Faculty Bibliography

Purpose of review/UNASSIGNED:To highlight recent research about frailty and its role as a predictor of adverse, long-term post-kidney transplant (KT) outcomes. Recent findings/UNASSIGNED:Frailty is easily measured using the physical frailty phenotype (PFP) developed by gerontologist Dr. Linda Fried and colleagues. In recent studies, >50% of KT recipients were frail (20%) or intermediately frail (32%) at KT admission. Frail recipients were at 1.3-times higher risk of immunosuppression intolerance and 2.2-times higher risk of mortality, even after accounting for recipient, donor, and transplant factors; these findings were consistent with those on short-term post-KT outcomes. Pilot data suggests that prehabilitation may be an intervention that increases physiologic reserve in frail KT recipients. Summary/UNASSIGNED:The PFP is a effective tool to measure frailty in ESRD that improves risk stratification for short-term and long-term post-KT outcomes. Interventions to improve physiologic reserve and prevent adverse KT outcomes, particularly among frail KT recipients, are needed.

Background:Frail obese community-dwelling older adults are at increased mortality risk. Among hemodialysis (HD) patients, frailty is common and associated with increased mortality risk; however, in dialysis, obesity is associated with decreased mortality risk. Whether the frail-obese phenotype is associated with increased mortality risk among HD patients remains unclear. Methods:This study included 370 incident HD patients enrolled in the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease (PACE) study. We measured frailty using the Fried phenotype, general obesity [body mass index (BMI) ≥30 kg/m2] and abdominal obesity [waist:hip ratio (WHR) ≥median WHR] and estimated their associations with mortality. Results:The mean age was 55 years, with 42% female, 73% African American, 57% diabetic and 52% frail. Frail HD patients had higher mean BMI (frail = 30.3 kg/m2, non-frail = 28.3 kg/m2; P = 0.02) and similar WHR (P = 0.8). Twenty-two percent were frail with general obesity and 27% were frail with abdominal obesity. Frailty was associated with 1.66-fold increased mortality risk [95% confidence interval (CI) 1.03-2.67]. BMI was associated with a decreased mortality risk [25.0-29.9 kg/m2 hazard ratio (HR) 0.53 (95% CI 0.31-0.93); ≥30 kg/m2 HR 0.34 (95% CI 0.19-0.62)]. Frailty was associated with elevated mortality risk among HD patients with general [HR 3.77 (95% CI 1.10-12.92)] and abdominal obesity [HR 2.38 (95% CI 1.17-4.82)]. Frailty was not associated with mortality among HD patients without general or abdominal obesity. Conclusions:In adults initiating HD, frailty was associated with elevated mortality risk, even among the obese. Frail-obese HD patients may be a high-risk, often-overlooked population, as obesity is assumed to be protective. Measurement of frailty and obesity may facilitate risk stratification.

AIM/OBJECTIVE:There is conflicting evidence regarding the safety and effectiveness of warfarin for atrial fibrillation (AF) treatment among older end-stage renal disease (ESRD) patients, and differences among subgroups are unclear. METHODS:Older dialysis patients who were newly diagnosed with AF (7/2007-12/2011) were identified in the United States Renal Data System. The adjusted hazard ratios (HR) of the outcomes (any stroke, ischaemic stroke, major bleeding, severe gastrointestinal bleeding, and death) by time-varying warfarin use were estimated using Cox regression accounting for the inverse probability of treatment weight. RESULTS:Among 5765 older dialysis patients with incident AF, warfarin was associated with significantly increased risk of major bleeding (HR = 1.50, 95% CI 1.33-1.68), but was not statistically associated with any stroke (HR = 0.92, 95% CI 0.75-1.12), ischaemic stroke (HR = 0.88, 95%CI 0.70-1.11) or gastrointestinal bleeding (HR = 1.03, 95% CI 0.80-1.32). Warfarin use was associated with a reduced risk of mortality (HR = 0.72, 95%CI 0.65-0.80). The association between warfarin and major bleeding differed by sex (male: HR = 1.29; 95%CI 1.08-1.55; female: HR = 1.67; 95%CI 1.44-1.93; P-value for interaction = 0.03). CONCLUSION/CONCLUSIONS:Older ESRD patients with AF who were treated with warfarin had a no difference in stroke risk, lower mortality risk, but increased major bleeding risk. The bleeding risk associated with warfarin was greater among women than men. The risk/benefit ratio of warfarin may be less favourable among older women.

