Table 2: Evidence for Patiromer in Heart Failure and Cardiorenal Populations.

Study	Design	Population	Primary/Key Outcome	Key Findings	Limitations
PEARL-HF 20118	Randomised, double-blind, placebo-controlled trial	Chronic HF with history of hyperkalaemia or CKD receiving spironolactone; n=105	Difference in serum potassium at week 4	Patiromer significantly reduced serum potassium and decreased the incidence of hyperkalaemia (7% versus 25% with placebo)	Small sample size; short follow-up; not powered for clinical outcomes
AMBER (HF subgroup) 201913	Randomised, double-blind, placebo-controlled trial	CKD (eGFR 25–45 ml/min/1.73 m²) with resistant hypertension; HF subgroup present (~45%); n=295 total	Persistence of spironolactone therapy at 12 weeks	Patiromer reduced hyperkalaemia and enabled greater continuation of spironolactone therapy	HF findings based on subgroup analysis; primary population CKD
DIAMOND 202214	Multicentre, randomised, double-blind, placebo-controlled withdrawal trial	Symptomatic HFrEF with current or prior hyperkalaemia receiving RAASI therapy; n=878 randomised	Serum potassium-adjusted area under the curve during randomised phase	Patiromer reduced recurrent hyperkalaemia and lowered RAASI dose reduction or discontinuation, allowing sustained optimisation of GDMT	Not powered for mortality or HF hospitalisation outcomes

CKD = chronic kidney disease; eGFR = estimated glomerular filtration rate; GDMT = guideline-directed medical therapy; HF = heart failure; HFrEF = heart failure with reduced ejection fraction; RAASI = renin–angiotensin–aldosterone system inhibitor.