De novo sirolimus with low-dose tacrolimus versus full-dose tacrolimus with mycophenolate mofetil after heart transplantation—8-year results

Wound complications frequency in heart transplant recipients on mammalian target of rapamycin inhibitors: A meta-analysis

A meta-analysis investigation was executed to measurethe wound complications (WCs) frequency in heart transplant (HT) recipients on mammalian target of rapamycin inhibitors (MTRIs). A comprehensive literature investigation till February 2023 was applied and 978 interrelated investigations were reviewed. The 10 chosen investigations enclosed 2173 individuals with HT were in the chosen investigations' starting point, 1164 of them were utilising MTRIs, and 1009 were utilising control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were utilised to compute the value of the WCs frequency in HT recipients on MTRIs by the dichotomous approaches and a fixed or random model. MTRIs had significantly higher WCs (OR, 1.53; 95% CI, 1.19-1.98, P = .001) compared with those with control in individuals with HT. MTRIs had significantly higher WCs compared with those with control in individuals with HT. However, care must be exercised when dealing with its values because of the low number of the nominated investigations and the low sample size of some of the nominated investigations for the meta-analysis.

Chronic kidney disease after lung transplantation in a changing era

Lung transplant (LTx) physicians are responsible for highly complex post-LTx care, including monitoring of kidney function and responding to kidney function loss. Better survival of the LTx population and changing patient characteristics, including older age and increased comorbidity, result in growing numbers of LTx patients with chronic kidney disease (CKD). CKD after LTx is correlated with worse survival, decreased quality of life and high costs. Challenges lie in different aspects of post-LTx renal care. First, serum creatinine form the basis for estimating renal function, under the assumption that patients have stable muscle mass. Low or changes in muscle mass is frequent in the LTx population and may lead to misclassification of CKD. Second, standardizing post-LTx monitoring of kidney function and renal care might contribute to slow down CKD progression. Third, new treatment options for CKD risk factors, such as diabetes mellitus, proteinuria and heart failure, have entered clinical practice. These new treatments have not been studied in LTx yet but are of interest for future use. In this review we will address the difficult aspects of post-LTx renal care and evaluate new and promising future approaches to slow down CKD progression.

Maintenance immunosuppression in heart transplantation: insights from network meta-analysis of various immunosuppression regimens

Previous studies have reported superiority of mechanistic target-of-rapamycin (mTOR) antagonists (mTA) over calcineurin inhibitors (CNI) as part of maintenance immunosuppression (IS) in mitigating cardiac allograft vasculopathy (CAV) after heart transplantation (HT). MEDLINE and EMBASE were searched through October 2019 for studies comparing maintenance IS with mTA + antimetabolites (AM), CNI + mTA or CNI + AM post HT. The main outcomes were all-cause mortality, CAV, acute rejection, CMV infections, and change in eGFR. To compare different IS antagonists, a random-effects network meta-analysis was performed. We used p-scores to rank best treatments per outcome. Our search identified fifteen eligible studies (5 studies comparing mTA + AM vs. CNI + AM, 9 comparing CNI + mTA vs. CNI + AM, 1 comparing mTA + AM vs. CNI + mTA, 8 using everolimus and 7 sirolimus as mTA) reporting the selected outcomes. We did not identify any statistical difference in all-cause mortality among the three IS regimens without heterogeneity among studies. CAV rates were significantly lower with CNI + mTA (odds ratio [OR] 0.53, 95% confidence interval [CI] 0.3-0.92). Acute rejection rates were significantly lower with CNI + AM (OR 0.26, 95% CI 0.12-0.56) and with CNI + mTA (OR 0.16, 95% CI 0.07-0.33) compared with mTA + AM without significant heterogeneity (I² = 43%, p = 0.9). CMV infections were significantly lower with mTA + AM (OR 0.13, 95% CI 0.03-0.46) and with CNI + mTA (OR 0.27, 95% CI 0.2-0.38) compared with CNI + AM without heterogeneity. mTA + AM led to higher eGFR compared with CNI + AM (9.06 ml/min/1.73 m2, 95% CI 3.15-14.97) and CNI + Mta (9.64 ml/min/1.73 m2, 95% CI 0.91-18.36), but the heterogeneity among studies was significant. CNI + mTA ranked better for CAV (p = 0.78), and acute rejection (p = 0.99) while mTA + AM for CMV infection (p = 0.94) and improvement in renal function (p = 0.93) than other regimens. Different IS regimens have similar effects on survival post HT, but CNI + mTA was associated with lower CAV rates, and acute rejection, while mTA + AM with less CMV infection post HT.