More than one-third of US adults have limited health literacy, putting them at risk of adverse clinical outcomes. We evaluated the prevalence of limited health literacy among 1578 adult kidney transplant (KT) candidates (May 2014-November 2017) and examined its association with listing for transplant and waitlist mortality in this pilot study. Limited health literacy was assessed at KT evaluation by using a standard cutoff score ≤5 on the Brief Health Literacy Screen (score range 0-12, lower scores indicate worse health literacy). We used logistic regression and adjusted Cox proportional hazards models to identify risk factors for limited health literacy and to quantify its association with listing and waitlist mortality. We found that 8.9% of candidates had limited health literacy; risk factors included less than college education (adjusted odds ratio [aOR] = 2.87, 95% confidence interval [CI]:1.86-4.43), frailty (aOR = 1.85, 95% CI:1.22-2.80), comorbidity (Charlson comorbidity index [1-point increase] aOR = 1.12, 95% CI: 1.04-1.20), and cognitive impairment (aOR = 3.45, 95% CI: 2.20-5.41) after adjusting for age, sex, race, and income. Candidates with limited health literacy had a 30% (adjusted hazard ratio = 0.70, 95% CI: 0.54-0.91) decreased likelihood of listing and a 2.42-fold (95% CI: 1.16- to 5.05-fold) increased risk of waitlist mortality. Limited health literacy may be a salient mechanism in access to KT; programs to aid candidates with limited health literacy may improve outcomes and reduce disparities.

BACKGROUND:Restoration of kidney function after kidney transplant generally improves cognitive function. It is unclear whether frail recipients, with higher susceptibility to surgical stressors, achieve such post-transplant cognitive improvements or whether they experience subsequent cognitive decline as they age with a functioning graft. METHODS:In this two-center cohort study, we assessed pretransplant frailty (Fried physical frailty phenotype) and cognitive function (Modified Mini-Mental State Examination) in adult kidney transplant recipients. To investigate potential short- and medium-term effects of frailty on post-transplant cognitive trajectories, we measured cognitive function up to 4 years post-transplant. Using an adjusted mixed effects model with a random slope (time) and intercept (person), we characterized post-transplant cognitive trajectories by pretransplant frailty, accounting for nonlinear trajectories. RESULTS:Of 665 recipients (mean age 52.0 years) followed for a median of 1.5 years, 15.0% were frail. After adjustment, pretransplant cognitive scores were significantly lower among frail patients compared with nonfrail patients (89.0 versus 90.8 points). By 3 months post-transplant, cognitive performance improved for both frail (slope =0.22 points per week) and nonfrail (slope =0.14 points per week) recipients. Between 1 and 4 years post-transplant, improvements plateaued among nonfrail recipients (slope =0.005 points per week), whereas cognitive function declined among frail recipients (slope =-0.04 points per week). At 4 years post-transplant, cognitive scores were 5.8 points lower for frail recipients compared with nonfrail recipients. CONCLUSIONS:On average, both frail and nonfrail recipients experience short-term cognitive improvement post-transplant. However, frailty is associated with medium-term cognitive decline post-transplant. Interventions to prevent cognitive decline among frail recipients should be identified.

