Outcomes and survival following heart retransplantation for cardiac allograft failure: a systematic review and meta-analysis

Outcomes of left-sided heart valve surgery after heart transplantation: a systematic review

As the survival after heart transplantation (HTx) is steadily improving, an increasing number of patients with late cardiac pathologies such as valvular disease is expected to rise. Nevertheless, no guidelines for indication of redo cardiac surgery after HTx exists. The aim of the present systematic review is to describe the results reported in the literature of surgical management of severe aortic and/or mitral valve disease. A systematic review was conducted including studies reporting on adult patients with severe mitral or aortic valve pathology needing surgery after their previous HTx. Exclusion criteria consisted in surgery with no left heart valve surgery, concomitant valve surgery during heart transplant, transcatheter interventions, and heterotopic HTx. A total of 35 papers met our inclusion criteria out of 2755 potentially eligible studies with 44 mitral valve surgery patients and 20 aortic valve surgery patients. In the entire population, the mean time from HTx to reintervention was 6.19 ± 5.22 years. After a mean follow-up of 2.78 ± 3.54 years and 1.53 ± 2.26 years from reintervention, 65.6% mitral and 86.7% aortic patients were reported as alive, respectively. As guidelines on cardiac surgery after HTx are currently lacking, left-sided valvular cardiac reinterventions can be considered a possible therapeutic approach in carefully selected patients. These interventions may not only improve the patient's functional status and survival, but may ultimately reduce the need for re-transplantation due to the chronic shortage of donor hearts. However, the support of more robust data is warranted.

Transcatheter valvular interventions after heart transplantation: A systematic review

An increasing number of patients experience late valvular disease after heart transplantation (HTx). While mostly being primarily addressed through surgical interventions, transcatheter valve procedures to treat these conditions are rising, particularly for unsuitable surgical candidates. This review aims at analyzing the outcomes of transcatheter valvular procedures in this subset of patients. A systematic review was conducted including studies reporting on adult patients requiring any form of transcatheter valvular intervention after a previous HTx. Studies involving a surgical approach, heterotopic heart transplants, or concomitant procedures performed during the transplant itself were excluded. Twenty-five articles with a total of 33 patients met the inclusion criteria, 10 regarding the aortic valve (14 patients), 5 the mitral valve (6 patients), and 6 the tricuspid valve (13 patients). In two cases, the procedure was recommended to stabilize the valvular lesion before re-transplantation, as both were very young patients. Overall, the mean time from heart transplantation to reintervention was 14.7 ± 9.5 years. The mean follow-up was 15.5 ± 13.5 months, and only one patient died 22.3 months after the intervention. There is a growing emergence of transcatheter interventions for valvular disease after heart transplantation, especially in cases where surgery is deemed high-risk or prohibitive. A different strategy may also be considered in young patients to permit longer allograft life before later re-transplantation. Although encouraging outcomes have been documented, additional research is required to establish the most appropriate approach within this specific subset of patients.

Early Postoperative Neurologic Events Are Associated With Worse Outcome and Fatal Midterm Survival After Adult Heart Transplantation

Background Neurologic events during primary stay in heart transplant (HTx) recipients may be associated with reduced outcome and survival, which we aim to explore with the current study. Methods and Results We screened and included all patients undergoing HTx in our center between September 2010 and December 2022 (n=268) and checked for the occurrence of neurologic events within their index stay. Neurologic events were defined as ischemic stroke, hemorrhage, hypoxic ischemic injury, or acute symptomatic neurologic dysfunction without central nervous system injury. The cohort was then divided into recipients with (n=33) and without (n=235) neurologic events after HTx. Using a multivariable Cox regression model, the association of neurologic events after HTx and survival was assessed. Recipients with neurologic events displayed a longer intensive care unit stay (30 versus 16 days; P=0.009), longer mechanical ventilation (192 versus 48 hours; P<0.001), and higher need for blood transfusion, and need for hemodialysis after HTx was substantially higher (81% versus 55%; P=0.01). Resternotomy (36% versus 26%; P=0.05) and mechanical life support (extracorporeal life support) after HTx (46% versus 24%; P=0.02) were also significantly higher in patients with neurologic events. Covariable-adjusted multivariable Cox regression analysis revealed a significant independent association of neurologic events and increased 30-day (hazard ratio [HR], 2.5 [95% CI, 1.0-6.0]; P=0.049), 1-year (HR, 2.2 [95% CI, 1.1-4.3]; P=0.019), and overall (HR, 2.5 [95% CI, 1.5-4.2]; P<0.001) mortality after HTx and reduced Kaplan-Meier survival up to 5 years after HTx (P<0.001). Conclusions Neurologic events after HTx were strongly and independently associated with worse postoperative outcome and reduced survival up to 5 years after HTx.

