Impact of prolonged ischemic time on pediatric heart transplantation outcomes: Improved outcomes in the most recent era

BACKGROUND

Impacts of ischemic time (IT) on pediatric heart transplant outcomes are multifactorial. We aimed to analyze the effect of prolonged IT on graft loss after pediatric heart transplantation. We hypothesized that graft survival with prolonged IT has improved across eras.

METHODS

Patients <18 years old in the Pediatric Heart Transplant Society database were included (N=6,765) and stratified by diagnosis and era (1993-2004, 2005-2009, and 2010-2019). Severe graft failure (SGF) was defined as death, retransplant, or need for mechanical circulatory support in the first 7 days post-transplant. Descriptive statistical methods were used to compare differences between patient characteristics and IT. Kaplan-Meier survival analysis compared freedom from graft loss, rejection, and infection. Multivariable analysis was performed for graft loss and SGF (hazard and logistic regression modeling, respectively).

RESULTS

Diagnoses were cardiomyopathy (N = 3,246) and congenital heart disease (CHD; N = 3,305). CHD were younger, more likely to have an IT ≥4.5 hours, and more likely to require extracorporeal membrane oxygenation or mechanical ventilation at transplant (all p < 0.001). Median IT was 3.6 hours (interquartile range 2.98-4.31; range 0-10.5). IT was associated with early graft loss (HR 1.012, 95% CI 1.005-1.019), but not when analyzed only in the most recent era. IT was associated with SGF (OR 1.016 95%CI 1.003-1.030).

CONCLUSIONS

Donor IT was independently associated with an increased risk of graft loss, albeit with a small effect relative to other risk factors. Graft survival with prolonged IT has improved in the most recent era but the risk of SGF persists.

Risk Factors for Descemet Membrane Endothelial Keratoplasty Rejection: Current Perspectives- Systematic Review

Descemet membrane endothelial keratoplasty (DMEK) is a corneal endothelial transplantation procedure with selective removal of a patient's defective Descemet membrane and endothelium. It is replaced with a healthy donor Descemet membrane and endothelium without a stromal component. Corneal graft rejection can be at the level of epithelium, stroma as well endothelium. DMEK graft rejection is relatively less common than rejection with DSAEK or penetrating keratoplasty, and a good outcome may be achieved with prompt management. The clinical picture of DMEK rejection is usually similar to endothelial rejection in Descemet Stripping Endothelial Keratoplasty (DSEK/DSAEK), which generally manifests as pain, redness, reduction in visual acuity, stromal edema, endothelial rejection line, keratic precipitates at the back of the cornea and corneal neovascularization. However, more subtle forms of rejection or immune reactions are more common in DMEK compared to DSAEK eyes. Early clinical diagnosis, prompt intervention, and meticulous management safeguard visual acuity and graft survival in these cases. Intensive topical steroids form the mainstay in the management of DMEK rejection. Sometimes, oral or intravenous steroids or other systemic immunomodulators may be required. DMEK graft failure can be primary or secondary, and failure usually requires a second procedure in the form of repeat DMEK or DSEK or penetrating keratoplasty (PKP). A detailed literature search was performed using search engines such as Google Scholar, PubMed, and Google books, and a comprehensive review on DMEK rejection was found to be lacking. This review is a comprehensive update on the risk factors, pathophysiology, primary and secondary graft failure, recent advances in diagnosis, prevention of rejection, and updates in the management of DMEK rejection. The review also discusses the differential diagnosis of DMEK failure and rejection, prognosis, and future perspectives considering DMEK failure and rejection.

Case Report: Primary graft failure due to a reversed lenticule in Descemet Stripping Automated Endothelial Keratoplasty

Introduction and importance: This report details the clinical features and management in a case of Descemet stripping automated endothelial keratoplasty (DSAEK) which had primary graft failure (PGF) due to an inverted yet attached lenticule. Presentation of case: A 66-year-old gentleman had poor visual recovery in the right eye after undergoing cataract surgery 12 years prior to presentation. The visual acuity was counting fingers and examination revealed endothelial decompensation. The patient underwent a DSAEK and postoperatively had a well attached lenticule. However, the cornea was edematous three weeks after the surgery and optical coherence tomography (OCT) revealed a reversed lenticule. The patient underwent a repeat DSAEK and had an uneventful postoperative course. The visual acuity was 20/40 after 7 months with a clear cornea and a well attached graft. Discussion: PGF is a rare complication following DSAEK which occurs due to poor endothelial function of the donor graft. Insertion of a reversed lenticule may get overlooked as a cause of PGF unless the graft edge profile is examined on an OCT scan. The graft in the current case was well attached despite its inverted position suggesting that graft adherence is perhaps not a function of the corneal endothelial pumps in isolation and may be driven by factors such as the intraocular pressure. Conclusion: A reversed DSAEK lenticule may have normal adherence to the host stroma and must be considered in cases with PGF. OCT of the graft edge is required for diagnosis before performing a repeat keratoplasty.

