Lower Lung Allocation Score Research Articles

Lung transplant waitlist outcomes among ABO blood groups vary based on disease severity

Blood group O candidates have lower lung transplantation rates despite having the most common blood group. We postulated that waitlist outcomes among these candidates and those with other blood types vary with disease severity and lung allocation score (LAS). We performed a retrospective cohort study of 32,772 waitlist candidates using the United Network of Organ Sharing registry from May 2005 to 2020. After identifying an interaction between blood group and LAS, we evaluated the association between blood group and waitlist outcomes within LAS quartiles using unadjusted and adjusted competing risk models. In the lowest LAS quartile, blood group O had a 20% reduced transplantation rate (SHR: 0.80, 95%CI: 0.75-0.85) and higher waitlist death/removal (1.33, 95%CI: 1.15-1.55) compared with group A. Blood group AB had a 52% higher transplantation rate (SHR: 1.52, 95%CI: 1.34-1.73) in the lowest LAS quartile compared with group A. In the highest LAS quartile, there was no difference in transplantation rates between groups O and A. In contrast, group B had a 19% reduced transplantation rate (SHR, 0.81 95%CI: 0.73-0.89) and AB had a 28% reduced transplantation rate (SHR: 0.72, 95%CI: 0.61-0.86) in the highest LAS quartile. Additionally, groups B and AB had increased risk of waitlist death/removal in the highest LAS quartile compared with A (SHR: 1.27, 95%CI: 1.08-1.48; SHR: 1.31, 95%CI: 1.00-1.72). Waitlist outcomes among ABO blood groups vary depending on illness severity, which is represented by LAS. Blood group O has lower transplantation rates at low LAS while groups B and AB have lower transplantation rates at high LAS.

Trends in use and three-year outcomes of hepatitis C virus–viremic donor lung transplants for hepatitis C virus–seronegative recipients

ObjectiveThe feasibility and 6-month outcome safety of lung transplants (LTs) from hepatitis C virus (HCV)-viremic donors for HCV-seronegative recipients (R–) were established in 2019, but longer-term safety and uptake of this practice nationally remain unknown. MethodsWe identified HCV-seronegative LT recipients (R–) 2015-2020 using the Scientific Registry of Transplant Recipients. We classified donors as seronegative (D–) or viremic (D+). We used χ2 testing, rank-sum testing, and Cox regression to compare posttransplant outcomes between HCV D+/R– and D–/R– LT recipients. ResultsHCV D+/R– LT increased from 2 to 97/year; centers performing HCV D+/R– LT increased from 1 to 25. HCV D+/R– versus HCV D–/R– LT recipients had more obstructive disease (35.7% vs 23.3%, P < .001), lower lung allocation score (36.5 vs 41.1, P < .001), and longer waitlist time (P = .002). HCV D+/R– LT had similar risk of acute rejection (adjusted odds ratio [aOR], 0.87; P = .58), extracorporeal membranous oxygenation (aOR, 1.94; P = .10), and tracheostomy (aOR, 0.42; P = .16); similar median hospital stay (P = .07); and lower risk of ventilator > 48 hours (aOR, 0.68; P = .006). Adjusting for donor, recipient, and transplant characteristics, risk of all-cause graft failure and mortality were similar at 30 days, 1 year, and 3 years for HCV D+/R– versus HCV D–/R– LT (all P > .1), as well as for high- (≥20/year) versus low-volume LT centers and high- (≥5/year) versus low-volume HCV D+/R– LT centers (all P > .5). ConclusionsHCV D+/R– and HCV D–/R– LT have similar outcomes at 3 years posttransplant. These results underscore the safety of HCV D+/R– LT and the potential benefit of expanding this practice further.

