OPTN/SRTR 2020 Annual Data Report: Liver

This year was marked by the COVID-19 pandemic, which altered transplant program activity and affected waitlist and transplant outcomes. Still, 8906 liver transplants were performed, an all-time high, across 142 centers in the United States, and pretransplant as well as graft and patient survival metrics, continued to improve. Living donation activity decreased after several years of growth. As of June 30, 2020, 98989 liver transplant recipients were alive with a functioning graft, and in the context of increasing liver transplant volume, the size of both the adult and pediatric liver transplant waitlists have decreased. On February 4, 2020, shortly before the pandemic began, a new liver distribution policy based on acuity circles was implemented, replacing donor service area- and region-based boundaries. A policy change to direct pediatric livers to pediatric recipients led to an increase in deceased donor transplant rates and a decrease in pretransplant mortality rate among children, although the absolute number of pediatric transplants did not increase in 2020. Among adults, alcohol-associated liver disease became the predominant indication for liver transplant in 2020. After implementation of the National Liver Review Board and lower waitlist priority for most exception cases in 2019, fewer liver transplants were being performed via exception points, and the transplant rate between those with and without hepatocellular carcinoma has equalized. Women continue to experience higher pretransplant mortality and lower rates of liver transplant than men.

OPTN/SRTR 2020 Annual Data Report: Living Donor Collective

The first successful solid organ transplant was a living donor kidney transplant in 1954. Since then, living donation has been an important source of organs for kidney and liver transplants in the United States. Unfortunately, the demand for organs has not kept pace with the supply, and unlike deceased donor transplant, there has been little growth in the number of living donor transplants over the past decade. To better understand possible barriers to living donation and long-term risks attributable to donation, the Health Resources and Services Administration (HRSA) directed the Scientific Registry of Transplant Recipients (SRTR) to establish a national registry of all living donor candidates and donors evaluated at US transplant programs to acquire lifetime follow-up information. Other goals include understanding the factors associated with candidate approval and variation in approval practices across centers. A pilot program was conducted from June 2018 through September 2020 to inform baseline data collection and registration processes. In September 2020, the registry began recruiting additional sites evaluating candidates for living donation. Here, we describe candidates registered at participating living donor kidney and liver programs, from June 2018 through the end of 2020. Not all programs submitted data throughout the whole period. Data for kidney and liver living donor candidates are presented separately.

OPTN/SRTR 2020 Annual Data Report: Heart

As we enter the third year of the new adult heart allocation policy, we are faced with the new challenges of the COVID-19 pandemic. In 2020, new listings (adult and pediatric) decreased slightly, with 4000 new listings in 2020, compared with 4087 in 2019; however, the number of adult heart transplants performed continued to increase, to 3715 in 2020. The number of pediatric heart transplants declined from 509 in 2019 to 465 in 2020. One-year and six-month posttransplant mortality rates in adult recipients have increased slightly since 2015 but have not significantly changed over the past decade. Overall, posttransplant mortality rates for adult recipients were 7.4% at six months and 9.4% at one year for transplants in 2019, 14.0% at three years for transplants in 2017, and 19.1% at five years for transplants in 2015. Although shorter-term posttransplant mortality rates have slightly increased, there has been a steady downward trend in longer-term mortality. Mortality rates for pediatric recipients were 5.7% at six months and 8.1% at one year for transplants in 2019, 11.6% at three years for transplants in 2017, and 15.2% at five years for transplants in 2015.

OPTN/SRTR 2019 Annual Data Report: Liver

This year was notable for changes to exception points determined by the geographic median allocation Model for End-Stage Liver Disease (MELD) and implementation of the National Liver Review Board, which took place on May 14, 2019. The national acuity circle liver distribution policy was also implemented but reverted to donor service area- and region-based boundaries after 1 week. In 2019, growth continued in the number of new waiting list registrations (12,767) and transplants performed (8,896), including living-donor transplants (524). Compared with 2018, living-donor liver transplants increased 31%. Women continued to have a lower deceased-donor transplant rate and a higher pretransplant mortality rate than men. The median waiting time for candidates with a MELD of 15-34 decreased, while the number of transplants performed for patients with exception points decreased. These changes may have been related to the policy changes that took effect in May 2019, which increased waiting list priority for candidates without exception status. Hepatitis C continued to decline as an indication for liver transplant, as the proportion of liver transplant recipients with alcohol-related liver disease and clinical profiles consistent with non-alcoholic steatohepatitis increased. Graft and patient survival have improved despite changing recipient demographics including older age, higher MELD, and higher prevalence of obesity and diabetes.

OPTN/SRTR 2019 Annual Data Report: Lung

The number of lung transplants performed continues to increase annually and reached an all-time high in 2019, with decreasing waitlist mortality. These trends are attributable to an increasing number of candidates listed for transplant each year and a continuing increase in the number of donors. Despite these favorable trends, 6.4% of lungs recovered for transplant were not transplanted in 2019, and strategies to optimize use of these available organs may reduce the number of waitlist even further. Time to transplant continued to decrease, as over 50% of candidates waited 3 months or less in 2019, yet regional heterogeneity remained despite policy changes intended to improve allocation equity. Small gains continued in posttransplant survival, with 1-year survival at 88.8%; 3 year, 74.4%; 5 year, 59.2%, and 10 year, 33.1 %.

OPTN/SRTR 2019 Annual Data Report: Heart

The new adult heart allocation policy was approved in 2016 and implemented in October 2018. This year's Annual Data Report provides early insight into the effects of this policy. In 2019, new listings continued to increase, with 4086 new candidates. Also in 2019, 3597 heart transplants were performed, an increase of 157 (4.6%) from 2018; 509 transplants occurred in children and 3088 in adults. Short- and long-term posttransplant mortality rates improved. Overall, Mortality rates for adult recipients were 6.4% at 6 months and 7.9% at 1 year for transplants in 2018, 14.4% at 3 years for transplants in 2016, and 20.1% at 5 years for transplants in 2014. Mortality rates for pediatric recipients were 6.3% at 6 months and 8.2% at 1 year for transplants in 2018, 10.3% at 3 years for transplants in 2016, and 17.8% at 5 years for transplants in 2014.

