Chronic renal insufficiency in heart transplant recipients: risk factors and management options

A Comprehensive Excursus of the Roles of Echocardiography in Heart Transplantation Follow-Up

Current guidelines for the care of heart transplantation recipients recommend routine endomyocardial biopsy and invasive coronary angiography as the cornerstones in the surveillance for acute rejection (AR) and coronary allograft vasculopathy (CAV). Non-invasive tools, including coronary computed tomography angiography and cardiac magnetic resonance, have been introduced into guidelines without roles of their own as gold standards. These techniques also carry the risk of contrast-related kidney injury. There is a need to explore non-invasive approaches providing valuable information while minimizing risks and allowing their application independently of patient comorbidities. Echocardiographic examination can be performed at bedside, serially repeated, and does not carry the burden of contrast-related kidney injury and procedure-related risk. It provides comprehensive assessment of cardiac morphology and function. Advanced echocardiography techniques, including Doppler tissue imaging and strain imaging, may be sensitive tools for the detection of minor myocardial dysfunction, thus providing insight into early detection of AR and CAV. Stress echocardiography may offer a valuable tool in the detection of CAV, while the assessment of coronary flow reserve can unravel coronary microvascular impairment and add prognostic value to conventional stress echocardiography. The review highlights the role of Doppler echocardiography in heart transplantation follow-up, weighting advantages and limitations of the different techniques.

Outcomes With Left Ventricular Assist Device in End-Stage Renal Disease: A Systematic Review

Renal dysfunction is a common comorbidity in patients with advanced heart failure who may benefit from mechanical circulatory support (MCS). Unfortunately, renal function may result after left ventricular assist device (LVAD) implantation. The purpose of this study is to examine the outcomes of advanced heart failure patients with end-stage renal disease (ESRD) requiring mechanical circulatory support as a bridge to transplant (BTT) or destination therapy (DT). We searched Medline, Embase, and Cochrane in September 2021. The following keywords were used: left ventricular assist device or LVAD and end-stage renal disease or ESRD. Our study included case reports, case series, descriptive studies, and randomized control trials. Review articles, guidelines, systematic reviews, and meta-analyses were excluded. We also excluded pediatric cases. We identified 278 articles; 92 were duplicated, 186 articles entered the screening phase, and 133 articles were excluded by title and abstract. After the full-text screening, 40 articles were excluded. This systematic review included 13 articles. Among the contraindications to LVAD implantation, a general contraindication is for patients found to have stage 4 chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR): <30 mL/minute/1.73 m²), while those on dialysis are an absolute contraindication LVAD implantation. Despite the limited data and publications on LVADs in patients with ESRD, LVAD implantation as a bridge to transplantation or destination therapy may be considered in selected patients without increasing morbidity and mortality. Therefore, shared decision-making around the treatment of advanced heart failure with these patients and the care team is essential.

Kidney Re-Transplantation after Simultaneous Heart and Kidney Transplant: Case Study and Literature Review

The kidney is one of most frequent transplants to be performed in multi-organ transplantation. A simultaneous heart and kidney transplant (SHKT) is the best-known treatment method in patients with severe heart failure and end-stage renal disease (ESRD). Here, the authors describe the case of a kidney re-transplantation after SHKT, which is in accordance with the majority of studies, and proves the safety of simultaneous procedures. The article highlights the complex care required after the transplant, followed by the multi-factor qualification for re-transplantation. In conclusion, the case shows that SHKT provides long-term favorable outcomes and enables a repeated kidney transplantation with satisfactory one-year follow-up results.

The role of non-invasive imaging modalities in cardiac allograft vasculopathy: an updated focus on current evidences

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse form of vasculopathy affecting almost 50% of patients after 10 years from heart transplant and represents the most common cause of long-term cardiovascular mortality among heart transplant recipients. The gold standard diagnostic technique is still invasive coronary angiography, which however holds potential for complications, especially contrast-related kidney injury and procedure-related vascular lesions. Non-invasive and contrast-sparing imaging techniques have been advocated and investigated over the past decades, in order to identify those that could replace coronary angiography or at least reach comparable accuracy in CAV detection. In addition, they could help the clinician in defining optimal timing for invasive testing. This review attempts to examine the currently available non-invasive imaging techniques that may be used in the follow-up of heart transplant patients, spanning from echocardiography to nuclear imaging, cardiac magnetic resonance and cardiac computed tomography angiography, weighting their advantages and disadvantages.

