure and pulmonary vascular resistance in patients with end stage kidney disease on dialysis.

Pulmonary Hypertension in Chronic Kidney Disease

There is a high prevalence of pulmonary hypertension in chronic kidney disease (CKD), with rates increasing as glomerular filtration rate declines. Pulmonary hypertension is associated with a higher risk of cardiovascular events and mortality in non-dialysis-dependent CKD stages 3 to 5, dialysis-dependent CKD, as well as kidney transplant recipients. The pathophysiology of pulmonary hypertension in CKD is multifactorial and includes higher pulmonary capillary wedge pressure caused by ischemic heart disease and cardiomyopathy, higher cardiac output caused by anemia and arteriovenous access used for hemodialysis, as well as potentially higher pulmonary vascular resistance. Treatment should focus on the underlying cause.

Kidney Transplantation Confers Survival Benefit for Candidates With Pulmonary Hypertension

Kidney transplantation (KT) is controversial in patients with pretransplant pulmonary hypertension (PtPH). We aimed to quantify post-KT graft and patient survival as well as survival benefit in recipients with PtPH.

Methods

Using UR Renal Data System (2000-2018), we studied 90 819 adult KT recipients. Delayed graft function, death-censored graft failure, and mortality were compared between recipients with and without PtPH using inverse probability weighted logistic and Cox regression. Survival benefit of KT was determined using stochastic matching and stabilized inverse probability treatment Cox regression.

Results

Among 90 819 KT recipients, 2641 (2.9%) had PtPH. PtPH was associated with higher risk of delayed graft function (odds ratio, 1.23; 95% CI, 1.10-1.36; P < 0.01), death-censored graft failure (hazard ratio [HR], 1.23; 95% CI, 1.11-1.38; P < 0.01), and mortality (HR, 1.56; 95% CI, 1.44-1.69; P < 0.01). However, patients with PtPH who received a KT had a 46% reduction in mortality (HR, 0.54; 95% CI, 0.48-0.61; P < 0.01) compared with those who remained on the waitlist.

Conclusions

Although PtPH is associated with inferior post-KT outcomes, KT is associated with better survival compared with remaining on the waitlist. Therefore, KT is a viable treatment modality for appropriately selected patients with PtPH.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Right Ventricular Dysfunction and Adverse Outcomes after Renal Transplantation

INTRODUCTION

Pulmonary hypertension is common among patients with end-stage renal disease, although data regarding the impact of right ventricular (RV) failure on postoperative outcomes remain limited. We hypothesized that echocardiographic findings of RV dilation and dysfunction are associated with adverse clinical outcomes after renal transplant.

METHODS

A retrospective review of adult renal transplant recipients at a single institution from January 2008 to June 2010 was conducted. Patients with transthoracic echocardiograms (TTEs) within 1 year leading up to transplant were included. The primary end point was a composite of delayed graft function, graft failure, and all-cause mortality.

RESULTS

Eighty patients were included. Mean follow-up time was 9.4 ± 0.8 years. Eight patients (100%) with qualitative RV dysfunction met the primary end point, while 39/65 patients (60.0%) without RV dysfunction met the end point (p = 0.026). Qualitative RV dilation was associated with a significantly shorter time to all-cause graft failure (p = 0.03) and death (p = 0.048). RV systolic pressure was not measurable in 45/80 patients (56%) and was not associated with outcomes in the remaining patients.

CONCLUSION

RV dilation and dysfunction are associated with adverse outcomes after renal transplant. TTE assessment of RV size and function should be a standard part of the pre-kidney transplant cardiovascular risk assessment.

Epidemiology, Pathogenesis, and Clinical Approach in Group 5 Pulmonary Hypertension

Pulmonary hypertension (PH) is recognized to be associated with a number of comorbid conditions. Based on these associations, PH is classified into 5 groups, considering common pathophysiologic drivers of disease, histopathologic features, clinical manifestations and course, and response to PH therapy. However, in some of these associated conditions, these characteristics are less well-understood. These include, among others, conditions commonly encountered in clinical practice such as sarcoidosis, sickle cell disease, myeloproliferative disorders, and chronic kidney disease/end stage renal disease. PH in these contexts presents a significant challenge to clinicians with respect to disease management. The most recent updated clinical classification schemata from the 6th World Symposium on PH classifies such entities in Group 5, highlighting the often unclear and/or multifactorial nature of PH. An in-depth review of the state of the science of Group 5 PH with respect to epidemiology, pathogenesis, and management is provided. Where applicable, future directions with respect to research needed to enhance understanding of the clinical course of these entities is also discussed.