Trends in Early Graft Failure Leading to Regrafting After Endothelial Keratoplasty in the United States

PURPOSE

The purpose of this study was to report trends in the prevalence of early graft failure after endothelial keratoplasty in the United States.

METHODS

Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) graft volumes were collected from records maintained by 6 major eye banks in the United States from January 1, 2013, to December 31, 2018. The prevalence and presumed cause of early graft failures (defined as a graft with persistent edema or regrafted within 8 weeks after keratoplasty) each year were sourced from surgeon-reported adverse events. Failed graft cases from the 3 eye banks were compared with nonfailures at the donor and recipient levels to perform subset analysis of factors associated with early graft failure.

RESULTS

A total of 51,887 endothelial keratoplasty tissues were distributed during the study period; 72% were DSAEK grafts. The total number of early graft failures reported was 168 of 14,284 (1.18%) for DMEK and 322 of 37,603 (0.86%) for DSAEK. Early DMEK failures decreased from 2013 (7.69%) to 2018 (0.68%). In generalized linear mixed model analyses adjusting for donor tissue characteristics, recipient age, and diagnosis, an association of borderline significance was found between higher donor age and early failure [odds ratio (95% confidence interval): 1.03 (1.00-1.05); unit change of 1 yr] and DSAEK [odds ratio 1.02 (1.00-1.04); unit of change 1 yr] cases.

CONCLUSIONS

The proportion of early graft failures in DMEK decreased over time and was comparable with failure rates in DSAEK at the end of the study period. The surgical learning curve might have played a role.

Primary Graft Failure, Infection, and Endothelial Cell Density in Corneal Transplants With Increased Death-to-Preservation Time

PURPOSE

To ascertain whether death-to-preservation time (DPT) is associated with donor endothelial cell density (ECD), primary graft failure (PGF), and infection.

METHODS

Donor corneas aged older than 10 years with ECD 2000 to 4500 cells/mm2 were procured between 2011 and 2018 by a single eye bank. Donor corneas were analyzed retrospectively for the main outcome measures of PGF, infection, and ECD. Means and proportions of study parameters were compared between corneas with long and short DPT, defined as greater or less than 14 hours, respectively, excluding corneas with a history of intraocular surgery or diabetes. Multivariate analyses were performed using logistic regression, adjusting for donor age at time of death, history of diabetes mellitus, and history of cataract surgery.

RESULTS

Among 12,015 corneas, those with long DPT had a statistically but not clinically significant higher ECD than that of corneas with short DPT (2754 vs. 2724 cells/mm2, P < 0.01). There was no difference in PGF and infections in corneas with long versus short DPT (0.28% vs. 0.26%, P = 0.86; 0.43% vs. 0.29%, P = 0.51, respectively).

CONCLUSIONS

Longer DPT is not associated with a clinically meaningful reduction in donor ECD, PGF, or infection.

Risk Factors for Severe Primary Graft Dysfunction in Infants Following Heart Transplant

Background

Previous studies suggest that infant heart transplant (HT) recipients are at higher risk of developing severe primary graft dysfunction (PGD) than older children. We sought to identify risk factors for developing severe PGD in infant HT recipients.

Methods and Results

We identified all HT recipients aged <1 year in the United States during 1996 to 2015 using the Organ Procurement and Transplant Network database. We linked their data to ELSO (Extracorporeal Life Support Organization) registry data to identify those with severe PGD, defined by initiation of extracorporeal membrane oxygenation support for PGD within 2 days following HT. We used multivariable logistic regression to assess risk factors for developing severe PGD. Of 1718 infants analyzed, 600 (35%) were <90 days old and 1079 (63%) had congenital heart disease. Overall, 134 (7.8%) developed severe PGD; 95 (71%) were initiated on extracorporeal membrane oxygenation support on the day of HT, 34 (25%) the next day, and 5 (4%) the following day. In adjusted analysis, recipient congenital heart disease, extracorporeal membrane oxygenation, or biventricular assist device support at transplant, recipient blood type AB, donor‐recipient weight ratio <0.9, and graft ischemic time ≥4 hours were independently associated with developing severe PGD whereas left ventricular assist device support at HT was not. One‐year graft survival was 48% in infants with severe PGD versus 87% without severe PGD.

