Evaluation of Risk Factors for Heart-Lung Transplant Recipient Outcome: An Analysis of the United Network for Organ Sharing Database

Procurement Trends, Indications, and Outcomes of Heart-Lung Transplantation in the Contemporary Era

BACKGROUND

Evolving trends in organ procurement and technological innovation prompted an investigation into recent trends, indications, and outcomes following combined heart-lung transplantation (HLTx).

METHODS

The United Network for Organ Sharing database was queried for all adult (≥18 years) HLTx performed between July 1, 2013 and June 30, 2023. Patients with previous transplants were excluded. The primary endpoint was the effect of donor, recipient, and transplantation characteristics on 1- and 5-year survival. Secondary analyses included a comparison of HLTx at high- and low-volume centers, an assessment of HLTx following donation after circulatory death (DCD), and an evaluation of HLTx volume over time. Cox proportional-hazards models were used to assess factors associated with mortality. Temporal trends were evaluated with linear regression.

RESULTS

After exclusions, 319 patients were analyzed, of whom 5 (1.6%) were DCD. HLTx volume increased from 2013 to 2023 (p < 0.001). One- and 5-year survival following HLTx was 84.0% and 59.5%, respectively. One-year survival was higher for patients undergoing HLTx at a high-volume center (88.3% vs. 77.9%; p = 0.012). After risk adjustment, extracorporeal membrane oxygenation support 72 h posttransplant and predischarge dialysis were associated with increased 1-year mortality (HR = 3.19, 95% CI = 1.86-5.49 and HR = 3.47, 95% CI = 2.17-5.54, respectively) and 5-year mortality (HR = 2.901, 95% CI = 1.679-5.011 and HR = 3.327, 95% CI = 2.085-5.311, respectively), but HLTx at a high-volume center was not associated with either.

CONCLUSIONS

HLTx volume has resurged, with DCD HLTx emerging as a viable procurement strategy. Factors associated with 1- and 5-year survival may be used to guide postoperative management following HLTx.

Advancing cardiac regeneration through 3D bioprinting: methods, applications, and future directions

Cardiovascular diseases (CVDs) represent a paramount global mortality concern, and their prevalence is on a relentless ascent. Despite the effectiveness of contemporary medical interventions in mitigating CVD-related fatality rates and complications, their efficacy remains curtailed by an array of limitations. These include the suboptimal efficiency of direct cell injection and an inherent disequilibrium between the demand and availability of heart transplantations. Consequently, the imperative to formulate innovative strategies for cardiac regeneration therapy becomes unmistakable. Within this context, 3D bioprinting technology emerges as a vanguard contender, occupying a pivotal niche in the realm of tissue engineering and regenerative medicine. This state-of-the-art methodology holds the potential to fabricate intricate heart tissues endowed with multifaceted structures and functionalities, thereby engendering substantial promise. By harnessing the prowess of 3D bioprinting, it becomes plausible to synthesize functional cardiac architectures seamlessly enmeshed with the host tissue, affording a viable avenue for the restitution of infarcted domains and, by extension, mitigating the onerous yoke of CVDs. In this review, we encapsulate the myriad applications of 3D bioprinting technology in the domain of heart tissue regeneration. Furthermore, we usher in the latest advancements in printing methodologies and bioinks, culminating in an exploration of the extant challenges and the vista of possibilities inherent to a diverse array of approaches.

Trends and Outcomes of Combined Heart-Kidney and Heart-Lung Transplantation Over the Past Two Decades

INTRODUCTION

Combined heart-kidney transplantation (HKTx) and combined heart-lung transplantation (HLTx) remain the definitive therapy for patients with end-stage heart failure with concomitant end-stage renal or lung failure. We sought to study trends and outcomes of HKTx and HLTx over the last two decades.

METHODS

The United Network for Organ Sharing registry was used to identify all adult patients (aged >18 y) who underwent HKTx and HLTx between 2001 and 2021. Patients were divided into 5-y groups by the year of transplantation (2001-2006, 2007-2011, 2012-2016, and 2017-2021). Primary outcome was 1-y posttransplantation mortality. Kaplan-Meier and multivariable Cox proportional hazards models were used for unadjusted and risk-adjusted survival analyses, respectively.

