Freedom From Graft Vessel Disease in Heart and Combined Heart- and Kidney-transplanted Patients Treated With Tacrolimus-based Immunosuppression

Combined Heart Kidney Transplantation Versus Heart Transplant in Patients with Renal Failure: Contemporary Insights and Future Perspectives

PURPOSE OF REVIEW

In this review, we aim to outline the criteria regarding the evaluation of patients with chronic renal disease (CKD) awaiting heart transplantation and discuss the outcomes of combined heart/kidney transplantation. Herein, we also review pathophysiology and risk factors that predispose to chronic kidney disease (CKD) and acute kidney injury (AKI) in patients with HF and after OHT.

RECENT FINDINGS

In patients with end-stage systolic heart failure (HF) and an estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2, orthotopic heart transplantation (OHT) alone is a relative contraindication, with a consensus that these patients are better served with heart-kidney transplant (HKT). However, there is significant variation between institutions regarding timing and indication for heart/kidney transplantation, with little data available to predict post-transplant outcomes. A Scientific Statement from American Heart Association was published detailing the indications, evaluation, and outcomes for Heart-Kidney Transplantation, and noted a steady rise in the incidence of heart/kidney dual organ transplants. Recently, the Organ Procurement and Transplantation Network (OPTN) Multi-Organ Transplantation Committee implemented a safety net policy for heart transplant recipients who do need meet criteria for simultaneous heart-kidney transplant in 2023 but with a likely need for sequential kidney transplantation. Optimization of organ distribution and patient outcomes after cardiac transplantation requires appropriate recipient selection. This review also outlines the criteria regarding the evaluation of patients with CKD awaiting heart transplantation and outcomes of combined HKT.

Characteristics and Outcomes of Patients Undergoing Combined Organ Transplantation (from the United Network for Organ Sharing)

Studies have shown that highly selected patients who underwent combined heart-kidney (HK) and heart-liver transplants (HLv) have short- and long-term outcomes comparable to those observed in primary heart transplantation (HT). Adults patients with stage D heart failure that underwent combined HK, HLv, and heart-lung (HL) were identified in the United Network for Organ Sharing registry from 1991 to 2016, with follow-up through March 2018. We conducted inverse probability of treatment weighting survival analysis of long-term survival stratified by type of combined organ transplant, accounting for donor, recipient, and operative characteristics. We identified 2,300 patients who underwent combined organ transplant (HK 1,257, HLv 212, HL 831). HL recipients were more likely white (77%), women (58%), with congenital heart disease (44.5%), and longer waiting list time (median 195 days). HK transplant increased significantly during the study period where as HL decreased significantly. Median survival was 12.2 years for HK (95% confidence intervals [CI] 10.8 to 12.8), 12 for HLv (95% CI 8.6 to 17.6) but significantly lower at 4.5 years for HL (95% CI 3.6 to 5.8). Combined HK and HLv transplantation rates are increasing and long-term survival is comparable to primary HT, unlike HL which is associated with decreasing trends and significantly lower survival.

To kidney or not to kidney: Applying lessons learned from the simultaneous liver-kidney transplant policy to simultaneous heart-kidney transplantation

As the medical community is increasingly offering transplantation to patients with increasing comorbidity burdens, the number of simultaneous heart-kidney (SHK) transplants is rising in the United States. How to determine eligibility for SHK transplant versus heart transplant alone is unknown. In this review, we situate this problem in the broader picture of organ shortage. We critically appraise available literature on outcomes in SHK versus heart transplant alone. We posit staged kidney-after-heart transplantation as a plausible alternative to SHK transplantation and review the pros and cons. Drawing lessons from the field of simultaneous liver-kidney transplant, we argue for an analogous policy for SHK transplant with standardized minimal eligibility criteria and a modified Safety Net provision. The new policy will serve as a starting point for comparing simultaneous versus staged approaches and refining the medical eligibility criteria for SHK.

Heart transplantation: challenges facing the field

There has been significant progress in the field of heart transplantation over the last 45 years. The 1-yr survival rates following heart transplantation have improved from 30% in the 1970s to almost 90% in the 2000s. However, there has been little change in long-term outcomes. This is mainly due to chronic rejection, malignancy, and the detrimental side effects of chronic immunosuppression. In addition, over the last decade, new challenges have arisen such as increasingly complicated recipients and antibody-mediated rejection. Most, if not all, of these obstacles to long-term survival could be prevented or ameliorated by the induction of transplant tolerance wherein the recipient's immune system is persuaded not to mount a damaging immune response against donor antigens, thus eliminating the need for chronic immunosuppression. However, the heart, as opposed to other allografts like kidneys, appears to be a tolerance-resistant organ. Understanding why organs like kidneys and livers are prone to tolerance induction, whereas others like hearts and lungs are tolerance-resistant, could aid in our attempts to achieve long-term, immunosuppression-free survival in human heart transplant recipients. It could also advance the field of pig-to-human xenotransplantation, which, if successful, would eliminate the organ shortage problem. Of course, there are alternative futures to the field of heart transplantation that may include the application of total mechanical support, stem cells, or bioengineered whole organs. Which modality will be the first to reach the ultimate goal of achieving unlimited, long-term, circulatory support with minimal risk to longevity or lifestyle is unknown, but significant progress in being made in each of these areas.

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.

Simultaneous thoracic and abdominal transplantation: can we justify two organs for one recipient?