Trends in marginal lung allograft survival: Advanced‐age donors improve

Although lung demand continues to outpace supply, 75% of potential donor lungs are discarded without being transplanted in the United States. To identify the discarded cohorts best suited to alleviate the lung shortage and reduce waitlist mortality, we explored changes in survival over time for five marginal donor definitions: age>60 years, smoking history>20 pack-years, PaO2 /FiO2 <300mmHg, purulent bronchoscopic secretions, and chest radiograph infiltrates. Our retrospective cohort study separated 27803 lung recipients in the UNOS Database into three 5-year eras by transplant date: 2005-2009, 2010-2014, and 2015-2019. Multivariable Cox proportional hazards regression and Kaplan-Meier analysis with log-rank test were used to compare survival across the eras. Three definitions-low PaO2 /FiO2 , purulent bronchoscopic secretions, and abnormal chest radiographs-did not bear out as truly marginal, demonstrating lack of significantly elevated risk. Advanced donor age demonstrated considerable survival improvement (HR (95% CI): 1.47 (1.26-1.72) in 2005-2009 down to 1.14 (.97-1.35) for 2015-2019), with protective factors being recipients <60 years, moderate recipient BMI, and low Lung Allocation Score (LAS). Donors with smoking history failed to demonstrate any significant improvement (HR (95% CI): 1.09 (1.01-1.17) in 2005-2009 increasing to 1.22 (1.08-1.38) in 2015-2019). Advanced donor age, previously the most significant risk factor, has improved to near-benchmark levels, demonstrating the possibility for matching older donors to healthier non-elderly recipients in selected circumstances. Low PaO2 /FiO2 , bronchoscopic secretions, and abnormal radiographs demonstrated survival on par with standard donors. Significant donor smoking history, a moderate risk factor, has failed to improve.

Safety of Single Lung Transplantation Post Donation Service Area-Specific Organ Distribution

<h3>Purpose</h3> The organ allocation change in 2017 removed donation service area (DSA) and was aimed at prioritizing donor lungs for patients with a higher lung allocation score (LAS). Given that patients who are listed for singe lung transplantation alone have, on average, a lower LAS, we hypothesized that this allocation change would negatively impact those listed for a single lung transplant. <h3>Methods</h3> A UNOS database analysis was performed for patients listed for an isolated single lung transplant. Data was queried 2.5 years prior to and after the allocation change with recipients from 1/2015-6/2017 deemed as pre-allocation and recipients from 1/2018-6/2020 as post-allocation. The primary outcome was waitlist time and post-transplant survival. <h3>Results</h3> 1,435 patients were identified: 753 pre-allocation patients and 682 post-allocation patients. In the post-allocation era, patients were less likely to be listed for single lung transplant alone (15% vs 12%, P<0.001). Post-allocation recipients were older (P<0.001), more likely to be hospitalized (P=0.033), and had a nominally higher LAS score at transplant (P=0.002). While donor distance was greater (P<0.001) in the post-allocation era, demographics were similar and PaO2/FiO2 was higher in post-allocation era donors (P<0.001). The change in allocation did not impact waitlist times (42 (16-114) vs 45 (13-122), P=0.898). Survival (87% vs 87%, P=0.889) and freedom from graft failure (P=0.964) at 1 year was similar in both groups. Patients in the post-allocation group were less likely to have severe primary graft dysfunction at 72h (24% vs 31%, P=0.043). <h3>Conclusion</h3> After removal of the DSA, there was a lower prevalence of listing for only single lung transplantation. However, waitlist times, available donor lungs, and post-transplant outcomes were similar, or potentially improved, after the allocation change. Given this, single lung transplantation appears to be a reasonable strategy for appropriate patients requiring lung transplantation.

Natural History of Pleural Complications After Lung Transplantation

Despite advances in lung transplantation, 5-year survival remains at 56%. Although the focus has been on chronic lung allograft dysfunction and infection, pleural complications in some may contribute to adverse outcomes. Therefore, we determined (1) the prevalence of, and risk factors for, pleural complications after lung transplantation and (2) their association with allograft function and mortality. From 2006 to 2017, 1039 adults underwent primary lung transplantation at Cleveland Clinic in Cleveland, Ohio. Multivariable analyses were performed in the multiphase mixed longitudinal and hazard function domains to identify risk factors associated with allograft function and survival. A total of 468 patients (45%) had pleural complications, including pleural effusion in 271 (26%), pneumothorax in 152 (15%), hemothorax in 128 (12%), empyema in 47 (5%), and chylothorax in 9 (1%). Risk factors for pleural complications within the first 3 months included higher recipient-to-donor weight ratio, lower recipient albumin, and recipient-to-donor race mismatch; risk factors extending beyond 3 months included older age, hypertension, smoking history, lower lung allocation score, and donor death from anoxia. Cardiopulmonary bypass and previous thoracic interventions were not risk factors in patients with pleural effusions who were treated with thoracentesis only, and forced expiratory volume in 1 second improved after drainage; however, repeat percutaneous or surgical interventions did not impart a similar benefit. Pleural complications were associated with worse survival. Pleural complications are common after lung transplantation and are associated with worse allograft function and survival. These complications are likely secondary to other underlying clinical problems. Malnourishment and size mismatch are modifiable risk factors.

