Evaluation of renal sodium handling in heart failure with preserved ejection fraction: A pilot study.

The pathophysiology behind sodium retention in heart failure with preserved ejection fraction (HFpEF) remains poorly understood. We hypothesized that patients with HFpEF have impaired natriuresis and diuresis in response to volume expansion and diuretic challenge, which is associated with renal hypo-responsiveness to endogenous natriuretic peptides. Nine HFpEF patients and five controls received saline infusion (0.25 mL/kg/min for 60 min) followed by intravenous furosemide (20 mg or home dose) 2 h after the infusion. Blood and urine samples were collected at baseline, 2 h after saline infusion, and 2 h after furosemide administration; urinary volumes were recorded. The urinary cyclic guanosine monophosphate (ucGMP)/plasma B-type NP (BNP) ratio was calculated as a measure of renal response to endogenous BNP. Wilcoxon rank-sum test was used to compare the groups. Compared to controls, HFpEF patients had reduced urine output (2480 vs.3541 mL; p = 0.028), lower urinary sodium excretion over 2 h after saline infusion (the percentage of infused sodium excreted 12% vs. 47%; p = 0.003), and a lower baseline ucGMP/plasma BNP ratio (0.7 vs. 7.3 (pmol/mL)/(mg/dL)/(pg/mL); p = 0.014). Patients with HFpEF had impaired natriuretic response to intravenous saline and furosemide administration and lower baseline ucGMP/plasma BNP ratios indicating renal hypo-responsiveness to NPs.

Heart Failure Hospitalization Risk associated with Iron Status in Veterans with CKD.

BACKGROUND AND OBJECTIVES: CKD is an independent risk factor for heart failure. Iron dysmetabolism potentially contributes to heart failure, but this relationship has not been well characterized in CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a historical cohort study using data from the Veterans Affairs Corporate Data Warehouse to evaluate the relationship between iron status and heart failure hospitalization. We identified a CKD cohort with at least one set of iron indices between 2006 and 2015. The first available date of serum iron indices was identified as the study index date. The cohort was divided into four iron groups on the basis of the joint quartiles of serum transferrin saturation (shown in percent) and ferritin (shown in nanograms per milliliter): reference (16%-28%, 55-205 ng/ml), low iron (0.4%-16%, 0.9-55 ng/ml), high iron (28%-99.5%, 205-4941 ng/ml), and function iron deficiency (0.8%-16%, 109-2783 ng/ml). We compared 1-year heart failure hospitalization risk between the iron groups using matching weights derived from multinomial propensity score models and Poisson rate-based regression. RESULTS: A total of 78,551 veterans met the eligibility criteria. The covariates were well balanced among the iron groups after applying the propensity score weights (n=31,819). One-year adjusted relative rate for heart failure hospitalization in the iron deficiency groups were higher compared with the reference group (low iron: 1.29 [95% confidence interval, 1.19 to 1.41]; functional iron deficiency: 1.25 [95% confidence interval, 1.13 to 1.37]). The high-iron group was associated with lower 1-year relative rate of heart failure hospitalization (0.82; 95% confidence interval, 0.72 to 0.92). Furthermore, the association between iron deficiency and heart failure hospitalization risk remained consistent regardless of the diabetes status or heart failure history at baseline. CONCLUSIONS: Iron deficiency, regardless of cause, was associated with higher heart failure hospitalization risk in CKD. Higher iron status was associated with lower heart failure hospitalization risks.

Modification of the effects of intensive systolic blood pressure control on kidney outcomes by baseline body mass index.

AIM: Obesity and intensive systolic blood pressure (SBP) control are independently associated with greater risk of acute kidney injury (AKI) and incident chronic kidney disease (CKD). We examined whether baseline body mass index (BMI) modifies the effects of intensive SBP lowering on AKI or incident CKD. METHODS: The systolic blood pressure intervention trial (SPRINT) randomized 9361 participants with high blood pressure to an SBP target of either <120 mm Hg or < 140 mm Hg. In a secondary analysis of 9210 SPRINT participants with a baseline BMI of ≥18.5 and < 50 kg/m2 , we examined the interactions of baseline BMI and SPRINT SBP intervention on subsequent AKI and incident CKD. RESULTS: Each 5 kg/m2 increase in baseline BMI was associated with higher risk of AKI (hazard ratio [HR] 1.12, 95% confidence interval [CI] 1.01 to 1.25) and incident CKD (HR 1.17, 95% CI 1.01 to 1.32). Intensive SBP control increased the risk of AKI (HR 1.68, 95% CI 1.22-2.11) and incident CKD (HR 3.49, 95% CI 2.47-4.94). The increased risk of AKI with intensive SBP control was consistent across the baseline BMI spectrum (linear interaction p = 0.55); however, the risk of incident CKD with SPRINT intervention increased with higher BMI (linear interaction p = 0.043). CONCLUSION: The increased risk of adverse kidney events seen with intensive SBP control in the SPRINT persisted across the baseline BMI spectrum. A higher baseline BMI was associated with an augmented risk of incident CKD with intensive SBP control.

