Associations of Serum and Dialysate Potassium Concentrations With Incident Atrial Fibrillation in a Cohort Study of Older US Persons Initiating Hemodialysis for Kidney Failure.

Introduction: Atrial fibrillation (AF) disproportionally affects persons on maintenance hemodialysis (HD). Associations of serum and dialysate potassium concentrations [K+] with AF incidence are poorly understood. Methods: We conducted a cohort study using Medicare claims merged with clinical data from a dialysis provider to determine whether serum-[K+] and/or dialysate-[K+] independently associated with AF incidence. Persons insured by fee-for-service Medicare aged ≥67 years at dialysis initiation and free from diagnosed AF prior to day 120 of dialysis were eligible. Serum-[K+] and dialysate-[K+] were assessed in 30-day intervals and patients were followed-up with for AF incidence in subsequent 30-day intervals. Results: During 2006 to 2011, 15,190 persons (mean age = 76.3 years) initiating HD had no prior AF diagnosis. Mean serum-[K+] was 4.5 mEq/l; dialysate-[K+] was 3 mEq/l in 34% and 2 mEq/l in 52% of patients. Followed-up over 21,907 person-years, 2869 persons had incident AF (incidence/100 person-years, 13.1 [95% confidence interval [CI], 12.6-13.6]). The multivariable-adjusted association of serum-[K+] with incident AF was J-shaped as follows: relative to a serum-[K+] of 4.5 mEq/l, lower serum-[K+] associated with increased AF risk, whereas confidence bands for higher serum-[K+] indicated no association. Dialysis against a dialysate-[K+] of 3 mEq/l versus 2 mEq/l independently associated with a 14% (95% CI, 5%-24%) lower incidence of AF. No effect modification between serum-[K+] and dialysate-[K+] was detected (P = 0.34). Conclusion: Lower serum-[K+] was independently associated with incident AF whereas elevated serum-[K+] was not. The findings support adoption of dialysate solutions with a dialysate-[K+] of 3 mEq/l, regardless of patients' serum-[K+], and elimination of lower dialysate-[K+] solutions from practice. Clinical trials randomizing patients to different dialysate-[K+] are warranted to establish causality.

SPRINT-A Kidney-Centric Narrative Review: Recent Advances in Hypertension.

Hypertension is a potent cardiovascular risk factor with deleterious end-organ effects and is especially prevalent among patients with chronic kidney disease. The SPRINT (Systolic Blood Pressure Intervention Trial) enrolled patients at an elevated cardiac risk including patients with mild to moderate chronic kidney disease and found that an intensive systolic blood pressure goal of <120 mm Hg significantly reduced the rates of adverse cardiovascular events and all-cause mortality and nonsignificantly reduced the rates of probable dementia; these results were consistent whether one had chronic kidney disease or not. However, results of intensive blood pressure therapy on chronic kidney disease progression were inconclusive, and there was an increased risk of incident chronic kidney disease and acute kidney injury, but the declines in kidney function appear to be hemodynamically driven and reversible. Overall, an intensive blood pressure target is effective in reducing cardiovascular disease and all-cause mortality and may reduce the risk of probable dementia in patients with mild to moderate chronic kidney disease. More studies are needed to determine its long-term effects on kidney function.

Oral Anticoagulation in Patients With End-Stage Kidney Disease on Dialysis and Atrial Fibrillation.

Patients with end-stage kidney disease (ESKD) have an elevated incidence of atrial fibrillation (AF) and are at increased risk for thromboembolic events. However, these patients are also at increased risk for bleeding and it is unclear whether they benefit from an oral anticoagulant. Point prevalent on July 1, 2015, only ~28% of dialysis patients with AF were on oral anticoagulation. Warfarin was the most commonly used oral anticoagulant, followed by apixaban, while dabigatran and rivaroxaban were rarely used. This article reviews the current evidence regarding each oral anticoagulant especially as they relate to patients with ESKD.

Identification of thioaptamer ligand against E-selectin: potential application for inflamed vasculature targeting.

Active targeting of a drug carrier to a specific target site is crucial to provide a safe and efficient delivery of therapeutics and imaging contrast agents. E-selectin expression is induced on the endothelial cell surface of vessels in response to inflammatory stimuli but is absent in the normal vessels. Thus, E-selectin is an attractive molecular target, and high affinity ligands for E-selectin could be powerful tools for the delivery of therapeutics and/or imaging agents to inflamed vessels. In this study, we identified a thiophosphate modified aptamer (thioaptamer, TA) against E-selectin (ESTA-1) by employing a two-step selection strategy: a recombinant protein-based TA binding selection from a combinatorial library followed by a cell-based TA binding selection using E-selectin expressing human microvascular endothelial cells. ESTA-1 selectively bound to E-selectin with nanomolar binding affinity (K(D) = 47 nM) while exhibiting minimal cross reactivity to P- and L-selectin. Furthermore, ESTA-1 binding to E-selectin on the endothelial cells markedly antagonized the adhesion (over 75% inhibition) of sLe(x) positive HL-60 cells at nanomolar concentration. ESTA-1 also bound specifically to the inflamed tumor-associated vasculature of human carcinomas derived from breast, ovarian, and skin but not to normal organs, and this binding was highly associated with the E-selectin expression level. Similarly, intravenously injected ESTA-1 demonstrated distinct binding to the tumor vasculature in a breast cancer xenograft model. Together, our data substantiates the discovery of a thioaptamer (ESTA-1) that binds to E-selectin with high affinity and specificity, thereby highlighting the potential application of ESTA-1 for E-selectin targeted delivery.