Evidence supports severe renal insufficiency as a relative contraindication to heart transplantation

Associated Factors and Impact of Persistent Renal Dysfunction in Pediatric Heart Transplantation

BACKGROUND

We evaluated the impact of significant renal dysfunction (SRD) on listing and pediatric heart transplantation (PHT) outcomes.

METHODS

The United Network of Organ Sharing registry was queried. Our cohort included 11,625 children listed for PHT (2000-2020). At listing, 1494 (13%) had SRD, defined as an estimated glomerular filtration rate of <45 mL/min/1.73 m2 and/or dialysis requirement. Characteristics of children with and without SRD were compared. SRD impact on outcomes was examined. Factors associated with waiting list mortality, persistent SRD at PHT, and post-PHT survival with and without simultaneous heart-kidney transplantation were assessed.

RESULTS

Compared with children with an estimated glomerular filtration rate >45 mL/min/1.73 m2, those with SRD had higher waiting list death (37% vs 14%, P < .01) and lower transplantation rate (51% vs 71%, P < .01). On multivariable analysis, SRD was associated with waiting list death (hazard ratio, 3.016; P < .0001). Among 767 children with SRD who received PHT, 361 (47%) had persistent SRD at the time of PHT. On multivariable analysis, factors associated with persistent SRD were older age (odds ratio [OR], 1.147 per year; 95% CI, 1.046-1.258 per year; P = .0035), bilirubin (OR, 1.127 per 1-mg/dL; 95% CI, 1.061-1.197 per 1-mg/dL; P < .0001), dialysis (OR, 1.839; 95% CI, 1.017-3.326; P = .0115), mechanical ventilation (OR, 1.972; 95% CI, 1.336-2.911; P = .0006), extracorporeal membrane oxygenation (OR, 1.747; 95% CI, 1.074-2.842; P = .0247), and not using a ventricular assist device (VAD) (OR, 0.498 [VAD use]; 95% CI, 0.277-0.895 VAD use; P = .0198). Post-PHT survival was 72%, 70%, and 56% (P < .01) at 8 years for PHT alone with improved renal function, simultaneous heart-kidney transplantation (n = 69), and PHT alone with persistent SRD, respectively.

CONCLUSIONS

SRD is associated with high waiting list death and decreased transplantation rate. Timely proper pre-PHT support with VAD could enhance kidney recovery. Simultaneous heart-kidney transplantation neutralized persistent SRD effect on survival and might be considered in high-risk patients such as those on dialysis, mechanical ventilation, or extracorporeal membrane oxygenation support.

The ABC of Heart Transplantation-Part 1: Indication, Eligibility, Donor Selection, and Surgical Technique

Cardiac transplantation represents the gold standard of treatment for selected patients with advanced heart failure who have poor functional capacity and prognosis despite guideline-directed medical therapy and device-based therapy. Proper patient selection and appropriate referral of patients to centers for the treatment of advanced heart failure are the first but decisive steps for screening patients eligible for cardiac transplantation. The eligibility and the decision to list for cardiac transplantation, even for patients with relative contraindications, are based on a multidisciplinary evaluation of a transplant team. This review will discuss the practical indications, the process of patient eligibility for cardiac transplantation, the principle of donor selection, as well as the surgical technique.

Incidence and Clinical Significance of Hyperkalemia Following Heart Transplantation

BACKGROUND

Hyperkalemia (HK) is a life-threatening complication following solid organ transplantation, and patients often need potassium-chelating agents and deviations from standard posttransplant protocols. This is the first study to report the incidence and clinical impact of hyperkalemia following heart transplantation.

METHODS

We retrospectively included patients who underwent heart transplantation at our institution between April 2014 and December 2018. Patients with multiorgan transplantation were excluded. Clinical outcomes of patients who had serum potassium >5.5 mEq/L in the first year posttransplant (HK group) were compared to patients who did not have serum potassium >5.5 mEq/L in the first year posttransplant (non-HK group).

RESULTS

A total of 143 patients were included in this study. During the first year posttransplant, cumulative incidence of serum potassium >5.0, >5.5, and >6.0 mEq/L was 96%, 63%, and 24%, respectively. Fifty-five percent of patients required treatment with potassium-chelating agents. Sulfamethoxazole-trimethoprim was discontinued because of HK in 39% of patients. Overall survival of patients in the HK group (n = 89) was comparable to that of patients in the non-HK group (n = 54, 91% vs 98% at 1 year, P = .19), whereas infection-free survival was significantly lower in the HK group (34% vs 53% at 1 year, P = .010). Multivariate analysis revealed pretransplant renal dysfunction (odds ratio = 2.62; 95% confidence interval, 1.18-5.80; P = .018) and use of mechanical circulatory support (odds ratio = 2.90; 95% confidence interval, 1.08-7.76; P = .035) as significant predictors of posttransplant hyperkalemia.