RESULTS

A total of 2301 HKTx and 567 HLTx patients were included. Between 2001 and 2021, HKTx volume increased from 25 to 344 patients (P < 0.001) and centers performing HKTx increased from 19 to 76 (P < 0.001). On unadjusted analysis, 1-y survival after HKTx improved from 86.7% in 2001-2006 to 89.0% in 2017-2021 (log-rank, P = 0.005). On risk-adjusted analysis, the hazard ratio of 1-y mortality for 2017-2021 was 0.62 (0.39-1.00, P = 0.048) compared with that for 2001-2006. Between 2001 and 2021, HLTx volume increased from 21 to 43 patients (P < 0.001) and centers performing HLTx increased from 12 to 20 (P = 0.047). On unadjusted analysis, 1-y survival after HLTx improved from 68.9% in 2001-2006 to 83.9% in 2017-2021 (log-rank, P = 0.600). On risk-adjusted analysis, the hazard ratio of 1-y mortality for 2017-2021 was 0.37 (0.21-0.67, P = 0.001) compared with that for 2001-2006.

CONCLUSIONS

Over the last two decades, HKTx volume substantially increased and HLTx experienced resurgent growth. One-year survival persistently improved for both procedures, especially over the past 5 y.

Revised Heart Allocation Policy Improved Waitlist Mortality and Waiting Time With Maintained Outcomes in En-Bloc Heart-Lung Transplant Candidates and Recipients

The revised United Network for Organ Sharing heart allocation policy was implemented in October 2018. Using a national transplant database, this study evaluated the transplant rate, waitlist mortality, waiting time, and other outcomes of en-bloc heart-lung transplantation recipients. Adult patients registered on the national database for heart-lung transplants before and after the policy update were selected as cohorts. Baseline characteristics, transplant rates, waitlist mortality, waiting times, and other outcomes were compared between the two periods. In total, 370 patients were registered for heart-lung transplants during the pre- and post-periods. There were significantly higher transplant rates, shorter waitlist times, and substantially reduced waitlist mortality in the post-period. Registered patients waitlisted in the post-period had significantly higher utilization of intra-aortic balloon pumps, extracorporeal membrane oxygenation, and overall life support, including ventricular assist devices. Transplant recipients had significantly longer ischemic times, increased transport distances, and shorter waiting times before transplantation in the post-policy period. Transplant recipients held similar short-term survival before and after the policy change (log-rank test, p = 0.4357). Therefore, the revised policy significantly improved access to en-bloc heart-lung allografts compared with the prior policy, with better waitlist outcomes and similar post-transplant outcomes.

Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension in Cape Town, South Africa

Background

Pulmonary endarterectomy (PEA) is the only definitive and potentially curative therapy for chronic thromboembolic pulmonary hypertension (CTEPH), associated with impressive improvements in symptoms and haemodynamics. However, it is only offered at a few centres in South Africa. The characteristics and outcomes of patients undergoing PEA in Cape Town have not been reported previously.

Objectives

To assess the difference in World Health Organization functional class (WHO-FC) before and at least 6 weeks after surgery.

Methods

We interrogated the adult cardiothoracic surgery database at the University of Cape Town between December 2005 and April 2021 for patients undergoing PEA at Groote Schuur Hospital and a private hospital.

Results

A total of 32 patients underwent PEA, of whom 8 were excluded from the final analysis owing to incomplete data or a histological diagnosis other than CTEPH. The work-up of these patients for surgery was variable: all had a computed tomography pulmonary angiogram, 7 (29%) had a ventilation/perfusion scan, 5 (21%) underwent right heart catheterisation, and none had a pulmonary angiogram. The perioperative mortality was 4/24 (17%): 1 patient (4%) had a cardiac arrest on induction of anaesthesia, 2 patients (8%) died of postoperative pulmonary haemorrhage, and 1 patient (4%) died of septic complications in the intensive care unit. Among the survivors, the median (interquartile range) improvement in WHO-FC was 2 (1 - 3) classes (p=0.0004); 10/16 patients (63%) returned to a normal baseline (WHO-FC I).

Conclusion

Even in a low-volume centre, PEA is associated with significant improvements in WHO-FC and a return to a normal baseline in survivors.

Study synopsis

What the study adds. South African patients undergoing pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) have a marked improvement in functional status, with many returning to a normal functional baseline. However, the small number of patients included in this study indicates that PEA is probably underutilised. Pre- and postoperative assessment is inconsistent, despite availability of established guidelines.Implications of the findings. More patients should be referred to specialist centres for assessment for this potentially curative procedure. Use of guidelines to standardise investigations and monitoring of patients with CTEPH may improve patient selection for surgery.