Current Status of Malignant Tumors after Organ Transplantation

Objective

To analyze the diagnosis and treatment of patients with concomitant malignant tumors after organ transplantation by compiling data from organ transplantation patients.

Methods

By searching CNKI and PubMed databases, we made a systematic analysis of the studies of postorgan transplantation complicating malignant tumors in the last decade.

Results

There were 10 articles on malignant tumors after renal transplantation, 8 articles on liver transplantation, 2 articles on heart transplantation, and 1 article on lung transplantation. The incidence of malignant tumors complicating renal transplantation is 10.4% in Europe, with skin cancer and Kaposi's sarcoma being common; the incidence in the United States is 3.4%, with PTLD having the highest incidence; the incidence of malignant tumors is relatively lowest in Asia, with gastrointestinal malignancies being the main ones. The mean time to complication of malignancy after renal transplantation is 3.83 years. The incidence of concurrent malignancies after liver transplantation is 8.8% in Europe, where skin cancer and Kaposi's sarcoma are common; 5.6% in Asia, where gastrointestinal tract tumors are prevalent; and 4.5% in the United States, where gastrointestinal tract tumors, PTLD, and hematologic diseases are predominant. The mean time to complication of malignancy after liver transplantation is 4.79 years. The incidence of malignancy after heart transplantation is 6.8-10.7%. The incidence of malignancy after lung transplantation is about 10.1%. Minimization of immunosuppression or modification of immunosuppression regimens may be a key component of cancer prevention. mTOR inhibitors and phenolate (MMF) reduce the incidence of de novo malignancies in patients after solid organ transplantation. Surgical treatment improves survival in patients with early malignancies. The use of external beam radiation therapy in the treatment of hepatocellular carcinoma is limited due to the risk of radiation liver disease.

Conclusions

The risk of concomitant malignancy needs to be guarded for 5 years of immunosuppressive therapy after organ transplantation surgery. Adjusting the immunosuppressive treatment regimen is an effective way to reduce concurrent malignancies. Systemic chemotherapy or radiotherapy requires vigilance against the toxic effects of drug metabolism kinetics on the transplanted organ.

Novel Immunosuppression in Solid Organ Transplantation

Solid organ transplantation and survival has improved tremendously in the last few decades, much of the success has been attributed to the advancements in immunosuppression. While steroids are being replaced and much of the immunosuppressive strategies focus on steroid free regimens, novel agents have introduced in the induction, maintenance, and treatment of acute rejection phase. MTOR inhibitors have helped with the renal sparing side effect from the calcineurin inhibitors, newer agents such as rituximab have decreased the incidence of donor-specific antibodies which led to decreased incidence of acute rejection reactions. In this chapter we discuss the newer therapies directed specifically for solid organ transplantation.

The Association Between Cytomegalovirus Infection and Cardiac Allograft Vasculopathy in the Era of Antiviral Valganciclovir Prophylaxis

Supplemental Digital Content is available in the text.

Previous studies on the association between cytomegalovirus (CMV) infection and cardiac allograft vasculopathy (CAV) were conducted on patients transplanted in the prevalganciclovir prophylaxis era. The aim of our study is to evaluate this relation in heart transplantation (HTx) recipients treated according to current prophylactic and immunosuppressive regimens.

Impact of tacrolimus versus cyclosporin A on renal function during the first year after heart transplant

AIMS

Nephrotoxicity of calcineurin inhibitors (CNIs) is associated with adverse events in patients undergoing heart transplant (HTx), although studies directly comparing tacrolimus (TAC) versus cyclosporin A (CsA), especially in combination with everolimus and low-dose CNIs approach, are limited. Thus, we sought to investigate the associations of TAC and CsA with clinical outcomes in HTx recipients, with specific focus on renal function.

METHODS AND RESULTS

From August 2007 to February 2017, 72 consecutive patients (39 treated with TAC vs. 33 with CsA) receiving de novo HTx in a single transplant centre were retrospectively evaluated. We used the instrumental variable method to account for unmeasured confounding. The study outcomes were percentage change in estimated glomerular filtration rates (eGFR) (safety endpoint) and biopsy-proven acute rejection (efficacy endpoint) within the first year after HTx. The enrolled patients (median age 40 years) were predominantly men (68%). There were no significant differences in baseline characteristics, including eGFR (64.8 [45.7-96.4] mL/min/1.73 m² in TAC vs. 65.6 [57.9-83.0] mL/min/1.73 m² for CsA; P = 0.48), other than sex (male, 49% for TAC vs. 91% for CsA; P < 0.001) between the two groups. Within the first year after HTx, 23 (59%) in the TAC group switched mycophenolate mofetil to everolimus, whereas 16 (48%) in the CsA group (P = 0.52). At 12 months, the rates of mortality and end-stage renal disease requiring renal replacement therapies were both 0%. In the instrumental variable analysis, no differences in renal function as well as graft rejection for 1 year after HTx existed between the TAC and CsA groups. These results were similar when taking into account of everolimus use.