Changes in brain functional connectivity and cognition related to white matter lesion burden in hypertensive patients from SPRINT.

PURPOSE: Hypertension is a risk factor for cognitive impairment; however, the mechanisms leading to cognitive changes remain unclear. In this cross-sectional study, we evaluate the impact of white matter lesion (WML) burden on brain functional connectivity (FC) and cognition in a large cohort of hypertensive patients from the Systolic Blood Pressure Intervention Trial (SPRINT) at baseline. METHODS: Functional networks were identified from baseline resting state functional MRI scans of 660 SPRINT participants using independent component analysis. WML volumes were calculated from structural MRI. Correlation analyses were carried out between mean FC of each functional network and global WML as well as WML within atlas-defined white matter regions. For networks of interest, voxel-wise-adjusted correlation analyses between FC and regional WML volume were performed. Multiple variable linear regression models were built for cognitive test performance as a function of network FC, followed by mediation analysis. RESULTS: Mean FC of the default mode network (DMN) was negatively correlated with global WML volume, and regional WML volume within the precuneus. Voxel-wise correlation analyses revealed that regional WML was negatively correlated with FC of the DMN's left lateral temporal region. FC in this region of the DMN was positively correlated to performance on the Montreal Cognitive Assessment and demonstrated significant mediation effects. Additional networks also demonstrated global and regional WML correlations; however, they did not demonstrate an association with cognition. CONCLUSION: In hypertensive patients, greater WML volume is associated with lower FC of the DMN, which in turn is related to poorer cognitive test performance. TRIAL REGISTRATION: NCT01206062.

Estimated GFR Variability and Risk of Cardiovascular Events and Mortality in SPRINT (Systolic Blood Pressure Intervention Trial).

RATIONALE AND OBJECTIVE: Although low estimated glomerular filtration rate (eGFR) is associated with cardiovascular disease (CVD) events and mortality, the clinical significance of variability in eGFR over time is uncertain. This study aimed to evaluate the associations between variability in eGFR and the risk of CVD events and all-cause mortality. STUDY DESIGN: Longitudinal analysis of clinical trial participants. SETTINGS AND PARTICIPANTS: 7,520 Systolic Blood Pressure Intervention Trial (SPRINT) participants ≥50 year of age with 1 or more CVD risk factors. PREDICTORS: eGFR variability, estimated by the coefficient of variation of eGFR assessments at the 6th, 12th, and 18-month study visits. OUTCOMES: The SPRINT primary CVD composite outcome (myocardial infarction, acute coronary syndrome, stroke, heart failure, or CVD death) and all-cause mortality from month 18 to the end of follow-up. ANALYTICAL APPROACH: Cox models were used to evaluate associations between eGFR variability and CVD outcomes and all-cause mortality. Models were adjusted for demographics, randomization arm, CVD risk factors, albuminuria, and eGFR at month 18. RESULTS: Mean age was 68 ± 9 years; 65% were men; and 58% were White. The mean eGFR was 73 ± 21 (SD) mL/min/1.73 m2 at 6 months. There were 370 CVD events and 154 deaths during a median follow-up of 2.4 years. Greater eGFR variability was associated with higher risk for all-cause mortality (hazard ratio [HR] per 1 SD greater variability, 1.29; 95% CI, 1.14-1.45) but not CVD events (HR, 1.05; 95% CI, 0.95-1.16) after adjusting for albuminuria, eGFR, and other CVD risk factors. Associations were similar when stratified by treatment arm and by baseline CKD status, when accounting for concurrent systolic blood pressure changes, use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and diuretic medications during follow up. LIMITATIONS: Persons with diabetes and proteinuria > 1 g/d were excluded. CONCLUSIONS: In trial participants at high risk for CVD, greater eGFR variability was independently associated with all-cause mortality but not CVD events.

