Faculty Bibliography

IMPORTANCE/UNASSIGNED:Identifying the mechanisms of structural racism, such as racial and ethnic segregation, is a crucial first step in addressing the persistent disparities in access to live donor kidney transplantation (LDKT). OBJECTIVE/UNASSIGNED:To assess whether segregation at the candidate's residential neighborhood and transplant center neighborhood is associated with access to LDKT. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:In this cohort study spanning January 1995 to December 2021, participants included non-Hispanic Black or White adult candidates for first-time LDKT reported in the US national transplant registry. The median (IQR) follow-up time for each participant was 1.9 (0.6-3.0) years. MAIN OUTCOME AND MEASURES/UNASSIGNED:Segregation, measured using the Theil H method to calculate segregation tertiles in zip code tabulation areas based on the American Community Survey 5-year estimates, reflects the heterogeneity in neighborhood racial and ethnic composition. To quantify the likelihood of LDKT by neighborhood segregation, cause-specific hazard models were adjusted for individual-level and neighborhood-level factors and included an interaction between segregation tertiles and race. RESULTS/UNASSIGNED:Among 162 587 candidates for kidney transplant, the mean (SD) age was 51.6 (13.2) years, 65 141 (40.1%) were female, 80 023 (49.2%) were Black, and 82 564 (50.8%) were White. Among Black candidates, living in a high-segregation neighborhood was associated with 10% (adjusted hazard ratio [AHR], 0.90 [95% CI, 0.84-0.97]) lower access to LDKT relative to residence in low-segregation neighborhoods; no such association was observed among White candidates (P for interaction = .01). Both Black candidates (AHR, 0.94 [95% CI, 0.89-1.00]) and White candidates (AHR, 0.92 [95% CI, 0.88-0.97]) listed at transplant centers in high-segregation neighborhoods had lower access to LDKT relative to their counterparts listed at centers in low-segregation neighborhoods (P for interaction = .64). Within high-segregation transplant center neighborhoods, candidates listed at predominantly minority neighborhoods had 17% lower access to LDKT relative to candidates listed at predominantly White neighborhoods (AHR, 0.83 [95% CI, 0.75-0.92]). Black candidates residing in or listed at transplant centers in predominantly minority neighborhoods had significantly lower likelihood of LDKT relative to White candidates residing in or listed at transplant centers located in predominantly White neighborhoods (65% and 64%, respectively). CONCLUSIONS/UNASSIGNED:Segregated residential and transplant center neighborhoods likely serve as a mechanism of structural racism, contributing to persistent racial disparities in access to LDKT. To promote equitable access, studies should assess targeted interventions (eg, community outreach clinics) to improve support for potential candidates and donors and ultimately mitigate the effects of segregation.

BACKGROUND:The Lung Allocation Score, implemented in 2005, prioritized lung transplant candidates by medical urgency rather than waiting list time and was expected to improve racial disparities in transplant allocation. We evaluated whether racial disparities in lung transplant persisted after 2005. METHODS:We identified all wait-listed adult lung transplant candidates in the United States from 2005 through 2021 using the Scientific Registry of Transplant Recipients. We evaluated the association between race and receipt of a transplant by using a multivariable competing risk regression model adjusted for demographics, socioeconomic status, Lung Allocation Score, clinical measures, and time. We evaluated interactions between race and age, sex, socioeconomic status, and Lung Allocation Score. RESULTS:We identified 33,158 candidates on the lung transplant waiting list between 2005 and 2021: 27,074 White (82%), 3350 African American (10%), and 2734 Hispanic (8%). White candidates were older, had higher education levels, and had lower Lung Allocation Scores (P < .001). After multivariable adjustment, African American and Hispanic candidates were less likely to receive lung transplants than White candidates (African American: adjusted subhazard ratio, 0.86; 95% CI, 0.82-0.91; Hispanic: adjusted subhazard ratio, 0.82; 95% CI, 0.78-0.87). Lung transplant was significantly less common among Hispanic candidates aged >65 years (P = .003) and non-White candidates from higher-poverty communities (African-American: P = .013; Hispanic: P =.0036). CONCLUSIONS:Despite implementation of the Lung Allocation Score, racial disparities persisted for wait-listed African American and Hispanic lung transplant candidates and differed by age and poverty status. Targeted interventions are needed to ensure equitable access to this life-saving intervention.