Evaluating age-based eligibility thresholds for heart re-transplantation - an analysis of the united network for organ sharing database

BACKGROUND

Risk-adjusted survival after late heart re-transplantation may be comparable to primary transplant, but the efficacy of re-transplantation in older candidates is not established. We evaluated outcomes after heart re-transplantation in recipients > 60 years.

METHODS

We identified 1026 adult patients undergoing isolated heart re-transplantation between 2003 and 2020 from the United Network for Organ Sharing database. Older recipients (> 60 years, n=177) were compared to younger recipients (≤ 60 years, n=849). Five and ten-year post-transplant survival was estimated using the Kalpan-Meier method and adjusted with multivariable Cox models.

RESULTS

Older recipients were more likely to be male and have diabetes or previous malignancies with higher baseline creatinine. They also more frequently required pre-transplant ECMO (11.9% vs. 6.8%, p=0.02) and received re-transplantation due to primary graft failure (13.6% vs. 8.5%, p=0.03). After the transplant, older recipients had a higher incidence of stroke (6.8% vs. 2.6%, p=0.01) and dialysis requirements (20.3% vs. 13.2%) before discharge (both p<0.05), and more frequently died from malignancy-related causes (16.3% vs. 3.9%, p<0.001). After adjustment, recipient age >60 was associated with an increased risk of both 5-year (HR 1.42, 95% CI 1.02-2.01, p=0.04) and 10-year mortality (HR 1.72, 95% CI 1.20-2.45, p=0.003). Restricted cubic spline showed a non-linear relationship between recipient age and 10-year mortality.

CONCLUSIONS

Heart re-transplantation in recipients > 60 years has inferior outcomes compared to younger recipients. Strict patient selection and close follow-up are warranted to ensure the appropriate utilization of donor hearts and to improve long-term outcomes.

Analysis of heart retransplantation outcomes in the new donor heart allocation system

Cardiac graft failure may require repeat heart transplantation (HTx). Outcomes of patients that undergo repeat HTx have not been well described. We compared patients that received repeat HTx with patients that received initial HTx by inquiring the United Network for Organ Sharing (UNOS) database between 2015 and 2021. The primary endpoint was all-cause mortality, while the role of baseline characteristics was also investigated. Patients were stratified according to whether they received initial HTx (n = 19,727, 97%) or repeat HTx (n = 578, 3%). Among the study population, 10,860 (53.5%) patients received a HTx using the old UNOS allocation system, whereas 9445 (46.5%) patients received a HTx after the implementation of the new UNOS donor allocation system in October 2018. In this sub-group of HTx recipients in the new allocation system era, the adjusted 1-year survival of repeat HTx patients remained lower than that of initial HTx patients (hazard ratio (HR): 1.19; 95% confidence interval (CI): 1.15, 3.18; p = 0.013). When we compared the 1-year survival of repeat HTx patients before and after the implementation of the new allocation system, the adjusted 1-year survival was similar between groups (HR: 1.14; 95% CI: 0.71, 1.84; p = 0.591). The unadjusted risk of 30-day mortality was not significantly different in the new vs old allocation system. Mortality associated with repeat HTx remained higher than initial HTx but the new donor allocation system implementation did not affect outcomes.