Five-year Outcomes of Pulmonary Hypertension With and Without Elevated Left Atrial Pressure in Patients Evaluated for Kidney Transplantation

BACKGROUND

Pulmonary hypertension (PH) is frequently reported in patients with advanced chronic kidney disease and is associated with early allograft failure and death. However, the causes of PH are heterogeneous, and patient prognosis may vary by etiologic subtype.

METHODS

Data from the University of North Carolina Cardiorenal Registry were examined to determine associations between PH, with or without elevated left atrial pressure (eLAP), and mortality in candidates for kidney transplantation. PH and eLAP were determined by Doppler echocardiography and by tissue Doppler imaging, respectively.

RESULTS

From 2006 to 2013, 778 registry patients were screened preoperatively by echocardiography. Most patients were black (64%) and men (56%); the mean age was 56 years. PH was identified in 97 (12%) patients; of these, eLAP was prevalent in half. During a median follow-up of 4.4 years, 179 (23%) received a kidney transplant, and 195 (25%) died. After adjustments for demographics, comorbidities, dialysis vintage, and kidney transplantation, PH was associated with twice the 5-year mortality (hazard ratio [HR] = 2.11; 95% confidence interval [CI]: 1.48-3.03), with stronger associations in the absence of eLAP (HR = 2.87; 95% CI: 1.83-4.49) than with eLAP (HR = 1.11; 95% CI: 0.57-2.17), P for interaction = 0.01.

CONCLUSIONS

The mortality risk associated with PH among patients with advanced chronic kidney disease appears to differ by etiology. Patients with PH in the absence of eLAP are at high risk of death and in need of focused attention. Future research efforts should investigate potential strategies to improve outcomes for these patients.

Echocardiography to Screen for Pulmonary Hypertension in CKD

Introduction

Pulmonary hypertension (PH) is a common yet incompletely understood complication of chronic kidney disease (CKD). Although transthoracic echocardiogram is commonly used to noninvasively estimate PH, it has not been validated in a CKD population. We investigated the utility of this diagnostic tool for CKD-associated PH in a large right heart catheterization (RHC) cohort.

Methods

We reviewed RHC and echocardiography data in 4036 patients (1714 with CKD) obtained between 2011 and 2014 at a single center. We used multivariate regression to determine the associations of echocardiography measurements with PH, and evaluated whether estimated glomerular filtration rate (eGFR) modified these associations. Using internal validation, we sequentially added measurements to predictive models and analyzed the incremental predictive performance using the change in the area under the receiver operating characteristic curve (ΔAUC) and net reclassification improvement.

Results

The echocardiography measurements most strongly associated with the diagnosis of PH included tricuspid regurgitant velocity (TRV), tricuspid annular plane systolic excursion (TAPSE), right atrial pressure, diastolic dysfunction, and right ventricular function. Among these measurements, eGFR significantly modified the associations of TAPSE and diastolic dysfunction with the diagnosis of PH. The model consisting of a combination of TRV, right atrial pressure, and TAPSE most accurately predicted the diagnosis of PH in a CKD population (AUC 0.82).

Conclusions

The optimal model to predict PH diagnosis included TRV, right atrial pressure, and TAPSE. Since TAPSE more strongly associated with PH in the CKD population, these findings support a CKD-specific approach to the development of noninvasive screening algorithms for PH.

The Association of Pretransplant Pulmonary Hypertension With Patient and Graft Survival After Kidney Transplantation: A Retrospective Cohort Study

BACKGROUND

Pulmonary hypertension (PH) has been well characterized in end-stage kidney disease and carries a grave prognosis. Its relationship to kidney transplantation outcomes is uncertain. The purpose of the present study was to characterize PH in kidney transplant candidates and to evaluate the relationship of PH to post-transplantation outcomes.

METHODS

A retrospective review of medical records and echocardiographic findings in all patients listed and transplanted at a large urban academic medical center from 2010 to 2015 was undertaken. PH (defined as echocardiographic evidence of pulmonary artery systolic pressure ≥ 35 mm Hg) was assessed along with demographics, and comorbidities for its relationship to patient, and graft survival by univariable and multivariable analysis.

RESULTS

Of 733 patients, 15.6% (115) had PH. PH in this population was primarily due to left ventricular (LV) diastolic dysfunction. Patient survival (78.3% vs 89.6%, P = .02) and the composite of patient and graft survival (70.7% vs 85.0%, P = .04) was reduced at 5 years in patients with PH as compared to patients with No PH, respectively. However, multivariable analysis suggested that age at presentation, race, and left ventricular systolic function but not PH were significantly associated with patient mortality or graft loss.

CONCLUSION

Reduced patient and graft survival seen in patients with pulmonary hypertension appears to be related to risk factors other than the pulmonary hypertension itself; therefore, pretransplant PH should not be considered as a barrier to kidney transplantation.