OPTN/SRTR 2018 Annual Data Report: Lung

The primary goal of US lung allocation policy is to ensure that candidates with the highest risk for mortality receive appropriate access to lung transplant. In 2018, 2562 lung transplants were performed in the US, reflecting a 31% increase over the past 5 years. More candidates are being listed for lung transplant, and the number of donors has increased substantially. Despite an increase of 84 lung transplants in 2018, 365 adult candidates died or became too sick to undergo transplant. In 2018, 24 new child (ages 0-11 years) candidates were added to the lung transplant waiting list. Fifteen lung transplants were performed in recipients aged 0-11 years, three in recipients aged younger than 1 year, two in recipients aged 1-5 years, and ten in recipients aged 6-11 years. Of 27 child candidates removed from the waiting list in 2018, 16 (59.3%) were removed due to undergoing transplant, six (22.2%) due to death, one (3.7%) due to improved condition, and one (3.7%) due to becoming too sick to undergo transplant.

OPTN/SRTR 2018 Annual Data Report: Deceased Organ Donation

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2018, there were 10,721 deceased donors, and this number has been increasing since 2010. The number of deceased donor transplants increased to 29,676 in 2018 from 28,582 in 2017, and this number has been increasing since 2012. The recent increase may be due in part to the rising number of deaths of young people due to the opioid epidemic. In 2018, 4994 organs were discarded, slightly more than 4813 in 2017. In 2018, 3755 kidneys, 278 pancreata, 707 livers, 3 intestines, 23 hearts, and 317 lungs were discarded. These numbers suggest an opportunity to increase numbers of transplants by reducing discards.

OPTN/SRTR 2018 Annual Data Report: Heart

The new adult heart allocation policy was approved in 2016 and implemented in October 2018, so its effect was not yet evident in 2018 data. However, the more granular data being collected are anticipated to allow for improved analyses. In 2018, new listings continued to increase; 3883 new adult and 685 new pediatric candidates were added. In 2018, 3440 heart transplants were performed, an increase of 167 over 2017; 473 transplants occurred in pediatric recipients and 2967 in adult recipients. Short-term and long-term posttransplant mortality improved. Overall 1-year survival for adults who underwent heart transplant in 2011-2013 was 90.3%, 3-year survival was 84.7%, and 5-year survival was 79.6%. Mortality rates for pediatric recipients were 4.5% at 6 months and in 5.9% at 1 year posttransplant, 12.5% at 3 years for transplants in 2014-2015, 14.8% at 5 years for transplants in 2012-2013, and 29.8% at 10 years for transplants performed in 2008-2009.

OPTN/SRTR 2018 Annual Data Report: Intestine

Despite medical and surgical advances in treatment of intestinal failure, intestine transplant still plays an important role. However, the number of new patients added to the intestine transplant waiting list has decreased over the past decade, reaching a low of 135 in 2018. The number of intestine donors also decreased, reaching a low of 106 in 2018, and the number of intestine transplants performed declined to its lowest level, 104, of which 59% were intestine-liver transplants. Graft failure has plateaued over the past decade. Patient survival for transplants in 2011-2013 varied by age and transplant type. Patient survival was lowest for adult intestine-liver recipients (1-and 5-year survival 66.7% and 49.1%, respectively) and highest for pediatric intestine recipients (1-and 5-year survival 89.1% and 76.4%, respectively).

OPTN/SRTR 2018 Annual Data Report: Hepatitis C

Direct acting antivirals (DAAs) have fundamentally changed the treatment of hepatitis C virus (HCV) infection and reduced the discard rate of HCV-infected organs by offering a treatment option with a high likelihood of cure posttransplant. This has spurred increased interest in transplanting organs from HCV-positive donors into recipients both with and without HCV. In this chapter, we examine data from 2007 to 2018 to determine trends in HCV (+) donor transplants across various organ types. Since 2015, willingness to accept HCV (+) organs increased for candidates waitlisted for kidney, lung, heart, and pancreas transplant, but decreased for those listed for intestine transplant. For candidates listed for liver transplant, willingness to accept HCV (+) organs decreased from 2007 to 2017, but began increasing in 2017. Willingness to accept was not concentrated in a single US geographic area, and there was substantial variation among transplant programs and donation service areas. Numbers of anti-HCV (+) donor kidney, heart, lung, and liver transplants have increased considerably in the past few years. Short-term allograft survival for kidney and liver transplant recipients of anti-HCV (+) organs appears to be comparable to that for recipients of anti-HCV (-) organs in an unadjusted analysis. However, an unadjusted analysis indicates that long-term allograft survival may be worse. Kidney transplant between HCV-infected donors and uninfected recipients with posttransplant DAA treatment is an emerging area. Short-term data are promising, with similar 1-year allograft survival compared with HCV-uninfected donor to HCV-uninfected recipient kidney transplants in unadjusted analyses. However, long-term data are lacking and close monitoring in the future is warranted.

OPTN/SRTR 2018 Annual Data Report: Pancreas

The overall number of pancreas transplants continued to increase to 1027 in 2018, after a nadir of 947 in 2015. New additions to waiting list remained stable, with 1485 candidates added in 2018. Proportions of patients with type II diabetes waiting for transplant (14.6%) and undergoing transplant (14.8%) have steadily increased since 2016. Waiting times for simultaneous pancreas/kidney transplant have decreased; median months to transplant was 13.5 for simultaneous pancreas/kidney transplant and 19.7 for pancreas transplant alone in 2018. Outcomes, including patient and kidney survival, as well as rejection rates, have improved consistently over the past several years. Pancreas graft survival data are being collected by the Organ Procurement and Transplantation Network and will be included in a future report once there are sufficient cohorts for analysis.

