Long-Term Survival Following Primary Graft Dysfunction Development in Lung Transplantation.

INTRODUCTION: Primary graft dysfunction (PGD) is a known risk factor for early mortality following lung transplant (LT). However, the outcomes of patients who achieve long-term survival following index hospitalization are unknown. We aimed to determine the long-term association of PGD grade 3 (PGD3) in patients without in-hospital mortality. METHODS: LT recipients were identified from the United Network for Organ Sharing Database. Patients were stratified based on the grade of PGD at 72 h (No PGD, Grade 1/2 or Grade 3). Groups were assessed with comparative statistics. Long-term survival was evaluated using Kaplan-Meier methods and a multivariable shared frailty model including recipient, donor, and transplant characteristics. RESULTS: The PGD3 group had significantly increased length of stay, dialysis, and treated rejection post-transplant (P < 0.001). Unadjusted survival analysis revealed a significant difference in long-term survival (P < 0.001) between groups; however, following adjustment, PGD3 was not independently associated with long-term survival (hazard ratio: 0.972; 95% confidence interval: 0.862-1.096). Increased mortality was significantly associated with increased recipient age and treated rejection. Decreased mortality was significantly associated with no donor diabetes, bilateral LT as compared to single LT, transplant in 2015-2016 and 2017-2018, and no post-transplant dialysis. CONCLUSIONS: While PGD3 remains a challenge post LT, PGD3 at 72 h is not independently associated with decreased long-term survival, while complications such as dialysis and rejection are, in patients who survive index hospitalization. Transplant providers should be aggressive in preventing further complications in recipients with severe PGD to minimize the negative association on long-term survival.

The Impact of Donor Smoking on Primary Graft Dysfunction and Mortality after Lung Transplantation.

Rationale: Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality after lung transplantation. Prior studies implicated proxy-defined donor smoking as a risk factor for PGD and mortality. Objectives: We aimed to more accurately assess the impact of donor smoke exposure on PGD and mortality using quantitative smoke exposure biomarkers. Methods: We performed a multicenter prospective cohort study of lung transplant recipients enrolled in the Lung Transplant Outcomes Group cohort between 2012 and 2018. PGD was defined as grade 3 at 48 or 72 hours after lung reperfusion. Donor smoking was defined using accepted thresholds of urinary biomarkers of nicotine exposure (cotinine) and tobacco-specific nitrosamine (4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol [NNAL]) in addition to clinical history. The donor smoking-PGD association was assessed using logistic regression, and survival analysis was performed using inverse probability of exposure weighting according to smoking category. Measurements and Main Results: Active donor smoking prevalence varied by definition, with 34-43% based on urinary cotinine, 28% by urinary NNAL, and 37% by clinical documentation. The standardized risk of PGD associated with active donor smoking was higher across all definitions, with an absolute risk increase of 11.5% (95% confidence interval [CI], 3.8% to 19.2%) by urinary cotinine, 5.7% (95% CI, -3.4% to 14.9%) by urinary NNAL, and 6.5% (95% CI, -2.8% to 15.8%) defined clinically. Donor smoking was not associated with differential post-lung transplant survival using any definition. Conclusions: Donor smoking associates with a modest increase in PGD risk but not with increased recipient mortality. Use of lungs from smokers is likely safe and may increase lung donor availability. Clinical trial registered with www.clinicaltrials.gov (NCT00552357).

HLA sensitization is associated with an increased risk of primary graft dysfunction after heart transplantation.

