Patiromer versus placebo to enable spironolactone use in patients with resistant hypertension and chronic kidney disease (AMBER): results in the pre-specified subgroup with heart failure

Aims The AMBER trial demonstrated that concomitant use of patiromer enabled the more persistent use of spironolactone by reducing the risk of hyperkalaemia in patients with resistant hypertension and advanced chronic kidney disease. We report herein the pre-specified subgroup analysis in patients with heart failure (HF). Methods and results Participants were randomly assigned (1:1) to receive either placebo or patiromer (8.4 g once daily), in addition to open-label spironolactone (starting at 25 mg once daily) and their baseline blood pressure medications. Dose titrations were permitted after 1 week for patiromer/placebo and after 3 weeks for spironolactone. The primary endpoint was the between-group difference at week 12 in the proportion of patients on spironolactone. Efficacy endpoints and safety were assessed in all randomized patients (intention to treat). A total of 295 patients were enrolled, of whom 132 (45%) had HF. In the HF subgroup, 68.1% of patients receiving placebo remained on spironolactone at week 12, compared with 84.1% of patients receiving patiromer (P = 0.0504). The reason for discontinuation from spironolactone use was hyperkalaemia in the majority of both groups. There was no significant interaction between the subgroups with HF and without HF (P = 0.8085) for the primary endpoint. Conclusions Consistent with the overall AMBER trial results, this pre-specified subgroup analysis in patients with HF, resistant hypertension and advanced chronic kidney disease demonstrated that patiromer enabled more persistent use of spironolactone by reducing the risk of hyperkalaemia.