Donor Noradrenaline Support Is Not Associated with Decreased Survival in Heart Transplant Recipients

Objective: Although the application of higher doses of norepinephrine (NE) in potential organ donors is a frequent reason for heart decline, its associations with outcomes after heart transplantation (HTx) are discussed controversially. Therefore, we aimed to explore donor NE support’s potential impact on outcomes in our single-center heart transplant cohort. Methods: All patients who had undergone HTx in our center between September 2010 and April 2022 (n = 241) were screened for eligibility. From those, all patients with complete data on donor NE support (n = 238) were included. Recipients were divided into three groups according to their donor NE support: without support (n = 26), with low support of 0.01−0.2 µg/kg/min (n = 132), and with high support of > 0.2 µg/kg/min (n = 80). Receiver operating characteristics (ROC) and Kaplan Meier analysis was used to investigate the association of donor NE support and mortality after heart transplantation. Recipient and donor variables, including peri- and postoperative characteristics, were reviewed and compared. Results: NE support in donors ranged between 0 and 2.94 µg/kg/min (median 0.13 µg/kg/min, IQR 0.05−0.26 µg/kg/min). No association between donor NE support and mortality after HTx was observed (AUC for overall survival 0.494). Neither Kaplan-Meier analysis in survival up to 5 years after transplantation (Log Rank p = 0.284) nor group comparisons showed significant differences between the groups. With few exceptions, baseline characteristics in recipients and donors were comparable between the groups. Regarding peri- and postoperative parameters, increasing donor NE support was associated with a longer duration of mechanical ventilation (68 h and 95 h vs. 47 h), longer postoperative IMC/ICU stay (14 vs. 15 vs. 19 days), and a higher need for mechanical life support post-HTx (26% and 39% vs. 12%). Conclusion: In this retrospective analysis, NE support in donors prior to heart transplantation was unrelated to differing survival after heart transplantation. However, higher doses of donor NE were associated with prolonged ventilation, longer duration on IMC/ICU, and a higher need for extracorporeal life support in recipients post-HTx.

Donor hypernatremia is associated with increased mortality after heart transplantation: A retrospective study

BACKGROUND AND AIMS

Donor hypernatremia has been associated with primary graft dysfunction in heart transplantation (HTx) and is correlated with impaired outcome following liver and renal transplantation. However, controversial data exist regarding the impact of sodium dysregulation on survival. This study aims to investigate the impact of donor sodium levels on early morbidity and short- and midterm survival following HTx.

METHODS

Between September 2010 and June 2021, a total of n = 218 patients underwent HTx in our center. From those, 214 could be included retrospectively in our study. For each donor, sodium levels were collected and different cut-off levels from 145 to 159 mmol/L were investigated by Kaplan-Meier-analysis. Then, recipients were divided in three groups regarding donor sodium: Normonatremia (133-145 mmol/L, n = 73), mild hypernatremia (146-156 mmol/L, n = 105) and severe hypernatremia (>156 mmol/L, n = 35). Recipient and donor variables were reviewed and compared, including peri- and postoperative characteristics and recipient survival after up to 5 years after transplantation.

RESULTS

All patients were comparable regarding baseline characteristics and perioperative parameters. Regarding early mortality, 90-day survival was significantly reduced only in patients with severe donor hypernatremia in comparison to normonatremia (90% vs. 71%, p = .02), but not in mild hypernatremia (89%, p = .89). One-year survival was comparable in all groups (p > .28).

CONCLUSION

Severe donor hypernatremia was associated with reduced short-term survival, while the correlation weakens > 1 year after HTx. As our study is limited due to the nature of its retrospective, single-center approach, future prospective studies are needed to evaluate the importance of donor management with regard to hypernatremia.

Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit

Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 (n = 241). Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days (≤50th percentile, n = 92), 4 to 7 days (50th–75th percentile, n = 80), and ≥8 days (≥75th percentile, n = 69). Donor LOS in the ICU ranged between 0 and 155 days (median 4, IQR 3–8 days). No association between the LOS in the ICU and survival after HTx was observed (AUC for overall survival 0.514). Neither the Kaplan–Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients’ peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.