Low Lung Allocation Score Predicts Poor Waitlist Outcomes for Patients on Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplantation

Extracorporeal membrane oxygenation (ECMO) is increasingly used as a bridge to lung transplantation in the United States. However, ECMO is not separately distinguished from assisted ventilation in the lung allocation score (LAS), and there is a wide range in LAS for candidates on ECMO. In this study, we examined the relationship between LAS and waitlist outcomes in patients on ECMO. This is a retrospective cohort study of lung transplant candidates on ECMO from 5/4/05 until 12/31/18 using data from the United Network for Organ Sharing. We modeled LAS as a continuous variable and as high LAS (top 50% of scores) versus low LAS (bottom 50% of scores). The LAS used was the first one calculated within two days of ECMO initiation. The primary outcomes were transplantation and a composite of death or removal from the waitlist for clinical deterioration. The secondary outcome was post-transplant survival. We used an adjusted competing risk regression model to compare waitlist outcomes and an adjusted Cox regression model to examine post-transplant survival. In total, 954 patients were bridged on ECMO with 594 (62.2%) receiving transplants and 329 (34.4%) dying or being removed from the waitlist. The mean LAS in the low and high LAS cohorts were 78.2 (SD ± 15.6) and 90.7 (SD ± 1.36), respectively. The low LAS cohort had decreased chance of transplant (SHR 0.80, 95% CI 0.67-0.96, p=0.02) and increased risk of death or waitlist removal (SHR 1.34, 95% CI 1.05-1.70, p=0.02) (Figure 1). For every 10 point increase in LAS, the risk of transplant increased by 14% (p<0.01) and the risk of death decreased by 11% (p=0.02). There was no difference in post-transplant survival time between the low and high LAS cohorts (HR 0.82, 95% CI 0.60-1.12, p=0.21). Among patients on ECMO as bridge to transplant, a lower LAS was associated with decreased risk of transplant and increased risk of death or clinical worsening without any difference in post-transplant survival.

Perioperative Characteristics Associated with Transfusion-Free Lung Transplantation

Blood transfusion during lung transplantation (LT) surgery is common. There is little evidence to identify potential candidates for transfusion-free LT surgery. We describe patient and procedural characteristics of LT patients in the era of ECMO and identify predictors of a successful transfusion-free surgery. In this single-center, retrospective analysis, all adult patients undergoing LT between 9/5/2016-2/28/2019 were included. Patients were grouped based on perioperative transfusions received over 72 hours; no products, 1-4 units PRBC, or >4 U PRBC. Donor and recipient characteristics were compared between the three groups by univariate and multivariate analysis. 241 LTs were performed over the time period; 235 were included and 6 multiorgan transplants were excluded. 41 patients (17.4%) received no blood transfusions, while 82.6% (N=194) received transfusions. Most patients (43%, N=101) received >4 U of product. Recipients requiring blood transfusions had associated prolonged ventilation, length of stay, PGD and worsened 1-year graft survival compared to those who did not. Donor characteristics were similar between groups (Fig 1). Older males with obstructive or restrictive lung disease undergoing an off-pump, single lung LT, with lower Lung Allocation Score (LAS), higher starting hemoglobin, shorter ischemic time and case length were associated with a transfusion free LT (Fig 1). In a multivariate analysis, positive predictors for transfusion-free LT included single LT (OR=6.27, p=0.0004), and higher preoperative hemoglobin (OR=1.35 per point, p.0231). Negative predictors included female sex (F v M, OR=0.13, p=0.0005) and higher LAS (OR=0.88 per point, p=0.0002). Predictors of transfusion free LT surgery include older males undergoing a single, off-pump LT procedure, with lower LAS scores and higher starting hemoglobin. This may guide decision making in exploring candidacy for transfusion-free LT or blood refusal patients in the era of ECMO.

The lung allocation score could evaluate allocation systems in countries that do not use the score.

