Review of Heart-Lung Transplantation at Stanford

Four decades of progress in heart-lung transplantation: Two hundred seventy-one cases at a single institution

OBJECTIVE

The objective of this study is to evaluate survival for combined heart-lung transplant (HLTx) recipients across 4 decades at a single institution. We aim to summarize our contemporary practice based on more than 271 HLTx procedures over 40 years.

METHODS

Data were collected from a departmental database and the United Network for Organ Sharing. Recipients younger than age 18 years, those undergoing redo HLTx, or triple-organ system transplantation were excluded, leaving 271 patients for analysis. The pioneering era was defined by date of transplant between 1981 and 2000 (n = 155), and the modern era between 2001 and 2022 (n = 116). Survival analysis was performed using cardinality matching of populations based on donor and recipient age, donor and recipient sex, ischemic time, and sex matching.

RESULTS

Between 1981 and 2022, 271 HLTx were performed at a single institution. Recipients in the modern era were older (age 42 vs 34 y; P < .001) and had shorter waitlist times (78 vs 234 days; P < .001). Allografts from female donors were more common in the modern era (59% vs 39%; P = .002). In the matched survival analysis, 30-day survival (97% vs 84%; P = .005), 1-year survival (89% vs 77%; P = .041), and 10-year survival (53% vs 26%; P = .012) significantly improved in the modern era relative to the pioneering era, respectively.

CONCLUSIONS

Long-term survival in HLTx is achievable with institutional experience and may continue to improve in the coming decades. Advances in mechanical circulatory support, improved maintenance immunosuppression, and early recognition and management of acute complications such as primary graft dysfunction and acute rejection have dramatically improved the prognosis for recipients of HLTx in our contemporary institutional experience.

Influence of cardiac diagnosis on outcomes of pediatric heart-lung transplantation

OBJECTIVE

Pediatric Heart-lung transplant (HLTX) is performed for endstage congenital heart disease (CHD) with irreversible pulmonary hypertension or non-congenital heart disease (NCHD) with end-stage heart and lung disease. CHD could influence the outcomes of HTLX due to increased complexity of the operation as compared to NCHD. In this study we evaluated the influence of cardiac diagnosis on outcomes of pediatric HTLX.

METHODS

The UNOS database (1987-2022) was queried for primary HTLX in patients <18 years. The data were extracted for demographics, pretransplant characteristics, post-transplant outcomes, and analyzed for the impact of cardiac diagnosis on post-transplant outcomes. Standard statistical tests were used. Survival was compared using the Kaplan-Meier method.

RESULTS

Ninety of the 213 patients who underwent HLTX had CHD. There were no demographic differences. Heart listing status was similar but with a higher LAS score for NCHD. NCHD had higher pre-operative life support use (mechanical ventilation, inotropes or dialysis) but the use of ECMO as a bridge to transplantation was similar. Wait-list times were longer for CHD. The ischemic times were similar. Post-transplant dialysis, stroke, prolonged mechanical ventilation, and rejection were similar. Survival at 30-days, 1-year, and long-term survival at 17 years was similar. Non-survivors at 30-days post-transplant were on life support, used ECMO as a bridge, had lower wait-list times, longer ischemic times and had strokes. Non-survivors at 1-year had similar factors in addition to a higher dialysis use.

CONCLUSION

Cardiac diagnosis had no impact on outcomes after Pediatric HLTX. Patients on life support or ECMO before transplantation were transplanted faster but with lower survival.

Ex vivo perfusion of the donor heart: Preliminary experience in high-risk transplantations

BACKGROUND

The number of heart transplantations (HTs) has decreased in France since 2017 (-5%/year) despite a stable rate of patients referred on the waiting list. Ex vivo heart perfusion (EVHP) is an innovative approach for organ preservation, reducing graft ischaemic time and facilitating continuous organ monitoring before transplantation.

AIM

To report our preliminary experience of seven donor hearts preserved with EVHP, including the first heart resuscitated after circulatory-determined death in France.