Conclusions

Infant HT recipients with severe PGD have poor graft survival. Although some recipient‐level risk factors are nonmodifiable, avoiding modifiable risk factors may mitigate further risk in infants at high risk of developing severe PGD.

Donor Left Ventricular Function Assessed by Echocardiographic Strain is a Novel Predictor of Primary Graft Failure After Orthotopic Heart Transplantation

OBJECTIVES

This study sought to determine the utility of donor left ventricular function assessment by echocardiographic left ventricular global longitudinal strain (LV GLS) in predicting primary graft failure (PGF) after orthotopic heart transplantation (HT).

DESIGN

Retrospective, observational study.

SETTING

Tertiary referral hospital.

PARTICIPANTS

Adult patients (>18 years) who underwent isolated HT.

INTERVENTIONS

Demographic, clinical, and echocardiographic data were collected on 100 patients who underwent HT between January 2010 and December 2019 at the authors' institution. The respective donor variables, as well as procedural factors, were reviewed and analyzed to assess their independent association with PGF. Standard donor echocardiographic measurements were supplemented by two-dimensional speckle-tracking echocardiography to obtain LV GLS. PGF was defined as per the International Society for Heart and Lung Transplantation 2014 consensus statement.

MEASUREMENTS AND MAIN RESULTS

PGF occurred in 40 of the 100 patients (40%). Initial univariate analysis found that RADIAL score, donor ejection fraction, and donor LV GLS were associated with PGF. However, in a multivariate Cox regression analysis, only RADIAL score and donor LV GLS remained significant predictors of PGF, with a p < 0.001. By receiver operating characteristic curve analysis, LV GLS at a cut-off value of -11.5% showed the greatest area under the curve (area under the curve = 0.889; 95% confidence interval, 0.826-0.952) and predicted PGF with 92.5% sensitivity and 65% specificity.

CONCLUSIONS

Impaired donor LV GLS was proven to be an independent predictor of PGF after HT.

Kinetics of neutrophil engraftment in allogeneic stem cell transplantation

Primary graft failure is a lethal complication that occurs after allogeneic stem cell transplantation (allo-SCT) and requires retransplantation. We retrospectively assessed 1,355 patients who underwent allo-SCT at our institute. Following allo-SCT, the cumulative incidence of subsequent neutrophil engraftment was calculated each day after day 5 among patients with white blood cell (WBC) count<100 cells/μL on the respective day. The number of patients with WBC count<100 cells/μL at days 14, 21, and 28 were 372, 55, and 21, respectively. In patients with WBC count<100 cells/μL on day 14, the cumulative incidence of engraftment was lower in recipients of peripheral blood stem cells (PBSCs) and cord blood (CB) compared with recipients of bone marrow (BM) (BM vs. PBSCs vs. CB, 93% vs. 79% vs. 77%, P<0.01). In patients with WBC count<100 cells/μL after day 14, the cumulative incidence of engraftment in recipients of PBSCs became progressively lower (25% at day 21 and 0% at day 28). In patients with WBC count<100 cells/μL on day 28, the cumulative incidence of engraftment was 100% in patients with donor chimerism≥95%, while it was only 13% in those with chimerism<95% (P<0.01). These data provide important information that could be useful in deciding the appropriate time for performing tests in patients with donor chimerism and in those that require retransplantation.

Risk of severe primary graft dysfunction in patients bridged to heart transplantation with continuous-flow left ventricular assist devices

BACKGROUND

Primary graft dysfunction (PGD) remains a significant cause of post-transplant morbidity and mortality. The exact mechanism and risk factors for this phenomenon remain unknown in the contemporary era.

METHODS

In this study we reviewed adult patients undergoing heart transplantation (HT) at our institution between 2009 and 2017. Severe PGD was defined as the need for mechanical circulatory support (MCS) within the first 24 hours after HT. Multivariate logistic regression analysis was used to identify risk factors for severe PGD, focusing on those bridged to transplant (BTT) with a continuous-flow left ventricular assist device (CF-LVAD).

