Impact of preexisting coronary artery and peripheral artery disease on outcomes in diabetic patients after kidney transplant

BACKGROUND

Atherosclerotic cardiovascular disease is highly prevalent in patients with end-stage kidney disease (ESKD). Kidney transplant (KT) improves patient survival and cardiovascular outcomes. The impact of preexisting coronary artery disease (CAD) and peripheral artery disease (PAD) on posttransplant outcomes remains unclear.

METHODS

This is a retrospective study utilizing the United States Renal Data System. Adult diabetic dialysis patients who underwent first KT between 2006 and 2017 were included. The study population was divided into four cohorts based on presence of CAD/PAD: (1) polyvascular disease (CAD + PAD); (2) CAD without PAD; (3) PAD without CAD; (4) no CAD or PAD (reference cohort). The primary outcome was 3-year all-cause mortality. Secondary outcomes were incidence of posttransplant myocardial infarction (MI), cerebrovascular accidents (CVA), and graft failure.

RESULTS

The study population included 19,329 patients with 64.4% men, mean age 55.4 years, and median dialysis duration of 2.8 years. Atherosclerotic cardiovascular disease was present in 28% of patients. The median follow up was 3 years. All-cause mortality and incidence of posttransplant MI were higher with CAD and highest in patients with polyvascular disease. The cohort with polyvascular disease had twofold higher all-cause mortality (16.7%, adjusted hazard ratio (aHR) 1.5, p < 0.0001) and a fourfold higher incidence of MI (12.7%, aHR 3.3, p < 0.0001) compared to the reference cohort (8.0% and 3.1%, respectively). There was a higher incidence of posttransplant CVA in the cohort with PAD (3.4%, aHR 1.5, p = 0.01) compared to the reference cohort (2.0%). The cohorts had no difference in graft failure rates.

CONCLUSIONS

Preexisting CAD and/or PAD result in worse posttransplant survival and cardiovascular outcomes in patients with diabetes mellitus and ESKD without a reduction in graft survival.

Nationwide Trends and Outcomes for Coronary Artery Bypass Grafting in End-Stage Kidney Disease and Stable Coronary Artery Disease

Patients with end-stage kidney disease (ESKD) on dialysis have an increased burden of coronary artery disease (CAD). This study assessed the trend and outcomes for coronary artery bypass surgery (CABG) in patients with ESKD and stable CAD. We conducted a longitudinal study using the United States Renal Data System of patients with ESKD and stable CAD who underwent CABG from the years 2009 to 2017. The outcomes included in-hospital, long-term mortality, and repeat revascularization. The follow-up was until death, end of Medicare AB coverage, or December 31, 2018. A total of 11,952 patients were identified. The mean age was 62.8 years, 68% were male, and 67% were white. The common co-morbidities included hypertension (97%), diabetes mellitus (75%), and congestive heart failure (53%). A significant decrease in CABG procedures from 2.9 to 1.3 procedures per 1,000 patients with ESKD (p <0.001) was noted during the years studied. The overall in-hospital mortality rate was 5.9%, and there was a significant decrease over the study period (p = 0.01). Although the 30-day mortality rate was 6.9% and remained steady (p = 0.14), the 1-year mortality rate was 22.8% and decreased significantly (p <0.001). At 5 years, the overall survival rate was 35%, and patients with internal mammary artery grafts showed better survival than those without (36% vs 25%). In conclusion, there has been a decrease in CABG procedures performed in patients with ESKD with stable CAD with decreasing in-hospital and 1-year mortality. Those with an internal mammary artery graft do better, but the overall long-term survival remains dismal in this population. There remains need for caution and individualization of revascularization decisions in this high-risk population.

Burden of Hypertensive Crisis in Patients With End-Stage Kidney Disease on Maintenance Dialysis: Insights From United States Renal Data System Database

BACKGROUND

There is paucity of information on the incidence, clinical characteristics, admission trends, and outcomes of hypertensive crisis (HTN-C) in patients with end-stage kidney disease (ESKD) who are on maintenance dialysis.