BackgroundEvaluating allocation system effects on lung transplantation and determining systemic flaws is difficult. The purpose of this study was to assess the Korean urgency-based lung allocation system using the lung allocation score.MethodsWe reviewed transplantation patients retrospectively. Candidates were classified into groups based on urgency. Status 0 designated hospitalized patients requiring ventilator and/or extracorporeal life support. The lung allocation score was calculated based on the recipient’s condition at transplantation.ResultsOne-hundred-twenty-three Status 0, 1, and 2/3 patients (40, 71, and 12, respectively) were enrolled. The median waiting time was 68 days. Nineteen Status 0 patients who received lung transplants deteriorated from non-Status 0 (median, 64 days). The lung allocation score showed a bimodal distribution (peaks around 45 and 90, corresponding with non-Status 0 and Status 0, respectively). Status 0 and the lung allocation score were independent risk factors for poor survival after adjustment for confounders (Status 0, hazard ratio, 2.788, p = 0.001; lung allocation score, hazard ratio, 1.025, p < 0.001). The lung allocation score cut-off for survival was 44. On dividing the non-Status 0 patients into 2 groups using the cut-off values and regrouping into Status 0, non-Status 0 with high lung allocation score (> 44), and non-Status 0 with low lung allocation score (< 44), we observed that non-Status 0 with high lung allocation score patients had better survival than Status 0 patients (p = 0.020) and poorer survival than non-Status 0 with low lung allocation score patients (p = 0.018).ConclusionsThe LAS demonstrated the characteristics of LTx recipients in Korea and the Korean allocation system needs to be revised to reduce the number of patients receiving LTx in Status 0. The LAS system could be used as a tool to evaluate lung allocation systems in countries that do not use the LAS system.

Lung transplant candidates with idiopathic pulmonary fibrosis and long-term pirfenidone therapy: Treatment feasibility influences waitlist survival.

Idiopathic pulmonary fibrosis (IPF) is a chronically progressive lung disease with exceptionally poor prognosis. While lung transplantation (LTx) is considered the last-resort therapeutic option, dismal waitlist mortality still hampers the salvage of patients with IPF. Pirfenidone, originally designed for IPF treatment, has increasingly been utilized. This study aimed to evaluate whether Pirfenidone could influence outcomes of patients with IPF on the Japanese LTx waitlist. This retrospective single-center cohort study included 25 consecutive patients with IPF who were registered as LTx candidates at our institution between July 1999 and August 2016. Patients with a history of pretransplant Pirfenidone therapy (Pirfenidone group) were compared with those with no history (non-Pirfenidone group). In total, 6 (24%) patients received Pirfenidone as pretransplant therapy for 45.2 (range, 18.6-66.8) months. During the treatment period, the Pirfenidone group achieved a significant reduction in the decline rate of the forced vital capacity (-6.2% vs. -0.3%, p = 0.04) and a lower lung allocation score (31 vs. 41, p = 0.013) compared with the non-Pirfenidone group. The Pirfenidone group exhibited 100% waitlist survival three years after registration that was comparable to other indications, and 66% of the patients were still alive at the time of organ availability. No patient in the Pirfenidone group developed Pirfenidone-related surgical complications postoperatively. Patients with IPF successfully managed with long-term Pirfenidone therapy achieved favorable outcomes after LTx registration, comparable to other patients with LTx indications. The tolerability to antifibrotic therapy can be a predictor of waitlist survival.

Multiple listing in lung transplant candidates: A cohort study.

Lung transplant candidates can be waitlisted at more than one transplant center, a practice known as multiple listing. The factors associated with multiple listing and whether multiple listing modifies waitlist mortality or likelihood of lung transplant is unknown. US lung transplant waitlist candidates were identified as either single or multiple listed using data from the Scientific Registry of Transplant Recipients. Characteristics of single and multiple listed candidates were compared and multivariable logistic regression was used to estimate associations with multiple listing. Multiple listed candidates were matched to single listed candidates using a combination of exact and propensity score matching methods. Cox proportional hazard models were used to estimate the relationship of multiple listing on waitlist mortality and receiving a transplant. Multiple listing occurred in 2.3% of lung transplant waitlist candidates. Younger age, female gender, white race, short stature, high antibody sensitization, college or postcollege education, lower lung allocation score, and a cystic fibrosis diagnosis were independently associated with multiple listing. Multiple listing was associated with an increased likelihood of lung transplant (adjusted hazard ratio [aHR] 2.74, 95% CI 2.37 to 3.16) but was not associated with waitlist mortality (aHR 0.99, 95% CI 0.68 to 1.44).