Body mass index is often used to determine kidney transplant (KT) candidacy. However, this measure of body composition (BC) has several limitations, including the inability to accurately capture dry weight. Objective computed tomography (CT)-based measures may improve pre-KT risk stratification and capture physiological aging more accurately. We quantified the association between CT-based BC measurements and waitlist mortality in a retrospective study of 828 KT candidates (2010-2022) with clinically obtained CT scans using adjusted competing risk regression. In total, 42.5% of candidates had myopenia, 11.4% had myopenic obesity (MO), 68.8% had myosteatosis, 24.8% had sarcopenia (probable = 11.2%, confirmed = 10.5%, and severe = 3.1%), and 8.6% had sarcopenic obesity. Myopenia, MO, and sarcopenic obesity were not associated with mortality. Patients with myosteatosis (adjusted subhazard ratio [aSHR] = 1.62, 95% confidence interval [CI]: 1.07-2.45; after confounder adjustment) or sarcopenia (probable: aSHR = 1.78, 95% CI: 1.10-2.88; confirmed: aSHR = 1.68, 95% CI: 1.01-2.82; and severe: aSHR = 2.51, 95% CI: 1.12-5.66; after full adjustment) were at increased risk of mortality. When stratified by age, MO (aSHR = 2.21, 95% CI: 1.28-3.83; P interaction = .005) and myosteatosis (aSHR = 1.95, 95% CI: 1.18-3.21; P interaction = .038) were associated with elevated risk only among candidates <65 years. MO was only associated with waitlist mortality among frail candidates (adjusted hazard ratio = 2.54, 95% CI: 1.28-5.05; P interaction = .021). Transplant centers should consider using BC metrics in addition to body mass index when a CT scan is available to improve pre-KT risk stratification at KT evaluation.

RATIONALE & OBJECTIVE/OBJECTIVE:Because of the high risk of waitlist mortality and posttransplant complications, kidney transplant (KT) patients may benefit from advance care planning (ACP) and palliative care consultation (PCC). We quantified the prevalence and racial disparities in ACP and PCC among KT candidates and recipients. STUDY DESIGN/METHODS:Prospective cohort study. SETTING & PARTICIPANTS/METHODS:2,575 adult KT candidates and 1,233 adult recipients (2008-2020). EXPOSURE/METHODS:Race and ethnicity. OUTCOMES/RESULTS:All reports of ACP and PCC were abstracted from chart review. ACP was defined as patient self-report of an advance directive, presence of an advance directive in the medical record, or a documented goals-of-care conversation with a provider. PCC was defined as an ordered referral or a documented palliative care note in the medical record. ANALYTICAL APPROACH/METHODS:Racial/ethnic disparities in ACP/PCC were estimated using adjusted logistic regression. RESULTS:21.4% of KT candidates and 34.9% of recipients engaged in ACP. There were racial/ethnic disparities in ACP among KT candidates (White, 24.4%; Black, 19.1%; Hispanic, 15%; other race and ethnicity, 21.1%; P=0.008) and recipients (White, 39.5%; Black, 31.2%; Hispanic, 26.3%; other race and ethnicity, 26.6%; P=0.007). After adjustment, Black KT recipients had a 29% lower likelihood of engaging in ACP (OR, 0.71; 95% CI, 0.55-0.91) than White KT recipients. Among older (aged≥65 years) recipients, those who were Black had a lower likelihood of engaging in ACP, but there was no racial disparity among younger recipients (P=0.020 for interaction). 4.2% of KT candidates and 5.1% of KT recipients engaged in PCC; there were no racial disparities in PCC among KT candidates (White, 5.3%; Black, 3.6%; Hispanic, 2.5%; other race and ethnicity, 2.1%; P=0.13) or recipients (White, 5.5%; Black, 5.6%; Hispanic, 0.0%; other race and ethnicity, 1.3%; P = 0.21). LIMITATIONS/CONCLUSIONS:Generalizability may be limited to academic transplant centers. CONCLUSIONS:ACP is not common among KT patients, and minoritized transplant patients are least likely to engage in ACP; PCC is less common. Future efforts should aim to integrate ACP and PCC into the KT process. PLAIN-LANGUAGE SUMMARY/UNASSIGNED:Kidney transplant (KT) candidates and recipients are at elevated risk of morbidity and mortality. They may benefit from completing a document or conversation with their palliative care provider that outlines their future health care wishes, known as advance care planning (ACP), which is a component of palliative care consultation (PCC). We wanted to determine how many KT candidates and recipients have engaged in ACP or PCC and identify potential racial disparities. We found that 21.4% of candidates and 34.9% of recipients engaged in ACP. After adjustment, Black recipients had a 29% lower likelihood of engaging in ACP. We found that 4.2% of KT candidates and 5.1% of KT recipients engaged in PCC, with no racial disparities found in PCC.

