March 2018: Abstract Roundup

Recurrent AKI Episodes Associated with Relevant Complications

Kidney Blood Pressure Research.

Following a first incidence of acute kidney injury (AKI) related to hospitalization, patients often experience recurrent AKI; however, there are few data available regarding the prognosis of recurrent episodes of AKI in the development of chronic kidney disease (CKD), cardiovascular events, and mortality. Eva Rodriguez, MD, PhD, and colleagues recently conducted a retrospective study among patients admitted to a single center from 2000 to 2010.

There were 359 patients who survived a hospital-related AKI episode; of those, 250 new episodes were seen in 122 patients. The study identified variables that were independently associated with new episodes, including type 2 diabetes mellitus (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.2-3.8; P=.001), ischemic heart disease (OR, 1.9; 95% CI, 1.1-3.6; P=.012), and serum creatinine level at first AKI event >2.6 mg/dL (OR, 1.2; 95% CI, 1.03-1.42; P=.02).

Patients with recurrent AKI were more likely to develop CKD during 4 years of follow-up (hazard ratio [HR], 2.2; 95% CI, 1.09-4.3; P=.003). Development of CKD occurred during the first 6 months following the initial AKI event in 44% of patients who developed CKD. Patients with recurrent AKI also experienced cardiovascular events compared with those with only one AKI episode (47.2% vs 24%; P=.001). At 4 years, mortality was higher in the subgroup with several AKI episodes compared with patients with only one AKI episode (HR, 4.5; 95% CI, 2.7-7.5; P<.001).

In conclusion, the researchers said, “Episodes of recurrent AKI have a high potential to be associated with relevant complications such as cardiovascular events, mortality, and CKD development.”


AKI Risk Factor for Post-Procedure Bleeding in Patients with Decompensated Cirrhosis

Liver International. doi:10.1111/liv.13712

In decompensated cirrhosis patients undergoing low-risk invasive procedures, bleeding can be life threatening or can lead to other complications. Despite abnormal coagulation parameters, the rate of procedure-related bleeding is low in unstratified cohorts of hospitalized patients with cirrhosis. Researchers, led by Adelina Hung, MD, recently conducted a retrospective chart review designed to identify patients with decompensated cirrhosis at high risk of developing bleeding related to low-risk procedures with the aim of assessing the value of preprocedure transfusions.

The study cohort included hospitalized patients with cirrhosis who developed post-paracentesis hemoperitoneum (PPH), confirmed by computed tomography (CT) scan, from January 2012 to August 2016. The cohort was compared with patients who were hospitalized during the same period in whom PPH was suspected but ruled out by CT scan. The chart review sought to determine the specifics of the adverse event, patient characteristics, and risk factors for bleeding.

Following multivariate analysis, the only independent predictor of PPH was acute kidney injury prior to paracentesis (odds ratio, 4.3; 95% confidence interval, 1.3-13.5; P=.01). The association persisted regardless of Model of End-Stage Liver Disease score, large volume paracentesis, sepsis, platelets, international normalized ratio, and hemoglobin levels.

“Infection/sepsis is generally considered predictive of bleeding in cirrhosis. Our study suggests that AKI, and not sepsis, is the most important predictor of postprocedure bleeding in patients with decompensated cirrhosis. Although end-stage renal disease is a known cause of bleeding in non-cirrhotic patients, there are new studies establishing AKI as a risk factor for post-procedure bleeding in cirrhosis. Future studies investigating blood product transfusion needs in cirrhosis prior to procedures should carefully look at AKI,” the researchers said.


Chronic Kidney Disease

Risk of CKD after Partial versus Radical Nephrectomy

Journal of the Society of Nephrology. 2018;29(1):207-216

There are few available data on the effectiveness of partial nephrectomy versus radical nephrectomy to preserve renal function in patients with kidney cancer. John T. Leppert, MD, and colleagues recently conducted an analysis to determine the risk of clinically significant (stage 4 and higher) chronic kidney disease (CKD) in patients treated for kidney cancer in the Veterans Health Administration from 2001 to 2013.

The overall incidence of stage 4 or higher CKD after radical (n=9759) or partial nephrectomy (n=4370) in patients with preoperative estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2 was 7.9%. Median time after surgery to stage 4 or higher CKD was 5 months, after which few patients progressed.