Everolimus Initiation With Early Calcineurin Inhibitor Withdrawal in De Novo Heart Transplant Recipients: Long-term Follow-up From the Randomized SCHEDULE Study

BACKGROUND

A calcineurin inhibitor (CNI)-free immunosuppressive regimen has been demonstrated to improve renal function early after heart transplantation, but long-term outcome of such a strategy has not been well described.

METHODS

In the randomized SCHEDULE trial, de novo heart transplant recipients received (1) everolimus with reduced-exposure CNI (cyclosporine) followed by CNI withdrawal at week 7-11 posttransplant or (2) standard-exposure cyclosporine, both with mycophenolate mofetil and corticosteroids; 95/115 randomized patients were followed up at 5-7 years posttransplant.

RESULTS

Mean measured glomerular filtration rate was 74.7 mL/min and 62.4 mL/min with everolimus and CNI, respectively. The mean difference was in favor of everolimus by 11.8 mL/min in the intent-to-treat population (P = 0.004) and 17.2 mL/min in the per protocol population (n = 75; P < 0.001). From transplantation to last follow-up, the incidence of biopsy-proven acute rejection (BPAR) was 77% (37/48) and 66% (31/47) (P = 0.23) with treated BPAR in 50% and 23% (P < 0.01) in the everolimus and CNI groups, respectively; no episode led to hemodynamic compromise. Coronary allograft vasculopathy (CAV) assessed by coronary intravascular ultrasound was present in 53% (19/36) and 74% (26/35) of everolimus- and CNI-treated patients, respectively (P = 0.037). Graft dimensions and function were similar between the groups. Late adverse events were comparable.

CONCLUSIONS

These results suggest that de novo heart transplant patients randomized to everolimus and low-dose CNI followed by CNI-free therapy maintain significantly better long-term renal function as well as significantly reduced CAV than patients randomized to standard CNI treatment. Increased BPAR in the everolimus group during year 1 did not impair long-term graft function.

The impact of severe acute kidney injury requiring renal replacement therapy on survival and renal function of heart transplant recipients - a UK cohort study

Severe acute kidney injury (AKI), defined as requiring renal replacement therapy (RRT), is associated with higher mortality postheart transplantation, but its long-term renal consequences are not known. Anonymized data of 3365 patients, who underwent heart transplantation between 1995 and 2017, were retrieved from the UK Transplant Registry. Multivariable binary logistic regression was performed to identify risk factors for severe AKI requiring RRT, Kaplan-Meier analysis to compare survival and renal function deterioration of the RRT and non-RRT groups, and multivariable Cox regression model to identify predicting factors of mortality and end-stage renal disease (ESRD). 26.0% of heart recipients received RRT post-transplant. The RRT group has lower survival rates at all time points, especially in the immediate post-transplant period. However, conditional on 3 months survival, older age, diabetes and coronary heart disease, but not post-transplant RRT, were the risk factors for long-term survival. The predicting factors for ESRD were insulin-dependent diabetes, renal function at transplantation, eGFR decline in the first 3 months post-transplant, post-transplant severe AKI and transplantation era. Severe AKI requiring RRT post-transplant is associated with worse short-term survival, but has no impact on long-term mortality. It also accelerates recipients' renal function deterioration in the long term.

Long-Term Effects of the Replacement of Calcineurin Inhibitors With Everolimus and Mycophenolate in Patients With Calcineurin Inhibitor-Related Nephrotoxicity

BACKGROUND

There is little evidence on the long-term effects of calcineurin inhibitor (CNI) withdrawal and substitution with everolimus and mycophenolate mofetil in maintenance therapy of patients who have received heart transplants and have concurrent CNI nephrotoxicity. Aims of this study were to evaluate the progression of renal dysfunction after discontinuation of CNIs and to monitor for major adverse events after therapy change.

METHODS

Data from 41 patients who underwent heart transplant and have different degrees of renal dysfunction (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m²), without evidence of proteinuria, and in whom CNI therapy was replaced by everolimus, were analyzed. At the time of CNI withdrawal, clinical parameters, echocardiographic data, blood tests of renal function, and monitoring of adverse events were recorded. The median follow-up period was 5 years ± 28 months.

