Faculty Bibliography

Communicating the current knowledge of medical outcomes after live kidney donation necessary to support donor candidates in well informed decision-making requires grounding in perspectives of comparison. Baseline risk (without donating), risk attributable to donation, and absolute risk (after donating) need to be considered. Severe perioperative complications and death are rare, but vary by demographic, clinical, and procedure factors. Innovative capture of "healthy" controls designed to simulate donor selection processes has identified higher risk of ESRD attributable to donation in two studies; importantly, however, the absolute 15-year ESRD incidence in donors remains very low (0.3%). In the first decade after donation, the risk of all-cause mortality and cardiovascular events is no higher than in healthy nondonors. Pregnancies in donors may incur attributable risk of gestational hypertension or preeclampsia (11% versus 5% incidence in one study). A modest rise in uric acid levels beginning early after donation, and a small (1.4%) increase in the 8-year incidence of gout, have also been reported in comparisons to healthy nondonors. As in the general population, postdonation outcomes vary by race, sex, and age. Efforts to improve the counseling and selection of living donors should focus on developing tools for tailored risk prediction according to donor characteristics, and ideally, compared with similar healthy nondonors.

OBJECTIVE:To determine the survival benefit of kidney transplantation in human immunodeficiency virus (HIV)-infected patients with end-stage renal disease (ESRD). SUMMARY BACKGROUND DATA:Although kidney transplantation (KT) has emerged as a viable option for select HIV-infected patients, concerns have been raised that risks of KT in HIV-infected patients are higher than those in their HIV-negative counterparts. Despite these increased risks, KT may provide survival benefit for the HIV-infected patient with ESRD, yet this important clinical question remains unanswered. METHODS:Data from the Scientific Registry of Transplant Recipients were linked to IMS pharmacy fills (January 1, 2001 to October 1, 2012) to identify and study 1431 HIV-infected KT candidates from the first point of active status on the waiting list. Time-dependent Cox regression was used to establish a counterfactual framework for estimating survival benefit of KT. RESULTS:Adjusted relative risk (aRR) of mortality at 5 years was 79% lower after KT compared with dialysis (aRR 0.21; 95% CI 0.10-0.42; P <0.001), and statistically significant survival benefit was achieved by 194 days of KT. Among patients coinfected with hepatitis C, aRR of mortality at 5 years was 91% lower after KT compared with dialysis (aRR 0.09; 95% CI 0.02-0.46; P < 0.004); however, statistically significant survival benefit was not achieved until 392 days after KT. CONCLUSIONS:Evidence suggests that for HIV-infected ESRD patients, KT is associated with a significant survival benefit compared with remaining on dialysis.

BACKGROUND:After kidney transplantation, early readmission is independently associated with graft loss and mortality. The mechanism of this association is poorly understood. Understanding the timeline of risk, that is, during the readmission hospitalization versus periods postreadmission, will provide additional insights. METHODS:We used national registry data to study 56 076 adult Medicare-primary first-time kidney transplant recipients from December 1999 to October 2011. Piecewise Cox proportional hazard models were used to estimate the association between graft loss, mortality, and readmission for 2 periods: readmission hospitalization and postreadmission. RESULTS:During the readmission hospitalization, graft loss was substantially higher (deceased donor kidney transplant [DDKT] without delayed graft function [DGF] hazard ratio: 24.634.447.9, P < 0.001; with DGF: 10.815.221.4, P < 0.001; live donor kidney transplant [LDKT]: 18.136.774.2, P < 0.001) and mortality was substantially higher (DDKT without DGF: 14.120.830.7, P < 0.001; with DGF: 9.0312.818.0, P < 0.001; LDKT: 9.0018.241.3, P < 0.001). Immediately after readmission discharge, graft loss (DDKT without DGF: 2.082.402.77, P < 0.001; with DGF: 1.832.142.51, P < 0.001; LDKT: 2.002.503.13, P < 0.001), and mortality (DDKT without DGF: 2.162.432.73, P < 0.001; with DGF: 1.832.162.88, P < 0.001; LDKT: 1.902.342.88, P < 0.001) remained elevated, but much less so. After readmission, the hazard of graft loss remained, but decreased 19% per year for DDKT recipients (time varying coefficient 0.780.810.85, P < 0.001) and 14% per year for LDKT recipients (0.790.860.93, P < 0.001). The hazard of mortality remained, but decreased 14% per year for DDKT recipients (0.830.860.89, P < 0.001) and 9% per year for LDKT recipients (0.850.910.98, P < 0.001). CONCLUSIONS:In conclusion, readmission is most strongly associated with graft loss and mortality during the readmission hospitalization, but also portends a lasting, albeit attenuated, risk postreadmission.