Compared with radical nephrectomy, partial nephrectomy was associated with a significantly lower relative risk of incident stage 4 or higher CKD in propensity score-matched cohorts (hazard ratio [HR], 0.34; 95% confidence interval [CI], 0.26-0.43). There was also an association between partial nephrectomy and a significantly lower relative risk of incident CKD stage 3b or higher (HR, 0.15; 95% CI, 0.11-0.19 vs radical nephrectomy) in a parallel analysis comparing patients undergoing partial nephrectomy with patients with normal or near-normal preoperative kidney function (eGFR ≥60 mL/min/1.73 m2) in propensity score-matched cohorts. Competing risk regression models yielded consistent results. The risk of mortality was also reduced in patients treated with partial nephrectomy (HR, 0.55; 95% CI, 0.49-0.62) compared with radical nephrectomy.

In conclusion, the researchers noted, “Compared with radical nephrectomy, partial nephrectomy was associated with a marked reduction in the incidence of clinically significant CKD and with enhanced survival. Postoperative decline in kidney function occurred mainly in the first year and appeared stable over time.”


Risk of Incident CKD and Progression to ESRD Increases with Air Pollution Levels

Journal of the American Society of Nephrology. 2018; 29(1):218-230

The association between elevated levels of fine particulate matter <2.5 µm in aerodynamic diameter (PM2.5) and increased risks of cardiovascular outcomes and mortality are well documented, but there are few data regarding the risk of chronic kidney disease (CKD) and end-stage kidney disease (ESRD). Utilizing the Environmental Protection Agency and Department of Veterans Affairs databases to create an observational cohort of US veterans (n=2,482,737), Benjamin Bowe, MD, and colleagues used survival models to assess the association between concentrations of PM2.5 and the risk of incident estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, incident CKD, decline in eGFR ≥30%, and ESRD. Median follow-up was 8.52 years.

At baseline, county-level exposure was defined as the annual average PM2.5 concentrations in 2004, and separately as time-varying where it was updated annually and as cohort participants moved. In analyses of baseline exposure (median, 11.8 µg/m3), there was an association between a 10-ug/m3 increase in PM2.5 concentration and increased risk of eGFR <60 mL/min/1.73 m2 (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.14-1.29), CKD (HR, 1.27; 95% CI, 1.17-1.38), decline in eGFR ≥30% (HR, 1.28; 95% CI, 1.18-1.39), and ESRD (HR, 1.26; 95% CI, 1.17-1.35).

In time-varying analyses, there were similar associations between a 10-µg/m3 increase in PM2.5 concentration and increased risk of eGFR <60 mL/min/1.73 m2, CKD, decline in eGFR ≥30%, and ESRD. Data from the National Aeronautics and Space Administration satellite yielded similar results.

“Our findings demonstrate a significant association between exposure to PM2.5 and risk of incident CKD, eGFR decline, and ESRD,” the researchers said.


Caloric Restriction and Exercise Combined Benefit CKD Patients

Journal of the American Society of Nephrology. 2018;29(1):250-259

Along with the increase in obesity worldwide, there is a steady increase in chronic kidney disease (CKD). Obesity is also a proinflammatory risk factor for progression of CKD and for cardiovascular disease. T. Alp Ikizler, MD, and colleagues conducted a pilot, randomized 2Í2 factorial design trial to test the hypothesis that “implementation of caloric restriction and aerobic exercise is feasible and can improve the proinflammatory metabolic milieu in patients with moderate-to-severe CKD.”

The cohort included 111 individuals who were randomized to receive caloric restriction and aerobic exercise, caloric restriction alone, aerobic exercise alone, or usual care. Of the 111 participants, 42% were women, 25% had diabetes, and 91% were hypertensive; a final cohort of 104 started the intervention and 92 completed the 4 months of the study. Primary outcomes of interest were change from baseline in absolute fat mass, body weight, plasma F2-isoprostant concentrations, and peak oxygen uptake (VO2 peak).

Compared with those in the usual care group, participants in the caloric restriction and aerobic exercise combined group had statistically significant decreases in body weight and body fat percentage. Participants in the caloric restriction alone group also had significant decreases in body weight and body fat percentage; those in the aerobic exercise alone group did not.

Those in the combined intervention group and those in each independent intervention group had significant decreases in F2-isporostant and interleukin 6 concentrations. There were no significant changes in VO2 peak, kidney function, or urine albumin-to-creatinine ratio in any of the groups.

In conclusion, the researchers said, “Four-month dietary caloric restriction and aerobic exercise had significant, albeit clinically modest, benefits on body weight, fat mass, and markers of oxidative stress and inflammatory response in patients with moderate-to-severe CKD. These results suggest healthy lifestyle interventions as a nonpharmacologic strategy to improve markers of metabolic health in these patients.”



