Urgent listing exceptions and outcomes in pediatric heart transplantation: Comparison to standard criteria patients.

United Network for Organ Sharing (UNOS) policy enables listing exceptions to avoid penalizing patients with waitlist mortality not captured by standard criteria. Outcomes among patients listed by exception have not been analyzed. We performed a retrospective analysis of pediatric (≤17 years of age, n = 4,706) listings (2006 to 2015) for primary, isolated heart transplantation within the UNOS data set, assessing Status 1A exception (n = 211, 4.5%) use across regions and patient characteristics and evaluating waitlist outcomes compared with candidates listed using standard criteria. Death or removal for reason other than transplant did not differ between exception and standard criteria patients at 1 month (11.7% vs 16.2%, p = not statistically significant [NS]), 2 months (18.2% vs 29.0%, p = 0.11) or overall (16.1% vs 22.0%, p = NS) on the waitlist. Rates were higher than among Status 1B patients (1 month: 2.8%; 2 months: 5.6%; overall: 14.9%; p < 0.0001). The cumulative incidence of competing risks (transplantation, death/removal for reasons other than transplant and removal) did not differ when comparing Status 1A exception patients with Status 1A standard criteria patients. Use of 1A exceptions varied across UNOS regions (1.9% to 22.3%, p < 0.0001). Risk-adjusted modeling identified patients more (hypertrophic cardiomyopathy: odds ratio [OR] = 2.8, 95% confidence interval [CI] 1.5 to 5.0; restrictive cardiomyopathy: OR = 2.7, 95% CI 1.7 to 4.3) and less (low socioeconomic status: OR = 0.7, 95% CI 0.5 to 1.0) likely to use an exception. Use of exceptions was uncorrelated with regional outcomes. Waitlist mortality among Status 1A exception patients is similar to that among those listed by standard criteria. However, variation in exception use across geography and demography may contribute to inequities in access to transplantation, particularly for those with low socioeconomic status. Standardization of practices may decrease regional variation and minimize inequities.

Davies RR ，McCulloch MA ，Haldeman S ，Gidding SS ，Pizarro C ... -  《-》

Regional variation in the use of 1A status exceptions for pediatric heart transplant candidates: is this equitable?

The use of status exceptions (SE) was recently publicized as a strategy to reduce waitlist times for children awaiting heart transplant (HTx). The aim of this study was to assess SE use across UNOS regions and compare survival in patients listed using a SE to those listed by standard criteria. The OPTN database was queried for all pediatric patients listed for HTx (2000-2014). SE use was compared across UNOS regions. Survival curves were generated and compared using the log-rank test. 1A SE use is uncommon, being utilized in 108 of 4587 pediatric 1A listings (2.4%). There is significant variability in SE use across UNOS regions (0.7%-16.4% of 1A listings, P < .001). Waitlist survival is significantly higher in candidates listed using a 1A SE compared to those listed by standard criteria (P = .001) and is similar to 1B listings. Regional variation in 1A SE use has the potential to introduce bias into a system designed to be equitable. Waitlist survival in patients listed using a SE is similar to those listed status 1B, suggesting these patients may not require 1A status. Careful review of pediatric heart allocation policies is needed to optimize patient outcomes and ensure a fair and unbiased allocation system.

Godown J ，McKane M ，Wujcik KA ，Mettler BA ，Dodd DA ... -  《-》

Sex Differences in Mortality Based on United Network for Organ Sharing Status While Awaiting Heart Transplantation.

There are sex differences in mortality while awaiting heart transplantation, and the reason remains unclear. We included all adults in the Scientific Registry of Transplant Recipients placed on the heart transplant active waitlist from 2004 to 2015. The primary end point was all-cause mortality. Multivariable Cox proportional hazards models were performed to evaluate survival by United Network for Organ Sharing (UNOS) status at the time of listing. Random survival forest was used to identify sex interactions for the competing risk of death and transplantation. There were 33 069 patients (25% women) awaiting heart transplantation. This cohort included 7681 UNOS status 1A (26% women), 13 027 UNOS status 1B (25% women), and 12 361 UNOS status 2 (26% women). During a median follow-up of 4.3 months, 1351 women and 4052 men died. After adjusting for >20 risk factors, female sex was associated with a significant risk of death among UNOS status 1A (adjusted hazard ratio, 1.14; 95% confidence interval, 1.01-1.29) and UNOS status 1B (adjusted hazard ratio, 1.17; 95% confidence interval, 1.05-1.30). In contrast, female sex was significantly protective for time to death among UNOS status 2 (adjusted hazard ratio, 0.85; 95% confidence interval, 0.76-0.95). Sex differences in probability of transplantation were present for every UNOS status, and >20 sex interactions were identified for mortality and transplantation. When stratified by initial UNOS status, women had a higher mortality than men as UNOS status 1 and a lower mortality as UNOS status 2. With >20 sex interactions for mortality and transplantation, further evaluation is warranted to form a more equitable allocation system.

