End-stage renal failure and cardiac mortality after heart transplantation

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

BACKGROUND/PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Chimerism and tolerance without GVHD or engraftment syndrome in HLA-mismatched combined kidney and hematopoietic stem cell transplantation

The toxicity of chronic immunosuppressive agents required for organ transplant maintenance has prompted investigators to pursue approaches to induce immune tolerance. We developed an approach using a bioengineered mobilized cellular product enriched for hematopoietic stem cells (HSCs) and tolerogenic graft facilitating cells (FCs) combined with nonmyeloablative conditioning; this approach resulted in engraftment, durable chimerism, and tolerance induction in recipients with highly mismatched related and unrelated donors. Eight recipients of human leukocyte antigen (HLA)-mismatched kidney and FC/HSC transplants underwent conditioning with fludarabine, 200-centigray total body irradiation, and cyclophosphamide followed by posttransplant immunosuppression with tacrolimus and mycophenolate mofetil. Subjects ranged in age from 29 to 56 years. HLA match ranged from five of six loci with related donors to one of six loci with unrelated donors. The absolute neutrophil counts reached a nadir about 1 week after transplant, with recovery by 2 weeks. Multilineage chimerism at 1 month ranged from 6 to 100%. The conditioning was well tolerated, with outpatient management after postoperative day 2. Two subjects exhibited transient chimerism and were maintained on low-dose tacrolimus monotherapy. One subject developed viral sepsis 2 months after transplant and experienced renal artery thrombosis. Five subjects experienced durable chimerism, demonstrated immunocompetence and donor-specific tolerance by in vitro proliferative assays, and were successfully weaned off all immunosuppression 1 year after transplant. None of the recipients produced anti-donor antibody or exhibited engraftment syndrome or graft-versus-host disease. These results suggest that manipulation of a mobilized stem cell graft and nonmyeloablative conditioning represents a safe, practical, and reproducible means of inducing durable chimerism and donor-specific tolerance in solid organ transplant recipients.

Long-term immunosuppression with anti-CD25 monoclonal antibodies in heart transplant patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD), a frequent and serious complication after heart transplantation, is associated with increased mortality. Current strategies include dose reduction or conversion from calcineurin inhibitors (CNIs) to either mycophenolate mofetil and/or rapamycin, with variable results and side-effect profiles.

METHODS

We evaluated the effectiveness of long-term anti-CD25 monoclonal antibody (MAb)-based immunosuppression in 17 adult heart transplant recipients with CKD at 10 +/- 5 years post-transplant. Seven patients had previously been switched to rapamycin but had untreatable side-effects and 10 patients were still on a CNI. The latter were matched with 10 control heart transplant patients whose renal function had remained stable over a similar post-transplant follow-up period, on CNI.

RESULTS

Anti-CD25 MAb were given over 13 +/- 10 months and were well tolerated with CD25 saturation monitoring (target <2% expression). Side-effects secondary to rapamycin resolved in 6 patients. The slope change of the creatinine clearance improved in patients in whom CNIs were discontinued (+0.335 ml/min/month vs -0.124 ml/min/month in controls, p = 0.03). Four patients died. Three died after 2, 6 and 7 months of follow-up, respectively, with the following diagnoses: acute renal failure (the patient refused dialysis); acute rejection (the patient had refused protocol endomyocardial biopsy); and perforated diverticulitis. The fourth patient died of pneumonia, 3 months after conversion from anti-CD25 MAb to rapamycin, because of poor venous access.

CONCLUSIONS

The use of long-term anti-CD25 MAb therapy as a potential replacement for CNI- and rapamycin-based immunosuppression is feasible. It is crucial that rejection surveillance be intensified. A randomized, controlled trial is required to confirm the benefits and safety of this strategy.

Combined heart-kidney transplantation: a review of recipient selection and patient outcomes

Elevated serum creatinine is a common finding among patients awaiting heart transplantation because of reduced renal perfusion in the setting of severe heart failure as well as overlapping risk factors for chronic kidney disease and heart disease. Patients with significant renal dysfunction preoperatively have worse outcomes with heart transplantation alone compared with those with normal renal function or those with renal dysfunction who undergo combined heart-kidney transplantation. Optimizing organ distribution and patient outcomes after cardiac transplantation requires appropriate recipient selection, including deciding which patients will benefit from combined heart-kidney transplantation. This review focuses on the evaluation of patients with chronic kidney disease awaiting heart transplantation and the outcomes of combined heart-kidney transplantation.