Prehabilitation is the process of enhancing preoperative functional capacity to improve tolerance for the upcoming stressor; it was associated with improved postoperative outcomes in a handful of studies, but never evaluated in transplantation. Kidney transplant (KT) candidates may be uniquely suited for prehabilitation because they experience a profound loss of functional capacity while waiting years on dialysis. To better understand the feasibility and effectiveness of prehabilitation in KT, we conducted a pilot study of center-based prehabilitation for candidates; this intervention consisted of weekly physical therapy sessions at an outpatient center with at-home exercises. We enrolled 24 participants; 18 participated in prehabilitation (75% of enrolled; 17% of eligible). 61% were male, 72% were African American, and mean age = 52 (SD = 12.9); 71% of participants had lower-extremity impairment, and 31% were frail. By 2 months of prehabilitation, participants improved their physical activity by 64% (P = 0.004) based on accelerometry. Participants reported high satisfaction. Among 5 prehabilitation participants who received KT during the study, length of stay was shorter than for age-, sex-, and race-matched control (5 vs 10 days; RR = 0.69; 95% CI:0.50-0.94; P = 0.02). These pilot study findings suggest that prehabilitation is feasible in pretransplant patients and may potentially be a strategy to improve post-KT outcomes.

BACKGROUND:Hemodialysis (HD) patients frequently experience pain. Previous studies of HD patients suggest increased opioid prescribing through 2010. It remains unclear if this trend continued after 2010 or declined with national trends. METHODS:Longitudinal cohort study of 484,745 HD patients in the United States Renal Data System/Medicare data. We used Poisson/negative binomial regression to estimate annual incidence rates of opioid prescribing between 2007 and 2014. We compared prescribing rates with the general US population using IQVIA's National Prescription Audit data. Outcomes included the following: percent of HD patients receiving an opioid prescription, rate of opioid prescriptions, quantity, days supply, morphine milligram equivalents (MME) dispensed per 100 person-days, and prescriptions per person. RESULTS:In 2007, 62.4% of HD patients received an opioid prescription. This increased to 63.2% in 2010 then declined to 53.7% by 2014. Opioid quantity peaked in 2011 at 73.5 pills per 100 person-days and declined to 62.6 pills per 100 person-days in 2014. MME peaked between 2010 and 2012 then declined through 2014. In 2014, MME rates were 1.8-fold higher among non-Hispanic patients and 1.6-fold higher among low-income patients. HD patients received 3.2-fold more opioid prescriptions per person compared to the general US population and were primarily prescribed oxycodone and hydrocodone. Between 2012 and 2014, HD patients experienced greater declines in opioid prescriptions per person (18.2%) compared to the general US population (7.1%). CONCLUSION:Opioid prescribing among HD patients declined between 2012 and 2014. However, HD patients continue receiving substantially more opioids than the general US population.

BACKGROUND:Kidney transplantation (KT) candidates often present with multiple comorbidities. These patients also have a substantial burden of frailty, which is also associated with increased mortality. However, it is unknown if frailty is merely a surrogate for comorbidity, itself an independent domain of risk, or if frailty and comorbidity have differential effects. Better understanding the interplay between these 2 constructs will improve clinical decision making in KT candidates. OBJECTIVE:To test whether comorbidity is equally associated with waitlist mortality among frail and nonfrail KT candidates and to test whether measuring both comorbidity burden and frailty improves mortality risk prediction. METHODS:We studied 2,086 candidates on the KT waitlist (November 2009 - October 2017) in a multicenter cohort study, in whom frailty and comorbidity were measured at evaluation. We quantified the association between Charlson comorbidity index (CCI) adapted for end-stage renal disease and waitlist mortality using an adjusted Cox proportional hazards model and tested whether this association differed between frail and nonfrail candidates. RESULTS:At evaluation, 18.1% of KT candidates were frail and 51% had a high comorbidity burden (CCI score ≥2). Candidates with a high comorbidity burden were at 1.38-fold (95% CI 1.01-1.89) increased risk of waitlist mortality. However, this association differed by frailty status (p for interaction = 0.01): among nonfrail candidates, a high comorbidity burden was associated with a 1.66-fold (95% CI 1.17-2.35) increased mortality risk; among frail candidates, here was no statistically significant association (HR 0.75, 95% CI 0.44-1.29). Adding this interaction between comorbidity and frailty to a mortality risk estimation model significantly improved prediction, increasing the c-statistic from 0.640 to 0.656 (p < 0.001). CONCLUSIONS:Nonfrail candidates with a high comorbidity burden at KT evaluation have an increased risk of waitlist mortality. Importantly, comorbidity is less of a concern in already high-risk patients who are frail.