Older patients with ESRD who receive a kidney transplant (KT) may develop post-KT dementia and Alzheimer's disease (AD) associated with their long-standing kidney disease and/or neurotoxic immunosuppressant agents. To investigate this possibility, we studied 40,918 older (aged ≥55 years) KT recipients (January 1, 1999 to December 31, 2011) linked to Medicare claims through the US Renal Data System. We estimated dementia and AD risk (cumulative incidence) and studied factors associated with these sequelae using competing risks models. We estimated the risk of death-censored graft loss and mortality after developing dementia or the AD subtype of dementia, separately, using adjusted Cox proportional hazards models. Older recipients had a 10-year dementia risk ranging from 5.1% for recipients aged 55-60 years to 17.0% for recipients aged ≥75 years; 10-year AD risk ranged from 1.0% to 6.7%, respectively. The strongest predictors for dementia and AD were older recipient age and pretransplant diabetes. The 10-year graft loss risk was 28.8% for those who did not develop dementia and 43.1% for those who did, and the corresponding mortality risks were 55.7% and 89.9%, respectively. Older recipients with dementia had a 1.52-fold (95% confidence interval, 1.39 to 1.68) increased risk of graft loss and a 2.38-fold (95% confidence interval, 2.26 to 2.49) increased risk of mortality. We observed similar results for AD. We conclude that older KT recipients have a high risk of post-KT dementia and AD, and these sequelae associate with a profound effect on patient and graft survival.

Implications of prescription opioid use for outcomes after liver transplantation (LT) have not been described. We integrated national transplant registry data with records from a large pharmaceutical claims clearinghouse (2008-2014; n = 29,673). Opioid fills on the waiting list were normalized to morphine equivalents (MEs), and exposure was categorized as follows: > 0-2 ME/day (level 1), > 2-10 ME/day (level 2), > 10-70 ME/day (level 3), and >70 ME/day (level 4). Associations (adjusted hazard ratio [aHR], _{95% LCL} aHR _{95% UCL} ) of pretransplant ME level with patient and graft survival over 5 years after transplant were quantified by multivariate Cox regression including adjustment for recipient, donor, and transplant factors, as well as propensity adjustment for opioid use. Overall, 9.3% of recipients filled opioids on the waiting list. Compared with no use, level 3 (aHR _1.06 1.28_1.55 ) and 4 (aHR _1.16 1.52_1.98 ) opioid use during listing were associated with increased mortality over 5 years after transplant. These associations were driven by risk after the first transplant anniversary, such that mortality >1-5 years increased in a graded manner with higher use on the waiting list (level 2, aHR, _1.00 1.27_1.62 ; level 3, aHR, _1.08 1.38_1.77 ; level 4, aHR, _1.49 2.01_2.72 ). Similar patterns occurred for graft failure. Of recipients with the highest level of opioids on the waiting list, 65% had level 3 or 4 use in the first year after transplant, including 55% with use at these levels from day 90-365 after transplant. Opioid use in the first year after transplant also bore graded associations with subsequent death and graft loss >1-5 years after transplant. Opioid use history may be relevant in assessing and providing care to LT candidates. Liver Transplantation 23 305-314 2017 AASLD.

Determining candidacy for live kidney donation among obese individuals remains challenging. Among healthy non-donors, body mass index (BMI) above 30 is associated with a 16% increase in risk of end-stage renal disease (ESRD). However, the impact on the ESRD risk attributable to donation and living with only one kidney remains unknown. Here we studied the risk of ESRD associated with obesity at the time of donation among 119 769 live kidney donors in the United States. Maximum follow-up was 20 years. Obese (BMI above 30) live kidney donors were more likely male, African American, and had higher blood pressure. Estimated risk of ESRD 20 years after donation was 93.9 per 10 000 for obese; significantly greater than the 39.7 per 10 000 for non-obese live kidney donors. Adjusted for age, sex, ethnicity, blood pressure, baseline estimated glomerular filtration rate, and relationship to recipient, obese live kidney donors had a significant 86% increased risk of ESRD compared to their non-obese counterparts (adjusted hazard ratio 1.86; 95% confidence interval 1.05-3.30). For each unit increase in BMI above 27 kg/m² there was an associated significant 7% increase in ESRD risk (1.07, 1.02-1.12). The impact of obesity on ESRD risk was similar for male and female donors, African American and Caucasian donors, and across the baseline estimated glomerular filtration rate spectrum. These findings may help to inform selection criteria and discussions with persons considering living kidney donation.

Morphometric assessments, such as muscle density and body fat distribution, have emerged as strong predictors of cardiovascular risk and postoperative morbidity and mortality. To date, no study has examined morphometric mortality risk prediction among kidney transplant (KT) candidates. KT candidates, waitlisted 2008-2009, were identified (n=96) and followed to the earliest of transplant, death, or administrative end of study. Morphometric measures, including abdominal adipose tissue, paraspinous and psoas muscle composition, and aortic calcification, were measured from CTs. Risk of waitlist mortality was examined using Cox proportional hazard regression. On adjusted analyses, radiologic measures remained independently and significantly associated with lower waitlist mortality; the addition of radiologic measures significantly improved model predictive ability over models containing traditional risk factors alone (net reclassification index: 0.56, 95% CI: 0.31-0.75). Higher psoas muscle attenuation (indicative of leaner muscle) was associated with decreased risk of death (aHR: 0.93, 95% CI: 0.91-0.96, P<.001), and for each unit increase in lean paraspinous volume, there was an associated 2% decreased risk for death (aHR: 0.98, 95% CI: 0.96-0.99, P=.03). Radiologic measures of lean muscle mass, such as psoas muscle attenuation and paraspinous lean volume, may improve waitlist mortality risk prediction and candidate selection.