White donor, younger donor and double lung transplant are associated with better survival in sarcoidosis patients

Sarcoidosis commonly affects the lung. Lung transplantation (LT) is required when there is a severe and refractory involvement. We compared post-transplant survival rates of sarcoidosis patients with chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). We also explored whether the race and age of the donor, and double lung transplant have any effect on the survival in the post transplant setting. We analyzed 9,727 adult patients with sarcoidosis, COPD, and IPF who underwent LT worldwide between 2005–2015 based on United Network for Organ Sharing (UNOS) database. Survival rates were compared with Kaplan-Meier, and risk factors were investigated by Cox-regression analysis. 469 (5%) were transplanted because of sarcoidosis, 3,688 (38%) for COPD and 5,570 (57%) for IPF. Unadjusted survival analysis showed a better post-transplant survival rate for patients with sarcoidosis (p < 0.001, Log-rank test). In Cox-regression analysis, double lung transplant and white race of the lung donor showed to have a significant survival advantage. Since double lung transplant, those who are younger and have lower Lung Allocation Score (LAS) at the time of transplant have a survival advantage, we suggest double lung transplant as the procedure of choice, especially in younger sarcoidosis subjects and with lower LAS scores.

Long-Term Survival in Bilateral Lung Transplantation for Scleroderma-Related Lung Disease

Lung disease is the leading cause of morbidity and death in scleroderma patients, but scleroderma is often considered a contraindication to lung transplantation because of concerns for worse outcomes. We evaluated whether 5-year survival in scleroderma patients after lung transplantation differed from other patients with restrictive lung disease. This was a single-center, retrospective cohort study of all patients undergoing bilateral lung transplantation for scleroderma-related pulmonary disease between January 2006 and December 2014. This cohort was compared with patients undergoing bilateral lung transplantation for nonscleroderma group D restrictive disease. Primary outcomes reported were 1-year and 5-year survival. Diagnoses were identified by United Network of Organ Sharing listing and were confirmed by clinical examination and prelisting workup. We compared 26 patients who underwent BLT for scleroderma and 155 patients who underwent BLT for group D restrictive disease. Overall, the nonscleroderma cohort was younger, with lower lung allocation score but no difference in functional status. Donor characteristics were not different between the cohorts. Survival at 1 year was not different (73.1% vs 80.0%, p= 0.323). Long-term survival at 5 years was also not significantly different (65.4% vs 66.5%, p= 0.608). Multivariate Cox proportional hazards analysis found no differences in survival between scleroderma and nonscleroderma group D restrictive disease (hazard ratio, 2.19; p= 0.122). Despite being at high risk for extrapulmonary complications, patients undergoing bilateral lung transplantation for scleroderma have similar 1-year and 5-year survival as those with restrictive lung disease. Transplantation is a reasonable treatment option for a carefully selected population of candidates.

Interaction of pre-transplant recipient characteristics and renal function in lung transplant survival

There has been little investigation into the potential interaction of recipient characteristics with the association of pre-transplant renal functions and survival after lung transplantation. In this study we tested the hypothesis that association of pre-transplant renal function and post-transplant mortality varies among recipient subgroups. We queried the United Network for Organ Sharing (UNOS) database for adult patients (≥18 years of age) undergoing lung transplantation between May 2005 and March 2015. The study population (n = 15,540) was split into 3 groups (90 to 150, 60 to 89.9 and 30 to 59.9 ml/min/1.73 m2) based on the estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration equation) at the time of listing. We utilized multivariable inverse probability weighted Cox proportional hazard models to compare the association of glomerular filtration rate (GFR) groups with mortality among recipient subgroups. Overall, there was an independent and graded inverse association between the estimated GFR (eGFR) and mortality, with the hazard of mortality significantly rising with listing eGFR <60 ml/min/1.73 m2. The association between low eGFR and mortality was more consistent and stronger for older (>45 years), non-African-American and non-diabetic patients as well as those with low lung allocation score (LAS <40). Among the diagnosis groups, patients with vascular diseases had the strongest association between low eGFR and poor survival. Sensitivity analyses conducted using an alternate equation to estimate the GFR (Modification of Diet in Renal Disease) supported these associations. Prognostic significance of pre-transplant renal functions varies significantly among recipient subgroups. It may be appropriate to develop a customized approach toward assessing and interpreting renal function to determine transplant candidacy.