State of the art - Extracorporeal membrane oxygenation as a bridge to thoracic transplantation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has revolutionized the treatment of refractory cardiac and respiratory failure, and its use continues to increase, particularly in adults. However, ECMO-related morbidity and mortality remain high.

MAIN TEXT

In this review, we investigate and expand upon the current state of the art in thoracic transplant and extracorporeal life support (ELS). In particular, we examine recent increase in incidence of heart transplant in patients supported by ECMO; the potential changes in patient care and selection for transplant in the years prior to updated United Network for Organ Sharing (UNOS) organ allocation guidelines versus those in the years following, particularly where these guidelines pertain to ECMO; and the newly revived practice of heart-lung block transplants (HLT) and the prevalence and utility of ECMO support in patients listed for HLT.

CONCLUSIONS

Our findings highlight encouraging outcomes in patients bridged to transplant with ECMO, considerable changes in treatment surrounding the updated UNOS guidelines, and complex, diverse outcomes among different centers in their care for increasingly ill patients listed for thoracic transplant.

National outcomes of bridge to multiorgan cardiac transplantation using mechanical circulatory support

BACKGROUND

Little is known regarding the profile of patients with multiorgan failure listed for simultaneous cardiac transplantation and secondary organ. In addition, few studies have reported how these patients are bridged with mechanical circulatory support (MCS). In this study, we examined national data of patients listed for multiorgan transplantation and their outcomes after bridging with or without MCS.

METHODS

United Network for Organ Sharing data were reviewed for adult multiorgan transplantations from 1986 to 2019. Post-transplant patients and total waitlist listings were examined and stratified according to MCS status. Survival was assessed via Cox regression in the post-transplant cohort and Fine-Gray competing risk regression with transplantation as a competing risk in the waitlist cohort.

RESULTS

There were 4534 waitlist patients for multiorgan transplant during the study period, of whom 2117 received multiorgan transplants. There was no significant difference in post-transplant survival between the MCS types and those without MCS in the whole cohort and heart-kidney subgroup. Fine-Gray competing risk regression showed that patients bridged with extracorporeal membrane oxygenation had significantly greater waitlist mortality compared with those without MCS when controlling for preoperative characteristics (subdistribution hazard ratio, 2.27; 95% confidence interval, 1.48-3.47; P < .001), whereas those bridged with a ventricular assist device had a decreased incidence of death compared with those without MCS (subdistribution hazard ratio, 0.78; 95% confidence interval, 0.63-0.96; P = .017).

CONCLUSIONS

MCS, as currently applied, does not appear to compromise the survival of multiorgan heart transplant patients. Waitlist data show that extracorporeal membrane oxygenation patients have profoundly worse survival irrespective of preoperative factors including organ type listed. Survival on the waitlist for multiorgan transplant has improved across device eras.

Modern outcomes of heart-lung transplantation: assessing the impact of the updated US allocation system

OBJECTIVES

In 2018, the United Network for Organ Sharing modified their heart allocation policy to reduce waitlist mortality and prioritize patients with the greatest acuity. Considering declining rates of combined heart-lung transplantation, this study sought to investigate the impact of the new allocation system on waitlist and post-transplant outcomes of patients listed for combined heart-lung transplantation.

METHODS

Adult patients listed for combined heart-lung transplant between 2012 and 2021 were included. Patients were stratified according to listing era. Competing risk regression was used to assess waitlist outcomes. Cox proportional hazards regression was used to establish risk factors for post-transplant mortality.

RESULTS

A total of 511 patients were included, of whom 295 (57.8%) were listed in era 1 and 216 (42.2%) in era 2. Era 2 was associated with increased likelihood of transplant (adjusted standard hazard ratio (aSHR): 1.60 [1.23-2.07]; P < 0.01) and decreased waitlist mortality (aSHR: 0.43 [0.25-0.73]; P < 0.01). Despite longer ischaemic times and increased use of preoperative veno-arterial extracorporeal membrane oxygenation (ECMO) in era 2, early post-transplant survival was equivalent. Predicted heart mass ratio <0.8 (Hazard ratio (HR); 3.24; P = 0.01), ventilator support (HR: 3.83; P < 0.01) and greater ischaemic times (HR: 1.80; P < 0.01) independently predicted the mortality. Procedures at high centre volumes (HR: 0.36; P = 0.04) were associated with decreased mortality. Use of ECMO was not predictive of mortality in the modern era.