Preliminary Trial of Intensive Blood Pressure Management in Hemodialysis Patients

Journal of the American Society of Nephrology. 2018;29(1):307-316

The optimal blood pressure target for patients receiving hemodialysis is unknown. Dana Miskulin, MD, and colleagues recently conducted a preliminary trial to determine the feasibility and safety and to shape the design of a full-scale trial. A secondary objective was to assess changes in left ventricular mass.

The preliminary trial randomized 126 hypertensive patients on dialysis to either a standardized predialysis systolic blood pressure of 110-140 mmHg (intensive arm) or 155-065 mmHg (standard arm). Median follow-up was 365 days.

There was no change in the 2-week moving average systolic blood pressure in the standard arm during the intervention period; at 4.5 months in the intensive arm, systolic blood pressure decreased from baseline 160 mmHg to 143 mmHg. From months 4 to 12, the mean separation in systolic blood pressure between arms was 12.9 mmHg.

There were four deaths in the intensive arm and one death in the standard arm. For the intensive arm versus the standard arm, the incidence rate ratio for major adverse cardiovascular events was 1.18 (95% confidence interval [CI], 0.40-3.33), for hospitalization 1.61 (95% CI, 0.87-2.97), and for vascular access thrombosis 3.09 (95% CI, 0.96-8.78). Median changes in left ventricular mass were similar in the two groups (–0.84 g in the intensive group and 1.4 g in the standard group).

“Although we identified a possible safety signal, the small size and short duration of the trial prevent definitive conclusions. Considering the high risk for major adverse cardiovascular events in patients receiving hemodialysis, a full-scale trial is needed to assess potential benefits of intensive hypertension control in this population,” the researchers said.



Telehealth Reduces Time and Costs Related to Pretransplant Evaluation

Transplantation. 2018; 102(2):279-283

There are few published data on the use of telehealth in transplantation for pretransplant evaluations and no prior reports on costs related to telehealth for pretransplant evaluations. Researchers, led by Rachel C. Forbes, MD, MBA, conducted a study designed to compare evaluation process costs for patients assessed initially by telehealth with costs for patients seen in person throughout the process.

The study included all patients approved at a single center from March 2013 through May 2016 for kidney transplant waitlist evaluation with decisions. Based partly on patient factors, patients approved for evaluation were scheduled for either an in-person visit or for an initial telehealth consultation. Clinically related and travel-related costs were calculated. Time estimates for patient time needed to complete the visit, time from application approval to initial visit, and time from application approval to decision were gathered. Comparisons were made using t tests.

The study period was 39 months for 302 patients. In the telehealth cohort, all categories of clinically or travel-related costs were significantly lower than the in-person visit cohort (P<.0001): total mean cost per patient was $656.11 for the telehealth cohort versus $1108.91 for the in-person cohort (P<.001).

Time needed to complete an evaluation was 1.7 days in the telehealth cohort versus 2.4 days in the in-person cohort (P<.001). Time to initial evaluation was 51.4 days in the telehealth cohort versus 87.9 days in the in-person cohort (P<.001). Participants in the telehealth cohort were older and had more comorbidities than participants in the in-person cohort.

The researchers said, “As telemedicine applications continue to proliferate, we present our experience with telehealth for initial kidney transplant waitlist evaluations with associated reductions in cost and time which may also improve access to transplantation.”


Transplantation Outcomes in Infants, 1984-2014

Transplantation. 2018;102(2):284-290

End-stage renal disease in infants <2 years of age is associated with increased morbidity and mortality. Blanche M. Chavers, MD, and colleagues evaluated long-term outcomes of kidney transplantation in infants at a single center. The evaluation included 136 infants who underwent kidney transplantation between 1984 and 2014. The researchers examined trends in survival rates and complications by era: 1984-1993, era 1; 1994-2003, era 2; and 2004-2014, era 3.

Patients were 92.6% white and 70.6% were males. Over the 30-year period, the initial length of hospital stay post-transplant declined 37% (P<.01). From era 1 to era 2, the 10-year death-censored graft survival improved from 60% to 80% (P=.04). There was no significant change across the eras in incidence of acute rejection, graft thrombosis, cytomegalovirus, or urine leaks. The frequency of diagnosis of Epstein-Barr virus increased from era 2 to era 3 (P<.01). Compared with eras 1 and 3, incidence of post-transplant lymphoproliferative disorder increased in era 2 (P=.03).

The researchers said, “Infants deserve earlier consideration for kidney transplant. Length of initial hospital stay and patient and graft survival rates after kidney transplantation have improved in infants since 1984.”