METHODS

Seven hearts were procured from donation after brain death (DBD) for HT or donation after circulatory-determined death (DCD) for research purposes (Protocol PFS20-004, Agence de la Biomédecine, La Plaine Saint-Denis, France). All grafts were preserved using the Organ Care System® (TransMedics Inc., Andover, MA, USA) for normothermic EVHP. Perfusion parameters were adjusted to achieve stable or decreasing arterial lactate trend consistent with suitability for organ transplantation.

RESULTS

Indications for EVHP were assessment of a marginal graft in four cases, prolonged preservation in two cases (anticipated duration for retrieval of recipient's heart>3hours) and resuscitation after circulatory-determined death in one case. Median duration of EVHP was 270 (interquartile range 216-343) minutes. five were transplanted, with a median ex situ preservation time (ischaemic time+EVHP time) of 334 (interquartile range 326-444) minutes. The two other grafts were discarded for HT. Three recipients had extracorporeal life support after HT, and presented complete cardiac recovery within a week after HT. One patient died at day 11 because of septic shock. The 3-month survival rate was 75% among recipients. Three months after HT, the left ventricular ejection fraction was>60% in all cases.

CONCLUSIONS

EVHP enabled safe prolonged preservation and assessment of marginal grafts. This approach provides an opportunity to expand the donor pool by resuscitating grafts from donors with extended criteria, including controlled DCD.

Waitlist and post-transplant outcomes for eisenmenger syndrome: A comparison of transplant strategies

BACKGROUND

End-stage Eisenmenger syndrome (ES) due to unrepaired atrial septal defect (ASD) or ventricular septal defect (VSD) is an indication for lung transplantation (LTx) or heart-lung transplantation (HLTx). Limited evidence exists as to the optimal transplant strategy for this unique population.

AIM

To describe waitlist characteristics and post-transplant outcomes in patients with ES-ASD or ES-VSD.

METHODS

Using the ISHLT Registry, data were extracted for all ES-ASD or ES-VSD patients who underwent transplantation between 1987 and 2018. Additional data were sought for patients listed for LTx or HLTx in the OPTN Registry during the same period. Early era was defined as 1987-2004, and current era was defined as 2005-2018.

RESULTS

In the current era, patients with ES-ASD or ES-VSD represented a lessening proportion of all LTx and HLTx. Compared to LTx for other indications, the odds of transplantation were significantly less for both ES-ASD 0.18 [0.07-0.50] and ES-VSD 0.03 [0.004-0.22]. In the early era, an equivalent survival was observed for ES-ASD who underwent HLTx versus LTx (p = 0.47), and superior survival for ES-VSD (p = 0.015). In contrast, ES-ASD patients who underwent LTx from the current era displayed better survival compared with HLTx, 10-year survival 52% vs 30% p = 0.036. Similar survival were observed for ES-VSD for both transplant strategies (p = 0.68).

CONCLUSION

LTx shows superior survival outcomes in the current era for ES ASD patients, and equivalent outcomes for ES-VSD. In the current era, ES-ASD or ES-VSD patients were less likely to be transplanted than other candidates for LTx.

Delineating the molecular and histological events that govern right ventricular recovery using a novel mouse model of pulmonary artery de-banding

AIMS

The temporal sequence of events underlying functional right ventricular (RV) recovery after improvement of pulmonary hypertension-associated pressure overload is unknown. We sought to establish a novel mouse model of gradual RV recovery from pressure overload and use it to delineate RV reverse-remodelling events.