Primary graft dysfunction (PGD) is a leading cause of early morbidity and mortality following heart transplantation (HT). We sought to determine the association between pretransplant human leukocyte antigen (HLA) sensitization, as measured using the calculated panel reactive antibody (cPRA) value, and the risk of PGD. METHODS: Consecutive adult HT recipients (n = 596) from 1/2015 to 12/2019 at 2 US centers were included. Severity of PGD was based on the 2014 International Society for Heart and Lung Transplantation consensus statement. For each recipient, unacceptable HLA antigens were obtained and locus-specific cPRA (cPRA-LS) and pre-HT donor-specific antibodies (DSA) were assessed. RESULTS: Univariable logistic modeling showed that peak cPRA-LS for all loci and HLA-A was associated with increased severity of PGD as an ordinal variable (all loci: OR 1.78, 95% CI: 1.01-1.14, p = 0.025, HLA-A: OR 1.14, 95% CI: 1.03-1.26, p = 0.011). Multivariable analysis showed peak cPRA-LS for HLA-A, recipient beta-blocker use, total ischemic time, donor age, prior cardiac surgery, and United Network for Organ Sharing status 1 or 2 were associated with increased severity of PGD. The presence of DSA to HLA-B was associated with trend toward increased risk of mild-to-moderate PGD (OR 2.56, 95% CI: 0.99-6.63, p = 0.053), but DSA to other HLA loci was not associated with PGD. CONCLUSIONS: Sensitization for all HLA loci, and specifically HLA-A, is associated with an increased severity of PGD. These factors should be included in pre-HT risk stratification to minimize the risk of PGD.

The Role of Recipient Thyroid Hormone Supplementation in Primary Graft Dysfunction After Heart Transplantation: A Propensity-Adjusted Analysis.

OBJECTIVES: To investigate whether recipient administration of thyroid hormone (liothyronine [T3]) is associated with reduced rates of primary graft dysfunction (PGD) after orthotopic heart transplantation. DESIGN: Retrospective cohort study. SETTING: Single-center, university hospital. PARTICIPANTS: Adult patients undergoing orthotopic heart transplantation. INTERVENTIONS: A total of 609 adult heart transplant recipients were divided into 2 cohorts: patients who did not receive T3 (no T3 group, from 2009 to 2014), and patients who received T3 (T3 group, from 2015 to 2019). Propensity-adjusted logistic regression was performed to assess the association between T3 supplementation and PGD. MEASUREMENTS AND MAIN RESULTS: After applying exclusion criteria and propensity-score analysis, the final cohort included 461 patients. The incidence of PGD was not significantly different between the groups (33.9% no T3 group v 40.8% T3 group; p = 0.32). Mortality at 30 days (3% no T3 group v 2% T3 group; p = 0.53) and 1 year (10% no T3 group v 12% T3 group; p = 0.26) were also not significantly different. When assessing the severity of PGD, there were no differences in the groups' rates of moderate PGD (not requiring mechanical circulatory support other than an intra-aortic balloon pump) or severe PGD (requiring mechanical circulatory support other than an intra-aortic balloon pump). However, segmented time regression analysis revealed that patients in the T3 group were less likely to develop severe PGD. CONCLUSIONS: These findings indicated that recipient single-dose thyroid hormone administration may not protect against the development of PGD, but may attenuate the severity of PGD.

Cardiac Transplantation: Physiology and Natural History of the Transplanted Heart.