BACKGROUND:Kidney transplant (KT) recipients have numerous risk factors for delirium, including those shared with the general surgical population (eg, age and major surgery) and transplant-specific factors (eg, neurotoxic immunosuppression medications). Evidence has linked delirium to long-term dementia risk in older adults undergoing major surgery. We sought to characterize dementia risk associated with post-KT delirium. METHODS:Using the United States Renal Data System datasets, we identified 35 800 adult first-time KT recipients ≥55 y. We evaluated risk factors for delirium using logistic regression. We evaluated the association between delirium and incident dementia (overall and by subtype: Alzheimer's, vascular, and other/mixed-type), graft loss, and death using Fine and Gray's subhazards models and Cox regression. RESULTS:During the KT hospitalization, 0.9% of recipients were diagnosed with delirium. Delirium risk factors included age (OR = 1.40, 95% CI, 1.28-1.52) and diabetes (OR = 1.38, 95% CI, 1.10-1.73). Delirium was associated with higher risk of death-censored graft loss (aHR = 1.52, 95% CI, 1.12-2.05) and all-cause mortality (aHR = 1.53, 95% CI, 1.25-1.89) at 5 y post-KT. Delirium was also associated with higher risk of dementia (adjusted subhazard ratio [aSHR] = 4.59, 95% CI, 3.48-6.06), particularly vascular dementia (aSHR = 2.51, 95% CI, 1.01-6.25) and other/mixed-type dementia (aSHR = 5.58, 95% CI, 4.24-7.62) subtypes. The risk of all-type dementia associated with delirium was higher for younger recipients aged between 55 and 64 y (Pinteraction = 0.01). CONCLUSIONS:Delirium is a strong risk factor for subsequent diagnosis of dementia among KT recipients, particularly those aged between 55 and 64 y at the time of transplant. Patients experiencing posttransplant delirium might benefit from early interventions to enhance cognitive health and surveillance for cognitive impairment to enable early referral for dementia care.