METHODS

We conducted a retrospective observational study of HTN-C admissions in patients with end-stage kidney disease using the United States Renal Data System. We identified patients with end-stage kidney disease aged ≥18 years on dialysis and were hospitalized for HTN-C from January 2006 to August 2015.

RESULTS

A total of 54 483 patients with end-stage kidney disease were hospitalized for HTN-C during the study period. After study exclusions, 37 214 patients were included in the analysis. A majority of patients were Black, there were more women than men and the South region of the country accounted for a great majority of patients. During the study period, hospitalization rates increased from 1060 per 100 000 beneficiary years to 1821 (P_trend<0.0001). Overall, in-hospital mortality, 30-day, and 1-year mortality were 0.6%, 2.3%, and 21.8%, respectively, and 30-day readmission rate was 31.1%. During the study period, most study outcomes showed a significant decreasing trend (in-hospital mortality 0.6%-0.5%, 30-day mortality 2.4%-1.9%, 1-year mortality 23.9%-19.7%, P_trend<0.0001 for all).

CONCLUSIONS

Hospitalizations for HTN-C have increased consistently during the decade studied. Although temporal trends showed improving mortality and readmission rates, the absolute rates were still high with 1 in 3 patients readmitted within 30 days and 1 in 5 patients dying within 1 year of index hospitalization.

Late-onset renal vein thrombosis: A case report and review of the literature

INTRODUCTION

Renal vein thrombosis, a rare complication of renal transplantation, often causes graft loss. Diagnosis includes ultrasound with Doppler, and it is often treated with anticoagulation or mechanical thrombectomy. Success is improved with early diagnosis and institution of treatment.

PRESENTATION OF CASE

We report here the case of a 29 year-old female with sudden development of very late-onset renal vein thrombosis after simultaneous kidney pancreas transplant. This resolved initially with thrombectomy, stenting and anticoagulation, but thrombosis recurred, necessitating operative intervention. Intraoperatively the renal vein was discovered to be compressed by a large ovarian cyst.

DISCUSSION

Compression of the renal vein by a lymphocele or hematoma is a known cause of thrombosis, but this is the first documented case of compression and thrombosis due to an ovarian cyst.

CONCLUSION

Early detection and treatment of renal vein thrombosis is paramount to restoring renal allograft function. Any woman of childbearing age may have thrombosis due to compression by an ovarian cyst, and screening for this possibility may improve long-term graft function in this population.

Blood group A isoagglutinins in A(2) → O simultaneous liver/kidney transplantation may not influence kidney function

We simultaneously transplanted a liver and kidney (SLK) into a 55-year-old woman with end-stage liver disease secondary to recurrent primary biliary cirrhosis. The patient was blood group O, the donor was A(2) (A, non-A1) and the patient's A isoagglutinin titer was 512. Good renal function was evident by normalization of her creatinine values following transplantation. Recovery was unremarkable and she was discharged on post op day 9. The patient has not experienced an episode of rejection in either organ during the 6 months of follow-up. This case is important because high A IgG isoagglutinin levels (8 or higher) in kidney alone A(2) → O transplantation are detrimental to outcome but do not affect outcome in liver alone A(2) → O transplants; however, no such anti-A titer data have been published for A(2) → O (or B) SLK transplantation.

IL-18 and urinary NGAL predict dialysis and graft recovery after kidney transplantation

