BACKGROUND: Mineralocorticoid receptor antagonists (MRAs) reduce systolic blood pressure (SBP) and increase serum potassium concentration ([K +]). This indirect comparison investigated any differences in SBP-lowering and hyperkalemia risk between finerenone, a nonsteroidal MRA, and the steroidal MRA spironolactone ± a potassium binder.

METHODS: In FIDELITY (a pooled analysis of FIDELIO-DKD and FIGARO-DKD), a subgroup of patients with treatment-resistant hypertension (TRH) and chronic kidney disease meeting eligibility criteria of the AMBER trial were identified (FIDELITY-TRH). The main outcomes were mean change in SBP, incidence of serum [K +] ≥5.5 mmol/L and hyperkalemia-associated treatment discontinuation. Results at ∼17 weeks were compared with 12 weeks from AMBER.

RESULTS: In 624 FIDELITY-TRH patients and 295 AMBER patients, the least squares mean change in SBP (mmHg) from baseline was -7.1 for finerenone and -1.3 for placebo {between-group difference -5.74 [95% confidence interval (CI) -7.99 to -3.49], P < .0001} versus -11.7 for spironolactone + patiromer and -10.8 for spironolactone + placebo [between-group difference -1.0 (95% CI -4.4-2.4), P = .58]. The incidence of serum [K +] ≥5.5 mmol/L was 12% for finerenone and 3% for placebo versus 35% with spironolactone + patiromer and 64% with spironolactone + placebo. Treatment discontinuation due to hyperkalemia was 0.3% for finerenone and 0% for placebo versus 7% for spironolactone + patiromer and 23% for spironolactone + placebo.

CONCLUSIONS: In patients with TRH and chronic kidney disease compared with spironolactone with or without patiromer, finerenone was associated with a lower SBP reduction and lower risk of hyperkalemia and treatment discontinuation. Trial Registration: AMBER (NCT03071263), FIDELIO-DKD (NCT02540993), FIGARO-DKD (NCT02545049).