OPTN/SRTR 2018 Annual Data Report: Kidney

Despite the ongoing severe mismatch between organ need and supply, data from 2018 revealed some promising trends. For the fourth year in a row, the number of patients waiting for a kidney transplant in the US declined and numbers of both deceased and living donor kidney transplants increased. These encouraging trends are tempered by ongoing challenges, such as a large proportion of listed patients with dialysis time longer than 5 years. The proportion of candidates aged 65 years or older continued to rise, and the proportion undergoing transplant within 5 years of listing continued to vary dramatically nationwide, from 10% to nearly 80% across donation service areas. Increasing trends in the recovery of organs from hepatitis C positive donors and donors with anoxic brain injury warrant ongoing monitoring, as does the ongoing discard of nearly 20% of recovered organs. While the number of living donor transplants increased, racial disparities persisted in the proportion of living versus deceased donors. Strikingly, the total number of kidney transplant recipients alive with a functioning graft is on track to pass 250,000 in the next 1-2 years. The total number of pediatric kidney transplants remained steady at 756 in 2018. Deeply concerning to the pediatric community is the persistently low level of living donor kidney transplants, representing only 36.2% in 2018.

OPTN/SRTR 2018 Annual Data Report: Liver

Data on adult liver transplants performed in the US in 2018 are notable for (1) continued growth in numbers of new waitlist registrants (11,844) and transplants performed (8250); (2) continued increase in the transplant rate (54.5 per 100 waitlist-years); (3) a precipitous decline in waitlist registrations and transplants for hepatitis-C-related indications; (4) increases in waitlist registrants and recipients with alcoholic liver disease and with clinical profiles consistent with non-alcoholic fatty liver disease; (5) increased use of hepatitis C virus antibody-positive donor livers; and (6) continued improvement in graft survival despite changing recipient characteristics such as older age and higher rates of obesity and diabetes. Variability in transplant rates remained by candidate race, hepatocellular carcinoma status, urgency status, and geography. The volume of pediatric liver transplants was relatively unchanged. The highest rate of pre-transplant mortality persisted for children aged younger than 1 year. Children underwent transplant at higher acuity than in the past, as evidenced by higher model for end-stage liver disease/pediatric end-stage liver disease scores and listings at status 1A and 1B at transplant. Despite higher illness severity scores at transplant, pediatric graft and patient survival posttransplant have improved over time.

OPTN/SRTR 2017 Annual Data Report: Heart

In 2017, 3273 heart transplants were performed in the United States. New listings continued to increase, and 3769 new adults were listed for heart transplant in 2017. Over the past decade, posttransplant mortality has declined. The number of new pediatric listings increased over the past decade, as did the number of pediatric heart transplants, although some fluctuation has occurred more recently. New listings for pediatric heart transplants increased from 481 in 2007 to 623 in 2017. The number of pediatric heart transplants performed each year increased from 330 in 2007 to 432 in 2017, slightly fewer than in 2016. Short-term and long-term mortality improved. Among pediatric patients who underwent transplant between 2015-2016, 4.8% had died by 6 months and 6.2% by 1 year.

OPTN/SRTR 2017 Annual Data Report: Lung

Each year since 2012, the number of lung transplants has increased, reflecting an increase in the number of donors, improved use of recovered organs, and more candidates being listed for transplant. However, the need for organs continues to outpace available donors. Despite an increase of 126 donors in 2017, 1360 candidates remained on the waiting list at the end of the year, and 326 patients died or became too sick to undergo transplant. Approximately 14,000 individuals were living with a lung transplant in 2017; 9492 were aged 50 years or older, 4075 were aged 18-49 years, and 408 were aged younger than 18 years.

OPTN/SRTR 2017 Annual Data Report: Deceased Organ Donation

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2017, 1,085,646 death and imminent death referrals were made to organ procurement organizations, of which 22,265 met the definition of eligible (11,673) or imminent neurological (10,592) deaths per OPTN policy. There were 10,286 deceased donors, and this number has been increasing since 2010. The number of organs authorized for recovery has also continued to increase since 2010. The recent increase may be in part due to the rising number of deaths of young individuals due to the opioid epidemic. In 2017, 4813 organs were discarded, including 3542 kidneys, 309 pancreata, 742 livers, 4 intestines, 33 hearts, and 272 lungs. These numbers suggest a need to reduce the number of organs discarded.

OPTN/SRTR 2017 Annual Data Report: Pancreas

In 2017, 1492 patients were added to the pancreas transplant waiting list, 964 listed as active, a slight increase from 2016. This is significant because for the first time in the past decade, the steady downward trend in additions to the waiting list has been reversed. Proportions of pancreas donors with cerebrovascular accident as cause of death decreased, with a concomitant increase in proportions with anoxia and head trauma. This is partly a result of the national opioid crisis, and it reflects increasing use of younger donors for pancreas transplant. The 2017 outcome report remains compromised by previous variation in reporting graft failure. Although the OPTN Pancreas Transplantation Committee has approved more precise definitions of pancreas graft failure, implementation of these definitions took place recently, and the data are not reflected in this report.

OPTN/SRTR 2017 Annual Data Report: Kidney

Many positive trends in kidney transplantation were notable in 2017. Deceased donor kidney transplant rates and counts continued to rise, the kidney transplant waiting list declined for the third year in a row after decades of growth, and both short- and long-term allograft survival continued to improve year over year. In total, more than 220,000 patients were living in the United States with a functioning allograft. With 3 years of data available since implementation of the new kidney allocation system, better prediction of longer-term results of the allocation policy changes became possible. The data also reveal several areas in need of improvement and attention. Overall, the challenge of providing adequate access to kidney transplant persisted nationally, with additional dramatic regional variation. The proportion of living donor kidney transplants in both adults and children continued to fall, and racial disparities in living donor kidney transplant grew in the past decade.