Lung Transplantation in Patients with High Lung Allocation Scores in the US: Evidence for the Need to Evaluate Score Specific Outcomes.

Objective. The lung allocation score (LAS) resulted in a lung transplantation (LT) selection process guided by clinical acuity. We sought to evaluate the relationship between LAS and outcomes. Methods. We analyzed Scientific Registry of Transplant Recipient (SRTR) data pertaining to recipients between 2005 and 2012. We stratified them into quartiles based on LAS and compared survival and predictors of mortality. Results. We identified 10,304 consecutive patients, comprising 2,576 in each LAS quartile (quartile 1 (26.3–35.5), quartile 2 (35.6–39.3), quartile 3 (39.4–48.6), and quartile 4 (48.7–95.7)). Survival after 30 days (96.9% versus 96.8% versus 96.0% versus 94.8%), 90 days (94.6% versus 93.7% versus 93.3% versus 90.9%), 1 year (87.2% versus 85.0% versus 84.8% versus 80.9%), and 5 years (55.4% versus 54.5% versus 52.5% versus 48.8%) was higher in the lower groups. There was a significantly higher 5-year mortality in the highest LAS group (HR 1.13, p = 0.030, HR 1.17, p = 0.01, and HR 1.17, p = 0.02) comparing quartiles 2, 3, and 4, respectively, to quartile 1. Conclusion. Overall, outcomes in recipients with higher LAS are worse than those in patients with lower LAS. These data should inform more individualized evidence-based discussion during pretransplant counseling.

Lung transplantation in idiopathic pulmonary fibrosis: a systematic review of the literature.

BackgroundIdiopathic pulmonary fibrosis (IPF) is a distinct form of interstitial pneumonia with unknown origin and poor prognosis. Current pharmacologic treatments are limited and lung transplantation is a viable option for appropriate patients. The aim of this review was to summarize lung transplantation survival in IPF patients overall, between single (SLT) vs. bilateral lung transplantation (BLT), pre- and post Lung Allocation Score (LAS), and summarize wait-list survival.MethodsA systematic review of English-language studies published in Medline or Embase between 1990 and 2013 was performed. Eligible studies were those of observational design reporting survival post-lung transplantation or while on the wait list among IPF patients.ResultsMedian survival post-transplantation among IPF patients is estimated at 4.5 years. From ISHLT and OPTN data, one year survival ranged from 75% - 81%; 3-year: 59% - 64%; and 5-year: 47% - 53%. Post-transplant survival is lower for IPF vs. other underlying pre-transplant diagnoses. The proportion of IPF patients receiving BLT has steadily increased over the last decade and a half. Unadjusted analyses suggest improved long-term survival for BLT vs. SLT; after adjustment for patient characteristics, the differences tend to disappear. IPF patients account for the largest proportion of patients on the wait list and while wait list time has decreased, the number of transplants for IPF patients has increased over time. OPTN data show that wait list mortality is higher for IPF patients vs. other diagnoses. The proportion of IPF patients who died while awaiting transplantation ranged from 14% to 67%. While later transplant year was associated with increased survival, no significant differences were noted pre vs. post LAS implementation; however a high LAS vs low LAS was associated with decreased one-year survival.ConclusionsIPF accounts for the largest proportion of patients awaiting lung transplants, and IPF is associated with higher wait-list and post-transplant mortality vs. other diagnoses. Improved BLT vs. SLT survival may be the result of selection bias. Survival pre- vs. post LAS appears to be similar except for IPF patients with high LAS, who have lower survival compared to pre-LAS. Data on post-transplant morbidity outcomes are sparse.