CONCLUSIONS

Irrespective of everolimus use with low-dose CNIs, our analysis using the instrumental variable method showed no differences in renal function as well as graft rejection during the first year after HTx between HTx recipients who received TAC or CsA.

The pharmaceutical management of cardiac allograft vasculopathy after heart transplantation

INTRODUCTION

Cardiac allograft vasculopathy (CAV) is a major limitation to long-term survival after heart transplantation. Its peculiar pathophysiology involves multifactorial pathways including immune-mediated and metabolic risk factors, which are associated with the development of specific pathological lesions. The often diffuse and chronic nature of the disease reduces the effectiveness of revascularization procedures, and pharmacological prevention of the disease is the sole therapeutic approach with some proven efficacy.

AREAS COVERED

In this article, after briefly outlining the risk factors for CAV, the authors revise the potential pharmacological approaches that may reduce the burden of CAV. While several therapies have shown convincing efficacy in terms of CAV prevention diagnosed by coronary imaging, very few have been reported to improve prognosis with any meaningful level of evidence.

EXPERT OPINION

The authors believe that a customizable approach is necessary for clinical practice given the currently available evidence. Furthermore, it is important, in the future, to address the glaring therapeutic gap of an effective treatment against donor-specific antibodies, whose effect on endothelial injury is currently one of the major mechanisms of CAV development and for which no pharmacological treatment is currently available.

mTOR Inhibition and Clinical Transplantation: Heart

This brief overview discusses recent data on the use of mammalian target of rapamycin (mTOR) inhibitors in heart transplantation. Trials on de novo use have shown good efficacy of mTOR inhibitors; however, adverse events are often seen. Conversion protocols in long-term patients are mainly used in patients with renal insufficiency. Calcineurin inhibitor minimization and conversion to calcineurin inhibitor-free protocols have proven to stabilize renal function in recent trials. Lastly, beneficial effects of mTORs against the development of graft vasculopathy, cytomeglovirus infection and malignancy have been shown. Nevertheless, lower tolerability of the drug has affected the long-term use in patients. Future consideration of using mTORs will be individualized protocols in special subpopulation after heart transplantation.

Five decades of pediatric heart transplantation: challenges overcome, challenges remaining

PURPOSE OF REVIEW

Pediatric heart transplants continue to be the therapy of choice for children with end stage heart failure. The interplay of limited donor supply, improvement in ventricular assist device (VAD) technology and utilization, and a focus on optimizing long-term outcomes make it critically important for practitioners to be aware of an evolving diagnostic and therapeutic arsenal.

RECENT FINDINGS

Data suitable to define best practices for pediatric heart transplantation consist of an amalgam of small single center series, registry reviews and judicious inference from adult studies. Large-scale prospective pediatric studies are essentially nonexistent; the pediatric heart transplant study group continues to be highly productive while new collaboratives are emerging.

SUMMARY

Outcomes for pediatric transplants continue to improve. Technology and innovation continue to drive shifts in management. Improvements in VAD support along with refinement of solid-phase assays require clinicians to develop a deeper understanding of pre and post transplant management of donor-specific antibodies and antibody-mediated rejection. Expertise in retransplantation and the care of adults with congenital heart disease will be critical in the future.

Outcomes associated with mammalian target of rapamycin (mTOR) inhibitors in heart transplant recipients: A meta-analysis

BACKGROUND

Data evaluating mTOR inhibitor use heart transplant (HT) patients comes from relatively small studies and controversy exists regarding their specific role. We performed a meta-analysis of randomized trials to evaluate the efficacy and safety of mTOR inhibitors in HT patients.

METHODS

We performed a systematic literature search of Medline and Embase through July 2017 identifying studies evaluating mTOR inhibitors in HT patients reporting effects on coronary allograft vasculopathy (CAV), renal function, acute cellular rejection (ACR), cytomegalovirus (CMV) infection, and discontinuation due to adverse drug events (ADE). Data were pooled using a random-effects model producing a mean difference (MD; for continuous data) or odds ratio (OR; for dichotomous data) and 95% confidence interval (CI).