Cardiorenal Syndrome in Renal Transplant Recipients: Prevalence, Clinical Presentation, Treatment, and Outcome

BACKGROUND

Data on the cardiorenal syndrome (CRS) in renal transplant recipients (RTR) are scarce. We investigated the prevalence, clinical presentation, treatment, and outcomes of patients with CRS in our renal transplant cohort.

METHODS

Charts and medical records of adult RTR were investigated to identify patients with renal allograft dysfunction and heart failure (HF) with reduced (HFrEF) or preserved (HFpEF) ejection fraction.

RESULTS

From December 2009 to December 2019, a total of 1,610 patients received a kidney allograft at our institution. CRS was diagnosed in 9 patients (0.56%) a median of 11 years after transplantation (4-20 years). Seven of the patients were male, and 2 were female. The median age when CRS was diagnosed was 71 years (64-80 years). The major presenting symptom was dyspnea. Five patients had HFrEF, and 4 had HFpEF. The patient's median basal creatinine clearance was 37 mL/min (range 29-77 mL/min). At hospitalization, it was decreased to 24 mL/min (range 13-45 mL/min). The patients were treated with diuretics, but 5 of them required extracorporeal fluid removal. At the 16-month follow-up (median), all patients with HFpEF were alive and had returned to initial levels of creatinine clearance. Two of the 5 HFrEF had died, and 2 needed permanent extracorporeal water removal.

CONCLUSION

CRS after renal transplantation was rare (<1.0%), but CRS in HFreF patients was associated with a poor outcome.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Diagnosis and Management of Pulmonary Hypertension in Patients With CKD

Pulmonary hypertension (PH) is a highly prevalent and important condition in adults with chronic kidney disease (CKD). In this review, we summarize the definition of PH, discuss its pathophysiology and classifications, and describe diagnostic and management strategies in patients with CKD, including those with kidney failure treated by kidney replacement therapy. In the general population, PH is classified into 5 groups based on clinical presentation, pathology, hemodynamics, and management strategies. In this classification system, PH in CKD is placed in a diverse group with unclear or multifactorial mechanisms, although underlying cardiovascular disease may account for most cases. CKD may itself directly incite pulmonary circulatory dysfunction and remodeling through uremic toxins, inflammation, endothelial dysfunction, and altered vasoregulation. Despite several studies describing the higher prevalence of PH in CKD and kidney failure, along with an association with poor outcomes, high-quality evidence is not available for its diagnostic and management strategies in those with CKD. In CKD not requiring kidney replacement therapy, volume management along with treatment of underlying risk factors for PH are critical. In those receiving hemodialysis, options are limited and transition to peritoneal dialysis may be considered if recurrent hypotension precludes optimal volume control.

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.

Cardiorenal Syndrome: Classification, Pathophysiology, Diagnosis, and Treatment Strategies: A Scientific Statement From the American Heart Association

Cardiorenal syndrome encompasses a spectrum of disorders involving both the heart and kidneys in which acute or chronic dysfunction in 1 organ may induce acute or chronic dysfunction in the other organ. It represents the confluence of heart-kidney interactions across several interfaces. These include the hemodynamic cross-talk between the failing heart and the response of the kidneys and vice versa, as well as alterations in neurohormonal markers and inflammatory molecular signatures characteristic of its clinical phenotypes. The mission of this scientific statement is to describe the epidemiology and pathogenesis of cardiorenal syndrome in the context of the continuously evolving nature of its clinicopathological description over the past decade. It also describes diagnostic and therapeutic strategies applicable to cardiorenal syndrome, summarizes cardiac-kidney interactions in special populations such as patients with diabetes mellitus and kidney transplant recipients, and emphasizes the role of palliative care in patients with cardiorenal syndrome. Finally, it outlines the need for a cardiorenal education track that will guide future cardiorenal trials and integrate the clinical and research needs of this important field in the future.

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.

Preoperative Noncoronary Cardiovascular Assessment and Management of Kidney Transplant Candidates

The pretransplant risk assessment for patients with ESKD who are undergoing evaluation for kidney transplant is complex and multifaceted. When considering cardiovascular disease in particular, many factors should be considered. Given the increasing incidence of kidney transplantation and the growing body of evidence addressing ESKD-specific cardiovascular risk profiles, there is an important need for a consolidated, evidence-based model that considers the unique cardiovascular challenges that these patients face. Cardiovascular physiology is altered in these patients by abrupt shifts in volume status, altered calcium-phosphate metabolism, high-output states (in the setting of arteriovenous fistulization), and adverse geometric and electrical remodeling, to name a few. Here, we present a contemporary review by addressing cardiomyopathy/heart failure, pulmonary hypertension, valvular dysfunction, and arrhythmia/sudden cardiac death within the ESKD population.