Continuation of Chronic Heart Failure Therapies During Heart Failure Hospitalization - a Review.

Randomized controlled trials have demonstrated the benefits of guideline-directed medical therapy in the outpatient setting for treatment of chronic heart failure. However, the benefits of continuation (or discontinuation) of major chronic heart failure therapies when treating acute heart failure during hospitalization are less clear. Real and anticipated worsening renal function, hyperkalemia and hypotension are the three major reasons for discontinuation of renin-angiotensin-aldosterone system inhibitors during hospitalization, and a failure to resume renin-angiotensin-aldosterone system inhibitors before discharge could worsen cardiovascular outcomes. Available data, mostly observational, shows that continuation or initiation of renin-angiotensin-aldosterone system inhibitors appears efficacious, safe, and well tolerated in majority of acute heart failure patients during hospitalization. Worsening renal function portends poor prognosis only if associated with congestion in acute heart failure, and clinicians should not de-escalate diuretic therapy routinely for worsening renal function.

Effect of Baseline Kidney Function on the Risk of Recurrent Stroke and on Effects of Intensive Blood Pressure Control in Patients With Previous Lacunar Stroke: A Post Hoc Analysis of the SPS3 Trial (Secondary Prevention of Small Subcortical Strokes).

Background We conducted a post hoc analysis of the SPS3 (Secondary Prevention of Small Subcortical Strokes) Trial to examine the association of chronic kidney disease (CKD) with recurrent stroke, and to assess whether baseline renal function modifies the effects of intensive systolic blood pressure control in patients with previous stroke. Methods and Results A total of 3020 patients with recent magnetic resonance imaging-defined symptomatic lacunar infarctions were randomized to a systolic blood pressure target of <130 mm Hg versus 130 to 149 mm Hg. Predefined primary outcomes were (all-recurrent) stroke and a composite of stroke, acute myocardial infarction, or all-cause death; secondary outcomes were acute myocardial infarction, all-cause death, and intracerebral hemorrhage individually. Among 3017 patients with baseline estimated glomerular filtration rate measurements, we evaluated, using Cox proportional hazards models, the association of CKD with recurrent stroke and effects of the blood pressure targets on outcomes using baseline estimated glomerular filtration rate both as a categorical and linear variable. Regardless of the randomized treatment, CKD at baseline was significantly associated with an increased risk of the primary cardiovascular composite outcome (hazard ratio, 1.7; 95% CI, 1.4-2.1), and all-recurrent stroke (1.5; 1.1-2.0). However, the effects of the lower systolic blood pressure intervention on the primary outcome were not influenced by baseline CKD status (P for interaction=0.62). Conclusions CKD increases the risk of recurrent stroke by 50% in patients with previous lacunar stroke. We found no definitive evidence that renal dysfunction modifies the effects of systolic blood pressure control in patients with previous stroke. Conclusive evidence for this will require adequately powered studies with moderate-to-advanced CKD. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

The Familiality of Rapid Renal Decline in Diabetes.

Sustained and rapid loss of glomerular filtration rate (GFR) is the predominant clinical feature of diabetic kidney disease and a requisite for the development of end-stage renal disease. Although GFR trajectories have been studied in several cohorts with diabetes and without diabetes, whether rapid renal decline clusters in families with diabetes has not been examined. To determine this, we estimated GFR (eGFR) from serum creatinine measurements obtained from 15,612 patients with diabetes at the University of Utah Health Sciences Center and established their renal function trajectories. Patients with rapid renal decline (eGFR slope < -5 mL/min/1.73 m2/year) were then mapped to pedigrees using extensive genealogical records from the Utah Population Database to identify high-risk rapid renal decline pedigrees. We identified 2,127 (13.6%) rapid decliners with a median eGFR slope of -8.0 mL/min/1.73 m2/year and 51 high-risk pedigrees (ranging in size from 1,450 to 24,501 members) with excess clustering of rapid renal decline. Familial analysis showed that rapid renal decline aggregates in these families and is associated with its increased risk among first-degree relatives. Further study of these families is necessary to understand the magnitude of the influence of shared familial factors, including environmental and genetic factors, on rapid renal decline in diabetes.