METHODS AND RESULTS

Surgical pulmonary artery banding (PAB) around a 26-G needle induced RV dysfunction with increased RV pressures, reduced exercise capacity and caused liver congestion, hypertrophic, fibrotic, and vascular myocardial remodelling within 5 weeks of chronic RV pressure overload in mice. Gradual reduction of the afterload burden through PA band absorption (de-PAB)-after RV dysfunction and structural remodelling were established-initiated recovery of RV function (cardiac output and exercise capacity) along with rapid normalization in RV hypertrophy (RV/left ventricular + S and cardiomyocyte area) and RV pressures (right ventricular systolic pressure). RV fibrotic (collagen, elastic fibres, and vimentin+ fibroblasts) and vascular (capillary density) remodelling were equally reversible; however, reversal occurred at a later timepoint after de-PAB, when RV function was already completely restored. Microarray gene expression (ClariomS, Thermo Fisher Scientific, Waltham, MA, USA) along with gene ontology analyses in RV tissues revealed growth factors, immune modulators, and apoptosis mediators as major cellular components underlying functional RV recovery.

CONCLUSION

We established a novel gradual de-PAB mouse model and used it to demonstrate that established pulmonary hypertension-associated RV dysfunction is fully reversible. Mechanistically, we link functional RV improvement to hypertrophic normalization that precedes fibrotic and vascular reverse-remodelling events.

Regulatory T-Cell Levels in the Longest Surviving Asian Patient After Heart-Lung Transplant

Heart-lung transplant is the most effective therapy for patients with end-stage cardiopulmonary disease. Here, we report an initial assessment of a 31-year-old man who had survived more than 11 years after heart-lung transplant, which represents the longest survival time in this procedure in Asian studies. At his 11th anniversary after transplant, extensive tests were carried out, especially to detect regulatory T-cell levels for the first time in a surviving heart-lung transplant recipient. Preliminarily data revealed the status of his immunologic function in relation to chronic allograft rejection. All data indicated that the patient was in good condition. This is the first study detecting regulatory T-cell levels in a heart-lung transplant patient.

Treatment of advanced group 2 PH

Pulmonary hypertension (PH) frequently occurs in patients with left heart disease (LHD), including heart failure with reduced and preserved ejection fraction and valvular heart disease. PH in patients with LHD is associated with worse outcomes making it an attractive target of therapy. Despite the strong rational for treatment, no clear benefits from treating with pulmonary arterial hypertension specific therapies in patients with PH from LHD have been found in clinical trials and some studies have demonstrated harm. Therefore, PH in the setting of LHD should be managed with optimal medical and surgical treatment of LHD and identification and treatment of comorbidities that could contribute to PH. Additionally, significant PH is a contraindication to heart transplantation and, in select patients with left heart failure, left ventricular unloading with prolonged inotrope infusion or left ventricular assist device implantation may successfully reduce pulmonary artery pressures and facilitate transplantation.

Clinical Outcomes of Heart-Lung Transplantation: Review of 10 Single-Center Consecutive Patients

BACKGROUND

Heart-lung transplantation (HLT) has provided hope to patients with end-stage lung disease and irreversible heart dysfunction. We reviewed the clinical outcomes of 10 patients who underwent heart-lung transplantation at Asan Medical Center.

METHODS

Between July 2010 and August 2014, a total of 11 patients underwent HLT at Asan Medical Center. After excluding one patient who underwent concomitant liver transplantation, 10 patients were enrolled in our study. We reviewed the demographics of the donors and the recipients' baseline information, survival rate, cause of death, and postoperative complications. All patients underwent follow-up, with a mean duration of 26.1±16.7 months.

RESULTS

Early death occurred in two patients (20%) due to septic shock. Late death occurred in three patients (38%) due to bronchiolitis obliterans (n=2) and septic shock (n=1), although these patients survived for 22, 28, and 42 months, respectively. The actuarial survival rates at one year, two years, and three years after HLT were 80%, 67%, and 53%, respectively.

CONCLUSION

HLT is a procedure that is rarely performed in Korea, even in medical centers with large heart and lung transplant programs. In order to achieve acceptable clinical outcomes, it is critical to carefully choose the donor and the recipient and to be certain that all aspects of the transplant procedure are planned in advance with the greatest care.

Heart-lung transplantation: pediatric indications and outcomes

As indications for heart-lung transplant (HLT) have changed to some degree in the past 30 years, this treatment is being used less frequently in children due to more advanced care of severe heart and lung disease. This is fortunate as the outcomes for HLT are poor compared to other solid organ transplants and this is mainly due to the poorer outcome of the lung graft.