CONCLUSIONS

The allocation policy change has led to improvements in waitlist outcomes in patients listed for heart-lung transplantation. Despite increased ischaemic times and use of ECMO, early post-transplant survival was equivalent.

Risk of recipient age on 1-year mortality after simultaneous heart-lung transplantation

BACKGROUND

Heart-lung transplantation (HLTx) is relatively uncommon, and there is a paucity of literature to suggest an age at which older recipients may be exposed to excess risk for mortality. This analysis aimed to identify a threshold of age that predicts adverse outcomes after HLTx.

METHODS

The United Network of Organ Sharing registry was used to identify adult patients undergoing HLTx from 2005 to 2021. The primary outcome was 1-year mortality. Threshold regression was used to identify the threshold at which age impacts 1-year mortality. Kaplan-Meier analysis was used to model survival, and Cox proportional hazards modeling was used for risk-adjustment.

RESULTS

We identified 453 patients undergoing HLTx. Threshold analysis identified that the risk for 1-year mortality was significantly elevated beyond an age of 58 years, and 47 (10.38%) patients were older than this threshold. On Kaplan-Meier analysis, 1-year survival was significantly lower in patients > 58 years compared to younger recipients (64.7% vs. 82.0%, p = .007). After risk adjustment, the hazard ratio for 1-year mortality in recipients older than 58 years was 2.27 (95% confidence interval [1.21-4.28], p = .011).

CONCLUSION

A threshold for recipient age of 58 years of age may avoid excess 1-year mortality after HLTx. However, patients older than this threshold demonstrate acceptable early and midterm survival, and the majority survive to 1 year. Advanced age should be considered in patient selection for HLTx, but may not be a contraindication for candidacy particularly in the absence of other risk factors.

Combined Heart-Lung Transplantation Outcomes in Asian Populations: National Database Analysis

BACKGROUND

Heart-lung transplantation (HLTx) is a definitive surgical procedure for end-stage cardiopulmonary failure. Studies to understand the relationship between ethnicity and race and outcomes after HLTx are needed to uphold equitable HLTx access to the increasingly diverse U.S. population facing advanced cardiopulmonary failure.

OBJECTIVES

This study sought to examine the outcomes of HLTx recipients of Asian origin, with emphasis on the ethnic and racial disparities in the outcomes.

METHODS

We analyzed data from the United Network for Organ Sharing (UNOS) for patients of ≥18 years of age who underwent HLTx between 1987 and 2021. Propensity-score matching was performed between Asian and non-Hispanic Whites (NHWs), with a 1:3 matching ratio based on the propensity score of each patient estimated by multivariable logistic regression.

RESULTS

We identified 42 Asian and Asian American heart-lung transplant recipients and 834 NHW recipients. In the pre-matched cohort, the median survival was 1,459 days (IQR: 1,080-2,692 days) in Asian recipients after transplantation, whereas it was 1,521 days (IQR: 1,262-1,841 days) in White recipients. Of the 876 recipients, 156 transplants were successfully matched (Asian, n = 36; NHW, n = 108). Among the post-transplantation outcomes, there were no significant differences in morbidity and mortality between Asian and NHW cohorts.

CONCLUSIONS

This large-scale analysis in Asian patients will have important implications in Asian countries that have relatively fewer HLTx surgeries. An outcome equivalent to NHW in Asian patients, as demonstrated in our study, could be the driving force for further expansion of HLTx surgeries in Asian countries.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

Pulmonary arterial hypertension in adults with congenital heart disease: markers of disease severity, management of advanced heart failure and transplantation

INTRODUCTION

Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is a progressive, life-limiting disease.

AREAS COVERED

In this paper, we review the classification and pathophysiology of PAH-CHD, including the mechanisms of disease progression and multisystem effects of disease. We evaluate current strategies of risk stratification and the use of biological markers of disease severity, and review principles of management of PAH-CHD. The indications, timing, and the content of advanced heart failure assessment and transplant listing are discussed, along with a review of the types of transplant and other forms of available circulatory support in this group of patients. Finally, the integral role of advance care planning and palliative care is discussed.