OPTN/SRTR 2017 Annual Data Report: Liver

Data on adult liver transplants performed in the US in 2017 are notable for (1) continued growth in numbers of new waitlist registrants (11,514) and of transplants performed (8,082); (2) continued increase in the transplant rate (51.5 per 100 waitlist-years); (3) a precipitous decrease in waitlist registrations and transplants for hepatitis C-related indications; (4) reciprocal increases in waitlist registrants and recipients with alcoholic liver disease and with clinical profiles consistent with non-alcoholic fatty liver disease; and (5) continued improvement in graft survival despite changing recipient characteristics such as older age and higher rates of obesity. Variability in transplant rates remained by candidate race, presence of hepatocellular carcinoma, urgency status (status 1A versus model for end-stage liver disease (MELD) score >35), and geography. More than half of all children listed for liver transplant in 2017 were aged younger than 5 years in 2017, and the highest rate of pretransplant mortality persisted for children aged younger than 1 year. Children underwent transplant at higher acuity than the past, as evidenced by higher MELD/pediatric end-stage liver disease scores and listings at status 1A and 1B. Higher acuity at transplant is likely due to lack of access to suitable donor organs, which has been compensated for by persistent trends toward use of partial or split liver grafts and ABO-incompatible grafts. Despite higher illness severity scores at transplant, pediatric graft and patient survival posttransplant have improved over time.

OPTN/SRTR 2017 Annual Data Report: Intestine

Despite improvements in medical and surgical treatment of intestinal failure, intestine transplant continues to play an important role. In 2017, 109 intestine transplants were performed, 62 in adults and 47 in children, reflecting the changed age distribution over the past decade of candidates waitlisted for intestine and intestine-liver transplant from largely pediatric to increasing proportions of adults. In 2017, 56.0% of candidates on the intestine list at any time during the year were aged younger than 18 years, with a decrease over time in those aged younger than 6 years and an increase in those aged 6-17 years. Adults accounted for 44.0% of candidates on the list at any time during the year, with an increase since 2013 in those aged 18-34 years and a decrease in those aged 35 years or older. By age, the pretransplant mortality rate was highest for adult candidates at 7.9 per 100 waitlist-years and lowest for pediatric candidates at 3.7 per 100 waitlist-years. Patient survival varied by age and type of transplant, and was lowest for adult intestine-liver recipients (1- and 5-year survival 66.7% and 42.6%, respectively) and highest for pediatric intestine recipients (1- and 5-year survival 86.2% and 75.4%, respectively).

Metformin use in the first year after kidney transplant, correlates, and associated outcomes in diabetic transplant recipients: A retrospective analysis of integrated registry and pharmacy claims data

While guidelines support metformin as a therapeutic option for diabetic patients with mild-to-moderate renal insufficiency, the frequency and outcomes of metformin use in kidney transplant recipients are not well described. We integrated national U.S. transplant registry data with records from a large pharmaceutical claims clearinghouse (2008-2015). Associations (adjusted hazard ratio, 95% LCL aHR95% UCL ) of diabetes regimens (with and excluding metformin) in the first year post-transplant with patient and graft survival over the subsequent year were quantified by multivariate Cox regression, adjusted for recipient, donor, and transplant factors and propensity for metformin use. Among 14 144 recipients with pretransplant type 2 diabetes mellitus, 4.7% filled metformin in the first year post-transplant; most also received diabetes comedications. Compared to those who received insulin-based regimens without metformin, patients who received metformin were more likely to be female, have higher estimated glomerular filtration rates, and have undergone transplant more recently. Metformin-based regimens were associated with significantly lower adjusted all-cause (aHR 0.18 0.410.91 ), malignancy-related (aHR 0.45 0.450.99 ), and infection-related (aHR 0.12 0.320.85 ) mortality, and nonsignificant trends toward lower cardiovascular mortality, graft failure, and acute rejection. No evidence of increased adverse graft or patient outcomes was noted. Use of metformin-based diabetes treatment regimens may be safe in carefully selected kidney transplant recipients.

Program-specific transplant rate ratios: Association with allocation priority at listing and posttransplant outcomes

The Scientific Registry of Transplant Recipients (SRTR) is considering more prominent reporting of program-specific adjusted transplant rate ratios (TRRs). To enable more useful reporting of TRRs, SRTR updated the transplant rate models to adjust explicitly for components of allocation priority. We evaluated potential associations between TRRs and components of allocation priority that could indicate programs' ability to manipulate TRRs by denying or delaying access to low-priority candidates. Despite a strong association with unadjusted TRRs, we found no candidate-level association between the components of allocation priority and adjusted TRRs. We found a strong program-level association between median laboratory Model for End-stage Liver Disease (MELD) score at listing and program-specific adjusted TRRs (r = .37; P < .001). The program-level association was likely confounded by regional differences in donor supply/demand and listing practices. In kidney transplantation, higher program-specific adjusted TRRs were weakly associated with better adjusted posttransplant outcomes (r = -.14; P = .035) and lower adjusted waitlist mortality rate ratios (r = -.15; P = .022), but these associations were absent in liver, lung, and heart transplantation. Program-specific adjusted TRRs were unlikely to be improved by listing candidates with high allocation priority and can provide useful information for transplant candidates and programs.

OPTN/SRTR 2016 Annual Data Report: Kidney

Data from 2016 show ongoing positive trends in short- and long-term allograft survival, and a decrease in the number of active listed candi- dates for the first time in more than a decade, with a concomitant in- crease in deceased donor kidney transplants. Transplant rates that had changed dramatically for some groups after implementation of the new kidney allocation system in 2014 are stabilizing, allowing for evaluation of new steady states and trends. Many challenges remain in adult kid- ney transplantation, including stagnant rates of living donor transplant, geographic disparities in access to transplant, racial disparities in living donor transplant, and overall a continuing demand for kidneys that far outpaces the supply. For pediatric recipients, a decline in the proportion of living donor transplants is of concern. In 2016, only 34.2% of pediatric transplants were from living donors, compared with 47.2% in 2005. The number of related donors decreased dramatically over the past decade, and the number of unrelated directed transplants performed in pediatric candidates remained low (50).