RESULTS

Fifty-six of 480 (11.7%) HT patients experienced severe PGD. Eighty percent of the severe PGD patients were BTT with a CF-LVAD (odds ratio [OR] 3.86, 95% confidence interval [CI] 1.94 to 7.68, p < 0.001). Among the BTT patients, significant associations between >1 year of CF-LVAD support (OR 2.48, 95% CI 1.14 to 5.40, p = 0.022), pre-HT creatinine (OR 3.35, 95% CI 1.42 to 7.92, p = 0.006), elevated central venous pressure/pulmonary capillary wedge pressure (CVP/PCWP) ratio (OR 3.32, 95% CI 1.04 to 10.60, p = 0.043), use of amiodarone before HT (OR 2.69, 95% CI 1.20 to 6.20, p = 0.022), and severe PGD were identified. RADIAL score did not accurately predict severe PGD in this contemporary cohort. Those patients who developed severe PGD had decreased 1-year post-transplant survival (78.3% vs 91.8%, p = 0.007).

CONCLUSIONS

Use of CF-LVAD as BTT is associated with an increased risk of severe PGD. Increased time on device support, renal dysfunction, right ventricular dysfunction as assessed by CVP/PCWP ratio, and pre-transplant amiodarone may identify those patients at high risk. Further research is warranted focusing on optimal timing of device implantation and transplantation, as well as the underlying mechanisms of PGD.

Effect of early allograft dysfunction on outcomes following liver transplantation

Early allograft dysfunction (EAD) following liver transplantation (LT) remains a challenge for patients and clinicians. We retrospectively analyzed the effect of pre-defined EAD on outcomes in a 10-year cohort of deceased-donor LT recipients with clearly defined exclusion criteria. EAD was defined by at least one of the following: AST or ALT >2000 IU/L within first-week post-LT, total bilirubin ≥10 mg/dL, and/or INR ≥1.6 on post-operative day 7. Ten patients developed primary graft failure and were analyzed separately. EAD occurred in 86 (36%) recipients in a final cohort of 239 patients. In univariate and multivariate analyses, EAD was significantly associated with mechanical ventilation ≥2 days or death on days 0, 1, PACU/SICU stay >2 days or death on days 0-2 and renal failure (RF) at time of hospital discharge (all P<.05). EAD was also significantly associated with higher one-year graft loss in both uni- and multivariate Cox hazard analyses (P=.0203 and .0248, respectively). There was no difference in patient mortality between groups in either of the Cox proportional hazard models. In conclusion, we observed significant effects of EAD on short-term post-LT outcomes and lower graft survival.

Haploidentical hematopoietic stem cell transplantation in a myelofibrosis patient with primary graft failure

The prognosis of patients affected by myelofibrosis (MF) is usually dismal and allogeneic hematopoietic stem cell transplantation (HSCT) remains the only cure. The number of HSCTs in MF patients has recently increased. However, a major obstacle is still represented by primary graft failure (PGF). Currently there are no definitive guidelines for the treatment of PGF and a second HSCT can be performed only when an allogeneic donor is rapidly available. Herein we report on a MF patient with PGF after an unrelated HSCT, who was rescued by a non-myeloablative, unmanipulated, haploidentical HSCT that resulted in persistent engraftment and bone-marrow fibrosis regression, but not in a long-term disease control. Based on this experience we briefly review the role of different conditioning regimens and hematopoietic stem cell sources in the setting of HSCT for MF patients with PGF. The role of haploidentical donors in MF patients lacking HLAmatched relatives is also discussed.

A multicenter study of primary graft failure after infant heart transplantation: impact of extracorporeal membrane oxygenation on outcomes

Primary graft failure is the major cause of mortality in infant HTx. The aim of this study was to characterize the indication and outcomes of infants requiring ECMO support due to primary graft failure after HTx. We performed a retrospective review of all infants (<1 yr) who underwent Htx from three institutions. From 1999 to 2008, 92 infants (<1 yr) received Htx. Sixteen children (17%) required ECMO after Htx due to low cardiac output syndrome. Eleven (69%) infants were successfully weaned off ECMO, and 9 (56%) infants were discharged with a mean follow-up of 2.3 ± 2.5 yr. Mean duration of ECMO in survivors was 5.4 days (2-7 days) compared with eight days (2-10 days) in non-survivors (p = NS). The five-yr survival rate for all patients was 75%; however, the five-yr survival rate was 40% in the ECMO cohort vs. 80% in the non-ECMO cohort (p = 0.0001). Graft function within one month post-Htx was similar and normal between ECMO and non-ECMO groups (shortening fraction = 42 ± 3 vs. 40 ± 2, p = NS). For infants, ECMO support for primary graft failure had a lower short-term and long-term survival rate vs. non-ECMO patients. Duration of ECMO did not adversely impact graft function and is an acceptable therapy for infants after HTx for low cardiac output syndrome.