Estimated Glomerular Filtration Rate at Transplant Listing and Other Predictors of Post-Heart Transplant Mortality and the Development of ESRD

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

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.

Post-transplant ejection fraction and renal failure in cardiac transplant recipients: An analysis of the OPTN database

BACKGROUND

Despite improved life expectancy from a heart transplant, transplant recipients remain at high risk for renal dysfunction and failure, including end-stage kidney disease (ESKD). The onset of ESKD is a poor prognostic marker and is associated with increased mortality in this setting, as in others. There is a need to identify risk factors for ESKD among heart transplant recipients in contemporary settings.

METHODS

We conducted an analysis of adult heart transplant recipients transplanted between 2008 and 2021 in the Organ Procurement and Transplantation Network database. 22 737 adult recipients of heart transplants alone were included in this analysis. We examined LVEF measured 1 year after transplant, and LVEF updated annually for association with ESKD using multivariate Cox regression models.

RESULTS

LVEF at 1-year after transplant was associated with ESKD in multivariate models (Hazard Ratio 1.33 per 10-unit decrease, 95% CI 1.23-1.43, p < .001). In multivariate models using categorized LVEF, mildly reduced ejection fraction (EF 40%-50%) was associated with ESKD (HR 1.76, 95% CI 1.45-2.14, p < .001), as was reduced ejection fraction (EF < 40%, HR 2.86, 95% CI 2.01-4.07, p < .001), relative to individuals with preserved ejection fraction (EF > 50%). These associations were consistent when using annually updated ejection fraction.

CONCLUSIONS

Post-transplant left ventricular ejection fraction has value in predicting end stage kidney disease among adults who receive heart transplants alone. LVEF is routinely measured as part of contemporary post heart transplant care, and a diminished LVEF should signal to clinicians that a recipient is at increased risk of renal failure.

Severely Reduced Kidney Function Assessed by a Single eGFR Determination at the Time of an Isolated Heart Transplant Does Not Predict Inevitable Posttransplant ESKD

BACKGROUND

Consensus guidelines advise simultaneous heart kidney transplantation (SHK) in heart candidates with an estimated glomerular filtration rate (eGFR) of <30 mL/min/1.73 m 2 . We hypothesize that a significant fraction of such patients would not need an SHK, even though a graded increase in mortality and end-stage kidney disease (ESKD) would be seen with decrements in eGFR.

METHODS

United Network of Organ Sharing data for isolated heart transplants between 2000 and 2020 were divided into two groups based on eGFR at transplant (≤20 mL/min/1.73 m 2 and 21-29 mL/min/1.73 m 2 ). The primary outcome was mortality and secondary outcome was ESKD posttransplant. Cox regression and cumulative incidence competing risk methods were used to compare risk of mortality and ESKD.

RESULTS

There was no difference in mortality (adjusted hazard ratio [aHR] 0.82 [95% confidence interval, CI: 0.60-1.11, P = 0.21]) or ESKD (aHR 1.01 [95% CI: 0.49-2.09, P = 0.96]) between the two groups (≤20 versus 21-29). The overall incidence of ESKD for the entire cohort at 1, 5, and 10 y were 1.5%, 9.5%, and 20%.

CONCLUSIONS

Although risk of ESKD is highest in heart candidates with an eGFR <30 mL/min/1.73 m 2 , <10% of patients reach ESKD within 5 y' and most will recover significant renal function posttransplant. More refined selection criteria are required to identify candidates for SHK.

The impact of changes in renal function during waitlist time on outcomes after heart transplantation

BACKGROUND AND AIM

This study evaluated the impact of changes in renal function during the waitlist period on posttransplant outcomes of orthotopic heart transplantation (OHT).

METHODS

The United Network for Organ Sharing registry was used to identify adult patients undergoing isolated OHT from 2010 to 2020. Patients were stratified by whether their National Kidney Foundation chronic kidney disease (CKD) stage improved, worsened, or remained unchanged between listing and transplantation. Univariate analysis and multivariable Cox regression were conducted to determine whether a change in estimated glomerular filtration rate (eGFR) or change in CKD stage predicted 1-year mortality after OHT.

RESULTS

Of 22,746 patients, the majority of patients remained in the same CKD stage (59.6%), and the frequencies of patients progressing to improved (19.3%) and worsened (21.1%) CKD stages were similar. Temporary mechanical circulatory support (MCS) was associated with improved CKD stage and durable MCS with worsened CKD stage (p < .001). Post-OHT dialysis was most common in patients with worsened CKD stage (13.2%) and least common in the improved cohort (9.4%) (p < .001). Kaplan-Meier unadjusted 1-year survival rates after OHT were similar between CKD change groups (log-rank p = .197). Multivariable analysis demonstrated no risk-adjusted effect of change in eGFR (p = .113) or change in CKD stage (p = .076) on 1-year mortality after OHT.

CONCLUSIONS

Approximately 20% of patients improve CKD stage and 20% worsen CKD stage between listing and OHT, with the remaining 60% having unchanged CKD stage. Worsening CKD stage predicts increased likelihood of post-OHT dialysis, but CKD stage change does not predict 1-year survival following OHT.