OPTN/SRTR 2016 Annual Data Report: Liver

Data on adult liver transplants performed in the US in 2016 are no-table for (1) the largest total number of transplants performed (7841); (2) the shortest median waiting time in recent history (11.3 months); (3) continued reduction in waitlist registrations and transplants for hepatitis C-related indications; (4) increasing numbers of patients whose clinical profiles are consistent with non-alcoholic fatty liver disease; and (5) equilibration of transplant rates in patients with and without hepatocellular carcinoma. Despite the increase in the number of available organs, waitlist mortality remained an important concern. Graft survival rates continued to improve. In 2016, 723 new active candidates were added to the pediatric liver transplant waiting list, down from a peak of 826 in 2005. The number of prevalent candidates (on the list on December 31 of the given year) was stable, 408 active and 169 inactive. The number of pediatric living donor liver transplants decreased from a peak of 79 in 2015 to 62 in 2016, with most from donors closely related to the recipients. Graft survival continued to improve over the past decade among recipients of deceased donor and living donor livers.

OPTN/SRTR 2016 Annual Data Report: Intestine

Despite improvements in medical and surgical treatment of intestinal failure, intestine transplant continues to play an important role. In 2016, a total of 147 intestine transplants were performed, 80 intestine-without-liver and 67 intestine-liver. Over the past decade, the age distribution of candidates waitlisted for intestine and intestine-liver transplant shifted from primarily pediatric to increasing proportions of adults. In 2016, 58.2% of candidates on the intestine list at any time during the year were aged younger than 18 years, with a decrease over time in those aged younger than 6 years and an increase in those aged 6-17 years. Adults accounted for 41.9% of candidates on the list at any time during the year, with a stable proportion of those aged 18-34 years and a decrease in those aged 35 years or older. By age, pretransplant mortality rate was highest for adult candidates at 11.7 per 100 waitlist years and lowest for children aged younger than 6 years at 2.2 per 100 waitlist years. For intestine transplants with or without a liver in 2009-2011, 1- and 5-year graft survival was 72.0% and 54.1%, respectively, for recipients aged younger than 18 years, and 70.5% and 44.1%, respectively, for recipients aged 18 years or older.

OPTN/SRTR 2016 Annual Data Report: Heart

In 2016, 3209 heart transplants were performed in the United States. New, active listings increased 57% since 2005. The number of adult heart transplant survivors continued to increase, and in 2016, 30,622 recipients were living with heart transplants. Patient mortality following transplant has declined. The number of pediatric candidates and transplants performed also increased. New listings for pediatric heart transplants increased from 454 in 2005 to 624 in 2016. The number of pediatric heart transplants performed each year increased from 319 in 2005 to 445 in 2016. Among pediatric patients who underwent transplant in 2015, death occurred in 5.9% at 6 months and 7.2% at 1 year.

OPTN/SRTR 2016 Annual Data Report: Economics

Medicare costs vary for solid organ transplant recipients by outcome: survival with graft function, survival with graft failure, and death. Average per-person per-year reimbursement was $75 thousand for kidney recipients who survived the first year posttransplant with a functioning graft, $171 thousand for those who required a return to dialysis or retransplant, and $350 thousand for those who died with function. For pancreas recipients: $105 thousand for those who survived the first year with a functioning graft, $120 thousand for those who survived pancreas failure, and $443 thousand for those who died with function. For liver recipients: $154 thousand for those who survived with a functioning graft, $388 thousand for those who required retransplant, and $740 thousand who died with function. For intestine recipients: $301 thousand for those who survived with a functioning graft and $1 million for those who died with function. For heart recipients: $272 thousand for those who survived with a functioning graft and $1.2 million for those who died with function. For lung recipients: $196 thousand for those who survived with a functioning graft, $642 thousand for those who required retransplant, and $761 thousand for those who died with function.

OPTN/SRTR 2016 Annual Data Report: Lung

In 2016, 2692 candidates aged 12 years or older were added to the lung transplant waiting list; 2345 transplants were performed, the largest number of any prior year. The median waiting time for listed candidates in 2016 was 2.5 months, and waiting times were shortest for group D candidates. The transplant rate increased to 191.9 transplants per 100 waitlist years in 2016, with a slight decrease in waitlist mortality to 15.1 deaths per 100 waitlist years. Short-term survival continued to improve, with a 6-month death rate of 6.6% and a 1-year death rate of 10.8% among recipients in 2015 compared with 8.0% and 13.3%, respectively, among recipients in 2014. Long-term survival rates remained unchanged; 55.6% of recipients were alive at 5 years. In 2016, 23 new candidates aged 0-11 years were added to the waiting list and 16 lung transplants were performed. Incidence of posttransplant mortality for lung transplant recipients aged 0-11 years who underwent transplant in 2014-2015 was 13.8% at 6 months and 19.6% at 1 year. Changes in waitlist and transplant demographic features continued to evolve following implementation of the revised lung allocation score in 2015. Some early trends that may be attributable to the revised LAS are shorter waiting times, stabilization of the number of group D candidates listed for transplant, and convergence of LAS with lower prevalence of extremely high scores.

OPTN/SRTR 2016 Annual Data Report: Deceased Organ Donation

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2016, 1,072,717 death and imminent death referrals were made to organ procurement organizations, of which 23,433 met the definition of eligible (10,717) or imminent (12,716) deaths per OPTN policy. There were 9971 deceased donors, and this number has been increasing since 2010. The number of organs authorized for recovery has also continued to increase since 2010. In 2016, 4859 organs were discarded, including 3631 kidneys, 317 pancreata, 739 livers, 8 intestines, 31 hearts, and 211 lungs. These numbers suggest a need to reduce the number of organs discarded.

OPTN/SRTR 2016 Annual Data Report: Pancreas

The number of pancreas transplants performed in the United States increased by 7.0% in 2016 over the previous year, the first such increase in more than a decade, largely attributable to an increase in simultaneous kidney pancreas transplants. Transplant rates increased in 2016, and mortality on the waiting list decreased. The declining enthusiasm for pancreas after kidney (PAK) transplants persisted. The uniform definition of graft failure was approved by the OPTN Board of Directors in 2015 and will be implemented in early 2018. Meanwhile, SRTR continues to refrain from reporting pancreas graft failure data. The OPTN/UNOS Pancreas Transplantation Committee is seeking to broaden allocation of pancreata across compatible ABO blood types in a proposal out for public comment July 31 to October 2, 2017. A new initiative to provide guidance on the benefits of PAK transplants is also out for public comment.

