Early rehospitalization after kidney transplantation: assessing preventability and prognosis

Early rehospitalization after kidney transplantation (KT) is common and may predict future adverse outcomes. Previous studies using claims data have been limited in identifying preventable rehospitalizations. We assembled a cohort of 753 adults at our institution undergoing KT from January 1, 2003 to December 31, 2007. Two physicians independently reviewed medical records of 237 patients (32%) with early rehospitalization and identified (1) primary reason for and (2) preventability of rehospitalization. Mortality and graft failure were ascertained through linkage to the Scientific Registry of Transplant Recipients. Leading reasons for rehospitalization included surgical complications (15%), rejection (14%), volume shifts (11%) and systemic and surgical wound infections (11% and 2.5%). Reviewer agreement on primary reason (85% of cases) was strong (kappa = 0.78). Only 19 rehospitalizations (8%) met preventability criteria. Using logistic regression, weekend discharge (odds ratio [OR] 1.59, p = 0.01), waitlist time (OR 1.10, p = 0.04) and longer initial length of stay (OR 1.42, p = 0.03) were associated with early rehospitalization. Using Cox regression, early rehospitalization was associated with mortality (hazard ratio [HR] 1.55; p = 0.03) but not graft loss (HR 1.33; p = 0.09). Early rehospitalization has diverse causes and presents challenges as a quality metric after KT. These results should be validated prospectively at multiple centers to identify vulnerable patients and modifiable processes-of-care.

Adsorption of Uremic Toxins Using Ti3C2Tx MXene for Dialysate Regeneration

The COVID-19 pandemic has become a major worldwide crisis. Although respiratory symptoms are a key feature of the disease, many people who are hospitalized with COVID-19 also suffer acute kidney injury, a condition that exacerbates patient mortality and may have to be treated through renal replacement therapy. Much of the focus on hospital capacity during the pandemic has centered on the availability of ventilators. However, supplies for dialysis treatment, including dialysate, have also run dangerously low in hospitals at the epicenter of the pandemic. Therefore, there is an urgent need to develop materials that can efficiently and rapidly regenerate dialysate, removing toxins and restoring electrolyte concentrations so that this vital resource remains readily available. In this work, Ti3C2Tx, a two-dimensional transition-metal carbide (MXene) that is known to efficiently adsorb urea, was used to remove creatinine and uric acid from an aqueous solution and dialysate, with a maximum adsorption capacity of 45.7 and 17.0 mg/g, respectively. We systematically analyzed and modeled the adsorption kinetics, isotherms, and thermodynamics, thus determining the rate-limiting step and adsorption mechanism. A fixed-bed column loaded with Ti3C2Tx was designed to further evaluate the adsorption performance under continuous fluid-flow conditions, mirroring conditions of continuous renal replacement therapy modalities. The maximum capacity and 50% breakthrough volume were calculated to further approach the practical application of Ti3C2Tx for removal of uremic toxins. Our findings suggest that Ti3C2Tx has the potential to be used as an efficient sorbent for the regeneration of dialysate, allowing for accelerated dialysate regeneration by removing filtered toxins and leading to more portable dialysis devices.

Trends in Prescribing Preferences for Antidiabetic Medications Among Patients With Type 2 Diabetes in the U.K. With and Without Chronic Kidney Disease, 2006-2020

OBJECTIVE

To evaluate trends in antidiabetic medication initiation patterns among patients with type 2 diabetes mellitus (T2DM) with and without chronic kidney disease (CKD).

RESEARCH DESIGN AND METHODS

A retrospective cohort study using the UK Clinical Practice Research Datalink (2006-2020) was conducted to evaluate the overall, first-, and second line (after metformin) medication initiation patterns among patients with CKD (n = 38,622) and those without CKD (n = 230,963) who had T2DM.

RESULTS

Relative to other glucose-lowering therapies, metformin initiations declined overall but remained the first-line treatment of choice for both patients with and those without CKD. Sodium-glucose cotransporter-2 (SGLT2i) use increased modestly among patients with CKD, but this increase was more pronounced among patients without CKD; by 2020, patients without CKD, compared with patients with CKD, were three (28.5% vs. 9.4%) and six (46.3% vs. 7.9%) times more likely to initiate SGLT2i overall and as second-line therapy, respectively. Glucagon-like peptide 1 receptor agonist (GLP-1RA) use was minimal regardless of CKD status (<5%), whereas both dipeptidyl peptidase-4 inhibitor (DPP4i) and sulfonylurea use remained high among patients with CKD. For instance, by 2020, and among patients with CKD, DPP4i and sulfonylureas constituted 28.3% and 20.6% of all initiations, and 57.4% and 30.3% of second-line initiations, respectively.

CONCLUSIONS

SGLT2i use increased among patients with T2DM, but this increase was largely driven by patients without CKD. Work is needed to identify barriers associated with the uptake of therapies with proven cardiorenal benefits (e.g., SGLT2i, GLP-1RA) among patients with CKD.