Development of proteinuria after switch to sirolimus-based immunosuppression in long-term cardiac transplant patients

Calcineurin-inhibitor therapy can lead to renal dysfunction in heart transplantation patients. The novel immunosuppressive (IS) drug sirolmus (Srl) lacks nephrotoxic effects; however, proteinuria associated with Srl has been reported following renal transplantation. In cardiac transplantation, the incidence of proteinuria associated with Srl is unknown. In this study, long-term cardiac transplant patients were switched from cyclosporine to Srl-based IS. Concomitant IS consisted of mycophenolate mofetil +/- steroids. Proteinuria increased significantly from a median of 0.13 g/day (range 0-5.7) preswitch to 0.23 g/day (0-9.88) at 24 months postswitch (p = 0.0024). Before the switch, 11.5% of patients had high-grade proteinuria (>1.0 g/day); this increased to 22.9% postswitch (p = 0.006). ACE inhibitor and angiotensin-releasing blocker (ARB) therapy reduced proteinuria development. Patients without proteinuria had increased renal function (median 42.5 vs. 64.1, p = 0.25), whereas patients who developed high-grade proteinuria showed decreased renal function at the end of follow-up (median 39.6 vs. 29.2, p = 0.125). Thus, proteinuria may develop in cardiac transplant patients after switch to Srl, which may have an adverse effect on renal function in these patients. Srl should be used with ACEi/ARB therapy and patients monitored for proteinuria and increased renal dysfunction.

Ischaemic heart disease is a risk factor for renal failure after heart transplantation

BACKGROUND

The improvement of a long-term outcomes of heart transplantation (HTx) has resulted in a new phenomenon; specifically, the development of renal dysfunction secondary to calcineurin inhibitor toxicity. This study was designed to assess the participation of risk factors in the development of renal dysfunction in HTx.

METHODS

Data from 310 patients undergoing HTx in our center between 1988-1998 with a post-operation survival period for minimum 5 years (n=155) were analyzed retrospectively. Study cohort was divided into two groups according to renal function estimated by serum creatinine in the fifth year (Group I n=72; serum creatinine > or = 150 micromol/l, Group II: n=83, serum creatinine < 150 micromol/l).

RESULTS

We noted that patients with serum creatinine > or = 150 micromol/l at 5 years post-HTx had renal function significantly worse as early as 1 month (p<0.01), and 1 year post-HTx (p<0.001). The risk for developing renal dysfunction after HTx was doubled in patients with a history of coronary artery disease (CAD), and 2.5 times higher in those with small body weight gain. End stage renal disease developed in 16 patients (10.3%) and renal transplantation was performed in 13 (8.4%) of them.

CONCLUSION

Our data documented that a history of CAD and limited weight gain is a major risk factor for development of renal dysfunction after HTx. Aggressive modification of risk factors for CAD may reduce the occurrence of this complication.

Risk stratification for renal transplantation after cardiac or lung transplantation: single-center experience and review of the literature

BACKGROUND

Long-term survival after heart (HTx) or lung (LuTx) transplantation increases the risk for end-stage renal disease (ESRD). After HTx ESRD was reported to enhance mortality, and kidney transplantation (KTx) was shown to improve survival. However, prognostic factors in ESRD after HTx or LuTx are largely unknown.

METHODS

Single-center observational study in HTx and LuTx patients who accessed the KTx waiting list; baseline characteristics were correlated with mortality.

RESULTS

KTx was performed in 15 of 65 study patients. Survival was comparable on the KTx waiting list and in reference patients from the same center without ESRD. KTx significantly improved survival (5 years' survival 84.6% with KTx vs. 56.5% on the KTx waiting list, p = 0.030). None of the baseline parameters predicted mortality in the KTx group. Only on the KTx waiting list BMI (median 24.7 vs. 20.7; p < 0.05) and left ventricular ejection fraction (LVEF, median 63 vs. 53%, p < 0.008) significantly correlated with survival.

CONCLUSIONS

The risk for mortality after HTx or LuTx is not increased by ESRD, provided that patients meet access criteria for the KTx waiting list. KTx improves survival in ESRD after HTx or LuTx. BMI and LVEF may predict outcome in HTx/LuTx patients on the KTx waiting list.

Statin therapy associated with a reduced risk of chronic renal failure after cardiac transplantation

BACKGROUND

Chronic renal failure (CRF) after heart transplantation is common, although risk factors for its development and potential preventive interventions are not well established.