Heart transplantation (HT) is one of the prodigious achievements in modern medicine and remains the cornerstone in the treatment of patients with advanced heart failure. Advances in surgical techniques, immunosuppression, organ preservation, infection control, and allograft surveillance have improved short- and long-term outcomes thereby contributing to greater clinical success of HT. However, prolonged allograft and patient survival following HT are still largely restricted by the development of late complications, including allograft rejection, infection, cardiac allograft vasculopathy (CAV), and malignancy. The introduction of mTOR inhibitors early after HT has demonstrated multiple protective effects against CAV progression, renal dysfunction, and tumorigenesis. Therefore, several HT programs increasingly use mTOR inhibitors with partial or complete withdrawal of calcineurin inhibitor (CNI) in stable HT patients to reduce complications risk and improve long-term outcomes. Furthermore, despite a substantial improvement in exercise capacity and health-related quality of life after HT as compared to advanced heart failure patients, most HT recipients remain with a 30% to 50% lower peak oxygen consumption (Vo 2 ) than that of age-matched healthy subjects. Several factors, including alterations in central hemodynamics, HT-related complications and alterations in the musculoskeletal system, and peripheral physiological abnormalities, presumably contribute to the reduced exercise capacity following HT. Cardiac denervation and subsequent loss of sympathetic and parasympathetic regulation are responsible for various physiological alterations in the cardiovascular system, which contributes to restricted exercise tolerance. Restoration of cardiac innervation may improve exercise capacity and quality of life, but the reinnervation process is only partial even several years after HT. Multiple studies have shown that aerobic and strengthening exercise interventions improve exercise capacity by increasing maximal heart rate, chronotropic response, and peak Vo 2 after HT. Novel exercise modalities, such as high-intensity interval training (HIT), have been proven as safe and effective for further improvement in exercise capacity, including among de novo HT recipients. Further developments have recently emerged, including donor heart preservation techniques, noninvasive CAV and rejection surveillance methods, and improvements in immunosuppressive therapies, all aiming at increasing donor availability and improving late survival after HT. © 2023 American Physiological Society. Compr Physiol 13:4719-4765, 2023.

Impact of total ischaemic time and disease severity class on graft function after bilateral lung transplantation.

OBJECTIVES: Total ischaemic time (IT) is considered a limiting factor in lung transplantation. In this retrospective study, we investigate effects of IT and disease burden on outcomes after bilateral lung transplantation. METHODS: A total of 1298 patients undergoing bilateral lung transplantation between January 2010 and May 2022 (follow-up 100%, median 54 months) were included. Pre-transplant diseases' severity (recipient body mass index, recipient age, previous lung transplantation, Tacrolimus immunosuppression, preoperative recipient extracorporeal membrane oxygenation support, lung volume reduction) for graft failure was individually calculated and-as IT-categorized. Vice versa adjusted Cox models were calculated. Considering competing risks, we assessed cumulative incidences of airway obstructive complications and chronic lung allograft dysfunction with death as competing risk factors for primary graft dysfunction were assessed by binary logistic regression. RESULTS: Higher disease burden significantly accelerated chronic lung allograft dysfunction and death occurrence (P < 0.001); IT did not. IT-adjusted disease burden strata showed 50% graft survival differences at 11 years after transplantation (range 24-74%), disease burden-adjusted IT strata 18% for all and 6% (54-60%) among those above 7 h. All significant primary graft dysfunction risk factors were diagnoses related, IT was not significantly important and odds ratios did not increase with IT. CONCLUSIONS: The eventual graft survival disadvantage that results from an IT between 7 and at least 11 h is negligible in contrast to frequent recipients' disease-based risk levels.

Mechanical circulatory support in severe primary graft dysfunction: Peripheral cannulation but not earlier implantation improves survival in heart transplantation.

BACKGROUND: Primary graft dysfunction (PGD) still affects 2% to 28% of heart transplants (HT). Severe PGD requires mechanical circulatory support (MCS) and is the main cause of death early after HT. Earlier initiation has been suggested to improve prognosis but the best cannulation strategy is unknown. METHODS: Analysis of all HT in Spain between 2010 and 2020. Early (<3 hours after HT) vs late initiation (≥3 hours after HT) of MCS was compared. Special focus was placed on peripheral vs central cannulation strategy. RESULTS: A total of 2376 HT were analyzed. 242 (10.2%) suffered severe PGD, 171 (70.7%) received early MCS and 71 (29.3%) late MCS. Baseline characteristics were similar. Patients with late MCS had higher inotropic scores and worse renal function at the moment of cannulation. Early MCS had longer cardiopulmonary bypass times and late MCS was associated with more peripheral vascular damage. No significant differences in survival were observed between early and late implant at 3 months (43.82% vs 48.26%; log-rank p = 0.59) or at 1 year (39.29% vs 45.24%, log-rank p = 0.49). Multivariate analysis did not show significant differences favoring early implant. Survival was higher in peripheral compared to central cannulation at 3 months (52.74% vs 32.42%, log-rank p = 0.001) and 1 year (48.56% vs 28.19%, log-rank p = 0.0007). In the multivariate analysis, peripheral cannulation remained a protective factor. CONCLUSIONS: Earlier MCS initiation for PGD was not superior, compared to a more conservative approach with deferred initiation. Peripheral compared to central cannulation showed superior 3-month and 1-year survival rates.