Current methods for predicting graft recovery after kidney transplantation are not reliable. We performed a prospective, multicenter, observational cohort study of deceased-donor kidney transplant patients to evaluate urinary neutrophil gelatinase-associated lipocalin (NGAL), IL-18, and kidney injury molecule-1 (KIM-1) as biomarkers for predicting dialysis within 1 wk of transplant and subsequent graft recovery. We collected serial urine samples for 3 d after transplant and analyzed levels of these putative biomarkers. We classified graft recovery as delayed graft function (DGF), slow graft function (SGF), or immediate graft function (IGF). Of the 91 patients in the cohort, 34 had DGF, 33 had SGF, and 24 had IGF. Median NGAL and IL-18 levels, but not KIM-1 levels, were statistically different among these three groups at all time points. ROC curve analysis suggested that the abilities of NGAL or IL-18 to predict dialysis within 1 wk were moderately accurate when measured on the first postoperative day, whereas the fall in serum creatinine (Scr) was not predictive. In multivariate analysis, elevated levels of NGAL or IL-18 predicted the need for dialysis after adjusting for recipient and donor age, cold ischemia time, urine output, and Scr. NGAL and IL-18 quantiles also predicted graft recovery up to 3 mo later. In summary, urinary NGAL and IL-18 are early, noninvasive, accurate predictors of both the need for dialysis within the first week of kidney transplantation and 3-mo recovery of graft function.

Association between delayed graft function and allograft and patient survival: a systematic review and meta-analysis

BACKGROUND

Delayed graft function (DGF) is a common complication of renal transplantation. The short-term consequences of DGF are well known, but the long-term relationship between DGF and patient and graft survival is controversial in the published literature. We conducted a systematic review and meta-analysis to precisely estimate these relationships.

METHODS

We performed a literature search for original studies published through March 2007 pertaining to long-term (>6 months) outcomes of DGF. The primary outcome was graft survival. Secondary outcomes were patient survival, acute rejection and kidney function.

RESULTS

When compared to patients without DGF, patients with DGF had a 41% increased risk of graft loss (RR 1.41, 95% CI 1.27-1.56) at 3.2 years of follow-up. There was no significant relationship between DGF and patient survival at 5 years (RR 1.14, 95% CI 0.94-1.39). The mean creatinine in the non-DGF group was 1.6 mg/dl. Patients with DGF had a higher mean serum creatinine (0.66 mg/dl, 95% CI 0.57-0.74) compared to patients without DGF at 3.5 years of follow-up. DGF was associated with a 38% relative increase in the risk of acute rejection (RR 1.38, 95% CI 1.29-1.47).

CONCLUSION

The results of this meta-analysis emphasize and quantify the long-term detrimental association between DGF and important graft outcomes like graft survival, acute rejection and renal function. Efforts to prevent and treat DGF should be aggressively investigated in order to improve graft survival given the deficit in the number of kidney donors.

Long-term renal outcomes after delayed graft function

Delayed graft function (DGF) describes dysfunction of the kidney allograft immediately after transplantation and is the most common complication in the immediate posttransplantation period. Although a standardized definition for DGF is lacking, it is most commonly defined as the need for dialysis within the first week after transplant. DGF is caused by a variety of factors related to the donor and recipient as well as organ procurement techniques. The occurrence of DGF affects both allograft and patient outcomes. In addition to prolonging hospital stay and increasing the costs associated with transplantation, DGF is associated with an increased incidence of acute rejection after transplantation and is associated with poorer long-term graft outcomes. Both immunologic and nonimmunologic mechanisms contribute to DGF. The risk factors for DGF that have been identified are reviewed as well as the impact of DGF on long-term outcomes.

Drug-induced crystal nephropathy: an update

BACKGROUND

Several medications that are insoluble in human urine are known to precipitate within the renal tubules. Intratubular precipitation of either exogenously administered medications or endogenous crystals (induced by certain drugs) can promote chronic and acute kidney injury, termed crystal nephropathy. Clinical settings that enhance the risk of drug or endogenous crystal precipitation within the kidney tubules include true or effective intravascular volume depletion, underlying kidney disease, and certain metabolic disturbances that promote changes in urinary pH favoring crystal precipitation.

OBJECTIVE

Identify and review previously described and recently recognized medications that cause crystal nephropathy.

METHOD

A literature review was performed, using PubMed, Ovid, and Google Scholar, focusing on drugs (sulfadiazine, acyclovir, indinavir, triamterene, methotrexate (MTX), orlistat, oral sodium phosphate preparation, ciprofloxacin) that cause crystal nephropathy.