METHODS

In this study we retrospectively assessed the cumulative incidence of CRF and identified independent predictors of CRF in heart transplant recipients between August 1986 and January 2003.

RESULTS

Among the 218 patients included in the analysis, the cumulative incidence of CRF was 4.5% at 5 years, and 19.6% at 10 years after transplant. Multivariate Cox modeling revealed that diabetes mellitus prior to transplant was associated with an increased risk of CRF (hazards ratio [HR] 7.11, p < 0.01), whereas factors associated with a reduced risk of CRF included a pre-transplant creatinine clearance > or = 60 ml/min/1.73 m2 (HR 0.30, p = 0.01) and treatment with a statin after transplant (HR 0.25, p < 0.01). Patients who developed CRF after transplant were at higher risk of death (HR 8.5, p < 0.01).

CONCLUSIONS

CRF is common after cardiac transplantation and is associated with substantial mortality. The reduced risk of CRF observed with statin therapy warrants prospective study, with particular emphasis on the mechanisms of progression to CRF in this population.

Mycophenolate Mofetil May Allow Cyclosporine and Steroid Sparing in De Novo Heart Transplant Patients

BACKGROUND

Mycophenolate mofetil (MMF) provides superior prophylaxis against acute rejection when compared with azathioprine (AZA) in heart and renal transplantation. However, it remains unclear whether this results in improved survival or reduced morbidity after heart transplantation.

METHOD

In a sequential study, 240 cardiac transplant patients were treated with either MMF (n=119) or AZA (n=121) both in combination with cyclosporine and corticosteroids after rabbit antithymocyte globulin induction.

RESULTS

By protocol lower cyclosporine levels were targeted in the MMF group during the first year (e.g. 203+/-52 ng/mL MMF vs. 236+/-59 ng/mL AZA, P=0.0006 at 6 months). Patient survival at 1 year (82% MMF vs. 79% AZA, P=0.55) and at 3 years was similar in both groups. The cumulative probability of receiving antirejection treatment within 1 year was lower in the MMF group, as was biopsy-proven acute rejection with International Society of Heart and Lung Transplantation grade > or =3A (24% vs. 35%, P=0.03). The MMF group also had fewer episodes requiring cytolytic therapy (6% vs. 13%, P=0.04) and more patients had steroids withdrawn by 1 year (66% vs. 32%, P<0.001). Renal function was better in the MMF group with lower creatinine levels at 1 year (133+/-45 vs. 155+/-46 micromol/L, P=0.0004). Calculated creatinine clearance (Cockcroft and Gault formula) at 1 year was also better (MMF 74+/-32 mL/min vs. AZA 62+/-24 mL/min, P=0.004).

CONCLUSION

Our results suggest that immunosuppression with MMF rather than AZA may allow lower cyclosporine levels, better renal function, and increased steroid weaning at 1 year while also achieving better control of acute rejection.

Renal protective strategies in heart transplant patients

PURPOSE OF REVIEW

Chronic renal failure associated with long-term calcineurin inhibitor immunosuppression is a substantial clinical problem in the heart transplant population, compounded by difficulties in identifying patients likely to develop renal dysfunction. Several approaches, however, have been developed or are being investigated to preserve renal function in heart transplant patients.

RECENT FINDINGS

Approaches to identify patients with an increased risk of developing renal dysfunction are being refined, and improved calcineurin inhibitor monitoring strategies are being investigated. Novel immunosuppressive regimens including mycophenolate mofetil and/or rapamycin that lack nephrotoxicity promise new therapeutic strategies with the efficacy of calcineurin inhibitor-based combinations. Temporary ('holiday') or permanent ('retirement') calcineurin inhibitor replacement with interleukin-2 receptor monoclonal antibodies has the potential to halt progressive renal dysfunction. Finally, emerging data on the renal protection afforded by angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, either singly or in combination, provide another avenue of investigation.

SUMMARY

Several strategies have demonstrated their potential to preserve or improve renal function in heart transplant patients in small studies. Large randomized controlled trials are necessary to determine the optimal strategies to prevent rejection while preserving renal function in the long-term management of heart transplant patients.