Intraoperative Red Blood Cell Transfusion and Primary Graft Dysfunction After Lung Transplantation.

BACKGROUND: In this international, multicenter study of patients undergoing lung transplantation (LT), we explored the association between the amount of intraoperative packed red blood cell (PRBC) transfusion and occurrence of primary graft dysfunction (PGD) and associated outcomes. METHODS: The Extracorporeal Life Support in LT Registry includes data on LT recipients from 9 high-volume (>40 transplants/y) transplant centers (2 from Europe, 7 from the United States). Adult patients who underwent bilateral orthotopic lung transplant from January 2016 to January 2020 were included. The primary outcome of interest was the occurrence of grade 3 PGD in the first 72 h after LT. RESULTS: We included 729 patients who underwent bilateral orthotopic lung transplant between January 2016 and November 2020. LT recipient population tertiles based on the amount of intraoperative PRBC transfusion (0, 1-4, and >4 units) were significantly different in terms of diagnosis, age, gender, body mass index, mean pulmonary artery pressure, lung allocation score, hemoglobin, prior chest surgery, preoperative hospitalization, and extracorporeal membrane oxygenation requirement. Inverse probability treatment weighting logistic regression showed that intraoperative PRBC transfusion of >4 units was significantly ( P < 0.001) associated with grade 3 PGD within 72 h (odds ratio [95% confidence interval], 2.2 [1.6-3.1]). Inverse probability treatment weighting analysis excluding patients with extracorporeal membrane oxygenation support produced similar findings (odds ratio [95% confidence interval], 2.4 [1.7-3.4], P < 0.001). CONCLUSIONS: In this multicenter, international registry study of LT patients, intraoperative transfusion of >4 units of PRBCs was associated with an increased risk of grade 3 PGD within 72 h. Efforts to improve post-LT outcomes should include perioperative blood conservation measures.

Primary Graft Dysfunction Is Associated With Development of Early Cardiac Allograft Vasculopathy, but Not Other Immune-mediated Complications, After Heart Transplantation.

BACKGROUND: We investigated associations between primary graft dysfunction (PGD) and development of acute cellular rejection (ACR), de novo donor-specific antibodies (DSAs), and cardiac allograft vasculopathy (CAV) after heart transplantation (HT). METHODS: A total of 381 consecutive adult HT patients from January 2015 to July 2020 at a single center were retrospectively analyzed. The primary outcome was incidence of treated ACR (International Society for Heart and Lung Transplantation grade 2R or 3R) and de novo DSA (mean fluorescence intensity >500) within 1 y post-HT. Secondary outcomes included median gene expression profiling score and donor-derived cell-free DNA level within 1 y and incidence of cardiac allograft vasculopathy (CAV) within 3 y post-HT. RESULTS: When adjusted for death as a competing risk, the estimated cumulative incidence of ACR (PGD 0.13 versus no PGD 0.21; P = 0.28), median gene expression profiling score (30 [interquartile range, 25-32] versus 30 [interquartile range, 25-33]; P = 0.34), and median donor-derived cell-free DNA levels was similar in patients with and without PGD. After adjusting for death as a competing risk, estimated cumulative incidence of de novo DSA within 1 y post-HT in patients with PGD was similar to those without PGD (0.29 versus 0.26; P = 0.10) with a similar DSA profile based on HLA loci. There was increased incidence of CAV in patients with PGD compared with patients without PGD (52.6% versus 24.8%; P = 0.01) within the first 3 y post-HT. CONCLUSIONS: During the first year after HT, patients with PGD had a similar incidence of ACR and development of de novo DSA, but a higher incidence of CAV when compared with patients without PGD.