RESULTS

In 52% of patients, there was a clear improvement in renal function (10.5 mL/min/1.73 m² of extra eGFR on average). The former were characterized by less advanced age and a short time from the heart transplant. The echocardiographic parameters showed a significant reduction in septum thickness (11.58 ± 2 mm vs 10.29 ± 2 mm; P = .0001) and in left ventricle posterior wall thickness (10.74 ± 1 mm vs 9.74 ± 1 mm; P = .0004). The incidence of late acute rejection and cardiac allograft vasculopathy was similar in our population compared to literature data.

CONCLUSIONS

A therapeutic switch from CNIs to everolimus and mycophenolate mofetil can improve renal function in patients with CNI nephrotoxicity, especially in those with a shorter time period from transplantation, without exposing them to a higher incidence of late acute rejection and cardiac allograft vasculopathy.

Factors Related to the Acute Cellular Rejection During the First Year After Heart Transplant

INTRODUCTION

The acute cellular rejection is recognized as a factor related to the long-term viability of the heart graft. We intend to establish which factors are associated with the acute cellular rejection during the first year post heart transplant using a longitudinal model with repeated measures.

METHODS

A retrospective cohort study was performed with all the patients who underwent heart transplant between 2005-2018 at the Hospital Universitario San Ignacio in Bogota, Colombia. In order to determine the factors associated with the development of acute cellular rejection, a generalized estimating equation approach was used, with an interchangeable correlation structure. The lowest value of quasi-likelihood information criterion and P < .05 was considered significant.

RESULTS

Fifty-five patients (49.3 ± 11.1 years old) were included. The mortality during the first month was 16.3% and the accumulated mortality during the first year was 23.6%. The incidence of the acute cellular rejection was higher during the third month after the transplant (79.9%); most of them were acute cellular rejection grade 1. The factors associated with the development of the rejection were the cyclosporine levels out of the therapeutic range in several periods of evaluation (P < .03) and the age of the receptor (P = .049).

CONCLUSIONS

Using advanced modeling methodologies of longitudinal data we identified that the factors associated with acute cellular rejection during the first year after the transplant are related to the therapeutic levels of the calcineurin inhibitor (cyclosporin) during the first 6 months of follow-up and the age of the receptor.

Changes in Renal Function After Heart Transplantation

Renal function after heart transplantation (HTx) typically follows a biphasic pattern and an initial decay within 1 to 2 years. Trajectory of renal function after HTx is less reported, especially in Asia. The aims of this cohort study were to describe the changes in HTx recipients' serum creatinine and estimated glomerular filtration rate (eGFR) levels 5 years following HTx in Taiwan.

METHODS

We retrospectively reviewed 5 years of 440 consecutive adult patients (≥ 18 years) who underwent first HTx from June 1987 to December 2014 at the National Taiwan University Hospital.

RESULTS

Among 422 participants, they received induction therapy consisting of intravenous rabbit antithymocyte globulin. Here, we illustrated the trends over the years by dividing the subjects into 2 groups based on their immunosuppressive regimen of transplantation (1987-2002 and 2003-2014) The pretransplantation median serum creatinine concentration level was 1.2 mg/dL, rose to 1.4 mg/dL at 3 months after surgery, and remained steady over 5 years after HTx. Pretransplant median eGFR was 67 mL/min/1.73 m².The median serum creatinine concentration level and eGFR at baseline were all significantly difference than pretransplantation (P > .05). This result has showed that an initial steep decline within 3 months after transplant remained stable 5 years after HTx.

CONCLUSION

As renal function deteriorates after HTx, we observed a steep decline in serum creatinine level and glomerular filtration rate within the 3 months after HTx, followed by a slow rate of deterioration over the following months. We found a time-related progressive deterioration in renal function during the 5 years after HTx.

Complications of Cardiac Transplantation

PURPOSE OF REVIEW

Despite the improvement in medical therapy for heart failure and the advancements in mechanical circulatory support, heart transplantation (HT) still remains the best therapeutic option to improve survival and quality of life in patients with advanced heart failure. Nevertheless, HT recipients are exposed to the risk of several potential complications that may impair their outcomes. In this article, we aim to provide a practical and scholarly framework for clinicians approaching heart transplant medicine, as well as a concise update for the experienced readers on the most relevant post-HT complications.