RESULTS/CONCLUSION

Sulfadiazine, acyclovir, indinavir, triamterene, and MTX are known to cause crystal nephropathy. Recently, several medications, including orlistat, ciprofloxacin, and oral sodium phosphate solution, along with underlying risk factors have been described as causing crystal nephropathy.

Marked variation in the definition and diagnosis of delayed graft function: a systematic review

BACKGROUND

The term delayed graft function (DGF) is commonly used to describe the need for dialysis after receiving a kidney transplant. DGF increases morbidity after transplantation, prolongs hospitalization and may lead to premature graft failure. Various definitions of DGF are used in the literature without a uniformly accepted technique to identify DGF.

METHODS

We performed a systematic review of the literature to identify all of the different definitions and diagnostic techniques to identify DGF.

RESULTS

We identified 18 unique definitions for DGF and 10 diagnostic techniques to identify DGF.

CONCLUSIONS

The utilization of heterogeneous clinical criteria to define DGF has certain limitations. It will lead to delayed and sometimes inaccurate diagnosis of DGF. Hence a diagnostic test that identifies DGF reliably and early is necessary. Heterogeneity, in the definitions used for DGF, hinders the evolution of a diagnostic technique to identify DGF, which requires a gold standard definition. We are in need of a new definition that is uniformly accepted across the kidney transplant community. The new definition will be helpful in promoting better communication among transplant professionals and aids in comparing clinical studies of diagnostic techniques to identify DGF and thus may facilitate clinical trials of interventions for the treatment of DGF.

Impact of acute kidney injury on long-term mortality after nonmyeloablative hematopoietic cell transplantation

Acute kidney injury (AKI) occurs frequently after nonmyeloablative hematopoietic cell transplantation (HCT). The severity of AKI after nonmyeloablative HCT has association with short-term mortality. However, the long-term effect of AKI on survival after nonmyeloablative HCT is not known. We performed a retrospective analysis of patients who underwent an HLA matched nonmyeloablative HCT between 1997 and 2006. Patients were followed for a median of 36 (range: 3-99) months. AKI occurring up to day 100 was defined as a >2-fold increase in serum creatinine or requirement of dialysis. Of the 358 patients who were included in the analysis, 200 (56%) had AKI, 158 (44%) had no AKI. Overall, 158 patients (43%) died during follow-up. After controlling for potential confounders, the adjusted hazard ratio for overall mortality associated with AKI was 1.57 (95 % confidence interval [CI] 1.2-2.3; P = .0006). The adjusted hazards ratio of nonrelapse mortality (NRM) associated with AKI was 1.72 (95% CI 0.9-3.1; P = .07). AKI is an independent predictor of overall mortality after nonmyeloablative HCT. This finding reiterates the importance of identifying preventative strategies in nonmyeloablative HCT for attenuating incidence and severity of AKI.

Arterial compliance in elderly men with chronic kidney disease

BACKGROUND/AIM

Chronic kidney disease (CKD) is associated with decreased arterial compliance (AC). The stage of development of impaired arterial function in CKD in relation to loss of glomerular filtration rate (GFR) is not known. This study's aim was to evaluate the relationship between GFR and AC in patients with CKD.

METHODS

We recruited 91 men aged > or =60 years with GFR 15-89 ml/min (mean 47 +/- 21) to evaluate the relationship between GFR and AC in a cross-sectional study. We measured AC at the brachial artery with an oscillometric device (brachial artery distensibility; BAD).

RESULTS

There was no correlation between GFR and BAD (r = 0.08, p = 0.44). When stratified according to CKD stages, all groups showed decreased BAD compared with reference values, and there were no differences among them (one-way ANOVA). Bivariate analyses showed statistically significant correlations between BAD and age (r = -0.23, p = 0.03), antihypertensive drug number (r = 0.27, p = 0.009) and serum hemoglobin (r = 0.24, p = 0.02), but only age and antihypertensive drug number remained significant markers of BAD in a multiple regression model.

CONCLUSION

Older men with CKD have impaired arterial function, but GFR and CKD stage have no relationship to the degree of decrease in brachial artery distensibility.