Can an old heart drug help patients bounce back after a crisis?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Male or female ≥ 18 years of age who have signed written informed consent and are willing and able to complete treatment and follow-up. 2. Recent hospitalization or emergency department visit for decompensated heart failure with reduced ejection fraction (HFrEF) (LVEF ≤ 40%). 3. Resting heart rate ≥ 60 bpm in patients without a pacemaker. 4. Distance walked on the 6-minute walk test (6MWT) ≤ 450 meters and/or less than 80% of the predicted value. 5. NT-proBNP ≥ 450 pg/mL, or ≥ 900 pg/mL in patients with atrial fibrillation, and/or echocardiographic criteria of congestion \- Exclusion Criteria: 1. Resting heart rate \< 60 bpm in sinus rhythm or \< 70 bpm in atrial fibrillation. 2. Myocardial infarction, acute coronary syndrome, myocarditis, percutaneous coronary intervention, or recent implantation (within the past 3 months) of cardiac resynchronization therapy (CRT), pacemaker, or implantable cardioverter-defibrillator (ICD); cardiac surgery or stroke within the past 30 days. 3. Estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m² (based on a sample obtained within the previous month). 4. Presence of a mechanical ventricular assist device. 5. Planned implantation of a ventricular assist device or cardiac transplantation. 6. Non-cardiac comorbidities with a limited life expectancy (less than or equal to the study duration). 7. Non-cardiac conditions (neurological or orthopedic) preventing performance of the 6-minute walk test (6MWT). 8. Body mass index (BMI) ≥ 35 kg/m². 9. Amyloid, hypertrophic obstructive, or constrictive cardiomyopathy. 10. Presence of an accessory atrioventricular conduction pathway (e.g., Wolff-Parkinson-White syndrome). 11. History of symptomatic or sustained ventricular tachyarrhythmia (≥ 30 seconds). 12. Intermittent complete atrioventricular block or Mobitz type II second-degree AV block without pacemaker or ICD. 13. Severe aortic valvular disease (grade III/III) with indication for invasive treatment. 14. Complex congenital heart disease. 15. Known hypersensitivity to digoxin (including prior adverse reactions). 16. Current treatment with digoxin. 17. Participation in another clinical trial (excluding observational registries). 18. Pregnant or breastfeeding women, or women with the potential to become pregnant during the study period. \-