Impact of pre-lung transplant statin use on the development of primary graft dysfunction.

BACKGROUND: Primary graft dysfunction (PGD) is a common occurrence following lung transplantation and contributes to short- and long-term morbidity and mortality. Current management strategies are limited, and robust data to support their use is lacking. Preventative strategies attenuating the recipient's inflammatory state suggest statin therapy may decrease the incidence and severity of PGD. This study aims to evaluate the impact of pre-transplant statin use on the incidence and severity of PGD following lung transplantation. METHODS: A retrospective cohort study was performed evaluating all patients undergoing bilateral lung transplantation from September 2012 to December 2019. The primary outcome was the incidence of PGD by grade, defined as the highest grade of PGD experienced in the first 72 h. Secondary outcomes included length of intensive care unit and hospital stays and mortality. RESULTS: Of the 357 patients included in the study, 107 received statin therapy prior to transplant (statin group) and 250 did not (no statin group). PGD occurred in 257 (72%) patients; in the entire cohort, 99 (28%) patients experienced PGD grade 1, 59 (17%) grade 2, and 99 (28%) grade 3. A significantly lower incidence of PGD was observed in the statin group (64.5% vs 75.2%, p = 0.039); however, the association did not remain significant on multinominal analysis for an overall incidence of any PGD (p = 0.275) or incidence of severe PGD (p = 0.240). Statin intensity was not associated with the development of PGD. CONCLUSIONS: Pre-transplant statin therapy did not appear to impact the development of PGD following lung transplantation. Future prospective studies should further evaluate the impact of statin intensity and duration on the incidence and severity of PGD.

Postoperative fibrinolytic resistance is associated with early allograft dysfunction in liver transplantation: A prospective observational study.

Perioperative dysfunction of the fibrinolytic system may play a role in adverse outcomes for liver transplant recipients. There is a paucity of data describing the potential impact of the postoperative fibrinolytic system on these outcomes. Our objective was to determine whether fibrinolysis resistance (FR), on postoperative day one (POD-1), was associated with early allograft dysfunction (EAD). We hypothesized that FR, quantified by tissue plasminogen activator thrombelastography, is associated with EAD. Tissue plasminogen activator thrombelastography was performed on POD-1 for 184 liver transplant recipients at a single institution. A tissue plasminogen activator thrombelastography clot lysis at 30 minutes of 0.0% was identified as the cutoff for FR on POD-1. EAD occurred in 32% of the total population. Fifty-nine percent (n=108) of patients were categorized with FR. The rate of EAD was 42% versus 17%, p <0.001 in patients with FR compared with those without, respectively. The association between FR and EAD risk was assessed using multivariable logistic regression after controlling for known risk factors. The odds of having EAD were 2.43 times (95% CI, 1.07-5.50, p =0.03) higher in recipients with FR [model C statistic: 0.76 (95% CI, 0.64-0.83, p <0.001]. An additive effect of receiving a donation after circulatory determination of death graft and having FR in the rate of EAD was observed. Finally, compared with those without FR, recipients with FR had significantly shorter graft survival time ( p =0.03). In conclusion, FR on POD-1 is associated with EAD and decreased graft survival time. Postoperative viscoelastic testing may provide clinical utility in identifying patients at risk for developing EAD, especially for recipients receiving donation after circulatory determination of death grafts.

Primary graft dysfunction grade 3 following pediatric lung transplantation is associated with chronic lung allograft dysfunction.