Rationale for treatment of hepatitis C virus infection in end-stage renal disease patients who are not kidney transplant candidates.

Hepatitis C virus (HCV) infection is a common problem in patients treated with maintenance hemodialysis (HD) and is associated with an increased morbidity and mortality and lower quality of life. The major causes of HCV-associated mortality are liver and cardiovascular-related death. HCV-infected HD patients have a higher prevalence of inflammation-related metabolic and vascular diseases, leading to high rates of cardiovascular mortality in patients with end-stage renal disease. In the current era of highly effective direct-acting antiviral regimens, HCV treatment may also confer hepatic, cardiovascular and other morbidity and mortality benefits even to dialysis-dependent patients who do not qualify for kidney transplantation. Currently, the most accepted regimens in this patient population include elbasvir/grazoprevir and glecaprevir/pibrentasvir.

Removal of vancomycin administered during dialysis by a high-flux dialyzer.

INTRODUCTION: Hemodialysis patients frequently receive vancomycin for treatment of gram-positive bacterial infections. This drug is most conveniently administered in outpatient dialysis units during the hemodialysis treatment. However, there is a paucity of data on the removal of vancomycin by high-flux polyamide dialyzers. METHODS: This is a prospective crossover study in which seven uninfected chronic hemodialysis patients at three dialysis units received vancomycin 1 gram intravenously over one hour immediately after the dialysis treatment (Phase 1), and vancomycin 1.5 grams during the last hour of dialysis treatment using a polyarylethersulfone, polyvinylpyrrolidone, polyamide high-flux (Polyflux 24R) dialyzer (Phase 2). There was a three-week washout period between phases. Serial serum vancomycin concentrations were used to determine the removal of vancomycin when administered during dialysis. FINDINGS: Dialysis removed 35 ± 15% (range 18-56%) of the vancomycin dose when administered during the last hour of dialysis. The calculated area under the curve (AUC) of vancomycin levels for 0-44.5 hours from the start of infusion were similar between the two phases (AUCPhase 1 884 ± 124 mg-hr/L, mean ± SD; AUCPhase 2 856 ± 208 mg-hr/L; P=0.72). Serum vancomycin concentrations immediately prior to the next dialysis treatment following vancomycin administration were also similar between the two phases (13.1 ± 2.7 mg/L in Phase 1 and 12.3 ± 3.3 mg/L in Phase 2; P=0.55). DISCUSSION: When using a polyarylethersulfone, polyvinylpyrrolidone, and polyamide high-flux HD membrane with a 24R Polyflux dialyzer, vancomycin can be administered during the last hour of dialysis if the dose that is prescribed for intra-dialysis dosing is empirically increased to account for intra-dialytic drug removal.

Physical Function and Physical Activity in Peritoneal Dialysis Patients.

BACKGROUND: Physical functioning (PF) and physical activity (PA) are low in patients treated with maintenance hemodialysis (MHD). Little information exists on this topic in patients treated with peritoneal dialysis (PD). The objective of this study was to compare PF and PA in patients with Stage-5 chronic kidney disease (CKD) treated with PD and in-center MHD. METHODS: Physical functioning was measured in 45 prevalent PD patients using standard physical performance measures that include gait speed, chair stand, standing balance, 6-minute-walk, incremental shuttle walk and self-reported PF using the short form (SF)-36 questionnaire. Physical activity was determined from self-report and using the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire. Scores for the short physical performance battery (SPPB) were calculated. In-center MHD patients were matched by age, gender, and diabetes status to the PD patients. RESULTS: Unadjusted comparisons showed significantly higher 6-minute-walk distance, shuttle-walk distance and hand-grip in the PD patients. Adjustment in multiple regression analysis resulted in only gait speed being significantly different between the groups. All test results in both groups were lower than reference values for age and gender in the general population, and were at the levels indicating impairment. Physical activity was not different between the 2 groups (average age 49 yrs), and both groups had weekly caloric expenditure from all exercise and from moderate-intensity exercise that was similar to older (> 70 yrs) community-dwelling adults. Adjusted association indicated that PA was significantly associated with shuttle-walk distance. CONCLUSIONS: Physical functioning and PA measures were low in both PD and MHD groups. Interventions to improve PA and PF should be strongly considered for both PD and MHD patients.