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

End-stage renal disease is a significant complication of heart transplantation (HTx), but our understanding of dialysis outcomes in HTx recipients remains limited. We performed a retrospective analysis looking at dialysis mortality in HTx recipients as compared to a matched dialysis cohort. We also examined outcomes with respect to kidney transplantation (KTx) in these cohorts. 2709 incident HTx recipients were captured from the Canadian Organ Replacement Register between 1981 and 2002. The incidence of dialysis after HTx was 3.9% (n = 105) and carried a greater crude mortality compared to HTx recipients not requiring dialysis (56.2% vs. 35.9%, p < 0.001). Compared to the matched dialysis cohort, survival of HTx patients on dialysis was also significantly worse (19% vs. 40%, p = 0.003). In those receiving a KTx, survival did not differ between the two cohorts; however, in those that did not receive a KTx the survival was significantly lower in the dialysis post-HTx group compared to the matched dialysis cohort (15.7% vs. 35.2%, p < 0.025). Our analysis suggests mortality on dialysis following HTx is greater than would be expected from a similar dialysis population, and KTx may abrogate some of this increased risk. Attention should be placed on preventing chronic kidney disease progression following HTx.

Multivariate Predictors of Heart Transplantation Outcomes in the Era of Chronic Mechanical Circulatory Support

BACKGROUND

Determining which pretransplantation (TX) characteristics predict the development of chronic renal dysfunction (CRD) or death after heart TX would enable more accurate risk assessment at the time of candidate evaluation.

METHODS

A cohort of 278 patients underwent TX in three hospitals between 1993 and 2002. Predictive models for CRD (serum creatinine consistently above 2 mg/dL) and allograft loss (death or re-TX) were constructed using logistic and Cox regression, respectively.

RESULTS

Using logistic regression, CRD was more likely to develop in TX patients if they had a larger body surface area (odds ratio [OR] = 5.8 per m2, 95% confidence interval [CI] = 1.04 to 31.9, p = 0.04) or were inotrope dependent (OR = 1.8, 95% CI = 0.90 to 3.7, p = 0.09). Notably, the implementation of mechanical circulatory support as bridge to transplantation decreased the risk of CRD (OR = 0.30, 95% CI = 0.12 to 0.72, p = 0.007). Cox analysis demonstrated independent predictive ability of improved survival for males (hazard ratio [HR] = 0.42, 95% CI = 0.21 to 0.83, p = 0.01). Worse survival was observed with prior sternotomy (HR = 3.5, 95% CI = 2.0 to 6.0, p < 0.001), diabetes mellitus (HR = 1.9, 95% CI = 0.98 to 3.9, p = 0.06), and elevated serum creatinine (HR = 2.8 per mg/dL, 95% CI = 1.3 to 5.8, p = 0.007).

CONCLUSIONS

Certain pretransplant characteristics clearly predispose a patient to the development of CRD or increased mortality after heart transplantation. Interestingly, the risk of CRD after heart transplantation is greater for patients bridged to transplant with inotropes than with mechanical circulatory support. When hemodynamically indicated, timely implementation of pretransplant mechanical circulatory support should be considered.

The Impact of Transforming Growth Factor-β1 Gene Polymorphism on End-Stage Renal Failure After Heart Transplantation

BACKGROUND

Nephrotoxicity is a major side effect of calcineurin inhibitors (CNI). Earlier we reported 8% of our heart transplant recipients reaching end-stage renal failure (ESRF). Now, with an extended follow up of 20 years, we re-evaluated the development of ESRF and studied its influence on survival and the impact of polymorphisms in codon 10 and 25 of the promoter region of transforming growth factor (TGF)-beta on the risk of ESRF.

METHODS

In all, 465 patients were transplanted between June 1984 and June 2005. All were on maintenance CNI treatment. Development of ESRF was studied in 402/465 (86.5%) patients surviving at least one year. Their median follow up was eight years, total observation time of 3,414 years. TGF-beta polymorphisms in codon 10 (Leu to Pro) and codon 25 (Arg to Pro) were analyzed with real-time polymerase chain reaction in a cohort of 237 patients, with an observation time of 2,329 years.

RESULTS

Ten-year survival of patients surviving at least one year was 58.5%. Seventy-three patients (18.2%) developed ESRF. Dialysis-free survival was 60% at 15 years. The relative risk for ESRF in Pro carriers was 2.9 (CI 1.5-5.8) compared to patients with the Leu/Leu genotype (P = 0.002), while Pro carriers had a RR of 2.6 (CI 1.4-4.8) compared to the Arg/Arg25 genotype (P = 0.002). Survival of patients with ESRF was 1.5 years (median).

