Black Race Is Associated With Higher Rates of Early-Onset End-Stage Renal Disease and Increased Mortality Following Liver Transplantation

Exception Policy Change Increased the Simultaneous Kidney-Liver Transplant Probability of Polycystic Disease in the Centers With High Median MELD at Transplantation

BACKGROUND

In 2019, Organ Procurement and Transplantation Network/United Network for Organ Sharing changed the exception policy for liver allocation to the median model for end-stage liver disease at transplantation (MMaT). This study evaluated the effects of this change on-waitlist outcomes of simultaneous liver-kidney transplantation (SLKT) for patients with polycystic liver-kidney disease (PLKD).

METHODS

Using the Organ Procurement and Transplantation Network/United Network for Organ Sharing registry, 317 patients with PLKD listed for SLKT between January 2016 and December 2021 were evaluated. Waitlist outcomes were compared between prepolicy (Era 1) and postpolicy (Era 2) eras.

RESULTS

One-year transplant probability was significantly higher in Era 2 than in Era 1 (55.7% versus 37.9%; P  = 0.001), and the positive effect on transplant probability of Era 2 was significant after risk adjustment (adjusted hazard ratio, 1.76; 95% confidence interval, 1.22-2.54; P  = 0.002 [ref. Era 1]), whereas waitlist mortality was comparable. Transplant centers were separated into the high and low MMaT groups with a score of 29 (median MMaT) and transplant probability in each group between eras was compared. In the high MMaT transplant centers, the 1-y transplant probability was significantly higher in Era 2 (27.5% versus 52.4%; P  = 0.003). The positive effect remained significant in the high MMaT center group (adjusted hazard ratio, 2.79; 95% confidence interval, 1.43-5.46; P  = 0.003 [ref. Era 1]) but not in the low MMaT center group. Although there was a difference between center groups in Era 1 ( P  = 0.006), it became comparable in Era 2 ( P  = 0.54).

CONCLUSIONS

The new policy increased 1-y SLKT probability in patients with PKLD and successfully reduced the disparities based on center location.

Pragmatic strategies to address health disparities along the continuum of care in chronic liver disease

Racial, ethnic, and socioeconomic disparities exist in the prevalence and natural history of chronic liver disease, access to care, and clinical outcomes. Solutions to improve health equity range widely, from digital health tools to policy changes. The current review outlines the disparities along the chronic liver disease health care continuum from screening and diagnosis to the management of cirrhosis and considerations of pre-liver and post-liver transplantation. Using a health equity research and implementation science framework, we offer pragmatic strategies to address barriers to implementing high-quality equitable care for patients with chronic liver disease.

Equity in liver transplantation: are we any closer?

PURPOSE OF REVIEW

As policies governing liver transplantation (LT) continue to change and influence clinical practice, it is important to monitor trends in equitable access and outcomes amongst patients. The purpose of this review is to closely examine recent advances and findings in health equity research in LT over the last 2 years; specifically evaluating inequities at the different stages of LT (referral, evaluation, listing, waitlist outcomes and post-LT outcomes).

RECENT FINDINGS

Advancements in geospatial analysis have enabled investigators to identify and begin to study the role of community level factors (such as neighborhood poverty, increased community capital/urbanicity score) in driving LT disparities. There has also been a shift in investigating center specific characteristics that contributes to disparities in waitlist access. Modification to the current model for end stage liver disease (MELD) score policy accounting for height differences is also crucial to eradicating the disparity in LT amongst sexes. Lastly, Black pediatric patients have been shown to have higher rates of death and worse posttransplant outcome after transitioning to adult healthcare.

SUMMARY

Although, there have been some advances in methodology and policies, inequities in waitlist access, waitlist outcomes and posttransplant outcomes continue to be pervasive in the field of LT. Future directions include expansion of social determinants of health measures, inclusion of multicenter designs, MELD score modification and investigation into drivers of worse posttransplant outcomes in Black patients.