BACKGROUND: Severe primary graft dysfunction (PGD) is associated with the development of bronchiolitis obliterans syndrome (BOS), the most common form of chronic lung allograft dysfunction (CLAD), in adults. However, PGD associations with long-term outcomes following pediatric lung transplantation are unknown. We hypothesized that PGD grade 3 (PGD 3) at 48- or 72-hours would be associated with shorter CLAD-free survival following pediatric lung transplantation. METHODS: This was a single center retrospective cohort study of patients ≤ 21 years of age who underwent bilateral lung transplantation between 2005 and 2019 with ≥ 1 year of follow-up. PGD and CLAD were defined by published criteria. We evaluated the association of PGD 3 at 48- or 72-hours with CLAD-free survival by using time-to-event analyses. RESULTS: Fifty-one patients were included (median age 12.7 years; 51% female). The most common transplant indications were cystic fibrosis (29%) and pulmonary hypertension (20%). Seventeen patients (33%) had PGD 3 at either 48- or 72-hours. In unadjusted analysis, PGD 3 was associated with an increased risk of CLAD or mortality (HR 2.10, 95% CI 1.01-4.37, p=0.047). This association remained when adjusting individually for multiple potential confounders. There was evidence of effect modification by sex (interaction p = 0.055) with the association of PGD 3 and shorter CLAD-free survival driven predominantly by males (HR 4.73, 95% CI 1.44-15.6) rather than females (HR 1.23, 95% CI 0.47-3.20). CONCLUSIONS: PGD 3 at 48- or 72-hours following pediatric lung transplantation was associated with shorter CLAD-free survival. Sex may be a modifier of this association.

Severe and Moderate Primary Graft Dysfunction in Adult Heart Recipients.

INTRODUCTION: The aims of this study were to determine the incidence of severe and moderate primary graft dysfunction (PGD) in our center, to identify, retrospectively, donors' and recipients' risk factors for PGD development, and to evaluate the impact of PGD within 30 days after heart transplantation. METHODS: Donors' and recipients' medical records of 64 consecutive adult cardiac transplantations performed between January 2016 and June 2017 were reviewed. The International Society for Heart and Lung Transplantation (ISHLT) criteria were used to diagnose moderate and severe PGD. Associations of risk factors for combined moderate/severe PGD were assessed with appropriate statistical analyses. RESULTS: Sixty-four patients underwent heart transplantation in this period. Twelve recipients (18.7%) developed severe or moderate PGD. Development of PGD was associated with previous donor cardiopulmonary resuscitation and a history of prior heart surgery in the recipient (P=0.01 and P=0.02, respectively). The 30-day in hospital mortality was similar in both PGD and non-PGD patients. CONCLUSION: The use of the ISHLT criteria for PGD is important to identify potential risk factor. The development of PGD did not affect short-term survival in our study. More studies should be done to better understand the pathophysiology of PGD.

Donor hyperoxia is a novel risk factor for severe cardiac primary graft dysfunction.

BACKGROUND: Primary graft dysfunction (PGD) is a major cause of early mortality following heart transplant (HT). Donor risk factors for the development of PGD are incompletely characterized. Donor management goals (DMG) are predefined critical care endpoints used to optimize donors. We evaluated the relationship between DMGs as well as non-DMG parameters, and the development of PGD after HT. METHODS: A cohort of HT recipients from 2 transplant centers between 1/1/12 and 12/31/19 was linked to their respective donors in the United Network for Organ Sharing (UNOS) DMG Registry (n = 1,079). PGD was defined according to modified ISHLT criteria. Variables were subject to univariate and multivariable multinomial modeling with development of mild/moderate or severe PGD as the outcome variable. A second multicenter cohort of 4,010 donors from the DMG Registry was used for validation. RESULTS: Mild/moderate and severe PGD occurred in 15% and 6% of the cohort. Multivariable modeling revealed 6 variables independently associated with mild/moderate and 6 associated with severe PGD, respectively. Recipient use of amiodarone plus beta-blocker, recipient mechanical circulatory support, donor age, donor fraction of inspired oxygen (FiO2), and donor creatinine increased risk whereas predicted heart mass ratio decreased risk of severe PGD. We found that donor age and FiO2 ≥ 40% were associated with an increased risk of death within 90 days post-transplant in a multicenter cohort. CONCLUSIONS: Donor hyperoxia at heart recovery is a novel risk factor for severe primary graft dysfunction and early recipient death. These results suggest that excessive oxygen supplementation should be minimized during donor management.