Simultaneous thoracic and abdominal (STA) transplantation is controversial because two organs are allocated to a single individual. We studied wait-list urgency, and whether transplantation led to successful outcomes. Candidates and recipients for heart-kidney (SHK), heart-liver (SHLi), lung-liver (SLuLi) and lung-kidney (SLuK) were identified through the United Network for Organ Sharing (UNOS) and outcomes were compared to single-organ transplantation. Since 1987, there were 1801 STA candidates and 836 recipients. Wait-list survival at 1- and 3 years for SHK (67.4%, 40.8%; N = 1420), SHLi (65.7%, 43.6%; N = 218) and SLuLi (65.7%, 41.0%; N = 122), was lower than controls (p < 0.001), whereas for SLuK (65.0%, 51.6%; N = 41) it was comparable (p = 0.34). All STA groups demonstrated similar 1- and 5 years posttransplant survival to thoracic controls. Compared to abdominal controls, 1- and 5 years posttransplant survival in SHK (85.3%, 74.0%; N = 684), SLuLi (75.5%, 59.0%; N= 42) and SLuK (66.7%, 55.6%; N = 18) was decreased (p < 0.01), but SHLi (85.9%, 74.3%; N = 92) was comparable (p = 0.81). In summary, STA candidates had greater risk of wait-list mortality compared to single-organ candidates. STA outcomes were similar to thoracic transplantation; however, outcomes were similar to abdominal transplantation for SHLi only. Although select patients benefit from STA, risk-exposure variables for decreased survival should be identified, aiming to eliminate futile transplantation.

Combined heart and kidney transplantation provides an excellent survival and decreases risk of cardiac cellular rejection and coronary allograft vasculopathy

BACKGROUND

We analyzed the results of combined heart-kidney transplantation (CHKTx) over a 10-year period.

METHODS

Between September 1996 and May 2007 at Mayo Clinic, 12 patients (age 52 ± 12.2 years) underwent CHKTx as a simultaneous procedure in 10 recipients and as a staged procedure in two recipients with unstable hemodynamics after heart transplantation.

RESULTS

There was no operative mortality. Patient survival rates for the CHKTx recipients at 1 and 3 months and 6 years were 91%, 83%, and 83% and did not differ from isolated heart transplantation (IHTx) recipients (97%, 95%, and 79%, P = 0.61). The freedom from cardiac allograft rejection (≥ grade 2) at 3 months was 73% for CHKTx and had not changed during further follow-up; for IHTx, freedom from rejection at 3 months and 1 and 6 years was 61%, 56%, and 42% (P = .08). Heart and renal allograft survival was 100% with and left ventricular ejection fraction 66% ± 8.4% and glomerular filtration rate 61 ± 25 at last follow-up. There were no signs of cardiac allograft vasculopathy in the CHKTx recipients.

CONCLUSION

CHKTx yields favorable long-term outcome, with a low incidence of cardiac rejection and vasculopathy. Simultaneous CHKTx appears feasible, if hemodynamics is satisfactory. This approach expands the selection criteria for transplantation in patients with coexisting end-stage cardiac and renal disease.

Long-term results of combined heart and kidney transplantation: a French multicenter study

BACKGROUND

Outcomes in recipients who have undergone combined heart and kidney transplantation have mainly been addressed in small, single-center studies. We studied long-term results of combined heart and kidney transplantation in a large multicenter cohort.

METHODS

Between 1984 and 2007, 67 consecutive patients (61 men and 6 women) from 3 French centers underwent combined heart and kidney transplantation. At transplantation, 38 (57%) were receiving dialysis. All patients received immediate triple immunosuppression therapy (anti-calcineurin, steroids, azathioprine, or mycophenolate).

RESULTS

Overall actuarial survival rates were 62.0%, 60.3%, 53.3%, and 46.5% at 1, 3, 5, and 10 years, respectively. These rates were similar to those observed in 2981 isolated heart recipients at the 3 participating centers during the same period (respectively, 71.0%, 65.2%, 60.1%, and 47.2%, p = 0.6). Survival tended to improve during the last decade (1996 to 2007) and reached 71.1%, 67.5%, and 60% at 1, 3, and 5 years. Cardiac allograft rejection requiring treatment occurred in 12 (17.9%). Coronary artery vasculopathy developed in 3 (9.3%). Kidney allograft rejection occurred in 9 (13.4%). Kidney graft survival was 95.9% at 1, 3, 5, and 10 years.

CONCLUSIONS

Long-term survival rates in a large cohort of combined heart and kidney recipients are similar to those of isolated heart recipients in France. The rates of acute heart and kidney rejection and angiographic coronary artery vasculopathy were low in this patient population.

Combined heart-kidney transplantation: the University of Wisconsin experience

BACKGROUND

Combined heart-kidney transplantation (HKTx) is increasing in frequency, but long-term outcomes are unknown and appropriately comparative analysis is lacking.

METHODS

This study was a retrospective review of prospectively collected data for 19 HKTx patients. Patient and graft survival, graft rejection and coronary allograft vasculopathy (CAV) were compared for HKTx vs recipients of a heart (n = 515) or kidney alone (n = 3,188) or both organs at separate time-points (n = 8).

RESULTS

Patient and graft survival did not differ for HKTx vs any group. HKTx time to first rejection episode was significantly prolonged for both organs vs single-organ recipients. The incidence of CAV was significantly lower for HKTx.

CONCLUSIONS

HKTx provides outcomes similar to those for solitary heart or kidney transplantation. There may be an immunologic advantage to receiving organs in a combined fashion. Such allocation of organs seems medically appropriate; however, more refined strategies are needed to identify optimal recipient populations.