Heart failure in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

The incidence and prevalence of heart failure (HF) and chronic kidney disease (CKD) are increasing, and as such a better understanding of the interface between both conditions is imperative for developing optimal strategies for their detection, prevention, diagnosis, and management. To this end, Kidney Disease: Improving Global Outcomes (KDIGO) convened an international, multidisciplinary Controversies Conference titled Heart Failure in CKD. Breakout group discussions included (i) HF with preserved ejection fraction (HFpEF) and nondialysis CKD, (ii) HF with reduced ejection fraction (HFrEF) and nondialysis CKD, (iii) HFpEF and dialysis-dependent CKD, (iv) HFrEF and dialysis-dependent CKD, and (v) HF in kidney transplant patients. The questions that formed the basis of discussions are available on the KDIGO website http://kdigo.org/conferences/heart-failure-in-ckd/, and the deliberations from the conference are summarized here.

The early outcomes of candidates with portopulmonary hypertension after liver transplantation

Background

Portopulmonary hypertension (PPH) was once regarded as a contraindicaton to liver transplantation (LT). However, growing evidence has indicated that PPH patients undergoing LT may show similar outcomes compared to those without PPH, and researchers have recommended it not be an absolute contraindication. Given this controversy, we aimed to identify and review the current evidence on this topic and to provide a comparison of the outcomes after LT between candidates with PPH and those without.

Methods

We systematically searched the MEDLINE, EMBASE and Cochrane Library databases for all studies that compared the outcomes of PPH patients and those without PPH after LT. All studies reporting outcomes of PPH patients versus those without PPH (Control) were further considered for inclusion in this meta-analysis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to compare the pooled data between PPH and Control groups.

Results

Eleven retrospective trials and one prospective, randomized, controlled trial, involving 37,686 transplant recipients were included. The PPH patients had increased 1-year mortality with an OR of 1.59 (95% CI = 1.26–2.01, P = 0.0001) compared to the control group. There was no significant difference in graft loss and 30-day mortality after LT between the two groups.

Conclusions

Patients with PPH who underwent LT had increased 1-year mortality compared to those without PPH, while graft loss and 30-day mortality were similar. Nevertheless, LT may be a reasonable therapeutic option for some patients with PPH, but further studies are needed to identify those select patients with PPH who would benefit most from LT.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0797-8) contains supplementary material, which is available to authorized users.

The New Kidney Donor Allocation System and Implications for Anesthesiologists

Given potential disparity and limited allocation of deceased donor kidneys for transplantation, a new federal kidney allocation system was implemented in 2014. Donor organ function and estimated recipient survival in this system has implications for perioperative management of kidney transplant recipients. Early analysis suggests that many of the anticipated goals are being attained. For anesthesiologists, implications of increased dialysis duration and burdens of end-stage renal disease include increased cardiopulmonary disease, challenging fluid, hemodynamic management, and central vein access. With no recent evidence to guide anesthesia care within this new system, we describe the kidney allocation system, summarize initial data, and briefly review organ systems of interest to anesthesiologists. As additional invasive and echocardiographic monitoring may be indicated, one consideration may be development of a dedicated anesthesiology team experienced in management and monitoring of complex patients, in a similar manner as has been done for liver transplant recipients.

In-Hospital Cardiovascular Complications After Pancreas Transplantation in the United States from 2003 to 2012

Large database studies detailing the risk of perioperative cardiovascular complications after pancreas transplant has been limited, perhaps because these outcomes are not captured by transplant registries. Greater data on the incidence and risks of such outcomes could provide additional insight for referring physicians and inform potential recipients of their risk. We performed a serial, cross-sectional analysis of the National Inpatient Sample, the largest publicly available inpatient database in the United States, to assess for the risk of cardiovascular complications after pancreas transplants in the United States from 2003 to 2012 (n = 13,399). Using multivariable logistic regression models, the risk of cardiovascular outcomes after simultaneous pancreas-kidney transplants (SPK) was compared with solitary pancreas transplants (pancreas after kidney and pancreas transplant alone [PAK + PTA]). The unadjusted prevalence of in-hospital cardiovascular complications was higher in SPK than PAK + PTA (5.5% vs 3.7%, p <0.001). After multivariable adjustment, SPK remained associated with significantly higher odds of any cardiovascular complication (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.21 to 1.80, p = 0.01), and particularly stroke (OR 13.41, 95% CI 4.78 to 37.63, p <0.001), compared with PAK + PTA. However, there was no difference in perioperative mortality (OR 0.78, 95% CI 0.54 to 1.12, p = 0.18). In conclusion, these findings highlight the association between uremia and stroke in pancreas transplant patients, as well as the need for improved preoperative cardiac risk assessment and perioperative management, especially in those who underwent SPK.