Uremic Toxins - Novel Arrhythmogenic Factor in Chronic Kidney Disease - Related Atrial Fibrillation

Cardiorenal syndrome: long road between kidney and heart

Almost 200 years ago, the first evidence described by Robert Bright (1836) showed the strong interaction between the kidneys and heart and, since then, the scientific community has dedicated itself to better understanding the mechanisms involved in the kidney-heart relationship, known in recent decades as cardiorenal syndrome (CRS). This syndrome includes a wide clinical variety that affects the kidneys and heart, in an acute or chronic manner. Moreover, it is well established in the literature that the immune system, the sympathetic nervous system, the renin-angiotensin-aldosterone, and the oxidative stress actively play a strong role in the cellular and molecular processes present in CRS. More recently, uremic molecules and epigenetic factors have been also shown to be key mediators in the development of syndrome. The present review intends to present the state of the art regarding CRS and to show the paths known, until now, in the long road between the kidneys and heart.

Inflammation and Oxidative Stress in Chronic Kidney Disease-Potential Therapeutic Role of Minerals, Vitamins and Plant-Derived Metabolites

Chronic kidney disease (CKD) is a debilitating pathology with various causal factors, culminating in end stage renal disease (ESRD) requiring dialysis or kidney transplantation. The progression of CKD is closely associated with systemic inflammation and oxidative stress, which are responsible for the manifestation of numerous complications such as malnutrition, atherosclerosis, coronary artery calcification, heart failure, anemia and mineral and bone disorders, as well as enhanced cardiovascular mortality. In addition to conventional therapy with anti-inflammatory and antioxidative agents, growing evidence has indicated that certain minerals, vitamins and plant-derived metabolites exhibit beneficial effects in these disturbances. In the current work, we review the anti-inflammatory and antioxidant properties of various agents which could be of potential benefit in CKD/ESRD. However, the related studies were limited due to small sample sizes and short-term follow-up in many trials. Therefore, studies of several anti-inflammatory and antioxidant agents with long-term follow-ups are necessary.

Indoxyl Sulphate is Associated with Atrial Fibrillation Recurrence after Catheter Ablation

Renal dysfunction results in the accumulation of various uremic toxins, including indoxyl sulphate (IS), and is a major risk factor for atrial fibrillation (AF). Experimental studies have demonstrated that IS exacerbates atrial remodelling via oxidative stress, inflammation, and fibrosis. However, its clinical impact on AF-promoting cardiac remodelling has not been described. Therefore, the purpose of this study was to clarify the relationship between basal IS levels and the 1-year outcomes after catheter ablation for the treatment of AF. Our prospective observational study included data from 125 patients with AF who underwent catheter ablation. Over a 1-year follow-up period, AF recurrence was identified in 21 patients. The 1-year AF-free survival was significantly lower in patients with high serum IS levels (≥0.65 μg/mL) than in those with low IS levels (60.1 ± 10.4% versus 85.2 ± 3.9%, P = 0.007). Univariable analysis identified that an IS concentration ≥ 0.65 μg/mL was associated with AF recurrence (hazard ratio [HR] = 3.10 [1.26-7.32], P = 0.015), and this association was maintained in multivariate analysis (HR = 3.67 [1.13-11.7], P = 0.031). Thus, in patients undergoing AF ablation, serum IS levels at baseline independently predict the recurrence of arrhythmia.

A Reliable Method: Purse-String Hemostasis for Arteriovenous Fistula or Arteriovenous Graft Cannulation after Percutaneous Transluminal Angioplasty

Percutaneous transluminal angioplasty (PTA) is the most common therapy used to treat dialysis patients with an occluded arteriovenous fistula (AVF) or arteriovenous graft (AVG). AVF or AVG hemostasis after PTA is time consuming, and it may be complicated with acute thrombosis of the AVF or AVG and re-bleeding from the puncture site. In this study, we prospectively studied 145 hemodialysis patients with occluded AVF or AVG using a modified purse-string suture with short tubing tourniquet technique for hemostasis following PTA, during which we used heparin and urokinase infusion. The results indicated that the modified technique for hemostasis of AVF orAVG was effective and safe in achieving immediate hemostasis withoutmanual compression in all patients.