Current landscape of kidney allocation: Organ procurement organization perspectives

Organ procurement organizations (OPOs) play a central role in the recovery, preservation, and distribution of deceased donor kidneys for transplantation in the United States. We conducted a national survey to gather information on OPO practices and perceived barriers to efficient organ placement in the face of the new circle-based allocation and asked for suggestions to overcome them. Of the 57 OPOs, 44 responded (77%). The majority of OPOs (61%) reported barriers to obtaining a kidney biopsy, including lack of an available pathologist. Most OPOs (55%) indicated barriers to pumping owing to a lack of available staff and transportation. Respondents agreed or strongly agreed that the new allocation system has worsened transportation challenges (85%), increased provisional acceptances of kidneys (66%), increased communication challenges with transplant centers (68%), and worsened the efficiency of organ allocation (83%). OPO-suggested solutions include making transplant centers more accountable for inefficient selection practices, developing reliable transportation options, and removing the requirement for national sharing. These findings underscore the need to examine closely the trade-offs of the new allocation system with respect to costs, organ ischemia, and discard. These findings may help inform practice and policy for overcoming transportation barriers and improving the efficiency of organ placement.

Abstract 128: Visit-to-visit Variability of Systolic BP and Renal Outcomes in the SPRINT Trial

Increased visit-to-visit variability (VVV) in systolic blood pressure is a known predictor of adverse CV events & in diabetics, is associated with higher risk of incident albuminuria & chronic kidney disease. However, the impact of VVV in SBP on renal outcomes in the absence of diabetes is unknown. We investigated the association between VVV in SBP & adverse CVE & renal events among non-diabetic participants in SPRINT cohort.

Methods: Primary exposure was quartile of within-person standard deviation of systolic blood pressure (SDBP). Primary outcomes 1) primary composite CV outcome from SPRINT study, 2) primary SPRINT renal outcome among those without CKD 3) incident albuminuria among those with & without CKD. We compared covariates by SDBP quartile, using ANOVA or chi-square tests. We fit incremental Cox hazards models to examine associations between SDBP & events. We performed sensitivity analyses for # visits in all models.

Results: Among 9361 participants, 8589 (92%) met inclusion criteria & comprised the primary analytic sample. The mean SBP across all quartiles was similar (137 - 141 mmHg). There was no association between quartile of SDBP and the primary composite cardiovascular outcome. There was a significant association between quartile of SDBP and incident CKD among those without baseline CKD. Among 3350 participants without baseline CKD and 942 participants with CKD, higher VVV in SBP was independently associated with increased risk of incident albuminuria, regardless of baseline CKD status. This association was robust after adjustment for the number of visits. The interaction between SDBP and the primary intervention was not statistically significant in the no CKD (p=0.11) or CKD groups (p=0.93).

Discussion: In this post-hoc analysis of SPRINT, we found that higher VVV in SBP is associated with greater risk of incident albuminuria among non-diabetic adults with and without baseline CKD. This association remained significant after adjustment for numerous potential confounders across follow-up. Our analysis demonstrates a significant association between VVV of SBP and incident albuminuria in patients with and without baseline CKD. This novel finding in an exclusively non-diabetic, hypertensive population deserves further investigation.

Financial Hardship and Age-Related Decrements in Kidney Function Among Black and White Adults in the Midlife in the United States Study

OBJECTIVE

This analysis examined if financial hardship was associated with age-related decrements in kidney function using a material-psychosocial-behavioral framework. We also tested if this association was mediated by comorbidity of cardiometabolic risk factors (obesity, elevated blood pressure, and insulin resistance).

METHODS

Data from 1361 non-Hispanic Black and White adults (ages 26-94 years; non-Hispanic Black = 258) were obtained from the Wave 3 and Refresher phases of the Midlife in the United States project. Kidney function was based on serum creatinine-based estimated glomerular filtration rate (eGFR; Chronic Kidney Disease Epidemiology Collaboration formula without race adjustment). Financial hardship was evaluated in three domains: material (income to poverty line ratio, health insurance coverage, and public/government financial assistance), psychological (perceived financial status, control over financial status, and perceived financial strains), and behavioral responses (financial adjustment/coping such as sold possessions and cutting back on spending).

RESULTS

More severe financial hardship (overall score and in each domain) was associated with age-related decrements in eGFR, even after adjusting for sociodemographic, education, and health-related covariates. The association between financial hardship and age-related decrements in eGFR was conditional on sex but not race. Finally, cardiometabolic risk factors mediated the association between financial hardship and age-related decrements in eGFR.

CONCLUSIONS

These findings affirm the negative effects of financial hardship on age-related decrements in renal clearance. In addition to incorporating traditionally used indicators of SES, such as education and income, future research on social hallmarks of aging should also consider the role of financial hardship on the aging process and age-related diseases.