Impact of congenital heart disease on outcomes of pediatric heart-lung transplantation

HLT is reserved for children with cardiopulmonary disease not amendable to alternative therapies. Children with CHD with or without ES may be considered for HLT. Outcomes of HLT in this population are not well described. To test the hypothesis that CHD without ES is associated with worse graft survival and identify factors associated with poor outcome, a retrospective analysis of the UNOS database was performed. One hundred and seventy-eight pediatric HLTs were performed between 1987 and 2011. CHD was the diagnosis in 65 patients, of which 34 had CHD without ES. Patients with CHD without ES had decreased patient survival (median 1.31 yr) compared with CHD with ES (4.80 yr, p = 0.05). On multivariable analysis, the following were associated with graft failure: CHD without ES (adjusted HR 1.69, 95% CI 1.09-2.62), younger age (1.04, 1.01-1.08), pretransplant mechanical ventilation (1.75, 1.01-3.06), pretransplant ECMO (3.07, 1.32-7.12), pretransplant PRAs (1.53, 1.06-2.20), and transplant era (1.85, 1.16-2.94). In children with CHD who require HLT, underlying physiology influences outcomes. Those without ES have a worse prognosis. The diagnosis of CHD without ES and preoperative factors may inform decisions in a complex patient population.

Neurologic aspects of multiple organ transplantation

Complex multiorgan failure may require simultaneous transplantation of several organs, including heart-lung, kidney-pancreas, or multivisceral transplantation. Solid organ transplantation can also be combined with hematopoietic stem cell transplantation to modulate immunologic response to a solid organ allograft. Combined multiorgan transplantation may offer a lower rate of allograft rejection and lower immunosuppression needs. In recent years, intestinal and multivisceral transplantations became viable as a rescue treatment for patients with irreversible intestinal failure who can no longer tolerate total parenteral nutrition with 70% survival after 5 years which is comparable to other types of solid organ allografts. Post-transplant neurologic complications were reported in up to 86% of allograft recipients and greatly overlap in intestinal and multivisceral allograft recipients, without a significant effect on the outcome of transplantation. Other common organ combinations in multiorgan transplantation include kidney-pancreas, which is mostly used for patients with renal failure and uncontrolled diabetes, and heart-lung for patients with congenital heart disease and idiopathic pulmonary arterial hypertension. Kidney-pancreas transplantation frequently results in an improvement of diabetic complications, including diabetic neuropathy. Heart-lung allograft recipients have very similar clinical course and spectrum of neurologic complications to lung transplant recipients. At this time there are no reports of an increased risk of graft-versus-host disease with combined transplantation of solid organ allograft and hematopoietic stem cells. Chronic immunosuppression and complex toxic-metabolic disturbances after multiorgan transplantation create a permissive environment for development of a wide spectrum of neurologic complications which largely resemble complications after transplantations of individual components of complex multiorgan allografts.

Characteristics of patients with survival longer than 20 years following heart transplantation

INTRODUCTION AND OBJECTIVES

The number of heart-transplant recipients exceeding 20 years of follow-up is steadily increasing. However, little is known about their functional status, comorbidities, and mortality. Identifying the predictors of prolonged survival could guide the selection of candidates for the low number of available donors.

METHODS

Functional status, morbidities, and mortality of heart-transplant patients between 1984 and 1992 were analyzed. To identify predictors of 20-year survival, a logistic regression model was constructed using the covariates associated with survival in the univariate analysis.