RATIONALE & OBJECTIVE/OBJECTIVE:Frailty is common in individuals with chronic kidney disease (CKD) and increases the risk of adverse outcomes in adults with kidney failure requiring dialysis. However, this relationship has not been thoroughly evaluated among those with non-dialysis-dependent CKD. STUDY DESIGN/METHODS:Prospective cohort study. SETTING & PARTICIPANTS/METHODS:2,539 adults in the Chronic Renal Insufficiency Cohort Study. EXPOSURE/METHODS:Frailty status assessed using 5 criteria: slow gait speed, muscle weakness, low physical activity, exhaustion, and unintentional weight loss. OUTCOME/RESULTS:Atherosclerotic events, incident heart failure, all-cause death, and cardiovascular death. ANALYTICAL APPROACH/METHODS:Cause-specific hazards models. RESULTS:, and the median urine protein was 0.2mg/day. Frailty status was as follows: 12% frail, 51% prefrail, and 37% nonfrail. Over a median follow-up of 11.4 years, there were 393 atherosclerotic events, 413 heart failure events, 497 deaths, and 132 cardiovascular deaths. In multivariable regression analyses, compared with nonfrailty, both frailty and prefrailty status were each associated with higher risk of an atherosclerotic event (HR, 2.03 [95% CI, 1.41-2.91] and 1.77 [95% CI, 1.35-2.31], respectively) and incident heart failure (HR, 2.22 [95% CI, 1.59-3.10] and 1.39 [95% CI, 1.07-1.82], respectively), as well as higher risk of all-cause death (HR, 2.52 [95% CI, 1.84-3.45] and 1.76 [95% CI, 1.37-2.24], respectively) and cardiovascular death (HR, 3.01 [95% CI, 1.62-5.62] and 1.78 [95% 1.06-2.99], respectively). LIMITATIONS/CONCLUSIONS:Self-report of aspects of the frailty assessment and comorbidities, which may have led to bias in some estimates. CONCLUSIONS:In adults with CKD, frailty status was associated with higher risk of cardiovascular events and mortality. Future studies are needed to evaluate the impact of interventions to reduce frailty on cardiovascular outcomes in this population. PLAIN-LANGUAGE SUMMARY/UNASSIGNED:Frailty is common in individuals with chronic kidney disease (CKD) and increases the risk of adverse outcomes. We sought to evaluate the association of frailty status with cardiovascular events and death in adults with CKD. Frailty was assessed according to the 5 phenotypic criteria detailed by Fried and colleagues. Among 2,539 participants in the CRIC Study, we found that 12% were frail, 51% were prefrail, and 37% were nonfrail. Frailty status was associated with an increased risk of atherosclerotic events, incident heart failure, and death.

BACKGROUND:Frailty is associated with poor outcomes in surgical patients including kidney transplant recipients. Transplant centers that measure frailty have better pre- and post-operative outcomes. However, clinical utility of existing tools is low due to time constraints. To address this major barrier to implementation in the pre-operative evaluation of patients, we developed an abridged frailty phenotype. METHODS:The abridged frailty phenotype was developed by simplifying the 5 Physical Frailty Phenotype (PFP) components in a two-center prospective cohort of 3,220 kidney transplant candidates and tested for efficiency (time to completion) in 20 candidates evaluation (1/2009-3/2020). We examined area under curve (AUC) and Cohen's kappa agreement to compare the abridged assessment with the PFP. We compared waitlist mortality risk (competing risks models) by frailty using the PFP and abridged assessment, respectively. Model discrimination was assessed using Harrell's C-statistic. RESULTS:Of 3,220 candidates, the PFP and abridged assessment identified 23.8% and 27.4% candidates as frail, respectively. The abridged frailty phenotype had substantial agreement (kappa=0.69, 95%CI:0.66-0.71) and excellent discrimination (area under the curve=0.861). Among 20 patients at evaluation, abridged assessment took 5-7 minutes to complete. The PFP and abridged assessment had similar associations with waitlist mortality (subdistribution hazard ratio [SHR]=1.62, 95%CI:1.26-2.08 vs. SHR=1.70, 95%CI:1.33-2.16) and comparable mortality discrimination (p=0.51). CONCLUSIONS:The abridged assessment is an efficient and valid way to identify frailty. It predicts waitlist mortality without sacrificing discrimination. Surgical departments should consider utilizing the abridged assessment to evaluate frailty in patients when time is limited.

