A set of indicators to assess the quality of care for patients hospitalized for heart failure was developed by an expert working group of the Italian Health Ministry. Because a better performance profile measured using these indicators does not necessarily translate to better outcomes, a study to validate these indicators through their relationship with measurable clinical outcomes and healthcare costs supported by the Italian National Health System was carried out. Residents of four Italian regions (Lombardy, Marche, Lazio, and Sicily) who were newly hospitalized for heart failure (irrespective of stage and New York Heart Association class) during 2014-2015 entered in the cohort and followed up until 2019. Adherence to evidence-based recommendations [i.e. renin-angiotensin-aldosterone system (RAS) inhibitors, beta-blockers, mineralocorticoid receptor antagonists (MRAs), and echocardiograms (ECCs)] experienced during the first year after index discharge was assessed. Composite clinical outcomes (cardiovascular hospital admissions and all-cause mortality) and healthcare costs (hospitalizations, drugs, and outpatient services) were assessed during the follow-up. The restricted mean survival time at 5years (denoted as the number of months free from clinical outcomes), the hazard of clinical outcomes (according to the Cox model), and average annual healthcare cost (expressed in euros per person-year) were compared between adherent and non-adherent patients. A non-parametric bootstrap method based on 1000 resamples was used to account for uncertainty in cost-effectiveness estimates. A total of 41406 patients were included in this study (46.3% males, mean age 76.9±9.4years). Adherence to RAS inhibitors, beta-blockers, MRAs, and ECCs were 64%, 57%, 62%, and 20% among the cohort members, respectively. Compared with non-adherent patients, those who adhered to ECCs, RAS inhibitors, beta-blockers, and MRAs experienced (i) a delay in the composite outcome of 1.6, 1.9, 1.6, and 0.6months and reduced risks of 9% (95% confidence interval, 2-14%), 11% (7-14%), 8% (5-11%), and 4% (-1-8%), respectively; and (ii) lower (€262, €92, and €571 per year for RAS inhibitors, beta-blockers, and MRAs, respectively) and higher costs (€511 per year for ECC). Adherence to RAS inhibitors, beta-blockers, and MRAs showed a delay in the composite outcome and a saving of costs in 98%, 84%, and 93% of the 1000 bootstrap replications, respectively. Strict monitoring of patients with heart failure through regular clinical examinations and drug therapies should be considered the cornerstone of national guidelines and audits.