Abstract
AIMS: Hypokalaemia is associated with cardiovascular events and mortality in patients with chronic kidney disease (CKD). This exploratory FIDELITY analysis, a prespecified pooled patient-dataset from FIDELIO-DKD and FIGARO-DKD, investigated the incidence and effect of hypokalaemia in patients with CKD and type 2 diabetes (T2D) treated with finerenone vs. placebo. METHODS AND RESULTS: Outcomes include the incidence of treatment-emergent hypokalaemia (serum potassium <4.0 or <3.5 mmol/L) and the effect of finerenone on cardiovascular composite outcome (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or hospitalization for heart failure) and arrhythmia composite outcome (new diagnosis of atrial fibrillation/atrial flutter, hospitalization due to arrhythmia, or sudden cardiac death) by baseline serum potassium subgroups. In the FIDELITY population, treatment-emergent hypokalaemia with serum potassium <4.0 and <3.5 mmol/L occurred in 41.1% and 7.5%, respectively. Hazards of cardiovascular and arrhythmia composite outcomes were higher in patients with baseline serum potassium <4.0 vs. 4.0-4.5 mmol/L [hazard ratio (HR) 1.16; 95% confidence interval (CI) 1.02-1.32, P = 0.022 and HR 1.20; 95% CI 1.00-1.44, P = 0.055, respectively]. Finerenone reduced the incidence of hypokalaemia with serum potassium <4.0 mmol/L (HR 0.63; 95% CI 0.60-0.66) and <3.5 mmol/L (HR 0.46; 95% CI 0.40-0.53) vs. placebo. Finerenone lessened the hazard of cardiovascular and arrhythmia events vs. placebo, irrespective of baseline serum potassium. CONCLUSION: A substantial proportion of patients with CKD and T2D experienced hypokalaemia, which was associated with an increased hazard of adverse cardiovascular outcomes. Finerenone reduced the incidence of hypokalaemia. Finerenone reduced the hazard of cardiovascular and arrhythmia outcomes irrespective of serum potassium subgroups. Clinical trials registration: FIDELIO-DKD and FIGARO-DKD are registered with ClinicalTrials.gov, numbers NCT02540993 and NCT02545049, respectively (funded by Bayer AG).