Optimally managing hyperkalemia in patients with cardiorenal syndrome

Renin-angiotensin-aldosterone system inhibitors (RAASi) are now a standard treatment in most patients with cardiovascular disease, especially in those with heart failure (HF). The European Society of Cardiology and the American College of Cardiology/American Heart Association gave a Class IA recommendation for the use of RAASi in the treatment of Classes II-IV symptomatic HF with reduced ejection fraction (HFREF), based on their strong clinical benefits of lowering all-cause mortality and HF hospitalizations in these subjects. However, RAASi therapy or adding mineralocorticoid receptor antagonists in subjects receiving background angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may be associated with an increased risk of hyperkalemia (HK), especially in those with reduced kidney function. As a result, a significant proportion of these subjects either have RAASi dose reduced or more often discontinued when they develop HK. Discontinuation of RAASi in patients hospitalized with HFREF was associated with higher postdischarge mortality and rehospitalization rates, while optimal dosing of RAASi significantly reduced median hospital stays, outpatient visits and related costs. Thus, effective treatment is required to lower potassium level and maintain normokalemia in subjects with HF and reduced kidney disease who develop or are at risk of HK, thus enabling them to continue their RAASi therapy and maximize benefits from RAASi. In this review, we provide an up-to-date review of the prevalence and significance of HK in patients with cardiorenal syndrome, as well as their optimal management of HK with recent novel therapies.