End-stage liver disease (ESLD) is associated with cognitive impairment ranging from subtle alterations in attention to overt hepatic encephalopathy that resolves after transplant. Natural language processing (NLP) may provide a useful method to assess cognitive status in this population. We identified 81 liver transplant recipients with ESLD (4/2013-2/2018) who sent at least one patient-to-provider electronic message pre-transplant and post-transplant, and matched them 1:1 to "healthy" controls-who had similar disease, but had not been evaluated for liver transplant-by age, gender, race/ethnicity, and liver disease. Messages written by patients pre-transplant and post-transplant and controls was compared across 19 NLP measures using paired Wilcoxon signed-rank tests. While there was no difference overall in word length, patients with Model for End-Stage Liver Disease Score (MELD) ≥ 30 (n = 31) had decreased word length in pre-transplant messages (3.95 [interquartile range (IQR) 3.79, 4.14]) compared to post-transplant (4.13 [3.96, 4.28], p = 0.01) and controls (4.2 [4.0, 4.4], p = 0.01); there was no difference between post-transplant and controls (p = 0.4). Patients with MELD ≥ 30 had fewer 6+ letter words in pre-transplant messages (19.5% [16.4, 25.9] compared to post-transplant (23.4% [20.0, 26.7] p = 0.02) and controls (25.0% [19.2, 29.4]; p = 0.01). Overall, patients had increased sentence length pre-transplant (12.0 [9.8, 13.7]) compared to post-transplant (11.0 [9.2, 13.3]; p = 0.046); the same was seen for MELD ≥ 30 (12.3 [9.8, 13.7] pre-transplant vs. 10.8 [9.6, 13.0] post-transplant; p = 0.050). Application of NLP to patient-generated messages identified language differences-longer sentences with shorter words-that resolved after transplant. NLP may provide opportunities to detect cognitive impairment in ESLD.

OBJECTIVES:To explore trends in liver transplantation (LT) and outcomes for older recipients for evaluation, counseling, and appropriate referral of this vulnerable group of older adults. DESIGN:Prospective national cohort study. SETTING:Scientific Registry of Transplant Recipients (January 1, 2003-December 31, 2016). PARTICIPANTS:Older (aged ≥ 65) deceased donor liver-only transplant recipients (n=8,627). MEASUREMENTS:We evaluated temporal changes in recipient, donor, and transplant characteristics and post-LT length of stay (LOS), acute rejection, graft loss, and mortality using logistic regression and Cox proportional hazards. RESULTS:LT in older adults almost quadrupled, from 263 in 2003 (9.5% of total LTs that year) to 1,144 in 2016 (20.7% of total LTs). Recent recipients were more likely to be female and African American and have a higher body mass index and Model for End-Stage Liver Disease score. Hepatitis C, nonalcoholic steatohepatitis, and hepatocellular carcinoma were the most common indications for LT in recent recipients. Odds of LOS longer than 2 weeks decreased 34% from 2003-06 to 2013-16 (adjusted odds ratio (aOR)=0.66, 95% confidence interval (CI)=0.57-0.76, P < .001), 1-year acute rejection decreased 30% (aOR=0.70, 95% CI=0.56-0.88, P = .002), all-cause graft loss decreased 54% (adjusted hazard ratio (aHR)=0.46, 95% CI=0.40-0.52, P < .001), and mortality decreased 57% (aHR=0.43, 95% CI=0.38-0.49, P < .001). CONCLUSION:Despite the substantial increase in the number of older adults undergoing LT and the severity of their condition, LOS, rejection, graft loss, and mortality have significantly decreased over time. These trends can help guide appropriate LT referral and counseling in older adults with end-stage liver disease. J Am Geriatr Soc 66:2321-2326, 2018.