Improved Outcomes in Severe Primary Graft Dysfunction After Heart Transplantation Following Donation After Circulatory Death Compared With Donation After Brain Death.

BACKGROUND: Primary graft dysfunction (PGD), the leading cause of early mortality after heart transplantation, is more common following donation after circulatory death (DCD) than donation after brain death (DBD). We conducted a single-center, retrospective cohort study to compare the incidence, severity and outcomes of patients experiencing PGD after DCD compared to DBD heart transplantation. METHODS AND RESULTS: Medical records were reviewed for all adult heart transplant recipients at our institution between March 2016 and December 2021. PGD was diagnosed within 24 hours after transplant according to modified International Society for Heart and Lung Transplant criteria. A total of 459 patients underwent isolated heart transplantation during the study period, 65 (14%) following DCD and 394 (86%) following DBD. The incidence of moderate or severe PGD in DCD and DBD recipients was 34% and 23%, respectively (P = 0.070). DCD recipients were more likely to experience severe biventricular PGD than DBD recipients (19% vs 7.4%; P = 0.004). Among patients with severe PGD, DCD recipients experienced shorter median (Q1, Q3) duration of post-transplant mechanical circulatory support (6 [4, 7] vs 9 [5, 14] days; P = 0.039), shorter median post-transplant hospital length of stay (17 [15, 29] vs 52 [26, 83] days; P = 0.004), and similar 60-day survival rates (100% [95% CI: 76.8%-100%] vs 80.0% [63.1%-91.6%]; P = 0.17) and overall survival (log-rank; P = 0.078) compared with DBD recipients. CONCLUSIONS: DCD heart transplant recipients were more likely to experience severe, biventricular PGD than DBD recipients. Despite this, DCD recipients with severe PGD spent fewer days on mechanical circulatory support and in the hospital than similar DBD patients. These findings suggest that patterns of graft dysfunction and recovery may differ between donor types, and they support the expansion of the heart-donor pool with DCD.

Increased severe primary graft dysfunction in left ventricular assist device patients following united network for organ sharing allocation changes.

INTRODUCTION: In 2018, the United Network for Organ Sharing (UNOS) implemented a new heart allocation system which prioritized patients on temporary support devices and left-ventricular assist device (LVAD) patients with complications. These changes have the potential to impact outcomes for patients bridged to transplant with an LVAD. METHODS: We performed a retrospective study of 168 adult heart transplant recipients at our center between 2016 and 2020 evaluating post-transplant outcomes before and after UNOS allocation changes. Donor and recipient data were retrieved from chart review and national databases. The primary outcome of this study was severe primary graft dysfunction (PGD) with secondary outcomes of 30-day readmission, 30-day mortality, and 1-year mortality. RESULTS: Incidence of severe PGD was similar in the overall cohort before and after the changes (10% vs. 15%, respectively, p = .3) and increased in the LVAD-bridged cohort (12% vs. 40%, respectively, p < .01). Secondary outcomes of readmission and survival were similar between all groups. Blood transfusion was predictive of severe PGD in multivariable modeling (OR 1.3 [1.11-1.59], p < .01).

Contemporary trends in PGD incidence, outcomes, and therapies.

