Digoxin and prognosis of heart failure in older patients with preserved ejection fraction: Importance of heart rate. Results from an observational and multicenter study. - Llàcer P; Núñez J; Bayés-Genís A; Conde Martel A; Cabanes Hernández Y; Díez Manglano J; Álvarez Rocha P; Soler Rangel L; Gómez Del Olmo V; Manzano L; Montero Pérez-Barquero M (European journal of internal medicine, 2019)