OBJECTIVE: Heart rate (HR) reduction is associated with improved outcomes in heart failure (HF). This multicenter, prospective, observational, and national registry aimed to evaluate resting HR and the impacts of HR-related medications in real-life clinical practice in patients with HF. METHODS: The Resting HR and Real-Life Treatment Modalities in Outpatients with Left Ventricular Systolic Dysfunction (REALITY HF) study enrolled 1054 patients with HF and left ventricular ejection fraction (LVEF) of <40% from 16 centers. Clinical characteristics, HR, and medications were noted (enrollment phase). A total of 487 patients with sinus rhythm and HR of ≥70 bpm were included in a further 4-month follow-up (FU) program (V0). Changes in HR and medications were reevaluated at 1-month (V1) and 4-month (V2) FU visits. The Kansas City Cardiomyopathy Questionnaire (KCCQ) was used to assess the quality of life (QoL) of 320 patients in a 4-month FU program. RESULTS: During enrollment, 794 patients (75.3%) were in sinus rhythm, in whom resting HR was 76.7±14 bpm, 69.1% had a resting HR of ≥70 bpm, 79.1% were receiving beta blocker (BB), and 6.1% were receiving ivabradine. Resting HR was lower in patients receiving BB (75.8±13 vs. 80.4±16 bpm; p=0.001); however, 65.8% of those still had a resting HR of ≥70 bpm. A significant association was found between elevated HR and worse New York Heart Association (NYHA) class, worse QoL, or lower LVEF. During the 4-month FU, adjustment of HR-lowering therapy was left to the physician's discretion. Resting HR significantly reduced from 83.6±12 (80) bpm at V0 to 78.6±13 (77) bpm at V1 (p=0.001) and further decreased to 73.0±11 (73) bpm at V2 (p=0.001). Patients achieving a resting HR of <70 bpm were 21.7% at V1 (p=0.001) and 39.9% at V2 (p=0.001). KCCQ significantly increased from 59.7±23 (62.7) at V0 to 73.1±18 (78.5) at V2 (p=0.001). In addition, patients with NYHA I increased from 22.2% at V0 to 29.2% at V1 and 39.4% at V2 (p=0.01). CONCLUSION: In real-life clinical practice, elevated HR is highly prevalent in HF despite widely used BB therapy and is associated with worse clinical picture. Therapeutic interventions targeting HR significantly reduce HR, and HR lowering is associated with improved clinical outcomes.