The "FIFTY SHADOWS" of the RALES Trial: Lessons about the Potential Risk of Dietary Potassium Supplementation in Patients with Chronic Kidney Disease

Hyperkalemia management: a multidisciplinary expert panel's perspective on the role of new potassium binders

Hyperkalemia is a potentially life-threatening condition frequently encountered in clinical practice, particularly among patients with chronic kidney disease, heart failure, diabetes, and hypertension and those undergoing treatment with renin-angiotensin-aldosterone system inhibitors (RAASi). The management of chronic and acute hyperkalemia is complex and requires timely intervention to prevent severe complications such as cardiac arrhythmias and sudden death. Traditional therapeutic approaches to chronic hyperkalemia, including dietary potassium restriction, use of diuretics, and administration of cation-exchange resins like sodium polystyrene sulfonate, often suffer from limitations like gastrointestinal side effects, variable efficacy, delayed onset of action, and RAASi treatment discontinuation. In recent years, the development of new potassium binders, specifically patiromer and sodium zirconium cyclosilicate (SZC), has revolutionized the management of hyperkalemia. Patiromer, a non-absorbed polymer, binds potassium in the gastrointestinal tract in exchange for calcium, thus facilitating its excretion. SZC operates by exchanging sodium and hydrogen ions for potassium, leading to efficient potassium removal. Both agents have demonstrated rapid and sustained reductions in serum potassium levels, coupled with favorable safety and tolerability profiles, in multiple clinical trials. This review article, authored by a multidisciplinary group of Portuguese experts in hyperkalemia management, provides an in-depth analysis of the efficacy and safety of current therapeutic strategies and highlights the clinical potential of new potassium binders. The introduction of patiromer and SZC offers significant advantages over traditional therapies, providing effective and better-tolerated options for patients. The review highlights the role of these novel agents in contemporary hyperkalemia management and calls for ongoing research to further refine treatment protocols and improve patient outcomes.

Albuminuria, Forgotten No More: Underlining the Emerging Role in CardioRenal Crosstalk

Kidneys have an amazing ability to adapt to adverse situations, both acute and chronic. In the presence of injury, the kidney is able to activate mechanisms such as autoregulation or glomerular hyperfiltration to maintain the glomerular filtration rate (GFR). While these adaptive mechanisms can occur in physiological situations such as pregnancy or high protein intake, they can also occur as an early manifestation of diseases such as diabetes mellitus or as an adaptive response to nephron loss. Although over-activation of these mechanisms can lead to intraglomerular hypertension and albuminuria, other associated mechanisms related to the activation of inflammasome pathways, including endothelial and tubular damage, and the hemodynamic effects of increased activity of the renin-angiotensin-aldosterone system, among others, are recognized pathways for the development of albuminuria. While the role of albuminuria in the progression of chronic kidney disease (CKD) is well known, there is increasing evidence of its negative association with cardiovascular events. For example, the presence of albuminuria is associated with an increased likelihood of developing heart failure (HF), even in patients with normal GFR, and the role of albuminuria in atherosclerosis has recently been described. Albuminuria is associated with adverse outcomes such as mortality and HF hospitalization. On the other hand, it is increasingly known that the systemic effects of congestion are mainly preceded by increased central venous pressure and transmitted retrogradely to organs such as the liver or kidney. With regard to the latter, a new entity called congestive nephropathy is emerging, in which increased renal venous pressure can lead to albuminuria. Fortunately, the presence of albuminuria is modifiable and new treatments are now available to reverse this common risk factor in the cardiorenal interaction.