RESULTS

A total of 39 patients who survived 20 years (26% of patients transplanted before 1992) were compared to 90 recipients from the same period who died between 1 and 20 years post-transplantation. Major complications were hypertension, renal dysfunction, infections, and cancer. After a mean follow-up of 30 months, 6 survivors had died, yielding a mortality rate of 6% per year (vs 2.5%-3% in years 1-19). Causes of mortality were infection (50%), malignancy (33%), and allograft vasculopathy (17%). Long-term survivors were younger and leaner, and had nonischemic cardiomyopathy and lower ischemic time. Logistic regression identified recipient age <45 years (odds ratio=3.9; 95% confidence interval, 1.6-9.7; P=.002) and idiopathic cardiomyopathy (odds ratio=3; 95% confidence interval, 1.4-7.8; P=.012) as independent predictors for 20-year survival.

CONCLUSIONS

One fourth of all heart-transplant patients in our series survived >20 years with the same graft, and most enjoy independent lives despite significant comorbidities. Recipient age <45 years and idiopathic cardiomyopathy were associated with survival beyond 2 decades. These data may help decide donor allocation.

Left ventricular assist device to avoid heart-lung transplant in an adolescent with dilated cardiomyopathy and severely elevated pulmonary vascular resistance

Orthotopic heart transplantation remains the definitive treatment of choice for patients with end-stage heart failure; however, elevated PVRI is a reported risk factor for mortality after heart transplant and, when severely elevated, is considered an absolute contraindication. Use of a ventricular assist device has been proposed as one treatment for reducing pulmonary vascular resistance index in potential heart transplant candidates refractory to medical vasodilator therapies. We report on a teenage patient with dilated cardiomyopathy and severely elevated PVRI, unresponsive to pulmonary vasodilator therapy, who underwent left ventricular assist device implantation to safely allow for aggressive pulmonary vasodilator therapy and to decrease PVRI. The resulting dramatic improvement in PVRI in a relatively short period of time allowed for successful heart transplantation, avoiding the need for heart-lung transplant.

Transplantation for Idiopathic Pulmonary Arterial Hypertension

Background—

Lung transplantation and heart-lung transplantation represent surgical options for treatment of medically refractory idiopathic pulmonary arterial hypertension. The effect of the lung allocation score on wait-list and transplantation outcomes in patients with idiopathic pulmonary arterial hypertension is poorly described.

Methods and Results—

Adults diagnosed with idiopathic pulmonary arterial hypertension and listed for transplantation in the 80 months before and after the lung allocation score algorithm was implemented (n=1430) were identified in the United Network for Organ Sharing thoracic registry. Patients were stratified by organ listed and pre– and post–lung allocation score era. The cumulative incidences of transplantation and mortality for wait-listed patients in both eras were appraised with competing outcomes analysis. Posttransplantation survival was assessed with the Kaplan-Meier method. These analyses were repeated in propensity-matched subgroups. Cox proportional hazards analysis evaluated the effect of prelisting and pretransplantation characteristics on mortality. We found that patients in the post–lung allocation score era had significantly worse comorbidities; nevertheless, both lung transplantation and heart-lung transplantation candidates in this era enjoyed lower wait-list mortality and a higher incidence of transplantation in unmatched and propensity-matched analyses. On multivariable analysis, heart-lung transplantation and double-lung transplantation were associated with improved survival from the time of wait-listing, as was being listed at a medium- to high-volume institution. Donor/recipient sex matching predicted posttransplantation survival.

Conclusions—

The incidence of transplantation has increased while wait-list mortality has decreased in patients with idiopathic pulmonary arterial hypertension wait-listed for transplantation in the post–lung allocation score era. Both heart-lung transplantation and double-lung transplantation are predictive of survival in transplantation candidates with idiopathic pulmonary arterial hypertension, as is being listed at a medium- to high-volume institution. Donor/recipient sex matching is associated with better posttransplantation survival.

Aggressive coronary artery vasculopathy after combined heart-lung transplantation

Combined heart-lung transplantation remains as a treatment option for patients with cardiopulmonary failure. There is speculation that lung grafts protect the heart from developing graft vasculopathy after combined heart-lung transplantation. This protective mechanism is more likely, at best, a delay in the onset of coronary artery vasculopathy. We present our experiences in two cases of an aggressive form of cardiac allograft vasculopathy after combined heart-lung transplantation that resulted in the death of both patients.