The Living Donor Collective: A Scientific Registry for Living Donors

In the setting of an overall decline in living organ donation and new questions about long-term safety, a better understanding of outcomes after living donation has become imperative. Adequate information on outcomes important to donors may take many years to ascertain and may be evident only by comparing large numbers of donors with suitable controls. Previous studies have been unable to fully answer critical questions, primarily due to lack of appropriate controls, inadequate sample size, and/or follow-up duration that is too short to allow detection of important risks attributable to donation. The Organ Procurement and Transplantation Network does not follow donors long term and has no prospective control group with which to compare postdonation outcomes. There is a need to establish a national living donor registry and to prospectively follow donors over their lifetimes. In addition, there is a need to better understand the reasons many potential donors who volunteer to donate do not donate and whether the reasons are justified. Therefore, the US Health Resources and Services Administration asked the Scientific Registry of Transplant Recipients to establish a national registry to address these important questions. Here, we discuss the efforts, challenges, and opportunities inherent in establishing the Living Donor Collective.

Predonation Prescription Opioid Use: A Novel Risk Factor for Readmission After Living Kidney Donation

Implications of opioid use in living kidney donors for key outcomes, including readmission rates after nephrectomy, are unknown. We integrated Scientific Registry of Transplant Recipients data with records from a nationwide pharmacy claims warehouse and administrative records from an academic hospital consortium to quantify predonation prescription opioid use and postdonation readmission events. Associations of predonation opioid use (adjusted odds ratio [aOR]) in the year before donation and other baseline clinical, procedural, and center factors with readmission within 90 days postdonation were examined by using multivariate logistic regression. Among 14 959 living donors, 11.3% filled one or more opioid prescriptions in the year before donation. Donors with the highest level of predonation opioid use (>305 mg/year) were more than twice as likely as nonusers to be readmitted (6.8% vs. 2.6%; aOR 2.49, 95% confidence interval 1.74-3.58). Adjusted readmission risk was also significantly (p < 0.05) higher for women (aOR = 1.25), African Americans (aOR = 1.45), spouses (aOR = 1.42), exchange participants (aOR = 1.46), uninsured donors (aOR = 1.40), donors with predonation estimated glomerular filtration rate <60 mL/min/1.73 m² (aOR = 2.68), donors with predonation pulmonary conditions (aOR = 1.54), and after robotic nephrectomy (aOR = 1.68). Predonation opioid use is independently associated with readmission after donor nephrectomy. Future research should examine underlying mechanisms and approaches to reducing risks of postdonation complications.

OPTN/SRTR 2015 Annual Data Report: Economics

While the costs to Medicare of solid organ transplants are varied and considerable, the total Medicare expenditure of $4.4 billion for solid organ transplant recipients in 2014 remained less than 1% of all Medicare expenditures. For patients covered by Medicare, the ratio of pre- to posttransplant cost of care varied widely by organ and within some organ categories by patient characteristics. This chapter reports pretransplant costs for all solid organ candidates covered by Medicare to allow investigators to further explore the relative cost of transplant compared with alternative management.

OPTN/SRTR 2015 Annual Data Report: Pancreas

The number of pancreas transplants performed in the United States stabilized over the last 3 years after nearly a decade of steady decline. Numbers of new additions to the list also stabilized during the same period. Notably, the persistent decline in pancreas after kidney transplants also seems to have abated, at least for now. The first full year of data after implementation of the new pancreas allocation system revealed no change in the distribution of organs between simultaneous pancreas-kidney (SPK) transplant and pancreas transplant alone. The percentage of kidneys used in SPK transplants was also unchanged. While a uniform definition of pancreas graft failure was approved in June 2015, it is awaiting implementation. Meanwhile, SRTR will refrain from publishing pancreas graft failure data in the program-specific reports. Therefore, it is difficult to track trends in outcomes after pancreas transplant over the past 2 years. New initiatives by the OPTN/UNOS Pancreas Transplantation Committee include facilitated pancreas allocation and broadened allocation of pancreata across compatible ABO blood types to increase organ utilization.

OPTN/SRTR 2015 Annual Data Report: Liver

Several notable developments in adult liver transplantation in the US occurred in 2015. The year saw the largest number of liver transplants to date, leading to reductions in median waiting time, in waitlist mortality for all model for end-stage liver disease categories, and in the number of candidates on the waiting list at the end of the year. Numbers of additions to the waiting list and of liver transplants performed in patients with hepatitis C virus infection decreased for the first time in recent years. However, other diagnoses, such as non-alcoholic fatty liver disease and alcoholic cirrhosis, became more prevalent. Despite large numbers of severely ill patients undergoing liver transplant, graft survival rates continued to improve. The number of new active candidates added to the pediatric liver transplant waiting list in 2015 was 689, down from a peak of 826 in 2005. The number of prevalent pediatric candidates (on the list on December 31 of the given year) continued to decline, to 373 active and 195 inactive candidates. The number of pediatric liver transplants peaked at 613 in 2008 and was 580 in 2015. The number of living donor pediatric liver transplants increased to its highest level, 79, in 2015; most were from donors closely related to the recipients. Pediatric graft survival rates continued to improve.

OPTN/SRTR 2015 Annual Data Report: Kidney

The first full year of data after implementation of the new kidney allocation system reveals an increase in deceased donor kidney transplants among black candidates and those with calculated panel-reactive antibodies 98%-100%, but a decrease among candidates aged 65 years or older. Data from 2015 also demonstrate ongoing positive trends in graft and patient survival for both deceased and living donor kidney transplants, but the challenges of a limited supply of kidneys in the setting of increasing demand remain evident. While the total number of patients on the waiting list decreased for the first time in a decade, this was due to a combination of a decrease in the number of candidates added to the list and an increase in the number of candidates removed from the list due to deteriorating medical condition, as well as an increase in total transplants. Deaths on the waiting list remained flat, but this was likely because of an increasing trend toward removing inactive candidates too sick to undergo transplant.