RESULTS

14 trials reported at least one outcome of interest. Change in mean maximal intimal thickness was significantly reduced with mTOR (-0.04 [-0.07 to -0.02]) compared to calcineurin inhibitor/mycophenolate mofetil (CNI/MMF). Rates of CMV infection were also significantly reduced (0.26; [0.2 to 0.32]) with mTOR regimens compared to CNI/MMF therapy. ACR was more frequent with CNI-sparing regimens 6.46 [1.55 to 26.95]). eGFR was significantly improved with CNI-sparing therapies (mean difference 12.09 mL/min [2.43 to 21.74]), but was similar between CNI/mTOR versus CNI/MMF regimens (p > 0.05). Rates of discontinuation due to ADE were higher in mTOR-containing regimens (OR 2.15 [1.28 to 3.60], p = 0.01), while mortality rates were similar (OR 0.91 [0.61 to 1.37], p = 0.62).

CONCLUSIONS

mTOR-containing regimens can attenuate CAV and CMV risk in HT recipients. A mTOR/MMF combination preserves renal function but increases the risk of ACR.

Postoperative management of heart transplantation patients

Heart transplant recipients are at risk for a number of post-transplantation complications such as graft dysfunction, rejection, and infection. The rates of many complications are decreasing over time, and prognosis is improving. However, these patients continue to experience significant morbidity and mortality. This review focuses on the optimal management of heart transplant recipients in the postoperative period, based on current knowledge. More information is needed about the best ways to predict, prevent, and treat primary graft dysfunction, right ventricular failure, and cellular and antibody-mediated rejection.

Metabolic consequences of modern immunosuppressive agents in solid organ transplantation

Among other factors, sophistication of immunosuppressive (IS) regimen accounts for the remarkable success attained in the short- and medium-term solid organ transplant (SOT) survival. The use of steroids, mycophenolate mofetil and calcineurin inhibitors (CNI) have led to annual renal graft survival rates exceeding 90% in the last six decades. On the other hand, attrition rates of the allograft beyond the first year have remained unchanged. In addition, there is a persistent high cardiovascular (CV) mortality rate among transplant recipients with functioning grafts. These shortcomings are in part due to the metabolic effects of steroids, CNI and sirolimus (SRL), all of which are implicated in hypertension, new onset diabetes after transplant (NODAT), and dyslipidemia. In a bid to reduce the required amount of harmful maintenance agents, T-cell-depleting antibodies are increasingly used for induction therapy. The downsides to their use are greater incidence of opportunistic viral infections and malignancy. On the other hand, inadequate immunosuppression causes recurrent rejection episodes and therefore early-onset chronic allograft dysfunction. In addition to the adverse metabolic effects of the steroid rescue needed in these settings, the generated proinflammatory milieu may promote accelerated atherosclerotic disorders, thus setting up a vicious cycle. The recent availability of newer agent, belatacept holds a promise in reducing the incidence of metabolic disorders and hopefully its long-term CV consequences. Although therapeutic drug monitoring as applied to CNI may be helpful, pharmacodynamic tools are needed to promote a customized selection of IS agents that offer the most benefit to an individual without jeopardizing the allograft survival.

New perspectives on mTOR inhibitors (rapamycin, rapalogs and TORKinibs) in transplantation

The macrolide rapamycin and its analogues (rapalogs) constitute the first generation of mammalian target of rapamycin (mTOR) inhibitors. Since the introduction of rapamycin as an immunosuppressant, there has been extensive progress in understanding its complex mechanisms of action. New insights into the function of mTOR in different immune cell types, vascular endothelial cells and neoplastic cells have opened new opportunities and challenges regarding mTOR as a pharmacological target. Currently, the two known mTOR complexes, mTOR complex (mTORC) 1 and mTORC2, are the subject of intense investigation, and the introduction of second-generation dual mTORC kinase inhibitors (TORKinibs) and gene knockout mice is helping to uncover the distinct roles of these complexes in different cell types. While the pharmacological profiling of rapalogs is advanced, much less is known about the properties of TORKinibs. A potential benefit of mTOR inhibition in transplantation is improved protection against transplant-associated viral infections compared with standard calcineurin inhibitor-based immunosuppression. Preclinical and clinical data also underscore the potentially favourable antitumour effects of mTOR inhibitors in regard to transplant-associated malignancies and as a novel treatment option for various other cancers. Many aspects of the mechanisms of action of mTOR inhibitors and their clinical implications remain unknown. In this brief review we discuss new findings and perspectives of mTOR inhibitors in transplantation.