RECENT FINDINGS

While recognizing that most of the treatments herein discussed are based more on experience than on solid scientific evidence, significant step forward has been made in particular in the recognition and management of primary graft dysfunction, antibody-mediated rejection, and renal dysfunction. Complications after HT may vary according to the time from surgery and can be related to graft function and pathology or to diseases and dysfunctions occurring in other organs or systems, mainly as side effects of immunosuppressive drugs and progression of pre-existing conditions. Future research needs to focus on improving precision diagnostics of causes of graft dysfunction and on reaching an optimal and customized balance between efficacy and toxicities of immunosuppressive strategies.

Cardiac Transplant Postoperative Management and Care

Heart failure impacts a multitude of individuals each year. Treatment is based on the progression of the disease and severity of symptoms. Cardiac transplant is the gold standard treatment of advanced heart failure, although the availability of organs limits the number of transplants received each year. Postoperative care and monitoring for cardiac transplant is complex and requires specialized nurses and providers at transplant centers for successful outcomes. This article outlines cardiac transplant from preoperative care through transplant, as well as posttransplant monitoring and care including discharge. Special attention is focused on management in the intensive care unit setting and potential complications that can occur in the immediate postoperative period. Interventions for potential complications are also highlighted.

Association of SNPs with the efficacy and safety of immunosuppressant therapy after heart transplantation

Aim: Studying the possible influence of SNPs on efficacy and safety of calcineurin inhibitors upon heart transplantation. Materials & methods: In 60 heart transplant patients treated with tacrolimus or cyclosporine, we studied a panel of 36 SNPs correlated with a series of clinical parameters during the first post-transplantation year. Results: The presence of serious infections was correlated to ABCB1 rs1128503 (p = 0.012), CC genotype reduced the probability of infections being also associated with lower blood cyclosporine concentrations. Lower renal function levels were found in patients with rs9282564 AG (p = 0.003), related to higher blood cyclosporine blood levels. A tendency toward increased graft rejection (p = 0.05) was correlated to rs2066844 CC in NOD2/CARD15, a gene related to lymphocyte activation. Conclusion: Pharmacogenetics can help identify patients at increased risk of clinical complications.

Original submitted 30 January 2015; revision submitted 27 March 2015

Advantageous effects of immunosuppression with tacrolimus in comparison with cyclosporine A regarding renal function in patients after heart transplantation

BACKGROUND

Nephrotoxicity is a serious adverse effect of calcineurin inhibitor therapy in patients after heart transplantation (HTX).

AIM

In this retrospective registry study, renal function within the first 2 years after HTX in patients receiving de novo calcineurin inhibitor treatment, that is, cyclosporine A (CSA) or tacrolimus (TAC), was analyzed. In a consecutive subgroup analysis, renal function in patients receiving conventional tacrolimus (CTAC) was compared with that of patients receiving extended-release tacrolimus (ETAC).

METHODS

Data from 150 HTX patients at Heidelberg Heart Transplantation Center were retrospectively analyzed. All patients were continuously receiving the primarily applied calcineurin inhibitor during the first 2 years after HTX and received follow-up care according to center practice.

RESULTS

Within the first 2 years after HTX, serum creatinine increased significantly in patients receiving CSA (P<0.0001), whereas in patients receiving TAC, change of serum creatinine was not statistically significant (P=not statistically significant [ns]). McNemar's test detected a significant accumulation of patients with deterioration of renal function in the first half year after HTX among patients receiving CSA (P=0.0004). In patients receiving TAC, no significant accumulation of patients with deterioration of renal function during the first 2 years after HTX was detectable (all P=ns). Direct comparison of patients receiving CTAC versus those receiving ETAC detected no significant differences regarding renal function between patients primarily receiving CTAC or ETAC treatment during study period (all P=ns).

CONCLUSION

CSA is associated with a more pronounced deterioration of renal function, especially in the first 6 months after HTX, in comparison with patients receiving TAC as baseline immunosuppressive therapy.