OPTN/SRTR 2015 Annual Data Report: Lung

In 2015, 2409 active candidates aged 12 years or older were added to the lung transplant waiting list; 2072 transplants were performed, the most of any year. The median waiting time for candidates listed in 2015 was 3.4 months; the shortest waiting time was for diagnosis group D. Despite the highest recorded transplant rate of 157 per 100 waitlist years, waitlist mortality continued a steady decade-long rise to a high of 16.5 deaths per 100 waitlist years. Measures of short- and long-term survival showed no trend toward improved overall survival in the past 5 years, except that 6-month death rates decreased from 9.4% in 2005 to 7.9% in 2014. At 5 years posttransplant, 55.5% of recipients remained alive. In 2015, 23 new child (ages 0-11 years) candidates were added to the list; 17 transplants were performed. Incidence of death was 6.1% at 6 months and 8.2% at 1 year for transplants in 2013-2014. Important policy changes will affect access to transplant. In February 2015, OPTN implemented a comprehensive revision of the lung allocation score to better reflect mortality risk. Broader geographic sharing of donor lungs for pediatric candidates and allowance for selected transplants across blood types for candidates aged younger than 2 years have been approved and are expected to improve pediatric access to transplant. The impact of these changes on lung transplant trends will be observed in the coming years.

OPTN/SRTR 2015 Annual Data Report: Heart

The number of heart transplant candidates and transplants performed continued to rise each year. In 2015, 2819 heart transplants were performed. In addition, the number of new adult candidates on the waiting list increased 51% since 2004. The number of adult heart transplant survivors continued to increase, and in 2015, 29,172 recipients were living with heart transplants. Patient mortality following transplant has declined. The number of pediatric candidates and transplants performed also increased. New listings for pediatric heart transplants increased from 451 in 2004 to 644 in 2015. The number of pediatric heart transplants performed each year increased from 297 in 2004 to 460 in 2015. Among pediatric patients who underwent transplant in 2014, death occurred in 7.2% at 6 months and 9.6% at 1 year.

OPTN/SRTR 2015 Annual Data Report: Intestine

Intestine and intestine-liver transplant remains important in the treatment of intestinal failure, despite decreased morbidity associated with parenteral nutrition. In 2015, 196 new patients were added to the intestine transplant waiting list, with equal numbers waiting for intestine and intestine-liver transplant. Among prevalent patients on the list at the end of 2015, 63.3% were waiting for an intestine transplant and 36.7% were waiting for an intestine-liver transplant. The pretransplant mortality rate decreased dramatically over time for all age groups. Pretransplant mortality was notably higher for intestine-liver than for intestine transplant candidates (respectively, 19.9 vs. 2.8 deaths per 100 waitlist years in 2014-2015). By age, pretransplant mortality was highest for adult candidates, at 19.6 per 100 waitlist years, and lowest for children aged younger than 6 years, at 3.6 per 100 waitlist years. Pretransplant mortality by etiology was highest for candidates with non-congenital types of short-gut syndrome. Numbers of intestine transplants without a liver increased from a low of 51 in 2013 to 70 in 2015. Intestine-liver transplants increased from a low of 44 in 2012 to 71 in 2015. Short-gut syndrome (congenital and non-congenital) was the main cause of disease leading to intestine and to intestine-liver transplant. Patient survival was lowest for adult intestine-liver recipients and highest for pediatric intestine recipients.

OPTN/SRTR 2015 Annual Data Report: Deceased Organ Donation

SRTR uses data collected by OPTN to calculate metrics such as donation/conversion rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2015, 1,072,828 death and imminent death referrals were made to Organ Procurement Organizations, of which 21,559 met the definition of eligible (9793) or imminent (11,766) deaths per OPTN policy. The number of deceased donors was 9080, and this number has been increasing since 2010. The number of organs authorized for recovery increased slightly to 65,086 in 2015, and the number recovered increased slightly to 25,762. In 2015, 4370 organs were discarded, including 3157 kidneys, 311 pancreata, 703 livers, 30 hearts, and 214 lungs. These numbers suggest a need to reduce the number of organs discarded.

Potential Implications of Recent and Proposed Changes in the Regulatory Oversight of Solid Organ Transplantation in the United States

Every 6 months, the Scientific Registry of Transplant Recipients (SRTR) publishes evaluations of every solid organ transplant program in the United States, including evaluations of 1-year patient and graft survival. The Centers for Medicare & Medicaid Services (CMS) and the Organ Procurement and Transplantation Network (OPTN) Membership and Professional Standards Committee (MPSC) use SRTR's 1-year evaluations for regulatory review of transplant programs. Concern has been growing that the regulatory scrutiny of transplant programs with lower-than-expected outcomes is harmful, causing programs to undertake fewer high-risk transplants and leading to unnecessary organ discards. As a result, CMS raised its threshold for a "Condition-Level Deficiency" designation of observed relative to expected 1-year graft or patient survival from 1.50 to 1.85. Exceeding this threshold in the current SRTR outcomes report and in one of the four previous reports leads to scrutiny that may result in loss of Medicare funding. For its part, OPTN is reviewing a proposal from the MPSC to also change its performance criteria thresholds for program review, to review programs with "substantive clinical differences." We review the details and implications of these changes in transplant program oversight.

Effects of High-Risk Kidneys on Scientific Registry of Transplant Recipients Program Quality Reports

There is a perception that transplanting high-risk kidneys causes programs to be identified as underperforming, thereby increasing the frequency of discards and diminishing access to transplant. Thus, the Organ Procurement and Transplantation Network (OPTN) has considered excluding transplants using kidneys from donors with high Kidney Donor Profile Index (KDPI) scores (≥0.85) when assessing program performance. We examined whether accepting high-risk kidneys (KDPI ≥0.85) for transplant yields worse outcome evaluations. Despite a clear relationship between KDPI and graft failure and mortality, there was no relationship between a program's use of high-KDPI kidneys and poor performance evaluations after risk adjustment. Excluding high-KDPI donor transplants from the June 2015 evaluations did not alter the programs identified as underperforming, because in every case underperforming programs also had worse-than-expected outcomes among lower-risk donor transplants. Finally, we found that hypothetically accepting and transplanting additional kidneys with KDPI similar to that of kidneys currently discarded would not adversely affect program evaluations. Based on the study findings, there is no evidence that programs that accept higher-KDPI kidneys are at greater risk for low performance evaluations, and risk aversion may limit access to transplant for candidates while providing no measurable benefit to program evaluations.