Movement is Life-Optimizing Patient Access to Total Joint Arthroplasty: Chronic Kidney Disease Disparities

Approximately 15% of the American adults have chronic kidney disease (CKD). Rates of CKD are higher in underserved communities: It is highest in African Americans (16%) and Hispanic individuals (14%). African Americans are more than 3 times as likely compared with their White counterparts to develop end-stage kidney disease, requiring dialysis or a kidney transplant. Rates of CKD are higher in the geriatric and socioeconomic disadvantaged populations, groups with higher rates of hip and knee osteoarthritis and with comorbidities, including obesity, diabetes mellitus, heart disease, and hypertension. CKD of any stage is associated with increased postoperative readmission, complications, and mortality. Patients on hemodialysis after total joint arthroplasty are at increased risk for complications, including periprosthetic joint infection, and given the reduction in risk after kidney transplant, there is varying opinion regarding whether patients on hemodialysis are safe arthroplasty candidates.

Recipient and Center Factors Associated With Immunosuppression Practice Beyond the First Year After Liver Transplantation and Impact on Outcomes

BACKGROUND

Immunosuppression is a critical aspect of post-transplant management, yet practices at intermediate and late time points after liver transplantation (LT) are poorly characterized.

METHODS

A retrospective cohort of 11 326 adult first LT alone recipients between 2007 and 2016 was identified by linking United Network for Organ Sharing transplant data to Medicare administrative claims. The immunosuppression regimen was obtained from Medicare billing claims. Factors associated with calcineurin inhibitor (CNI) monotherapy at 1-, 3-, and 5-y post-LT were investigated using mixed-effects logistic regression. Center practice heterogeneity was evaluated. The association of immunosuppression regimen (time-updating) with patient and graft survival was studied.

RESULTS

CNI monotherapy was used in 51.9% at 1-y post-LT and 68.6% at 5-y post-LT. Center-specific rates ranged from 20.0%-79.9% to 15.4%-95.2%, respectively. CNI monotherapy at 1- and 3-y post-LT was less likely among Black recipients ( P = 0.027 and P = 0.015 versus White, respectively). CNI plus antimetabolite was associated with improved adjusted patient (hazard ratio, 0.59; P < 0.001) and graft (hazard ratio, 0.62; P < 0.001) survival versus CNI monotherapy. The benefit of CNI plus antimetabolite on patient and graft survival increased with older age.

CONCLUSIONS

In this first longitudinal analysis of LT immunosuppression practices among Medicare beneficiaries, a CNI plus antimetabolite approach led to improved outcomes. Significant center heterogeneity in practice was observed.

Intraoperative risk factors of acute kidney injury after liver transplantation

Acute kidney injury (AKI) is one of the most common complications of liver transplantation (LT). We examined the impact of intraoperative management on risk for AKI following LT. In this retrospective observational study, we linked data from the electronic health record with standardized transplant outcomes. Our primary outcome was stage 2 or 3 AKI as defined by Kidney Disease Improving Global Outcomes guidelines within the first 7 days of LT. We used logistic regression models to test the hypothesis that the addition of intraoperative variables, including inotropic/vasopressor administration, transfusion requirements, and hemodynamic markers improves our ability to predict AKI following LT. We also examined the impact of postoperative AKI on mortality. Of the 598 adult primary LT recipients included in our study, 43% (n = 255) were diagnosed with AKI within the first 7 postoperative days. Several preoperative and intraoperative variables including (1) electrolyte/acid-base balance disorder (International Classification of Diseases, Ninth Revision codes 253.6 or 276.x and International Classification of Diseases, Tenth Revision codes E22.2 or E87.x, where x is any digit; adjusted odds ratio [aOR], 1.917, 95% confidence interval [CI], 1.280-2.869; p = 0.002); (2) preoperative anemia (aOR, 2.612; 95% CI, 1.405-4.854; p = 0.002); (3) low serum albumin (aOR, 0.576; 95% CI, 0.410-0.808; p = 0.001), increased potassium value during reperfusion (aOR, 1.513; 95% CI, 1.103-2.077; p = 0.01), and lactate during reperfusion (aOR, 1.081; 95% CI, 1.003-1.166; p = 0.04) were associated with posttransplant AKI. New dialysis requirement within the first 7 days postoperatively predicted the posttransplant mortality. Our study identified significant association between several potentially modifiable variables with posttransplant AKI. The addition of intraoperative data did not improve overall model discrimination.