Double Lung Transplants Have Significantly Improved Survival Compared With Single Lung Transplants in High Lung Allocation Score Patients

Historically, double lung transplantation survival rates are higher than those of single lung transplantation, but in critically ill patients a single lung transplant, with less associated operative morbidity, could afford a better outcome. This article evaluates how survival is affected in patients who have a high lung allocation score (LAS) and receive a single versus a double lung transplant. The UNOS Thoracic Transplant Database for lung transplants from January 2005 to June 2012 was used for analysis. Propensity matching was used to minimize differences between the high and low LAS groups and between single and double lung transplants in the high LAS group. Within this database, there were 8,778 patients, of whom 8,050 had an LAS less than 75 and 728 had an LAS greater than or equal to 75. Kaplan-Meier survival curves stratified by high and low LAS, and by single versus double lung transplants, showed a marked decrease in survival (p<0.001) in those with a high LAS who received a single lung transplant when compared with those with a high LAS who received a double lung transplant. This was a much greater difference in survival than was present in the low LAS patient population. Despite a higher operative morbidity, patients who had a high LAS did substantially better in terms of survival if two lungs were transplanted rather than only one, with a larger difference in survival than for patients with a lower LAS.

Single-lung transplantation can be performed with acceptable outcomes using selected donors with heavy smoking history

We attempt to determine if adult, single-lung transplantation could be performed with acceptable results in heavy-smoking donors (HSDs; > 20 pack-years). The United Network of Organ Sharing database was examined for adult single-lung transplantation from 2005 to 2011. Of the 3,704 single-lung transplantations, 498 (13.4%) were from HSDs. The 2 groups were similar in recipient age (60.6 vs. 60.7 years, p = 0.20), male gender (61.3% vs. 59.8%, p = 0.54), ischemic time (4.1 vs. 4.2 hours, p = 0.11), and pre-transplant forced expiratory volume in 1 second (FEV1; 41.1% vs. 40.0% predicted). Recipients of HSDs had lower lung allocation score (39.7 vs. 38.0, p = 0.02), less human leukocyte antigen mismatches (4.6 vs. 4.5, p = 0.01), and higher class I panel reactive antibody (2.9% vs. 3.8%, p < 0.001). HSDs were older (33.0 vs. 41.3 years, p < 0.001) and less likely male (62.5 vs. 56.0%, p = 0.01). Recipients with HSDs had longer length of stay (20.5 vs. 23.0 days, p < 0.001) and lower peak FEV1 after single-lung transplantation (80.1% vs. 73.4%, p < 0.001). Freedom from bronchiolitis obliterans syndrome (p = 0.64), post-single-lung transplantation decrement in FEV1 (p = 0.07), and median survival (1,516 vs. 1,488 days, p = 0.10) were similar. Multivariable analysis found receiving lungs from actively smoking HSDs was associated with mortality (hazard ratio [HR], 1.23, 95% confidence interval [CI], 1.05-1.45; p = 0.01). Use of HSDs who were not actively smoking was not associated with mortality (HR, 0.84; 95% CI, 0.59-1.19; p = 0.33). Mortality was associated with recipient age, longer ischemic time, race mismatch, class I panel reactive antibody > 10%, mechanical ventilation, and extracorporeal membrane oxygenation as a bridge to transplantation. Although single-lung transplantation with actively smoking HSDs results in worse results, outcomes are acceptable and should continue to be considered.

Single Lung Transplantation Using Donors with Heavy Smoking History Can Be Safely Performed