BACKGROUND:Statins are the third most prescribed drug class in kidney transplant recipients as cardiovascular disease is the leading cause of death in this population. However, statins' safety profile remains unclear in kidney transplant recipients who are uniquely burdened by concomitant immunosuppression and comorbidities. We conducted a national study to characterize the association of statin use with adverse events in kidney transplant recipients. METHODS:We studied adult (18 years or older) single-organ kidney transplant recipients in 2006-2016 with Medicare as primary payer ( n =57,699). We used prescription drug claims to capture statin use and International Classification of Diseases 9/10 diagnosis codes to capture statin-related adverse events (post-transplant diabetes mellitus, hemorrhagic stroke, cataract, liver injury, and rhabdomyolysis). We conducted multivariable Cox regression for each outcome with statin use as a time-varying exposure. RESULTS:Post-transplant diabetes mellitus was the most common outcome (5-year Kaplan-Meier incidence; 43% in statin users versus 35% in nonusers), followed by cataract (22% versus 12%), liver injury (2% versus 3%), hemorrhagic stroke (1.9% versus 1.4%), and rhabdomyolysis (1.5% versus 0.9%). In our multivariable analysis, statin use was associated with higher hazard of post-transplant diabetes mellitus (adjust hazard ratio [aHR], 1.12; 95% confidence interval [95% CI], 1.07 to 1.18), cataract (aHR, 1.22; 95% CI, 1.14 to 1.31), and rhabdomyolysis (aHR, 1.37; 95% CI, 1.10 to 1.71) but lower hazard of liver injury (aHR, 0.82; 95% CI, 0.71 to 0.95). Statin use was not associated with hemorrhagic stroke (aHR, 1.04; 95% CI, 0.86 to 1.26). CONCLUSIONS:Statins seem to be generally well tolerated in kidney transplant recipients. However, statin use might be associated with slightly higher risk of post-transplant diabetes mellitus, cataract, and rhabdomyolysis.

Background Pre-liver transplant (LT) sarcopenia is associated with poor survival. Methods exist for measuring body composition with use of CT scans; however, it is unclear which components best predict post-LT outcomes. Purpose To quantify the association between abdominal CT-based body composition measurements and post-LT mortality in a large North American cohort. Materials and Methods This was a retrospective cohort of adult first-time deceased-donor LT recipients from 2009 to 2018 who underwent pre-LT abdominal CT scans, including at the L3 vertebral level, at Johns Hopkins Hospital. Measurements included sarcopenia (skeletal muscle index [SMI] <50 in men and <39 in women), sarcopenic obesity, myosteatosis (skeletal muscle CT attenuation <41 mean HU for body mass index [BMI] <25 and <33 mean HU for BMI ≥25), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and VAT/SAT ratio. Covariates in the adjusted models were selected with use of least absolute shrinkage and selection operator regression with lambda chosen by means of 10-fold cross-validation. Cox proportional hazards models were used to quantify associations with post-LT mortality. Model discrimination was quantified using the Harrell C-statistic. Results A total of 454 recipients (median age, 57 years [IQR, 50-62 years]; 294 men) were evaluated. In the adjusted model, pre-LT sarcopenia was associated with a higher hazard ratio (HR) of post-LT mortality (HR, 1.6 [95% CI: 1.1, 2.4]; C-statistic, 0.64; P = .02). SMI was significantly negatively associated with survival after adjustment for covariates. There was no evidence that myosteatosis was associated with mortality (HR, 1.3 [95% CI: 0.86, 2.1]; C-statistic, 0.64; P = .21). There was no evidence that BMI (HR, 1.2 [95% CI: 0.95, 1.4]), VAT (HR, 1.0 [95% CI: 0.98, 1.1]), SAT (HR, 1.0 [95% CI: 0.97, 1.0]), and VAT/SAT ratio (HR, 1.1 [95% CI: 0.90, 1.4]) were associated with mortality (P = .15-.77). Conclusions Sarcopenia, as assessed on routine pre-liver transplant (LT) abdominal CT scans, was the only factor significantly associated with post-LT mortality. © RSNA, 2022 See also the editorial by Ruehm in this issue.