BACKGROUND: We sought to describe trends in extracorporeal membrane oxygenation (ECMO) use, and define the impact on PGD incidence and early mortality in lung transplantation. METHODS: Patients were enrolled from August 2011 to June 2018 at 10 transplant centers in the multi-center Lung Transplant Outcomes Group prospective cohort study. PGD was defined as Grade 3 at 48 or 72 hours, based on the 2016 PGD ISHLT guidelines. Logistic regression and survival models were used to contrast between group effects for event (i.e., PGD and Death) and time-to-event (i.e., death, extubation, discharge) outcomes respectively. Both modeling frameworks accommodate the inclusion of potential confounders. RESULTS: A total of 1,528 subjects were enrolled with a 25.7% incidence of PGD. Annual PGD incidence (14.3%-38.2%, p = .0002), median LAS (38.0-47.7 p = .009) and the use of ECMO salvage for PGD (5.7%-20.9%, p = .007) increased over the course of the study. PGD was associated with increased 1 year mortality (OR 1.7 [95% C.I. 1.2, 2.3], p = .0001). Bridging strategies were not associated with increased mortality compared to non-bridged patients (p = .66); however, salvage ECMO for PGD was significantly associated with increased mortality (OR 1.9 [1.3, 2.7], p = .0007). Restricted mean survival time comparison at 1-year demonstrated 84.1 days lost in venoarterial salvaged recipients with PGD when compared to those without PGD (ratio 1.3 [1.1, 1.5]) and 27.2 days for venovenous with PGD (ratio 1.1 [1.0, 1.4]). CONCLUSIONS: PGD incidence continues to rise in modern transplant practice paralleled by significant increases in recipient severity of illness. Bridging strategies have increased but did not affect PGD incidence or mortality. PGD remains highly associated with mortality and is increasingly treated with salvage ECMO.

Recipient Comorbidities for Prediction of Primary Graft Dysfunction, Chronic Allograft Dysfunction and Survival After Lung Transplantation.

Since candidates with comorbidities are increasingly referred for lung transplantation, knowledge about comorbidities and their cumulative effect on outcomes is scarce. We retrospectively collected pretransplant comorbidities of all 513 adult recipients transplanted at our center between 1992-2019. Multiple logistic- and Cox regression models, adjusted for donor-, pre- and peri-operative variables, were used to detect independent risk factors for primary graft dysfunction grade-3 at 72 h (PGD3-T72), onset of chronic allograft dysfunction grade-3 (CLAD-3) and survival. An increasing comorbidity burden measured by Charleston-Deyo-Index was a multivariable risk for survival and PGD3-T72, but not for CLAD-3. Among comorbidities, congestive right heart failure or a mean pulmonary artery pressure >25 mmHg were independent risk factors for PGD3-T72 and survival, and a borderline risk for CLAD-3. Left heart failure, chronic atrial fibrillation, arterial hypertension, moderate liver disease, peptic ulcer disease, gastroesophageal reflux, diabetes with end organ damage, moderate to severe renal disease, osteoporosis, and diverticulosis were also independent risk factors for survival. For PGD3-T72, a BMI>30 kg/m2 was an additional independent risk. Epilepsy and a smoking history of the recipient of >20packyears are additional independent risk factors for CLAD-3. The comorbidity profile should therefore be closely considered for further clinical decision making in candidate selection.

Reduction of primary graft dysfunction using cytokine adsorption during organ preservation and after lung transplantation.

Despite improvements, lung transplantation remains hampered by both a scarcity of donor organs and by mortality following primary graft dysfunction (PGD). Since acute respiratory distress syndrome (ARDS) limits donor lungs utilization, we investigated cytokine adsorption as a means of treating ARDS donor lungs. We induced mild to moderate ARDS using lipopolysaccharide in 16 donor pigs. Lungs were then treated with or without cytokine adsorption during ex vivo lung perfusion (EVLP) and/or post-transplantation using extracorporeal hemoperfusion. The treatment significantly decreased cytokine levels during EVLP and decreased levels of immune cells post-transplantation. Histology demonstrated fewer signs of lung injury across both treatment periods and the incidence of PGD was significantly reduced among treated animals. Overall, cytokine adsorption was able to restore lung function and reduce PGD in lung transplantation. We suggest this treatment will increase the availability of donor lungs and increase the tolerability of donor lungs in the recipient.

Post-Transplant Extracorporeal Membrane Oxygenation for Severe Primary Graft Dysfunction to Support the Use of Marginal Donor Hearts.

Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18 years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7 days following OHT (range: 1-12 days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.