Hsich EM ，Blackstone EH ，Thuita L ，McNamara DM ，Rogers JG ，Ishwaran H ，Schold JD ... -  《-》

Impact of the 2016 revision of US Pediatric Heart Allocation Policy on waitlist characteristics and outcomes.

US Pediatric Heart Allocation Policy was recently revised, deprioritizing candidates with cardiomyopathy while maintaining status 1A eligibility for congenital heart disease (CHD) candidates on "high-dose" inotropes. We compared waitlist characteristics and mortality around this change. Status 1A listings decreased (70% to 56%, P < .001) and CHD representation increased among status 1A listings (48% vs 64%, P < .001). Waitlist mortality overall (subdistribution hazard ratio [SHR] 0.96, P = .63) and among status 1A candidates (SHR 1.16, P = .14) were unchanged. CHD waitlist mortality trended better (SHR 0.82, P = .06) but was unchanged for CHD candidates listed status 1A (SHR 0.92, P = .47). Status 1A listing exceptions increased 2- to 3-fold among hypertrophic and restrictive cardiomyopathy candidates and 13.5-fold among dilated cardiomyopathy (DCM) candidates. Hypertrophic (SHR 6.25, P = .004) and restrictive (SHR 3.87, P = .03) cardiomyopathy candidates without status 1A exception had increased waitlist mortality, but those with DCM did not (SHR 1.26, P = .32). Ventricular assist device (VAD) use increased only among DCM candidates ≥1 years old (26% vs 38%, P < .001). Current allocation policy has increased CHD status 1A representation but has not improved their waitlist mortality. Excessive DCM status 1A listing exceptions and continued status 1A prioritization of children on stable VADs potentially diminish the intended benefits of policy revision.

Magnetta DA ，Godown J ，West S ，Zinn M ，Rose-Felker K ，Miller S ，Feingold B ... -  《-》

Trends in the Use of Inotropes to List Adult Heart Transplant Candidates at Status 1A.

The number of adult heart transplant candidates waiting at the most urgent status 1A has increased over time despite the expansion of geographic sharing of hearts in 2006. We aimed to determine whether candidates listed with inotropes contribute to the excess status 1A candidates. The initial registrations of all adult heart-only candidates listed from 2000 to 2015 were analyzed using the Scientific Registry of Transplant Recipients data set. Trends in listing status, justifications, and candidate factors were measured. Adjusted trends in listing status pre- and post-geographic sharing were estimated using multilevel logistic regression. Competing risks models provided trends in transplant-free waitlist survival. There were 46 853 adult heart-alone listings during 2000 to 2015. Pre-sharing, status 1A listing was unchanged over time (adjusted odds ratio, 0.98; 95% confidence interval, 0.78-1.23). Post-sharing, the adjusted odds of status 1A listing increased 117% over 9 years (adjusted odds ratio 2.17, 95% confidence interval, 1.82-2.58). The number of candidates listed as status 1A with inotropes increased by 193 a year, whereas the dobutamine, dopamine, and milrinone doses used decreased 49%, 55%, and 29% (P<0.001). The risk of waitlist death or deterioration of status 1A inotrope candidates relative to status 2 candidates decreased 62% for 2006 to 2010 and 70% for 2011 to 2015 compared with that for 2003 to 2006. After the wider geographic sharing of hearts in 2006, transplant programs used multiple inotropes to list candidates at status 1A more frequently with progressively lower doses. Concurrently, the status 1A inotrope candidate waitlist outcomes improved substantially. These trends suggest that overtreatment with multiple inotropes contributes to the current critical excess of status 1A candidates.

Parker WF ，Garrity ER Jr ，Fedson S ，Churpek MM ... -  《-》