Variation in Comedication Use According to Kidney Transplant Immunosuppressive Regimens: Application of Integrated Registry and Pharmacy Claims Data

BACKGROUND

Modern immunosuppression therapies (ISx) have many side effects, and transplant recipients must take an array of "comedications" to help mitigate complications. Comedication use patterns are not well described in large, representative samples because of lack of data.

METHODS

We integrated national U.S. transplant registry data with pharmacy records (2005-2010) from a large pharmaceutical claims clearinghouse to examine treatments for anemia, metabolic disorders, and infections in relation to ISx regimens in months 6-12 post-transplantation (N = 22,453). Associations of ISx with comedication use (adjusted odds ratio [aOR]) were quantified with multivariate logistic regression including adjustment for recipient, donor, and transplant factors.

RESULTS

Compared to a reference regimen of tacrolimus, mycophenolic acid, and prednisone, sirolimus-based ISx was associated with significantly more common use of erythropoiesis-stimulating agents (aOR 2.52, 95% confidence interval [CI] 2.06-3.09), iron (aOR 2.26, 95% CI 1.92-2.65), statins (aOR 1.47, 95% CI 1.33-1.63), fibrates (aOR 2.35, 95% CI 1.90-2.90), and phosphorous binders (aOR 2.85, 95% CI 1.80-4.50). Patterns were similar after adjustment for first-year estimated glomerular filtration rate, except the association with phosphorous binders was no longer significant. Cyclosporine-based ISx was associated with more common erythropoiesis-stimulating agent use, including after estimated glomerular filtration rate adjustment (aOR 1.61, 95% CI 1.24-2.10). Compared to those who were being administered triple ISx, recipients receiving tacrolimus-based dual and monotherapies had lower use of statins, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEi/ARBs), and antibacterial agents. Recipients of steroid-free ISx were less commonly treated for post-transplantation diabetes.

CONCLUSIONS

Alternate ISx regimens are associated with varying treatment requirements for hematologic, metabolic. and infectious complications. Comedication use should be considered in the cost-effectiveness and individualization of ISx regimens.

Heart

As the number of candidates listed for heart transplant continues to rise, it is encouraging that the number of heart transplants also continues to rise steadily each year. Evaluation of waitlist activity demonstrates a growing number of adult candidates removed from the list due to undergoing transplant, but also growing numbers of adult candidates added to the list over the past 3 years. In 2014, 2679 heart transplants were performed, an increase of 28.4% since 2003, and the number of people living with a transplanted heart continued to increase. The number of new pediatric candidates added to the heart transplant waiting list increased to 593 in 2014. The number of pediatric heart transplants performed each year increased from 293 in 2003 to 410 in 2014. Almost 60% of pediatric candidates waiting on December 31, 2014, had been waiting for less than 1 year, compared with 43.0% in 2004. Among pediatric patients who underwent transplant in 2008-2012, overall cumulative incidence of death at 1, 3, and 5 years was 9.2%, 14.7%, and 18.3%, respectively.

Pancreas

Even though pancreas transplant numbers have steadily declined over the past decade, new listings increased in 2014 compared with the previous year, notably for pancreas transplant alone (PTA) and simultaneous pancreas-kidney transplant. The number of new PTAs also increased over the past two years. Whether this is a sustainable trend remains to be seen. Significant events in 2014 included implementation of a new pancreas allocation system and development of a proposed uniform definition of pancreas graft failure. Meanwhile, overall pancreas transplant rates and outcomes continued to improve. Substantial decline in pancreas after kidney transplants remains a serious concern. SRTR has not published pancreas graft failure data in the program-specific reports for the past two years. While this will not change in the near future, the acceptance of a uniform definition of graft failure is a crucial first step toward resuming graft failure reporting. Continued improvements and innovation, both surgical and immunological, will be critical to keep pancreas transplant as a viable option for treatment of insulin-dependent diabetes. As alternative therapies for diabetes such as islet transplant and artificial pancreas are evolving, improved outcomes with minimizations of complications are more important than ever.

Economics

While the costs to Medicare of solid organ transplants are varied and considerable, the total Medicare expenditure of $4.2 billion for solid organ transplant recipients in 2013 remains less than 1% of all Medicare expenditures. Kidney transplant remains one of the most cost-effective surgical interventions in medicine and exhibits a rare feature in that it is generally known to be cost-saving in the long term. For patients covered by Medicare, lung transplant is one of the more costly solid organ transplants performed. This chapter reports pretransplant costs for lung candidates to allow investigators to further explore the relative cost of lung transplant compared with alternative management.

Estimated GFR for Living Kidney Donor Evaluation

All living kidney donor candidates undergo evaluation of GFR. Guidelines recommend measured GFR (mGFR), using either an endogenous filtration marker or creatinine clearance, rather than estimated GFR (eGFR), but measurement methods are difficult, time consuming and costly. We investigated whether GFR estimated from serum creatinine (eGFRcr) with or without sequential cystatin C is sufficiently accurate to identify donor candidates with high probability that mGFR is above or below thresholds for clinical decision making. We combined the pretest probability for mGFR thresholds <60, <70, ≥80, and ≥90 mL/min per 1.73 m(2) based on demographic characteristics (from the National Health and Nutrition Examination Survey) with test performance of eGFR (categorical likelihood ratios from the Chronic Kidney Disease Epidemiology Collaboration) to compute posttest probabilities. Using data from the Scientific Registry of Transplant Recipients, 53% of recent living donors had predonation eGFRcr high enough to ensure ≥95% probability that predonation mGFR was ≥90 mL/min per 1.73 m(2) , suggesting that mGFR may not be necessary in a large proportion of donor candidates. We developed a Web-based application to compute the probability, based on eGFR, that mGFR for a donor candidate is above or below a range of thresholds useful in living donor evaluation and selection.