Intracerebral bleeding in donors is associated with reduced short-term to midterm survival of heart transplant recipients

Aim

The quality of the donor heart is known to have a crucial effect on outcome after heart transplantation (HTx). Although leading to brain death in the end, the initial cause of death of the donor and its potential influences on organ quality are heterogeneous. However, it is still controversial to which extent the donor cause of death is associated with outcome or survival post‐HTx.

Methods and results

We included all patients undergoing HTx in our centre between September 2010 and June 2021 (n = 218). Recipients were divided in five groups related to their donor cause of death: intracerebral bleeding (‘ICB’, n = 95, 44%), traumatic brain injury (‘trauma’, n = 54, 25%), hypoxic brain damage (‘hypoxic’, n = 34, 16%), cerebrovascular (‘vascular’, n = 15, 7%), or other cause (n = 20, 9%). Baseline characteristics, perioperative parameters, and survival after 30 and 90 days as well as 5 years after transplantation were collected.

Results

Intracerebral bleeding in donors compared with traumatic brain injury is associated with higher probability of need for ECLS post‐HTx (35% vs. 19%, P = 0.04) and significantly reduced survival up to 5 years post‐HTx (i.e. 1 year survival: 61% vs. 95%, P < 0.0001). Although other conditions also show significant changes in outcome and survival, the effect is strongest for ICB, where survival is also reduced compared with all other causes (1 year: 61% vs. 89%, P < 0.0001).

Conclusions

In this retrospective analysis, donor cause of death is associated with differing outcome and survival after HTx. Intracerebral bleeding hereby shows strongest decline in outcome and survival in comparison with all other causes.

Heart transplantation: focus on donor recovery strategies, left ventricular assist devices, and novel therapies

Heart transplantation is advocated in selected patients with advanced heart failure in the absence of contraindications. Principal challenges in heart transplantation centre around an insufficient and underutilized donor organ pool, the need to individualize titration of immunosuppressive therapy, and to minimize late complications such as cardiac allograft vasculopathy, malignancy, and renal dysfunction. Advances have served to increase the organ donor pool by advocating the use of donors with underlying hepatitis C virus infection and by expanding the donor source to use hearts donated after circulatory death. New techniques to preserve the donor heart over prolonged ischaemic times, and enabling longer transport times in a safe manner, have been introduced. Mechanical circulatory support as a bridge to transplantation has allowed patients with advanced heart failure to avoid progressive deterioration in hepato-renal function while awaiting an optimal donor organ match. The management of the heart transplantation recipient remains a challenge despite advances in immunosuppression, which provide early gains in rejection avoidance but are associated with infections and late-outcome challenges. In this article, we review contemporary advances and challenges in this field to focus on donor recovery strategies, left ventricular assist devices, and immunosuppressive monitoring therapies with the potential to enhance outcomes. We also describe opportunities for future discovery to include a renewed focus on long-term survival, which continues to be an area that is under-studied and poorly characterized, non-human sources of organs for transplantation including xenotransplantation as well as chimeric transplantation, and technology competitive to human heart transplantation, such as tissue engineering.

Results of heart retransplantation: subanalysis of the Spanish Heart Transplant Registry

INTRODUCTION AND OBJECTIVES

Heart retransplantation (ReHT) is controversial in the current era. The aim of this study was to describe and analyze the results of ReHT in Spain.

METHODS

We performed a retrospective cohort analysis from the Spanish Heart Transplant Registry from 1984 to 2018. Data were collected on donors, recipients, surgical procedure characteristics, immunosuppression, and survival. The main outcome was posttransplant all-cause mortality or need for ReHT. We studied differences in survival according to indication for ReHT, the time interval between transplants and era of ReHT.

