In DETERMINE-Reduced [24], HFrEF patients had left ventricular ejection fraction (LVEF) ≤ 40%, NT-proBNP ≥ 400 pg/mL (≥300 pg/mL if hospitalized for HF in the past 12 months, ≥800 pg/mL if they had atrial fibrillation), and estimated glomerular filtration rate (eGFR) ≥ 25 mL/min/1.73 m2. The gene discussed is NPPB; the disease is atrial fibrillation.