Impact of Race-Adjusted Glomerular Filtration Rate Estimation on Eligibility for Simultaneous Liver-Kidney Transplantation

Estimated glomerular filtration rate (eGFR) is adjusted for Black race in commonly used formulas. This has potential implications for access to simultaneous liver-kidney transplantation (SLKT) as qualifying criteria rely on eGFR. We performed a retrospective study of United Network for Organ Sharing national transplant registry data between February 28, 2002, and March 31, 2019, to evaluate the proportion of Black patients who would be reclassified as meeting SLKT criteria (as defined per current policies) if race adjustment were removed from 2 prominent eGFR equations (Modification of Diet in Renal Disease-4 [MDRD-4] and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]). Of the 7937 Black patients listed for transplant during the study period, we found that 3.6% would have been reclassified as qualifying for chronic kidney disease (CKD)-related SLKT with removal of race adjustment for MDRD-4, and 3.0% would have been reclassified with CKD-EPI; this represented 23.7% and 18.7% increases in SLKT candidacy, respectively. Reclassification impacted women more than men (eg, 4.5% versus 3.0% by MDRD-4; P < 0.05). In an exploratory analysis, patients meeting SLKT criteria by race-unadjusted eGFR equations were significantly more likely to receive liver transplantation alone (LTA) compared with SLKT. Approximately 2.0% of reclassified patients required kidney transplantation within 1 year of LTA versus 0.3% of nonreclassified patients. In conclusion, race adjustment in eGFR equations may impact SLKT candidacy for 3.0% to 4.0% of Black patients listed for LTA overall. Approximately 2.0% of patients reclassified as meeting SLKT criteria require short-term post-LTA kidney transplantation. These data argue for developing novel algorithms for glomerular filtration rate estimation free of race to promote equity.

Significant improvements, but consistent disparities in survival for African Americans after liver transplantation

Despite improvements in survival across races in the past 20 years, African Americans have worse liver transplant outcomes after orthotopic liver transplantation (OLT). This study aims at quantifying the change in disparities between African Americans and other races in survival after OLT. We retrospectively analyzed the United Network for Organ Sharing (UNOS) database for patient data for candidates who received a liver transplant between January 1, 2007 and December 31, 2017. Multivariate Cox proportional hazards regression indicated similar decreases in mortality over time for each race with a decrease in mortality for African Americans: 2010-2012 (HR = .930), 2012-2015 (HR = .882), and 2015-2017 (HR = .883) when compared to 2007-2010. Risk of mortality for African Americans compared to Caucasians varied across the 4 eras: 2007-2010 (HR = 1.083), 2010-2012 (HR = 1.090), 2012-2015 (HR = 1.070), and 2015-2017 (HR = 1.125). While African Americans have seen increases in survival in the past decade, a similar increase in survival for other races leaves a significant survival disparity in African Americans.

Changes and mediators of survival disparity among Black liver transplant recipients in the United States

A landmark 2002 study identified Black liver transplant (LT) recipients as having lower post-LT survival compared to other races. While persistent disparities exist, changes over time and mediating factors are understudied. Capturing LT recipients between 2002 and 2018 in UNOS, we used logistic regression and Cox proportional-hazard models to calculate differences in post-LT mortality among races. We examined interactions between transplant year and race. A mediation analysis assessed biologic and environmental factors potentially associated with race differences in post-LT survival. The cohort included 46,997 LT recipients (3898 Black;36,560 White;6539 Hispanic). In most years, Black (vs. White) LT recipients had a higher probability of age-adjusted mortality, not observed among Hispanics. In multivariable analysis, Blacks (vs. Whites) had higher (aHR = 1.15, 95% CI 1.07-1.24), whereas Hispanics had lower (aHR = 0.78, 95% CI 0.72-0.83) risk of mortality. Differences in post-LT mortality among Blacks (vs. Whites) narrowed between 2002 and 2009, were similar between 2010 and 2013, and may have worsened between 2014 and 2018. Race differences were larger for mortality beyond 1-year post-LT (vs. within 1-year), and among non-HCV (vs. HCV). Alcohol-associated liver disease (ALD) was the strongest mediator (13.9%, 95% CI 8.7-32.7%) of the Black-White disparity in 2010-2018. Our analyses suggest disparities may worsen with longer follow-up, as HCV recedes with elimination efforts, and with further increases in ALD.