RESULTS

A total of 7592 heart transplants (HT) and 173 (2.3%) ReHT were studied (median age, 52.0 and 55.0 years, respectively). Cardiac allograft vasculopathy was the most frequent indication for ReHT (42.2%) and 59 patients (80.8%) received ReHT >5 years after the initial transplant. Acute rejection and primary graft failure decreased as indications over the study period. Renal dysfunction, hypertension, need for mechanical ventilation or intra-aortic balloon pump and longer cold ischemia time were more frequent in ReHT. Median follow-up for ReHT was 5.8 years. ReHT had worse survival than HT (weighted HR, 1.43; 95%CI, 1.17-1.44; P<.001). The indication of acute rejection (HR, 2.49; 95%CI, 1.45-4.27; P<.001) was related to the worst outcome. ReHT beyond 5 years after initial HT portended similar results as primary HT (weighted HR, 1.14; 95%CI, 0.86-1.50; P<.001).

CONCLUSIONS

ReHT was associated with higher mortality than HT, especially when indicated for acute rejection. ReHT beyond 5 years had a similar prognosis to primary HT.

Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement on Heart Transplantation: Patient Eligibility, Selection, and Post-Transplantation Care

Significant practice-changing developments have occurred in the care of heart transplantation candidates and recipients over the past decade. This Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement provides evidence-based, expert panel recommendations with values and preferences, and practical tips on: (1) patient selection criteria; (2) selected patient populations; and (3) post transplantation surveillance. The recommendations were developed through systematic review of the literature and using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The evolving areas of importance addressed include transplant recipient age, frailty assessment, pulmonary hypertension evaluation, cannabis use, combined heart and other solid organ transplantation, adult congenital heart disease, cardiac amyloidosis, high sensitization, and post-transplantation management of antibodies to human leukocyte antigen, rejection, cardiac allograft vasculopathy, and long-term noncardiac care. Attention is also given to Canadian-specific management strategies including the prioritization of highly sensitized transplant candidates (status 4S) and heart organ allocation algorithms. The focus topics in this position statement highlight the increased complexity of patients who undergo evaluation for heart transplantation as well as improved patient selection, and advances in post-transplantation management and surveillance that have led to better long-term outcomes for heart transplant recipients.

Everolimus-Eluting Second-Generation Stents for Treatment of De Novo Lesions in Patients with Cardiac Allograft Vasculopathy

Background

Cardiac allograft vasculopathy is a major cause of cardiac allograft rejection. Percutaneous coronary intervention has become the main form of treatment of significant focal lesions. Despite the significance of the problem, data remain scarce. With a large population of transplant recipients undergoing coronary angiography at our center, we decided to analyze the implications of the use of everolimus-eluting second-generation stents by performing 6-month clinical and angiographic follow-up.

Material/Methods

From December 2012 and August 2019, 319 patients after heart transplantation undergoing coronary angiography at our institution were analyzed. Subsequently, 22 patients underwent de novo angioplasty with second-generation everolimus-eluting stents. The primary study endpoint was angiographic restenosis as evaluated by quantitative coronary angiography. Secondary outcomes included binary restenosis, target lesion revascularization, and cardiac death during the follow-up period (6 months).

Results

Patient comorbidities included hypertension (77.3%), type 2 diabetes mellitus (68.2%), dyslipidemia (68.2%), and obesity (31.8%). Primary success was obtained in all of the treated lesions. The analysis of quantitative coronary angiography after 6-month follow-up revealed low late lumen loss (0.22±0.40). Significant restenosis was observed in 1 of the cases. There were no deaths in the 6-month observation period.

Conclusions

In the analyzed population, invasive strategy with second-generation everolimus-eluting stents for de novo lesions in cardiac allograft vasculopathy resulted in a low rate of binary restenosis, low late lumen loss, and no deaths during the 6-month follow-up.

Perioperative Management of the Cardiac Transplant Recipient

Management of the cardiac transplant recipient includes careful titration of inotropes and vasopressors. Recipient pulmonary hypertension and ventilatory status must be optimized to prevent allograft right ventricular failure. Vasoplegia, coagulopathy, arrhythmias, and renal dysfunction also require careful management to achieve an optimal outcome. Primary graft dysfunction (PGD) can be an ominous problem after cardiac transplantation. Although mild degrees of PGD may be managed medically, mechanical circulatory support with extracorporeal membrane oxygenation or temporary ventricular assist devices may be required. Retransplantation may be necessary in some cases.