Purpose We attempt to determine if adult, single lung transplantation (SLT) could be safely performed in heavy smoking donors (HSD). Methods and Materials The UNOS database was examined from 2005-2011 to determine if using HSD (>20 pack years) provided mortality risk. Results Of 3,704 SLT, 498 (13.4%) were from HSD. The two were similar in recipient age (60.6 vs 60.7 years, p=0.20), male gender (61.3 vs 59.8%, p=0.54), and ischemic time (4.1 vs 4.2 hrs, p=0.11). Recipients of HSD had lower lung allocation score (39.7 vs 38.0, p=0.02), less HLA mismatches (4.6 vs 4.5, p=0.01), and higher Class I PRA (2.9 vs 3.8%, p Conclusions Single lung transplantation can be safely performed using HSD. Cox Proportional Hazards Regression Analysis HR 95%CI p Heavy Smoking Donor 1.15 0.99-1.34 0.07 Female Donor 1.03 0.91-1.16 0.66 Donor Age 19-39 Ref Ref Ref Donor Age ≤18 1.00 0.85-1.17 0.98 Donor Age 40-49 1.06 0.91-1.23 0.45 Donor Age 50-59 1.06 0.90-1.26 0.47 Donor Age ≥60 1.26 0.98-1.62 0.07 Ischemic Time Ref Ref Ref Ischemic Time 6-8 hrs 0.91 0.72-1.34 0.07 Ischemic Time 8-10 hrs 2.15 1.22-3.81 0.01 Ischemic Time >10 hrs 0.63 0.20-2.00 0.63 Recipient Female Gender 0.85 0.76-0.96 0.01 White Ref Ref Ref Black 0.98 0.55-1.73 0.93 Hispanic 1.12 0.62-2.00 0.72 HLA Mismatches ≥4 1.00 0.89-1.13 0.72 Recipient Age 1.01 1.00-1.01 0.04 Sex Mismatch 1.04 0.92-1.17 0.41 Retransplant 1.04 0.89-1.21 0.66 Class I PRA >10% 1.23 1.06-1.42 0.01 Pre-op Ventilator 2.63 2.07-3.34 Pre-op ECMO 4.28 2.07-3.34

High Lung Allocation Score Is Associated With Increased Morbidity and Mortality Following Transplantation

The lung allocation score (LAS) was initiated in May 2005 to allocate lungs based on medical urgency and posttransplant survival. The purpose of this study was to determine if there is an association between an elevated LAS at the time of transplantation and increased postoperative morbidity and mortality. The United Network for Organ Sharing provided de-identified patient-level data. Analysis included lung transplant recipients aged >or= 12 years who received transplants between April 5, 2006, and December 31, 2007 (n = 3,836). Recipients were stratified into three groups: LAS < 50 (n = 3,161, 83.87%), LAS 50 to 75 (n = 411, 10.9%), and LAS >or= 75 (n = 197, 5.23%), referred to as low LAS (LLAS), intermediate LAS (ILAS), and high LAS (HLAS), respectively. The primary outcome was posttransplant graft survival at 1 year. Secondary outcomes included length of stay and in-hospital complications. HLAS recipients had significantly worse actuarial survival at 90 days and 1 year compared with LLAS recipients. When transplant recipients were stratified by disease etiology, a trend of decreased survival with elevated LAS was observed across all major causes of lung transplant. HLAS recipients were more likely to require dialysis or to have infections compared with LLAS recipients (P < .001). In addition, length of stay was higher in the HLAS group when compared with the LLAS group (P < .001). HLAS is associated with decreased survival and increased complications during the transplant hospitalization. Whereas the LAS has improved organ allocation through decreased waiting list deaths and waiting list times, lower survival and higher morbidity among HLAS recipients suggests that continued review of LAS scoring is needed to ensure optimal long-term transplant survival.

The Lung Allocation Score and Survival in Lung Transplant Candidates with Chronic Obstructive Pulmonary Disease

The Lung Allocation Score (LAS), devised to prioritize candidates awaiting lung transplantation (LTX), is calculated using the predicted duration of survival on the wait list while also considering the recipient's likelihood of post-transplant survival. This score is generated based, in part, on the severity of the candidate's comorbid illnesses. The actual relationship between the LAS and survival is unknown. The current study was performed to evaluate the relationship between the LAS and both wait-list survival and post-transplant survival in candidates with COPD. The study was a retrospective analysis of 41 LTX candidates with chronic obstructive pulmonary disease (COPD) as well as a cohort of 17 candidates who survived to receive a graft. The study was conducted at a university hospital transplant center. Thirty-six of 41 candidates survived to transplant. The LAS of these survivors was 32.62 +/- 1.06 and was significantly lower than the score of 34.45 +/- 1.19 of the nonsurvivors (P < 0.01). The LAS also exhibited a negative association with survival to transplant (P < 0.05, beta = -1.39). A cohort of 17 LTX recipients was chosen for post-transplant analysis in which 13 survived at least 1 year. In this cohort the LAS did not exhibit significant association with 1-year post-transplant survival (P = 0.58, beta = -0.25). As might be anticipated by virtue of its calculation being based in part on the existence and severity of comorbid conditions, a lower LAS was associated with improved survival to transplantation in LTX candidates with COPD. However, the pretransplant calculation of the LAS was not associated with actual post-transplant survival.