EXPERT OPINION/COMMENTARY

All patients with PAH-CHD should be followed up in expert centers, where they can receive appropriate risk assessment, PAH therapy, and supportive care. Referral for transplant assessment should be considered if there continue to be clinical high-risk features, persistent symptoms, or acute heart failure decompensation despite appropriate PAH specific therapy. Expert management of PAH-CHD patients, therefore, requires vigilance for these features, along with a close relationship with local advanced heart failure services and a working knowledge of listing criteria, which may disadvantage congenital heart disease patients.

Advances in 3D bioprinting technology for cardiac tissue engineering and regeneration

Cardiovascular disease is still one of the leading causes of death in the world, and heart transplantation is the current major treatment for end-stage cardiovascular diseases. However, because of the shortage of heart donors, new sources of cardiac regenerative medicine are greatly needed. The prominent development of tissue engineering using bioactive materials has creatively laid a direct promising foundation. Whereas, how to precisely pattern a cardiac structure with complete biological function still requires technological breakthroughs. Recently, the emerging three-dimensional (3D) bioprinting technology for tissue engineering has shown great advantages in generating micro-scale cardiac tissues, which has established its impressive potential as a novel foundation for cardiovascular regeneration. Whether 3D bioprinted hearts can replace traditional heart transplantation as a novel strategy for treating cardiovascular diseases in the future is a frontier issue. In this review article, we emphasize the current knowledge and future perspectives regarding available bioinks, bioprinting strategies and the latest outcome progress in cardiac 3D bioprinting to move this promising medical approach towards potential clinical implementation.

Changes in multiorgan heart transplants following the 2018 allocation policy change

BACKGROUND

This study evaluated the impact of the heart allocation policy change in 2018 on the characteristics and outcomes of multiorgan transplants involving heart allografts.

METHODS

Adults undergoing multiorgan heart transplantation from 2010 to 2020 were identified from the United Network for Organ Sharing (UNOS) registry. Transplants were stratified into occurring before versus after the October 2018 heart allocation change. The primary outcome was 1-year survival following transplantation. A Cox proportional hazards model was used to evaluate the risk-adjusted effect of the allocation policy change on outcomes between cohorts.

RESULTS

A total of 1832 patients underwent multiorgan heart transplantation during the study period with 245 (13.37%) undergoing heart-lung transplantation, 244 (13.32%) undergoing heart-liver transplantation, and 1343 (73.31%) undergoing heart-kidney transplantation. There was a higher utilization of temporary MCSDs as well as longer ischemic times for all three types of transplantation following the policy change. Heart-lung and heart-liver recipients had a similar 1-year survival before and after the policy change (each p > .05). Renal failure requiring dialysis (29.5% vs. 39.4%, p = .001) as well as 1-year survival (88% vs. 82%; log-rank p = .01) were worse in the heart-kidney cohort after the organ allocation system modification.

CONCLUSIONS

This study demonstrates similar trends in multiorgan transplants as has been observed in isolated heart transplants following the allocation change, including more frequent utilization of temporary mechanical support and longer ischemic times. Although outcomes have remained comparable in the new allocation era with heart-lung and heart-liver transplants, heart-kidney recipients have a worse 1-year survival following the change.

Relation of Length of Survival After Orthotopic Heart Transplantation to Age of the Donor

We aim to evaluate the impact of donor age on the outcomes in orthotropic heart transplantation recipients. The United Network for Organ Sharing database was queried for adult patients (age; ≥60) underwent first-time orthotropic heart transplantation between 1987 and 2019 (n = 18,447). We stratified the cohort by donor age; 1,702 patients (9.2%) received a heart from a donor age of <17 years; 11,307 patients (61.3%) from a donor age of 17 ≥, < 40; 3,525 patients (19.1%) from a donor age of 40 ≥, < 50); and 1,913 patients (10.4%) from a donor age of ≥50. There was a significant difference in the survival likelihood (p < 0.0001) based on donor's age-based categorized cohort, however, the median survival was 10.5 years in the cohort in whom the donor was <17, 10.3 years in whom the donor was 17 ≥, < 40, 9.4 years in whom the donor was 40 ≥, < 50, and 9.0 years in whom the donor was ≥ 50. Additionally, there was no significant difference in the episode of acute rejection (p = 0.19) nor primary graft failure (p = 0.24). In conclusion, this study demonstrated that patients receiving hearts from the donor age of ≥50 years old showed slight inferior survival likelihood, but appeared to be equivalent median survival.