BACKGROUND:There is increasing evidence questioning the use of warfarin for atrial fibrillation (AF) among older adults with end stage renal disease (ESRD). We assessed the patterns and determinants of warfarin utilization among these patients in the US. METHODS:We assembled a cohort of older adults (age ≥65) undergoing dialysis with incident AF from July 2007 to November 2011 from the US Renal Data System (USRDS). We used descriptive statistics to characterize warfarin utilization within 30 days of AF discharge, and logistic regression to quantify patient characteristics associated with warfarin initiation. RESULTS:Among 5730 older adults undergoing dialysis with incident AF, 15.5% initiated warfarin. Among 2906 patients with high risk of bleeding, 12.7% initiated warfarin; whereas 14.9% initiated warfarin among 4824 patients with high risk of stroke. After adjustment for patient characteristics, warfarin initiation was lower among patients who were older [odds ratio (OR) = 0.74 per 10-year increase, 95% confidence interval (CI) 0.66-0.83] and those with a history of diabetes (OR = 0.75, 95% CI 0.63-0.90), myocardial infarction (OR = 0.64, 95% CI 0.50-0.80), or bleeding (OR = 0.63, 95% CI 0.50-0.80). There was no association between sex, race, or dialysis modality and warfarin initiation. Among patients who initiated warfarin, 46.8% discontinued warfarin use after a median treatment length of 8.6 months. CONCLUSION/CONCLUSIONS:Despite the unclear benefit and increased bleeding risk of warfarin treatment in patients with ESRD, 1 in 8 older adults undergoing dialysis with incident AF in the US who had high risk of bleeding used warfarin. Changes to warfarin therapy due to discontinuation were common after initiation.

BACKGROUND:The Physician Payments Sunshine Act (PSSA) is a government initiative that requires all biomedical companies to publicly disclose payments to physicians through the Open Payments Program (OPP). The goal of this study was to use the OPP database and evaluate all nonresearch-related financial transactions between plastic surgeons and biomedical companies. METHODS:Using the first wave of OPP data published on September 30, 2014, we studied the national distribution of industry payments made to plastic surgeons during a 5-month period. We explored whether a plastic surgeon's scientific productivity (as determined by their h-index), practice setting (private versus academic), geographic location, and subspecialty were associated with payment amount. RESULTS:Plastic surgeons (N = 4195) received a total of US $5,278,613. The median (IQR) payment to a plastic surgeon was US $115 (US $35-298); mean, US $158. The largest payment to an individual was US $341,384. The largest payment category was non-CEP speaker fees (US $1,709,930) followed by consulting fees (US $1,403,770). Plastic surgeons in private practice received higher payments per surgeon compared with surgeons in academic practice (median [IQR], US $165 [US $81-$441] vs median [IQR], US $112 [US $33-$291], rank-sum P < 0.001). Among academic plastic surgeons, a higher h-index was associated with 77% greater chance of receiving at least US $1000 in total payments (RR/10 unit h-index increase = 1.47 1.772.11, P < 0.001). This association was not seen among plastic surgeons in private practice (RR = 0.89 1.091.32, P < 0.4). CONCLUSIONS:Plastic surgeons in private practice receive higher payments from industry. Among academic plastic surgeons, higher payments were associated with higher h-indices.

Currently trials of immunosuppression in transplantation are in decline because their objectives remain focused on improving acute rejection rates and graft survival in the first 12 months. With 1 year renal graft survival rates of greater than 90% the best that can be hoped for is noninferiority trial outcomes compared with current standard of care. Current trial design is not leading to novel therapies improving long-term outcomes and safety, and hence important unmet clinical needs in transplantation remain unanswered. Issues that need to be addressed include but are not limited to: prevention of subclinical rejection in the first year, better 5- and 10-year graft outcomes, more effective treatment for high immunological risk and sensitized (including donor-specific antibody) patients, immunosuppressive combinations that are better tolerated by patients with fewer side effects and less morbidity and mortality. In September 2015, the Transplantation Society convened a group of transplant clinical trial experts to address these problems. The aims were to substantially realign the priorities of clinical trials for renal transplant immunosuppression with the current unmet needs and to propose new designs for clinical trials for transplant immunosuppression. Moving forward, the transplant community needs to provide trial data that will identify superior treatment options for patient subgroups and allow new agents to be evaluated for efficacy and safety and achieve timely regulatory approval. Trial designs for new transplant immunosuppression must be intelligently restructured to ensure that short- and long-term clinical outcomes continue to improve.