CONCLUSIONS

The incidence of HK following heart transplantation was high, with more than half of patients requiring any therapeutic interventions, and HK was related to an increase in infection events.

Current state of kidney utilization in multiorgan transplants

PURPOSE OF REVIEW

In the United States, the leading indication for kidney transplant is primary kidney dysfunction arising from chronic hypertension and diabetes. However, an increasing indication for kidney transplantation is secondary kidney dysfunction in the setting of another severe organ dysfunction, including pancreas, liver, heart, and lung disease. In these settings, multiorgan transplantation is now commonly performed. With the increasing number of multiorgan kidney transplants, an assessment of guidelines and trends for in multiorgan kidney is necessary.

RECENT FINDINGS

Although the utilization of kidney transplants in combined liver-kidney transplant was sharply rising, following the introduction of the 'safety net' policy, combined liver-kidney transplant numbers now remain stable. There is an increasing trend in the utilization of kidney transplantation in heart and lung transplantation. However, as these surgeries were historically uncommon, guidelines for patients who require simultaneous heart or lung transplants are limited and are often institution specific.

SUMMARY

Strict guidelines need to be established to assess candidacy for kidney transplantation in multiorgan failure patients, particularly for combined heart-kidney and lung-kidney patients.

Renal Outcomes in Patients Bridged to Heart Transplant With a Left Ventricular Assist Device

BACKGROUND

Patients with end-stage heart failure are increasingly being bridged to heart transplant (BTT) with mechanical circulatory support; however the association between a left ventricular assist device (LVAD) BTT strategy and posttransplant renal outcomes is unclear. The aim of this study was to analyze the association of LVAD BTT with the development of posttransplant renal failure using a large national registry.

METHODS

We queried the 2009 to 2018 United Network for Organ Sharing registry for all adults undergoing first-time heart or heart-kidney transplantation and stratified patients by use of pretransplant durable LVAD. The primary outcome of interest was posttransplant renal failure, which was evaluated with multivariable logistic regression.

RESULTS

Of 18,307 patients meeting inclusion criteria, 7887 were (43%) and 10,420 were not (57%) BTT with an LVAD. BTT patients had slightly better baseline renal function (estimated glomerular filtration rate, 68.7 vs 65.8 mL/min, P < .001) and were less likely to receive a heart-kidney transplant (2.7% vs 4.8%, P < .001). On multivariable logistic regression, LVAD BTT strategy was not independently associated with posttransplant renal failure (odds ratio, 1.13; 95% confidence interval, 0.86-1.49). Similarly LVAD BTT among patients with preoperative renal dysfunction was not associated with posttransplant renal failure (adjusted odds ratio, 1.40; 95% confidence interval, 0.91-2.18).

CONCLUSIONS

BTT with an LVAD does not appear to be associated with worse renal outcomes regardless of baseline renal function. Furthermore, an LVAD BTT strategy in patients with chronic kidney disease may enable clinicians to identify candidates suitable for isolated heart transplantation without increasing their risk for posttransplant renal failure.

Variations in Criteria and Practices for Heart Transplantation Listing Among Pediatric Transplant Cardiologists

Ethical issues in pediatric heart transplantation (Htx) include resource allocation, benefit, and burden assessment in high-risk recipients, and informed consent. Practice patterns and decision-making was investigated using an internet survey with 47-multiple choice items and vignette-based questions. Of 43 pediatric Htx cardiologists contacted, 28 (65%) responded. Respondents reported that an overall median 1-month survival of 73% (range 50-100%), 1-year survival of 70% (range 50-85%), 5-year survival of 50% (range 40-85%), and 10-year survival of 50% (range 25-85%) was adequate to offer Htx. Based on vignettes presented, 100% of those surveyed would offer Htx to a straightforward 12-year old with end-stage dilated cardiomyopathy and a 7-year old with hypoplastic left heart syndrome with protein losing enteropathy. Thirty percent of physicians would offer Htx to a patient status post a Fontan procedure with mutliple co-morbidities. Seventy-five percent of physicians would offer Htx despite proven non-adherence. Considerable variability exists in the practice patterns of pediatric heart transplant cardiologists with regards to decision-making while evaluating patients for listing. Disagreements among pediatric Htx cardiologists exist when there are concerns for non-adherence and associated multiple co-morbidities. Further work is needed to understand these variations and develop consensus for pediatric Htx organ allocation.

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.