Haemodynamic parameters associated with renal function prior to and following heart transplantation

AIMS

Abnormal renal function is a common feature in patients on heart transplant waiting lists. This study aimed to identify the haemodynamic parameters associated with decreased estimated glomerular filtration rate (eGFR) in patients listed for heart transplantation (HT) and renal function improvement following HT.

METHODS AND RESULTS

A total of 176 adults (52 years old, 81% men) with available right heart catheterization (RHC) listed in our centre for HT between 2014 and 2019 were studied. Cardiac catheterization measurements were obtained at time of HT listing evaluation. Changes in renal function were assessed between RHC and 6 months after HT. Median eGFR was 63 mL/min/1.73 m2 at time of RHC. Central venous pressure > 10 mmHg was associated with a two-fold increase in the likelihood of eGFR < 60 mL/min/1.73 m2 at time of RHC (adjusted odd ratio, 2.2; 95% confidence interval, 1.1-4.7; P = 0.04). In the 134 patients (76%) who underwent HT during follow-up, eGFR decreased by 7.9 ± 29.7 mL/min/1.73 m2 from RHC to 6 months after HT. In these patients, low cardiac index (<2.1 L/min/m2 ) at initial RHC was associated with a (adjusted) 6 month post-HT eGFR improvement of 12.2 mL/min/1.73 m2 (P = 0.018). Patients with eGFR < 60 mL/min/1.73 m2 and low cardiac index at time of RHC exhibited the greatest eGFR improvement (delta eGFR = 18.3 mL/min/1.73 m2 ) while patients with eGFR ≥ 60 mL/min/1.73 m2 and normal cardiac index had a marked decrease in eGFR (delta eGFR = -27.7 mL/min/1.73 m2 , P < 0.001).

CONCLUSIONS

Central venous pressure is the main haemodynamic parameter associated with eGFR < 60 mL/min/1.73 m2 in patients listed for HT. Low cardiac index prior to HT is associated with post-transplant renal function recovery.

Impact of changing renal function, while waiting for a heart transplant, on post-transplant mortality and development of end stage kidney disease

Heart transplantation is a viable option for end stage heart disease but long-term complications such as chronic kidney disease are being increasingly recognized. We sought to investigate the effect of change in estimated glomerular filtration rate (eGFR) during the heart transplant waitlist period on post-transplant mortality and end stage kidney disease (ESKD). We analysed the United Network of Organ Sharing heart transplant database from 2000 to 2017. Multivariable Cox regression with restricted cubic splines and cumulative incidence competing risk (CICR) methods were used to compare the effects of change in eGFR on mortality and ESKD, respectively. A total of 19 412 patients met our inclusion criteria. Mortality increased with increasing loss of eGFR (adjusted hazard ratio increased from 1.02 [confidence interval (CI) 1.01-1.04, P = 0.008] for 10% loss to 1.15 (CI 1.06-1.26, P = 0.001) for 50% loss of eGFR. Similarly, risk of ESKD also increased monotonically with increasing loss of renal function [subdistribution hazard ratio increased from 1.12 (CI 1.09-1.14, P < 0.001) to 2.0 (CI 1.74-2.3, P < 0.001)] as loss of eGFR increased from 10% to 50%. Overall, we found that loss of >10% of eGFR resulted in higher risk of mortality and higher risk of ESKD.

Renal Function in Patients with or without a Left Ventricular Assist Device Implant During Listing for a Heart Transplant

Background

Left ventricular assist device (LVAD) implantation may improve kidney function, but in patients awaiting heart transplantation, the long-term effects of LVAD implantation on renal function and subsequent clinical outcome are unclear.

Material/Methods

We analyzed data in patients with LVAD implants (n=139) and without LVAD implants (n=1038) who were listed for a heart transplant at our institution between 2000 and 2019. The primary endpoint was an impairment in renal function (decrease of creatinine-based estimated glomerular filtration rate [eGFR] by ≥30%) up to a maximum of 2 years after listing. Secondary endpoints were chronic kidney disease stage 4 or 5, heart transplantation, survival during listing, and 1-year survival after transplantation.

Results

Values for eGFR increased after LVAD implantation (P=0.001) and were higher at the time of waitlisting in the LVAD group than in the non-LVAD group (P=0.002), but were similar between groups at the end of waitlisting (P=0.75). Two-year freedom from renal impairment was 50.6% and 66.7% in the LVAD and non-LVAD groups, respectively, with a multivariable-adjusted hazard ratio for the LVAD versus the non-LVAD group of 1.78 (95% confidence interval 1.19–2.68; P=0.005). Two-year freedom from chronic kidney disease stages 4–5 was similar between study groups (LVAD group: 83.5%; non-LVAD group: 80.1%; =0.50). The 2-year probability of transplantation was slightly lower in the LVAD group than in the non-LVAD group (50.0% and 55.8%, respectively, P=0.017). However, 2-year survival on the waiting list and 1-year survival after transplantation did not differ significantly between study groups (P-values >0.20).

Conclusions

Our data indicate a transient improvement in creatinine-based eGFR values by LVAD implantation without influencing survival.