• Age 40-84 years (both inclusive) at the time of signing the informed consent.

• Documented symptomatic heart failure (HF) diagnosed greater than or equal to (≥) 180 days prior to screening with at least weekly need for oral diuretic treatment, and New York Heart Association class II-III at screening.

• Clinically stable and on optimized doses and unchanged drug classes of guideline-directed HF therapy ≥ 45 days prior to randomisation.

• Left ventricular ejection fraction (LVEF) less than (\<) 50 percent (%) as assessed by echocardiography at screening, measured by central laboratory.

• Left ventricular mass indexed to body surface area (LVMi) greater than (\>) 88 gram per meter square (g/m\^2) for female participants and \>102 g/m\^2 for male participants as assessed by echocardiography at screening, using the truncated ellipsoid method measured by central laboratory.

• Left ventricular end-diastolic diameter indexed to body surface area (LVEDDi)≥3.0 cm/m\^2 for male participants and ≥3.1 centimeter per meter square (cm/m\^2) for female participants as assessed by echocardiography at screening, measured by central laboratory.

• Body mass index 18.5-40 kilogram per meter square (kg/m\^2) (both inclusive) and body weight less than or equal to (≤) 140 kilogram (kg). Body mass index is calculated in the electronic case report form based on height and body weight at the screening visit (visit 1).

• N-terminal pro B-type natriuretic peptide (NT-proBNP) ≥ 300 picograms per milliliter (pg/mL); NT-proBNP ≥600 pg/mL if atrial fibrillation/flutter is present at time of screening, measured by central laboratory.