Impact of advanced clinical fellowship training on future research productivity and career advancement in adult cardiac surgery

BACKGROUND

Advanced clinical fellowships are important for training surgeons with a niche expertise. Whether this additional training impacts future academic achievement, however, remains unknown. Here, we investigated the impact of advanced fellowship training on research productivity and career advancement among active, academic cardiac surgeons. We hypothesized that advanced fellowships do not significantly boost future academic achievement.

METHODS

Using online sources (eg, department webpages, CTSNet, Scopus, Grantome), we studied adult cardiac surgeons who are current faculty at accredited United States cardiothoracic surgery training programs, and who have practiced only at United States academic centers since 1986 (n = 227). Publicly available data regarding career advancement, research productivity, and grant funding were collected. Data are expressed as counts or medians.

RESULTS

In our study, 78 (34.4%) surgeons completed an advanced clinical fellowship, and 149 (65.6%) did not. Surgeons who pursued an advanced fellowship spent more time focused on surgical training (P < .0001), and those who did not were more likely to have completed a dedicated research fellowship (P = .0482). Both groups exhibited similar cumulative total publications (P = .6862), H-index (P = .6232), frequency of National Institutes of Health grant funding (P = .8708), and time to achieve full professor rank (P = .7099). After stratification by current academic rank, or by whether surgeons pursued a dedicated research fellowship, completion of an advanced clinical fellowship was not associated with increased research productivity or accelerated career advancement.

CONCLUSION

Academic adult cardiac surgeons who pursue advanced clinical fellowships exhibit similar research productivity and similar career advancement as those who do not pursue additional clinical training.

Pressure Overload Greatly Promotes Neonatal Right Ventricular Cardiomyocyte Proliferation: A New Model for the Study of Heart Regeneration

Background Current mammalian models for heart regeneration research are limited to neonatal apex amputation and myocardial infarction, both of which are controversial. RNAseq has demonstrated a very limited set of differentially expressed genes between sham and operated hearts in myocardial infarction models. Here, we investigated in rats whether pressure overload in the right ventricle, a common phenomenon in children with congenital heart disease, could be used as a better animal model for heart regeneration studies when considering cardiomyocyte proliferation as the most important index. Methods and Results In the rat model, pressure overload was induced by pulmonary artery banding on postnatal day 1 and confirmed by echocardiography and hemodynamic measurements at postnatal day 7. RNA sequencing analyses of purified right ventricular cardiomyocytes at postnatal day 7 from pulmonary artery banding and sham-operated rats revealed that there were 5469 differentially expressed genes between these 2 groups. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed that these genes mainly mediated mitosis and cell division. Cell proliferation assays indicated a continuous overproliferation of cardiomyocytes in the right ventricle after pulmonary artery banding, in particular for the first 3 postnatal days. We also validated the model using samples from overloaded right ventricles of human patients. There was an approximately 2-fold increase of Ki67/pHH3/aurora B-positive cardiomyocytes in human-overloaded right ventricles compared with nonoverloaded right ventricles. Other features of this animal model included cardiomyocyte hypotrophy with no fibrosis. Conclusions Pressure overload profoundly promotes cardiomyocyte proliferation in the neonatal stage in both rats and human beings. This activates a regeneration-specific gene program and may offer an alternative animal model for heart regeneration research.

Elevated neutrophil to lymphocyte ratio is associated with poor long-term survival and graft failure after lung transplantation

PURPOSE

We aimed to assess the prognostic value of Neutrophil to Lymphocyte Ratio (NLR) on long-term outcomes and graft dysfunction after lung transplantation.

METHODS

We retrospectively reviewed all patients receiving a lung transplant at our institution from 2011 to 2014. The primary exposure was elevated NLR at the time of transplant, defined by NLR>4. The primary outcomes were graft failure and three-year all-cause mortality. Multivariate logistic regression and Kaplan-Meier survival analysis were used to analyze outcomes.

RESULTS

95 patients were included. 40 patients (42%) had an elevated NLR. Elevated NLR was associated with graft failure (OR: 4.7 [1.2-18.8], p = 0.02), and three-year mortality (OR: 5.4 [1.3-23.2], p = 0.03) on multivariate logistic regression. Patients with elevated NLR demonstrated significantly lower survival on Kaplan-Meier analysis (50% versus 74%, p = 0.02). The c-statistic for our multivariate model was 0.91.

CONCLUSION

Elevated neutrophil to lymphocyte ratio is associated with poor long-term survival and graft failure after lung transplantation.