Simultaneous liver-kidney transplantation (SLKT) is increasingly common in the United States. However, little is known about the renal-related outcomes following SLKT, which are essential to maximize the health of these allografts. We examined the factors impacting renal function following SLKT. This is an observational multicenter cohort study from the US Multicenter SLKT Consortium consisting of recipients of SLKT aged ≥18 years of transplantations performed between February 2002 and June 2017 at 6 large US centers in 6 different United Network for Organ Sharing regions. The primary outcome was incident post-SLKT stage 4-5 chronic kidney disease (CKD) defined as <30 mL/minute/1.73 m² or listing for kidney transplant. The median age of the recipients (n = 570) was 58 years (interquartile range, 51-64 years), and 37% were women, 76% were White, 33% had hepatitis C virus infection, 20% had nonalcoholic steatohepatitis (NASH), and 23% had alcohol-related liver disease; 68% developed ≥ stage 3 CKD at the end of follow-up. The 1-year, 3-year, and 5-year incidence rates of post-SLKT stage 4-5 CKD were 10%, 12%, and 16%, respectively. Pre-SLKT diabetes mellitus (hazard ratio [HR], 1.45; 95% CI, 1.00-2.15), NASH (HR, 1.58; 95% CI, 1.01-2.45), and delayed kidney graft function (HR, 1.72; 95% CI, 1.10-2.71) were the recipient factors independently associated with high risk, whereas the use of tacrolimus (HR, 0.44; 95% CI, 0.22-0.89) reduced the risk. Women (β = -6.22 ± 2.16 mL/minute/1.73 m² ; P = 0.004), NASH (β = -7.27 ± 3.27 mL/minute/1.73 m² ; P = 0.027), and delayed kidney graft function (β = -7.25 ± 2.26 mL/minute/1.73 m² ; P = 0.007) were independently associated with low estimated glomerular filtration rate at last follow-up. Stage 4-5 CKD is common after SLKT. There remains an unmet need for personalized renal protective strategies, specifically stratified by sex, diabetes mellitus, and liver disease, to preserve renal function among SLKT recipients.

We aimed to understand the contemporary changes in the characteristics and the determinants of outcomes among simultaneous liver-kidney transplantation (SLKT) recipients at 6 liver transplantation centers in the United States. We retrospectively enrolled SLKT recipients between 2002 and 2017 in the US Multicenter SLKT Consortium. We analyzed time-related trends in recipient characteristics and outcomes with linear regression and nonparametric methods. Clustered Cox regression determined the factors associated with 1-year and overall survival. We enrolled 572 patients. We found significant changes in the clinical characteristics of SLKT recipients: as compared with 2002, recipients in 2017 were older (59 versus 52 years; P < 0.001) and more likely to have chronic kidney disease (71% versus 33%; P < 0.001). There was a marked improvement in 1-year survival during the study period: 89% in 2002 versus 96% in 2017 (P < 0.001). We found that the drivers of 1-year mortality were SLKT year, hemodialysis at listing, donor distance, and delayed kidney allograft function. The drivers of overall mortality were an indication of acute kidney dysfunction, body mass index, hypertension, creatinine at SLKT, ventilation at SLKT, and donor quality. In this contemporary cohort of SLKT recipients, we highlight changes in the clinical characteristics of recipients. Further, we identify the determinants of 1-year and overall survival to highlight the variables that require the greatest attention to optimize outcomes.

Cardiovascular disease is a leading complication after both liver and kidney transplantation. Factors associated with and rates of cardiovascular events (CVEs) after simultaneous liver-kidney transplant (SLKT) are unknown. This was a retrospective cohort study of adult SLKT recipients between 2002 and 2017 at six centers in six United Network for Organ Sharing regions in the US Multicenter SLKT Consortium. The primary outcome was a CVE defined as hospitalization due to acute coronary syndrome, arrhythmia, congestive heart failure, or other CV causes (stroke or peripheral vascular disease) within 1 year of SLKT. Among 515 SLKT subjects (mean age ± SD, 55.4 ± 10.6 years; 35.5% women; 68.1% White), 8.7% had a CVE within 1 year of SLKT. The prevalence of a CVE increased from 3.3% in 2002-2008 to 8.9% in 2009-2011 to 14.0% in 2012-2017 ( p  = 0.0005). SLKT recipients with a CVE were older (59.9 vs. 54.9 years, p  < 0.0001) and more likely to have coronary artery disease (CAD) (37.8% vs. 18.4%, p  = 0.002) and atrial fibrillation (AF) (27.7% vs. 7.9%, p  = 0.003) than those without a CVE. There was a trend toward older age by era of SLKT ( p  = 0.054). In multivariate analysis adjusted for cardiac risk factors at transplant, age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02, 1.11), CAD (OR, 3.62; 95% CI, 1.60, 8.18), and AF (OR, 2.36; 95% CI, 1.14, 4.89) were associated with a 1-year CVE after SLKT. Conclusion : Among SLKT recipients, we observed a 4-fold increase in the prevalence of 1-year CVEs over time. Increasing age, CAD, and AF were the main potential explanatory factors for this trend independent of other risk factors. These findings suggest that CV risk protocols may need to be tailored to this high-risk population.

The burden of early hospitalization (within 6 months) following simultaneous liver-kidney transplant (SLKT) is not known. We examined risk factors associated with early hospitalization after SLKT and their impact on patient mortality conditional on 6-month survival. We used data from the US Multicenter SLKT Consortium cohort study of all adult SLKT recipients between 2002 and 2017 who were discharged alive following SLKT. We used Poisson regression to model rates of early hospitalizations after SLKT. Cox regression was used to identify risk factors associated with mortality conditional on survival at 6 months after SLKT. Median age (N = 549) was 57.7 years (interquartile range [IQR], 50.6-63.9) with 63% males and 76% Whites; 33% had hepatitis C virus, 20% had non-alcohol-associated fatty liver disease, 23% alcohol-associated liver disease, and 24% other etiologies. Median body mass index (BMI) and Model for End-Stage Liver Disease-sodium scores were 27.2 kg/m² (IQR, 23.6-32.2 kg/m² ) and 28 (IQR, 23-34), respectively. Two-thirds of the cohort had at least one hospitalization within the first 6 months of SLKT. Age, race, hospitalization at SLKT, diabetes mellitus, BMI, and discharge to subacute rehabilitation (SAR) facility after SLKT were independently associated with a high incidence rate ratio of early hospitalization. Number of hospitalizations within the first 6 months did not affect conditional survival. Early hospitalizations after SLKT were very common but did not affect conditional survival. Although most of the risk factors for early hospitalization were nonmodifiable, discharge to SAR after initial SLKT was associated with a significantly higher incidence rate of early hospitalization. Efforts and resources should be focused on identifying SLKT recipients at high risk for early hospitalization to optimize their predischarge care, discharge planning, and long-term follow-up.