CONCLUSION

We found a highly significant association between TGF-beta polymorphisms and CNI induced ESRF after heart transplantation (HTx). Pro carriers of either codon 10 or 25 had a 2.6 to 2.9 times increased risk of developing ESRF. As ESRF after HTx results in high mortality rates these patients should no longer receive CNI-based immunosuppression.

Determination of renal function in long-term heart transplant patients by measurement of urinary retinol-binding protein levels

Significant improvements have been noted in heart transplantation with the advent of cyclosporine. However, cyclosporine use is associated with significant side effects, such as chronic renal failure. We were interested in evaluating the incidence of long-term renal dysfunction in heart transplant recipients. Fifty-three heart transplant recipients were enrolled in the study. Forty-three patients completed the entire evaluation and follow-up. Glomerular (serum creatinine, creatinine clearance measured, and creatinine clearance calculated) and tubular functions (urinary retinol-binding protein, uRBP) were re-analyzed after 18 months. At the enrollment time, the prevalence of renal failure ranged from 37.7 to 54% according to criteria used to define it (serum creatinine > or = 1.5 mg/dL and creatinine clearance <60 mL/min). Mean serum creatinine was 1.61 +/- 1.31 mg/dL (range 0.7 to 9.8 mg/dL) and calculated and measured creatinine clearances were 67.7 +/- 25.9 and 61.18 +/- 25.04 mL min-1 (1.73 m(2))-1, respectively. Sixteen of the 43 patients who completed the follow-up (37.2%) had tubular dysfunction detected by increased levels of uRBP (median 1.06, 0.412-6.396 mg/dL). Eleven of the 16 patients (68.7%) with elevated uRBP had poorer renal function after 18 months of follow-up, compared with only eight of the 27 patients (29.6%) with normal uRBP (RR = 3.47, P = 0.0095). Interestingly, cyclosporine trough levels were not different between patients with or without tubular and glomerular dysfunction. Renal function impairment is common after heart transplantation. Tubular dysfunction, assessed by uRBP, correlates with a worsening of glomerular filtration and can be a useful tool for early detection of renal dysfunction.

Survival Beyond 10 Years Following Heart Transplantation: The Cleveland Clinic Foundation Experience

BACKGROUND

Long-term survival after heart transplantation is a desirable although challenging goal.

METHODS

We analyzed clinical outcomes in the cohort of 170 patients who have undergone heart transplantation at The Cleveland Clinic Foundation and survived >10 years.

RESULTS

We found 10-year and 15-year survival rates of 54% and 41%, respectively, in these patients, but there was also a high incidence of complications, such as hypertension, renal dysfunction, transplant vasculopathy, and malignancy.

CONCLUSIONS

Long-term survival following cardiac transplantation is possible although complications are frequent. Beyond 10 years, malignancy is a major cause of death.

Impact of TGFβ1 gene polymorphisms on late renal function in pediatric heart transplantation

Late renal dysfunction may affect long-term outcome of nonrenal transplant recipients. We hypothesized that transforming growth factor beta1 (TGFbeta1) might play a role in the fibrogenic mechanisms leading to renal dysfunction. The aim was to determine whether TGFbeta1 gene polymorphisms are associated with renal outcome in pediatric heart recipients. Eighty-eight patients underwent a first heart transplantation at the age of 7.1 +/- 6.5 years, received tacrolimus-based immunosuppression, and were followed for > or =1 year (6.7 +/- 3.2 years). Creatinine clearance (CrCl; ml/mn/1.73 m2) was calculated (Schwartz) before transplant, then at 1 month, 6 months, and 1 year, and yearly up to 7 years. Impaired function was defined as CrCl <80 ml/mn/1.73 m2. Mean CrCl decreased from 120 +/- 53 ml/mn/1.73 m2 before transplant to 98 +/- 40, 96 +/- 37, 102 +/- 30, and 101 +/- 38 ml/mn/1.73 m2 at, respectively, 6 months and 1, 5 (n = 58), and 7 years (n = 33). The TGFbeta1 high-producer genotype had worse CrCl than intermediate and low producers at every time point, despite similar pretransplant CrCl (pretransplant = 120 +/- 53 vs 118 +/- 55 ml/mn/1.73 m2 [p = 0.8], 1 year = 92 +/- 38 vs 113 +/- 30 ml/mn/1.73 m2 [p = 0.03]) and similar tacrolimus levels. The TGFbeta1 high-producer genotype was associated with CrCl < 80 ml/mn/1.73 m2. The TGFbeta1 high-producer genotype is associated with renal dysfunction in pediatric heart recipients.